JP2005100947A - Nonaqueous secondary battery anode material, method for manufacturing same and nonaqueous secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a decrease in charging and discharge capacity when the charging and discharge is repeated. <P>SOLUTION: The nonaqueous secondary battery anode material includes a lithium manganese nickel cobalt oxide consisting of lithium, manganese, nickel, cobalt and oxygen. The lithium manganese nickel cobalt oxide having a layered structure designated by Li[Li<SB>[(1-2x-y)/3]</SB>Ni<SB>x</SB>Co<SB>y</SB>Mn<SB>[(2-x-2y)/3]</SB>]O<SB>2</SB>that satisfies the conditions of 0.2<x<0.5, 0<y<0.2, and 1<2x+y. The method of producing the lithium manganese nickel cobalt oxide includes a step of producing a Ni-Co-Mn composite hydroxide by the reaction of a solution comprising a nickel salt and a cobalt salt with a strong alkaline solution, a step of producing a Ni-Co-Mn oxyhydroxide by oxidizing the composite oxide, a step of producing a starting mixture by mixing the Ni-Co-Mn oxyhydroxide with the lithium compound, and a step of producing a lithium transition metal composite oxide by firing the starting mixture in air. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a positive electrode material used for a nonaqueous secondary battery, a method for producing the same, and a nonaqueous secondary battery using the positive electrode material. More specifically, the present invention relates to a positive electrode material used for a non-aqueous secondary battery suitable for a non-aqueous secondary battery for 4 V, a manufacturing method thereof, and a non-aqueous secondary battery using the same.

In general, as shown in FIG. 4, the concept of the non-aqueous secondary battery is that an electrolyte 3 is stored in a container 2 whose interior is partitioned into a first chamber 2a and a second chamber 2b by a separator 1a. The positive electrode 4 is accommodated in the chamber 2 a while being immersed in the electrolytic solution 3, and the negative electrode 5 is accommodated in the second chamber 2 b while being immersed in the electrolytic solution 3. In this non-aqueous secondary battery 1, the positive electrode 4 is obtained by pouring or impregnating a slurry containing an active material on an aluminum mesh plate, and then heating and drying the poultice or impregnated material to attach the active material to the aluminum mesh plate. The negative electrode 5 is formed in a plate shape with carbon or metal lithium typified by graphite or the like.
Examples of the active material to be attached to the positive electrode 4, lithium-cobalt composite oxide such as LiCoO ₂ Conventionally, lithium nickel composite oxide such as LiNiO _2, a metal oxide such as lithium manganese composite oxide such as LiMn ₂ O ₄ Is generally used.

Batteries using the lithium cobalt composite oxide are used in most batteries because of their high structural stability. However, cobalt contained in complex oxides has various problems such as high material costs, low reserves, and severe environmental regulations in exhaust and drainage, and further mass production and enlargement of batteries. As a result, the above problem may become serious.
In addition, a battery using the above lithium nickel composite oxide has a large theoretical capacity and an appropriate discharge potential, but on the other hand, a change in charge / discharge potential related to a change in crystal structure that occurs during the charge / discharge process and a progress of charge / discharge cycle. However, a drastic solution has not been made to the decrease in charge / discharge capacity due to the collapse of the crystal structure accompanying the above, and there has been a problem that the characteristic stability and reliability of the battery are insufficient.

Furthermore, the secondary battery using the above lithium manganese composite oxide can charge and discharge at a capacity close to the theoretical capacity, has no danger of explosion due to ignition, and has an unobtainable advantage of extremely high thermal safety. However, there is a problem that the theoretical capacity is slightly inferior to the battery using the other two composite oxides.
On the other hand, in recent years, Li [Li _{[(1-2x) / 3]} Ni _x Mn _{[(2-x) / 3]} ] has been proposed as a solution for solving the above-described problems in the three types of conventionally used active materials. Development of a lithium nickel manganese composite oxide such as O ₂ is underway for practical use (see, for example, Non-Patent Document 1). And in the active material consisting of this lithium nickel manganese composite oxide, the energy density is improved, the cost is reduced, and the safety is enhanced.
Journal of Power Sources, 112,2002,634-638

However, in the active material comprising the lithium nickel manganese composite oxide, although the discharge capacity in the initial stage is large, the expansion and contraction of the crystal accompanying charge / discharge is not sufficiently suppressed, and the regularity of the crystal is insufficient. For this reason, when charging / discharging is repeated, the charge / discharge capacity decreases, and the cycle characteristics cannot be sufficiently improved.
An object of the present invention is to provide a positive electrode material for a non-aqueous secondary battery capable of improving cycle characteristics by suppressing a decrease in charge / discharge capacity due to repeated charge / discharge, and a non-aqueous secondary battery using the same. There is to do.

The invention according to claim 1 is an improvement of a positive electrode material for a non-aqueous secondary battery using lithium manganese nickel cobalt oxide comprising lithium, manganese, nickel, cobalt and oxygen.
The characteristic structure is that lithium manganese nickel cobalt oxide has a layered structure and Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] O. ₂ and satisfying the conditions of 0.2 <x <0.5 and 0 <y <0.2 and satisfying the condition of 1 <2x + y.
In the positive electrode material for a non-aqueous secondary battery according to claim 1, the layer structure of the oxide is clean because it contains cobalt, and charging and discharging are repeated by making the relationship between x and y in nickel and cobalt in this way. However, it is possible to suppress a decrease in charge / discharge capacity.

The invention according to claim 2 represents a layered structure represented by the composition formula Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] O _2. It is a manufacturing method of the positive electrode material for non-aqueous secondary batteries which has.
The characteristic point is that a composite hydroxide synthesis step of reacting an aqueous solution of nickel salt, cobalt salt and manganese salt with a strong alkaline aqueous solution to obtain a Ni—Co—Mn composite hydroxide, and its Ni—Co—Mn An oxidation step of oxidizing a composite hydroxide to obtain a Ni-Co-Mn oxyhydroxide, a raw material mixing step of mixing the Ni-Co-Mn oxyhydroxide and a lithium compound to obtain a raw material mixture, And firing the raw material mixture in the atmosphere to obtain a lithium transition metal composite oxide.
In the method for producing a positive electrode material for a non-aqueous secondary battery according to claim 2, Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] A layered lithium manganese nickel cobalt oxide expressed as O ₂ and satisfying the conditions of 0.2 <x <0.5 and 0 <y <0.2 and satisfying the condition of 1 <2x + y is relatively easy. Can be obtained.
The firing of the raw material mixture in the air is preferably performed at 900 to 1100 ° C., and the nickel salt, cobalt salt and manganese salt are preferably sulfate, nitrate or chloride, respectively.

The invention according to claim 5 is a non-aqueous secondary battery using the positive electrode material for non-aqueous secondary battery according to claim 1.
The invention according to claim 6 is a non-aqueous secondary battery using the positive electrode material for a non-aqueous secondary battery manufactured by the method according to any one of claims 2 to 4.

As described above, according to the present invention, there is provided a positive electrode material for a non-aqueous secondary battery using a lithium manganese nickel cobalt oxide having a layered structure composed of lithium, manganese, nickel, cobalt and oxygen, and Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] O ₂ , 0.2 <x <0.5 and 0 <y <0. 2 is satisfied and 1 <2x + y is satisfied, cobalt is included to clean the oxide layered structure, and a reduction in charge / discharge capacity can be suppressed even after repeated charge / discharge. A positive electrode material for a water secondary battery can be obtained.
Further, a composite hydroxide synthesis step of reacting an aqueous solution of a nickel salt, a cobalt salt and a manganese salt with a strong alkaline aqueous solution to obtain a Ni—Co—Mn composite hydroxide, and the Ni—Co—Mn composite hydroxide The oxidation step of oxidizing Ni to Co-Mn oxyhydroxide, the raw material mixing step of mixing the Ni-Co-Mn oxyhydroxide and a lithium compound to obtain a raw material mixture, and the raw material mixture A lithium manganese nickel cobalt oxide having such a layered structure can be obtained relatively easily by including a firing step of firing in the atmosphere to obtain a lithium transition metal composite oxide.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the lithium secondary battery 10 is a sheet-like laminate in this embodiment, and includes a positive electrode current collector plate 11, a positive electrode 12 including a positive electrode active material, an electrolyte sheet 13, and a negative electrode active material. And a negative electrode current collector plate 15 are laminated in this order. The positive electrode current collector plate 11 is made of an aluminum plate, and the negative electrode current collector plate 15 is made of a copper plate. Moreover, as a positive electrode active material contained in the positive electrode 12, lithium manganese nickel cobalt oxide which consists of lithium, manganese, nickel, cobalt, and oxygen is used for the active material main body. As the negative electrode active material contained in the negative electrode 14, a graphite-based active material is used. Furthermore, as the electrolyte sheet 13, a polyethylene oxide sheet containing an electrolytic solution is used.

The lithium manganese nickel cobalt oxide used as the positive electrode material has a layered structure and is Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] O. _It is expressed as ₂ . In this case, x satisfies the condition of 0.2 <x <0.5, and y satisfies the condition of 0 <y <0.2. That is, x is more than 0.2 and less than 0.5, and y is more than 0 and less than 0.2. A preferable value of x is more than 0.2 and less than 0.4, and more preferably more than 0.2 and less than 0.3. On the other hand, the preferred value of y is more than 0 and less than 0.1, and more preferably more than 0.02 and less than 0.08.

  Here, x needs to be more than 0.2 and less than 0.5. When x is 0.2 or less, the amount of Ni contributing to heavy discharge is insufficient and the discharge capacity is reduced. This is because, when x is 0.5 or more, the balance with Mn, which mainly maintains the crystal layered structure, is lost, and the cycle characteristics deteriorate. In addition, y needs to be greater than 0 and less than 0.2. The fact that y is 0 indicates that no cobalt is present, and the layered structure of the crystal cannot be cleaned by cobalt. However, the cycle characteristics cannot be improved. Further, if y is 0.2 or more, the amount of Ni contributing to heavy discharge is insufficient and the discharge capacity is reduced.

  Further, the lithium manganese nickel cobalt oxide used as the positive electrode material is required to satisfy the condition of 1 <2x + y in the relationship between x and y. That is, this condition requires that Ni be greater than Mn. This is because if the value of 2x + y is 1 or less, Ni is equal to Mn or Mn is more than Ni, and Ni for charge / discharge is insufficient, resulting in a decrease in discharge capacity. At the same time, by satisfying the condition of 2x + y> 1, the lithium content becomes 1.0 or more, thereby increasing the structural stability of the crystal and improving the cycle characteristics.

This method for producing lithium manganese nickel cobalt oxide includes a composite hydroxide synthesis step, an oxidation step, a raw material mixing step, and a firing step. Hereinafter, each step will be described.
(1) The composite hydroxide synthesis step is a step of obtaining an Ni—Co—Mn composite hydroxide by reacting an aqueous solution of nickel salt, cobalt salt and manganese salt with a strong alkaline aqueous solution. As a salt containing nickel as a cation, considering that it is water-soluble, for example, nickel nitrate, nickel sulfate, nickel chloride and the like can be used. Examples of the salt containing cobalt as a cation include cobalt nitrate, cobalt sulfate, and cobalt chloride. Furthermore, as a salt containing manganese as a cation, for example, manganese nitrate, manganese sulfate, manganese chloride, or the like can be used. In particular, it is desirable to use a nitrate as each salt because it is difficult to remain in the resulting composite hydroxide.

  As an aqueous solution of nickel salt, cobalt salt and manganese salt, for example, an aqueous solution prepared by preparing an aqueous solution of each salt and mixing them can be used. The aqueous salt solution is preferably prepared so that the concentration of the salt is 0.5 to 2M from the viewpoint of satisfying both the reactivity and the yield. And what is necessary is just to prepare so that the ratio of Ni, Co, and Mn contained in the obtained Ni-Co-Mn composite hydroxide may become a thing according to the composition of the target lithium transition metal composite oxide. For example, a nickel salt, a cobalt salt, and a manganese salt are mixed so that a molar ratio of Ni: Co: Mo = 2 to 5: 0 to 2: 4.3 to 6 is obtained.

  As the strong alkaline aqueous solution, a lithium hydroxide aqueous solution, a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, ammonia water or the like can be used. Among these, it is desirable to use a lithium hydroxide aqueous solution in view of the point that it is difficult to remain in the generated composite hydroxide and a stable concentration can be maintained. When using a lithium hydroxide aqueous solution, it is desirable to use one having a concentration of about 0.5 to 2M. In order to perform the above reaction uniformly, for example, a strong alkaline aqueous solution may be dropped into the aqueous solution containing the salt to perform the reaction. The reaction is preferably carried out with stirring. Conditions such as the stirring speed, the pH value of the strong alkaline aqueous solution, the reaction temperature, etc. affect the particle size of the resulting Ni—Co—Mn composite hydroxide. do it. For example, the pH value of the strong alkaline aqueous solution is desirably adjusted so as to be substantially constant during the reaction, and the value is desirably 11-12. The reaction temperature is preferably 20 to 40 ° C. in order to obtain an appropriate reaction rate.

  (2) The oxidation step is a step of obtaining Ni—Co—Mn oxyhydroxide by oxidizing the Ni—Co—Mn composite hydroxide obtained in the above-described composite hydroxide synthesis step. The oxidation method of the Ni—Co—Mn composite hydroxide is not particularly limited. In the composite hydroxide synthesis step, the Ni—Co—Mn composite hydroxide is obtained as a precipitate in an aqueous solution. Therefore, for example, the Ni—Co—Mn composite hydroxide can be oxidized by maintaining the suspension after the reaction in the composite hydroxide synthesis step in the atmosphere. In this case, in order to promote the oxidation reaction, it is desirable to hold the agitation while bubbling air into the suspension. Moreover, since the oxidation reaction proceeds at room temperature, the suspension may be kept at room temperature. Moreover, according to the said method, since a Ni-Co-Mn oxyhydroxide is obtained as a deposit, this can be filtered, wash | cleaned etc., and can use for the following process. In addition, when the particle diameter of the obtained Ni—Co—Mn oxyhydroxide is small and difficult to filter, for example, by performing aging to maintain the suspension after reaction at a predetermined temperature The particles may be grown and then filtered. The aging conditions are not particularly limited, but may be performed at a temperature of 40 to 90 ° C. for about 24 hours. As another method, for example, Ni-Co-Mn oxyhydroxide can be obtained by spray drying the suspension after the reaction.

  (3) The raw material mixing step is a step of obtaining a raw material mixture by mixing the Ni—Co—Mn oxyhydroxide obtained in the oxidation step described above and a lithium compound. As the lithium compound, lithium hydroxide, lithium carbonate, lithium nitrate, or the like can be used. In particular, it is desirable to use lithium hydroxide because of its high reactivity. The mixing of the Ni—Co—Mn oxyhydroxide and the lithium compound may be performed by a method used for mixing ordinary powders. Specifically, it may be mixed using, for example, a ball mill, a mixer, a mortar or the like. Further, the mixing ratio of the Ni—Co—Mn oxyhydroxide and the lithium compound is such that the composition of the target lithium transition metal composite oxide, that is, Li: (Ni + Co + Mn) is approximately 1 to 1.3: The ratio may be set to 1.

(4) The firing step is a step in which the raw material mixture obtained in the raw material mixing step is fired in the air to obtain a lithium transition metal composite oxide. The firing temperature is desirably in the range of 900 to 1100 ° C. This is because if the firing temperature is lower than 900 ° C., the reaction does not proceed sufficiently and the crystallinity is lowered. On the other hand, when the temperature exceeds 1100 ° C., lithium is evaporated, and the composition easily loses lithium. Note that the firing time may be a time sufficient to complete the firing, and is usually performed for about 3 to 10 hours.
In the positive electrode material for a non-aqueous secondary battery manufactured in this way, the volume change accompanying the charge / discharge cycle is small, and the reduction in charge / discharge capacity can be suppressed even when charge / discharge is repeated. Therefore, when producing a non-aqueous secondary battery by producing a positive electrode using a positive electrode material made of this lithium manganese nickel cobalt oxide, producing a negative electrode using a negative electrode active material made of graphite containing lithium, Even if charging / discharging is repeated, it is possible to obtain a nonaqueous secondary battery capable of suppressing a decrease in charge / discharge capacity.

Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
First, 2 liters of 1M lithium hydroxide aqueous solution was prepared in a sealed container filled with nitrogen gas. Next, 1M nickel nitrate, cobalt nitrate, and manganese nitrate aqueous solutions were mixed so that the molar ratio of Ni: Co: Mn was 35: 5: 52 to obtain a 1 liter aqueous solution. To this aqueous solution, the above lithium hydroxide aqueous solution was dropped so that the molar ratio of Li: (Ni + Co + Mn) was 1.17: 1, and Ni—Co—Mn composite hydroxide was precipitated. The reaction temperature was 30 ° C., and the pH value during the reaction was 11-12. Then, the suspension in which the Ni—Co—Mn composite hydroxide was precipitated was stirred while bubbling air and held at room temperature for 1 day to oxidize the Ni—Co—Mn composite hydroxide. Ni-Co-Mn oxyhydroxide was used. Further, the suspension was aged by holding at 80 ° C. for 10 hours, and then the precipitate was separated by filtration and washed with water to obtain Ni—Co—Mn oxyhydroxide. Next, the obtained Ni—Co—Mn oxyhydroxide and lithium hydroxide were mixed so that the molar ratio of Li: (Ni + Co + Mn) was 1: 1, and baked at 1000 ° C. for 5 hours in the air. As a result, a lithium transition metal composite oxide was obtained. When the composition of the lithium transition metal composite oxide was confirmed by composition analysis, the composition formula Li ₁ . ₀₈ Ni ₀ . ₃₅ Co ₀ . ₀₅ Mn ₀ . It was a lithium transition metal composite oxide represented by ₅₂ O ₂ . This lithium transition metal composite oxide was taken as Example 1.

<Examples 2 to 5>
Lithium transition metal composite oxide in which the mixing ratio of each aqueous solution of nickel nitrate, cobalt nitrate, and manganese nitrate, that is, only the ratio of Ni and Co contained in the Ni—Co—Mn composite hydroxide is different in the method in Example 1 Four more were produced. Among the obtained lithium transition metal composite oxides, the composition formula Li ₁ . ₀₇ Ni ₀ . A lithium transition metal composite oxide represented by ₃₅ Co _0.1 Mn _0.48 O ₂ was taken as Example 2, and the composition formula Li ₁ . ₀₅ Ni ₀ . Example 3 was a lithium transition metal composite oxide represented by ₃₅ Co _0.15 Mn _0.45 O ₂ . Furthermore, among the obtained lithium transition metal composite oxides, a lithium transition metal composite oxide represented by the composition formula Li _1.15 Ni _0.25 Co _0.05 Mn _0.55 O ₂ was taken as Example 4, and the composition formula Li ₁ . Example 5 was a lithium transition metal composite oxide represented by ₀₅ Ni _0.4 Co _0.05 Mn _0.58 O ₂ .

<Comparative Examples 1-5>
Lithium transition metal composite oxide in which the mixing ratio of each aqueous solution of nickel nitrate, cobalt nitrate, and manganese nitrate, that is, only the ratio of Ni and Co contained in the Ni—Co—Mn composite hydroxide is different in the method in Example 1 5 types were manufactured. Among the obtained lithium transition metal composite oxides, a lithium transition metal composite oxide represented by a composition formula Li _1.22 Ni _0.15 Co _0.05 Mn _0.58 O ₂ was used as Comparative Example 1, and a composition formula Li ₁ Ni _0.55 Co _0.05 Mn _{0.45 was used.} The lithium transition metal composite oxide represented by O ₂ was used as Comparative Example 2, and the lithium transition metal composite oxide represented by the composition formula Li ₁ Ni _0.3 Co _0.4 Mn _0.3 O ₂ was used as Comparative Example 3. Further, among the obtained lithium transition metal composite oxides, a lithium transition metal composite oxide represented by the composition formula Li _1.1 Ni _0.35 Mn _0.55 O ₂ was used as Comparative Example 4, and the composition formula Li ₁ Ni _0.4 Co _0.3 Mn _{0.3 was used.} A lithium transition metal composite oxide represented by O ₂ was used as Comparative Example 5.

<Comparative test 1 and evaluation>
Positive electrodes were produced using the positive electrode materials for secondary batteries of Examples 1 to 5 and Comparative Examples 1 to 5. Specifically, lithium manganese nickel cobalt oxide (positive electrode material) of Examples 1 to 5 and Comparative Examples 1 to 5 is mixed with a binder and a conductive auxiliary agent to prepare a slurry, and this slurry is positive electrode by a doctor blade method. After being stretched on a sheet and dried, this positive electrode sheet was laminated on a positive electrode current collector to produce positive electrodes.
These positive electrodes were attached to the charge / discharge cycle test apparatus 21 as shown in FIG. In this device 21, an electrolytic solution 23 (lithium salt dissolved in an organic solvent) is stored in a container 22, and the positive electrode 12 is added to the electrolytic solution 23 together with a negative electrode 14 (metallic lithium) and a reference electrode 24 (metallic lithium). Further, the positive electrode 12, the negative electrode 14, and the reference electrode 24 are electrically connected to a potentiostat 25 (potentiometer), respectively. A charge / discharge cycle test was performed using this apparatus, and the initial discharge capacity and capacity retention rate of each positive electrode were measured. In addition, a capacity | capacitance retention rate means the value which represented the value with respect to the initial stage discharge capacity of% after performing 20 cycles charge / discharge with%. Table 1 shows the initial discharge capacity of the positive electrode, the discharge capacity after 20 cycles, and the capacity retention together with the composition of lithium manganese nickel cobalt oxide.

  As is apparent from Table 1, it can be seen that Comparative Examples 1-5 are inferior to Examples 1-5 in both discharge capacity and retention rate. On the other hand, in Examples 1-5, it is superior to Comparative Examples 1-5 in both discharge capacity and its retention rate, and it turns out that even if charging / discharging is repeated, the fall of charging / discharging capacity | capacitance can be suppressed.

<Comparative test 2 and evaluation>
Nonaqueous secondary batteries were produced using the positive electrode active material powders of Examples 1 to 5, and changes in discharge potential with respect to changes in discharge capacity of these secondary batteries when 4.5 V was applied were measured. The result is shown in FIG.
As is apparent from FIG. 3, it was found that the discharge capacity and potential (vs. Li / Li ⁺ ) characteristics of the secondary batteries of Examples 1 to 5 are in a range that is practically excellent.

The principal part cross-section block diagram of the nonaqueous secondary battery of embodiment of this invention. The apparatus used for the charging / discharging cycle test of the positive electrode material for non-aqueous secondary batteries of an Example and a comparative example. The figure which shows the characteristic of the discharge capacity and electric potential (vs. Li / Li ^<+> ) of a non-aqueous secondary battery when 4.5V produced using the positive electrode active material powder of Examples 1-5 is applied. Cross-sectional expansion explanatory drawing which shows the structure of a non-aqueous secondary battery typically.

Explanation of symbols

  10 Non-aqueous secondary battery

Claims (6)

In the positive electrode material for non-aqueous secondary battery using lithium manganese nickel cobalt oxide consisting of lithium, manganese, nickel, cobalt and oxygen,
The lithium manganese nickel cobalt oxide has a layered structure and is represented as Li [Li _{[(1-2x-y) / 3]} Ni _x Co _y Mn _{[(2-x-2y) / 3]} ] O ₂ ,
Satisfy the conditions of 0.2 <x <0.5 and 0 <y <0.2;
And the condition of 1 <2x + y is satisfy | filled. The positive electrode material for nonaqueous secondary batteries characterized by the above-mentioned. Composition formula _{Li [Li [(1-2x-y} ) / 3] Ni x Co y Mn [(2-x-2y) / 3]] positive electrode for nonaqueous secondary battery having represented by layered structure O ₂ A method of manufacturing a material,
A composite hydroxide synthesis step in which an aqueous solution of nickel salt, cobalt salt and manganese salt is reacted with a strong alkaline aqueous solution to obtain a Ni-Co-Mn composite hydroxide;
An oxidation step of oxidizing the Ni-Co-Mn composite hydroxide to obtain a Ni-Co-Mn oxyhydroxide;
A raw material mixing step of mixing the Ni-Co-Mn oxyhydroxide and a lithium compound to obtain a raw material mixture;
A method for producing a positive electrode material for a non-aqueous secondary battery, comprising: calcining the raw material mixture in the air to obtain a lithium transition metal composite oxide.   The method for producing a positive electrode material for a non-aqueous secondary battery according to claim 2, wherein the raw material mixture is baked in the atmosphere at 900 to 1100 ° C.   The method for producing a positive electrode material for a non-aqueous secondary battery according to claim 2 or 3, wherein the nickel salt, cobalt salt and manganese salt are sulfate, nitrate or chloride, respectively.   A non-aqueous secondary battery using the positive electrode material for a non-aqueous secondary battery according to claim 1. The non-aqueous secondary battery using the positive electrode material for non-aqueous secondary batteries manufactured by the method of any one of Claims 2 thru | or 4.

Images