JP2004186149A - Positive electrode material for li ion secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode material for Li ion secondary battery that has superior high temperature characteristics without having capacity degradation and separation of spinel surface, in the Li ion secondary battery positive electrode material obtained by mixing and baking a Li compound, a Mn compound, an Al compound. <P>SOLUTION: This is a positive electrode material for Li ion secondary battery which contains a spinel type lithium manganate as expressed by general formula Li<SB>1+x</SB>Mn<SB>2-x-y</SB>Al<SB>y</SB>O<SB>4</SB>and which contains Al in non-solid solution state not dissolved in the spinel type lithium manganate 20-80% of the total Al contained in the positive electrode material. By having a part of the Al added existing in a state not solid-soluted in the spinel, the high temperature characteristics can be improved. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a positive electrode material for a Li ion secondary battery containing an Al element.

  In recent years, many batteries using Li-Mn spinel (abbreviation for spinel-type lithium manganate; the same applies hereinafter) as a positive electrode material of a Li-ion secondary battery are commercially available. However, when Li-Mn spinel is used as a cathode material of a Li-ion secondary battery, there is a problem that the battery is deteriorated at a high temperature.

  Thus, as one of the methods for improving the high-temperature characteristics of a Li-ion secondary battery using Li-Mn spinel as a positive electrode material, there is a method of reducing the specific surface area to reduce the elution amount of Mn. In order to reduce the specific surface area, there are a method of raising the firing temperature and a method of adding a B-based oxide. However, when the specific surface area is reduced at the same time, there is a problem that it is difficult to obtain a high capacity.

  A method has also been proposed in which the spinel structure is stabilized by substituting a part of Mn in the Li-Mn spinel with another element to suppress the elution of Mn and to suppress the deterioration of the Li-Mn spinel. However, there is a problem that it is difficult to obtain a high capacity because the capacity decreases with an increase in the replacement amount.

  As another method, a method of coating the surface of a Li-Mn spinel with another element has been proposed. For example, Patent Literature 1 proposes lithium composite oxide particles in which an alkali metal oxide and a metal oxide are coated with one or more layers using water, an aqueous acid solution, or alcohol.

Patent Document 2 proposes an active material for a non-aqueous secondary battery in which the concentration of an element Al synthesized using aluminum isopropoxide continuously decreases from the surface toward the inside.
JP 2001-313034 A JP-A-2001-196063

  An object of the present invention is to provide a positive electrode material for a Li-ion secondary battery having excellent high-temperature characteristics without causing a problem of a decrease in capacity or peeling of a coat layer on a Li-Mn spinel surface.

  The present inventors have conducted intensive studies and found that in the cathode material containing spinel-type lithium manganate, a part of the added Al exists in the cathode material in an undissolved state that does not dissolve in the spinel structure. Thus, they found that the high-temperature characteristics of a Li-ion secondary battery using the same were drastically improved, and conceived the present invention based on such findings.

According to a first aspect of the present invention, there is provided a positive electrode material for a Li ion secondary battery obtained by mixing and firing a Li compound, a Mn compound and an Al compound, wherein the positive electrode material has a general formula Li _{1 + x} Mn _2-xy Al _y O _The undissolved Al that contains spinel-type lithium manganate represented by ₄ (referred to as “Li—Mn spinel”) and is not dissolved in the Li—Mn spinel is converted into 20% of the total Al contained in the positive electrode material. The present invention proposes a positive electrode material for a Li-ion secondary battery, which is characterized by containing about 80%.

According to a second aspect of the present invention, there is provided a positive electrode material for a Li ion secondary battery obtained by mixing and firing a Li compound, a Mn compound, an Al compound and an M element compound (M element: substitution element), Li _{1 + x} Mn _2-xyz Al _y M _z O ₄ It contains a Li-Mn spinel represented by, and does not form a solid solution in the Li-Mn spinel. A positive electrode material for a Li-ion secondary battery characterized by containing 20 to 80% of the total Al is proposed.

According to a third aspect of the present invention, there is provided a positive electrode material for a Li ion secondary battery obtained by mixing and firing a Li compound, a Mn compound, an Al compound and a B element compound, wherein the positive electrode material has a general formula Li _{1 + x} Mn _{2- It} contains Li-Mn spinel represented by _xy Al _y O ₄ , and contains 20 to 80% of undissolved Al not solid-dissolved in the Li-Mn spinel, based on the total Al contained in the positive electrode material. A positive electrode material for a Li-ion secondary battery, characterized by the following, is proposed.

According to a fourth aspect of the present invention, there is provided a positive electrode material for a Li-ion secondary battery obtained by mixing and firing a Li compound, a Mn compound, an Al compound, an M element compound (M element: substitution element) and a B element compound. Te, contains Li-Mn spinel represented by the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4, and the Al of the undissolved state without being dissolved in the Li-Mn spinel, a positive electrode A positive electrode material for a Li-ion secondary battery characterized by containing 20 to 80% of the total Al contained in the material is proposed.

  Higher temperature characteristics are improved when a part of Al is dissolved in Li-Mn spinel and another part is in a non-dissolved state rather than all solid solution in Li-Mn spinel. It turned out to be. At this time, the Al present in the undissolved state is not added after firing the Li-Mn spinel, but needs to be fired simultaneously with the Li-Mn spinel.

  The upper limit and the lower limit of the numerical range specified by the present invention are within the scope of the present invention as long as they have the same operation and effect as those within the numerical range, even if they slightly deviate from the specified numerical range. Include the meaning of inclusion.

  Next, the best mode for carrying out the present invention will be described, but the scope of the present invention is not limited to only the following embodiments.

  The positive electrode material according to the present invention can be obtained by mixing a Li compound, a Mn compound and an Al compound, or an M element compound, and baking the mixture. Further, if necessary, the compound can be obtained by adding the element B compound to the compound, that is, the spinel constituent element compound, mixing and firing.

(material)
Examples of the Li compound, that is, the Li raw material include LiOH, Li ₂ CO ₃ , LiNO ₃ , LiOH · H ₂ O, Li ₂ O, and other fatty acid lithium and lithium halide. Among them, lithium hydroxide, carbonate and nitrate are preferred.

As the Mn compound, that is, as the Mn raw material, any one of manganese dioxide, trimanganese tetroxide, dimanganese trioxide, manganese carbonate, and the like, or a mixture of two or more kinds selected from these can be used.
The average particle size of the Mn compound is preferably 5 to 30 μm. When the average particle size is 5 to 30 μm, when processing into a thick film having a thickness of about 100 μm as a positive electrode material of a non-aqueous electrolyte secondary battery, a uniform film thickness is formed without excessive cracking or the like. easy. In addition, if the spinel-type lithium manganate is synthesized from electrolytic manganese dioxide having an average particle diameter in this range, a positive electrode material suitable for film formation can be manufactured without additional pulverization.
As manganese dioxide, chemically synthesized manganese dioxide (CMD), electrolytic manganese dioxide (EMD), manganese carbonate or natural manganese dioxide can be used.

As the Al compound, that is, the Al raw material, any one of aluminum hydroxide, aluminum fluoride (AlF ₃ ), and the like, or a mixture of two or more kinds selected from these can be used.

  Examples of the additional element other than Al that replaces part of Mn, ie, M element, include metal elements such as Mg, Ni, Co, Cr, Fe, Zn, Sn, Cu, and Ti. As the M element compound, an oxide, a hydroxide, a nitrate, a carbonate, a dicarboxylate, a fatty acid salt, an ammonium salt, or the like of these substitution elements, or a mixture of two or more kinds selected from these. Can be used. Among them, it is preferable to use any of oxides, hydroxides, and carbonates of Mg, Fe, Co, Ni, and Zn, or a mixture of two or more kinds selected from these.

As the element B compound, that is, B (boron) raw material, lithium tetraborate (Li ₂ B ₄ O ₇ ), B ₂ O ₃ , H ₃ BO _{3 and the} like are preferably used.

(mixture)
As for the mixing ratio of the raw materials, a Li compound, a Mn compound, an Al compound, and if necessary, an M element compound and a B element compound may be mixed in an appropriate ratio, but preferably, a general formula Li _{1 + x} Mn _2-xy Al preferably mixed with weighed _y O _4, or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4 calculates each spinel structure element content such that the composition represented by and spinel structure element compound .
By mixing the Al compound in the general formula _{Li 1 + x Mn 2-xy} Al y O 4 , or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4 or Al amount having a composition represented by Although it is possible to increase the amount of Al in the undissolved state, the proportion of the amount of Mn in the whole Li-Mn spinel powder becomes relatively low, so that the discharge capacity decreases. Therefore, as described above, the general formula _{Li 1 + x Mn 2-xy} Al y O 4 , or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O a composition expressed by ₄ Al amount of Al compound Is preferably added.
Note that the B element is not a spinel constituent element. The B element compound is preferably added so as to be 0.01 to 5% by weight, particularly 0.1 to 1% by weight based on the obtained Li-Mn spinel.

  The mixing method is not particularly limited as long as it can be uniformly mixed. For example, the respective raw materials may be added simultaneously or in an appropriate order using a known mixer such as a mixer, and may be stirred and mixed in a dry system.

The raw material mixed as described above may be fired as it is, or may be granulated to a predetermined size and fired.
The granulation method may be wet or dry, and may be extrusion granulation, tumbling granulation, fluidized granulation, mixing granulation, spray drying granulation, pressure molding granulation, or flake granulation using a roll or the like. . However, in the case of wet granulation, it is necessary to sufficiently dry before firing. The drying may be performed by a known drying method such as spray heat drying, hot air drying, vacuum drying, freeze drying and the like.

(Fired)
The raw material powder mixed as described above may be fired in a firing furnace at an appropriate temperature of about 600 ° C. or more and 1000 ° C. or less in an air atmosphere for an appropriate time, and among them, no B element compound is added. In this case, firing at 800 to 1000C, particularly 810 to 850C is preferable. In addition, when the element B compound is added, it is preferable to bake at 600 to 800 ° C, especially 650 to 730 ° C.
Increasing the firing temperature can increase the amount of Al dissolved in the spinel structure.
On the other hand, B does not form a solid solution in the Li-Mn spinel, but has a function of accelerating the sintering of the Li-Mn spinel in the firing process. Can be enhanced. Therefore, the undissolved amount of Al can be adjusted by controlling the firing temperature and the amount of B added.
Here, the firing temperature means the product temperature at the highest firing temperature of the firing furnace.

The calcination time, that is, the time for maintaining the calcination temperature is preferably 0.5 to 20 hours, and after maintaining for a predetermined time, it is preferable to lower the temperature and leave it at room temperature for slow cooling.
As the firing furnace, a rotary kiln or a stationary furnace can be used. The firing atmosphere may be an air atmosphere or an oxidizing atmosphere.

(Li-Mn spinel powder)
Li-Mn spinel powder obtained in the above manner, the general formula _{Li 1 + x Mn 2-xy} Al y O 4 spinel-type lithium manganate represented by or formula _{Li 1 + x Mn 2-xyz} Al spinel type lithium manganate represented by _y M _z O _4, containing Al which is present in undissolved state without being dissolved in the spinel-type lithium manganate.

If the Al present in the undissolved state is 20 to 80% of the added Al, that is, 20 to 80% of the total Al contained in the positive electrode material, the high-temperature cycle characteristics of the battery can be improved. Preferably it is ~ 55%.
As a method for quantifying Al existing in an undissolved state, a Li-Mn spinel powder is immersed in an acid obtained by mixing sulfuric acid: water: hydrogen peroxide = 1: 16: 3 and stirred for 1 minute. The amount of Al in the dissolved and undissolved Li-Mn spinel can be calculated as the amount of undissolved Al.

Al present in the undissolved state in the Li-Mn spinel powder does not need to be added after the firing of the Li-Mn spinel, but must be fired simultaneously with the Li-Mn spinel. It has been confirmed that when added after firing of Li-Mn spinel, battery characteristics are not improved. This can be inferred that Al existing completely independently of the Li-Mn spinel does not contribute to the battery characteristics, and that Al existing on the particle surface of the Li-Mn spinel contributes to the battery characteristics.
In addition, when the M element compound is not added, all of the Al present in the undissolved state exists in the state of the aluminum oxide compound, and when the M element compound is added, almost all of the Al exists in the aluminum oxide compound. It has been confirmed that Al exists in a state and a part of Al forms a compound with M element.

  The spinel-type lithium manganate is preferably composed of two or more phases of Li-Mn spinels having different lattice constants. When the added Al or M element forms a solid solution only in part or on the surface of the Li-Mn spinel, two or more phases of Li-Mn spinel having different lattice constants are generated. It is expected that this Li-Mn spinel has a large amount of substitution of Al and the like and a small amount of Mn eluted, and the presence of this on the particle surface suppresses the reaction of the Li-Mn spinel with the electrolytic solution. Can be expected.

The specific surface area of the positive electrode material is preferably in the range of 0.3 to ² m ² / g, particularly 0.3 to ¹ m ² / g, and particularly preferably in the range of 0.3 to 0.7 m ² / g. When the specific surface area is within this range, the high-temperature characteristics are less likely to be degraded due to an increase in the amount of Mn eluted in the electrolytic solution.

(Application)
The Li-Mn spinel powder obtained as described above is subjected to a crushing treatment with a vibration mill or a roller mill, if necessary, and then mixed with a conductive material, a binder, a filler, etc., and kneaded. An agent (paste) is applied to a positive electrode current collector made of, for example, a stainless steel mesh, roll-pressed, and then heated and dried under reduced pressure to produce a positive electrode.
Further, if necessary, the positive electrode can be manufactured by press-molding the above-mentioned mixture into an appropriate shape such as a disc shape and performing heat treatment under vacuum as necessary.

The positive electrode formed from the Li-Mn spinel powder of the present invention is suitable as a positive electrode material for a lithium ion battery, particularly a nonaqueous solvent-based lithium ion battery. For example, a material such as lithium or carbon capable of occluding and desorbing lithium is used for a negative electrode, and a lithium salt such as lithium hexafluorophosphate (LiPF ₆ ) is dissolved in a mixed solvent such as ethylene carbonate-dimethyl carbonate for a non-aqueous electrolyte. A non-aqueous solvent-based lithium-ion battery can be configured by using the above.
Non-aqueous solvent-based lithium-ion batteries configured in this manner can be used, for example, in notebook computers, mobile phones, cordless phone handsets, video movies, LCD televisions, electric shavers, portable radios, headphone stereos, backup power supplies, memory cards, and other electronic devices. It can be used for medical devices such as devices, pacemakers and hearing aids, and drive power supplies for electric vehicles.

  Next, the present invention will be described in more detail based on examples and comparative examples.

(Example 1)
A mixture of 989.9 g of electrolytic manganese dioxide having an average particle size of about 23 μm, 218.6 g of lithium carbonate, 8.65 g of aluminum hydroxide, and 2 g of lithium tetraborate was formed so as to have a composition of Li _1.02 Mn _1.96 Al _0.02 O ₄ , It was baked at 690 ° C. for 10 hours. Thereafter, the temperature was lowered to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature to obtain a Li—Mn spinel powder containing Li _1.02 Mn _1.96 Al _0.02 O ₄ .

The obtained Li-Mn spinel powder was mixed at a mass ratio of Li-Mn spinel powder: conductive material: binder = 0.5: 0.3: 0.2 to form a sheet, and then punched out to form a positive electrode. A coin-type battery was prepared using 1M-LiPF ₆ / PC: DMC (1: 1) as an electrolyte and Li metal as a negative electrode, and a normal temperature cycle charge / discharge test and a high temperature cycle charge / discharge test were performed.
The room temperature cycle charge / discharge test was performed on a coin-type battery under the conditions of temperature: 25 ° C., charge condition: 0.2 C, charge end voltage: 4.3 V, discharge condition: 0.2 C, discharge end voltage = 3.0 V. The battery was repeatedly charged and discharged, and the battery capacity (mAh / g) after each cycle was measured. At this time, the highest capacity after 1 to 10 cycles was obtained, and this is shown in Table 1 as the capacity. The ratio of the capacity at the eighth cycle to the maximum capacity was determined from the number of cycles indicating the maximum capacity, and the ratio was shown in Table 1 as an eight-cycle maintenance rate (%).
The high-temperature cycle charge / discharge test was performed on a coin-type battery under the following conditions: temperature: 60 ° C., charge condition: 0.6 C, charge end voltage: 4.3 V, discharge condition: 0.6 C, discharge end voltage: 3.0 V. The charge and discharge were repeated, and the capacity (mAh / g) after each cycle was measured. At this time, the ratio of the capacity at the 25th cycle to the maximum capacity was determined from the number of cycles indicating the highest capacity, and the ratio was shown in Table 1 as a high-temperature cycle maintenance rate (%).

The amount of undissolved Al was measured by dispersing 20 g of the obtained Li-Mn spinel powder in 400 cc of an acid mixed with sulfuric acid: water: hydrogen peroxide = 1: 16: 3, stirring for 1 minute, The solution was filtered through a filter having a pore size of 0.8 μm, and judgment was made based on the analysis result of the dissolved residue on the filter. The dissolved residue was dissolved in an acid, and those not dissolved were melted and analyzed.
ICP emission spectroscopy was used for the analysis.
The undissolved amount was determined by using, as an index, the ratio of the amount of Al remaining on the filter to the amount of added Al expressed as 100 parts (%). Table 1 shows the results.
In addition, as a result of performing X-ray diffraction on the dissolved residue of the Li—Mn spinel powder, it was found that all were Al oxides (Al ₂ O ₃ ).

  The undissolved amounts of Al, Mg, Mn, and Li are shown as ratios to the added amounts. In addition, in this method, since the melting residual amount of Mg may not be measured accurately, it is described as a reference value.

(Example 2)
984.8 g of electrolytic manganese dioxide having an average particle size of about 23 μm, 218.6 g of lithium carbonate, 8.65 g of aluminum hydroxide, 2.31 g of magnesium oxide, and 2.31 g of Li _1.02 Mn _1.95 Al _0.02 Mg _0.01 O ₄ having a mean particle size of about 23 μm. 2 g of lithium borate was mixed and fired at 690 ° C. for 10 hours. Thereafter, the temperature was lowered to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature to obtain a Li—Mn spinel powder containing Li _1.02 Mn _1.96 Al _0.02 O ₄ .
The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

  Further, the obtained Li-Mn spinel was subjected to X-ray diffraction, and the results are shown in FIG. As a result, a shoulder appeared on the right side of the peak of the Li-Mn spinel, and it was found that the Li-Mn spinel was not composed of a single phase but composed of two or more Li-Mn spinels having different lattice constants.

  Simultaneously, X-ray diffraction was performed on the dissolved residue of Li—Mn spinel when the acid was dissolved in the same manner as in Example 1, and the results are shown in FIG. From this, it was inferred that most were Al oxides and Al-M (M = Li, Mn, Mg) oxides.

(Example 3)
A mixture of 984.8 g of electrolytic manganese dioxide having an average particle size of about 23 μm, 218.6 g of lithium carbonate, 8.65 g of aluminum hydroxide, and 2.31 g of magnesium oxide was formed to have a composition of Li _1.02 Mn _1.95 Al _0.02 Mg _0.01 O _4. And baked at 790 ° C. for 10 hours. Thereafter, the temperature was lowered to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature to obtain a Li—Mn spinel powder containing Li _1.02 Mn _1.95 Al _0.02 Mg _0.01 O ₄ . The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Comparative Example 1)
The raw materials mixed in the same amount as in Example 2 were fired at 700 ° C., which was higher than that in Example 1, for 10 hours, cooled to 500 ° C. at 10 ° C./hr, and allowed to cool to room temperature. The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Comparative Example 2)
The raw materials mixed in the amount of Example 2 were fired at 650 ° C., which was lower than that of Example 1, for 10 hours, cooled to 500 ° C. at 10 ° C./hr, and allowed to cool to room temperature. The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Comparative Example 3)
A mixture of 984.8 g of electrolytic manganese dioxide having an average particle size of about 23 μm, 218.6 g of lithium carbonate, 8.65 g of aluminum hydroxide, and 2.31 g of magnesium oxide was formed to have a composition of Li _1.02 Mn _1.95 Al _0.02 Mg _0.01 O _4. And baked at 690 ° C. for 10 hours. Thereafter, the temperature was lowered to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature to obtain a Li—Mn spinel powder containing Li _1.02 Mn _1.95 Al _0.02 Mg _0.01 O ₄ .
The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Comparative Example 4)
A high temperature cycle test was performed by adding Al ₂ O ₃ powder to the Li—Mn spinel powder prepared in Comparative Example 1 at 3 wt% based on the weight of the Li—Mn spinel.

  From the above results, it was found that when the amount of undissolved Al was large, the high-temperature cycle characteristics were excellent. In particular, considering the values of Comparative Examples and Examples, the undissolved amount of Al is 20 to 80%, preferably 30 to 60%, and especially 35 to 35% of the amount of added Al, that is, the total amount of Al contained in the positive electrode material. It has been found that 55% is preferable.

(Example 4)
The raw material mixed in the amount of Example 2 was fired at 680 ° C. for 10 hours, then cooled to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature.
The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Example 5)
The raw material mixed in the amount of Example 2 was calcined at 670 ° C. for 10 hours, then cooled to 500 ° C. at 10 ° C./hr, and then allowed to cool to room temperature.
The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.

(Comparative Example 5)
The raw materials mixed in the amount of Example 2 were fired at 660 ° C. for 10 hours, at a firing temperature lower than that of Example 2, cooled down to 500 ° C. at 10 ° C./hr, and allowed to cool to room temperature.
The obtained Li-Mn spinel powder was evaluated in the same manner as in Example 1.
Table 2 shows the obtained results.

FIG. 2 is an X-ray diffraction diagram showing a state of two or more phases of Li—Mn spinels having different lattice constants according to the present invention. FIG. 4 is an X-ray diffraction diagram showing a state of a portion that does not form a solid solution in the Li—Mn spinel according to the present invention.

Claims (10)

A positive electrode material for a Li ion secondary battery obtained by mixing and firing a Li compound, a Mn compound and an Al compound,
The positive electrode material contains spinel-type lithium manganate represented by the general formula Li _{1 + x} Mn _2-xy Al _y O ₄ , and contains undissolved Al that is not dissolved in the spinel-type lithium manganate. A positive electrode material for a Li-ion secondary battery, comprising 20 to 80% of the total Al content. A positive electrode material for a Li ion secondary battery obtained by mixing and firing a Li compound, a Mn compound, an Al compound and a substitution element (M element) compound,
Formula _{Li 1 + x Mn 2-xyz} Al y M z O containing spinel-type lithium manganate represented by _4, and the Al of the undissolved state without being dissolved in the spinel-type lithium manganate, positive A positive electrode material for a Li-ion secondary battery, comprising 20 to 80% of the total Al contained in the material.   3. The positive electrode material for a Li-ion secondary battery according to claim 1, wherein Al existing in an undissolved state is fired simultaneously with spinel-type lithium manganate.   When the positive electrode material for a Li-ion secondary battery is dissolved in an acid obtained by mixing sulfuric acid: water: hydrogen peroxide = 1: 16: 3 with stirring for 1 minute, 20 to 20% of the total Al contained in the positive electrode material is dissolved. The positive electrode material for a Li-ion secondary battery according to any one of claims 1 to 3, wherein 80% of the positive electrode material remains undissolved without being dissolved.   The positive electrode material for a Li-ion secondary battery according to any one of claims 1 to 4, wherein the spinel-type lithium manganate comprises two or more phases of spinel-type lithium manganate having different lattice constants. The positive electrode material for a Li-ion secondary battery according to any one of claims 1 to 5, wherein the specific surface area of the positive electrode material is in a range of 0.3 to ² m2 / g. A cathode material for a Li-ion secondary battery obtained by mixing and firing a B element compound in addition to the spinel constituent element compound,
As a spinel type lithium manganate, containing spinel-type lithium manganate represented by the general formula _{Li 1 + x Mn 2-xy} Al y O 4 , or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4 The positive electrode material for a Li-ion secondary battery according to any one of claims 1 to 6, wherein Formula _{Li 1 + x Mn 2-xy} Al y O 4 , or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4 and so as to be weighed each spinel structure element compound composition were mixed, 800 The positive electrode material for a Li-ion secondary battery according to any one of claims 1 to 6, which is obtained by firing at a temperature of from 1000C to 1000C. Weigh general formula _{Li 1 + x Mn 2-xy} Al y O 4 , or the general formula _{Li 1 + x Mn 2-xyz} Al y M z O 4 in such a composition the spinel structure element compounds, these spinels constituent elements The cathode material for a Li-ion secondary battery according to claim 7, which is obtained by adding a B element to a compound, mixing and baking the mixture at 600 to 800 ° C. A Li-ion secondary battery comprising the positive electrode material according to any one of claims 1 to 9 for a positive electrode.

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