JP2017004912A - Spinel lithium-manganese composite oxide and method for producing the same, and lithium ion secondary battery and electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spinel lithium-manganese composite oxide with which high charge/discharge capacitive characteristics can be obtained when the spinel lithium-manganese composite oxide is used as a positive electrode active material of an electrochemical device.SOLUTION: A spinel lithium-manganese composite oxide used as an active material of a positive electrode of an electrochemical device is characterized in that the mass ratio of fluorine ions with respect to the spinel lithium-manganese composite oxide is 500 ppm or more and 15,000 ppm or less, the fluorine ions being eluted into an eluate that is obtained by dispersing the spinel lithium-manganese composite oxide with ultra pure water, and the composition of the spinel lithium-manganese composite oxide is represented by the following general formula (1): LiMnMOF(-0.1≤x<1, 0≤z<2, 0≤a≤4)...(1) (in the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu and Zn.).SELECTED DRAWING: None

Description

  The present invention relates to a spinel lithium manganese composite oxide and a method for producing the same, and an electrochemical device and a lithium ion secondary battery using the spinel lithium manganese composite oxide.

  In recent years, small electronic devices typified by mobile terminals and the like have become widespread, and further downsizing, weight reduction, and long life have been strongly demanded. In response to such market demands, development of secondary batteries capable of obtaining a high energy density, in particular, being small and light is underway. This secondary battery is not limited to a small electronic device, but is also considered to be applied to a large-sized electronic device represented by an automobile or the like, or an electric power storage system represented by a house.

  Among them, lithium ion secondary batteries are highly expected because they are small and easy to increase in capacity. This is because an energy density higher than that of a lead battery or a nickel cadmium battery can be obtained.

  A lithium ion secondary battery includes an electrolyte solution together with a positive electrode, a negative electrode, and a separator. The positive electrode and the negative electrode include a positive electrode active material and a negative electrode active material related to the charge / discharge reaction.

In recent years, spinel lithium manganese (LiMn ₂ O ₄ ) has attracted attention as a positive electrode active material for lithium ion secondary batteries.

This LiMn ₂ O ₄ has a strong binding force between manganese and oxygen, hardly releases oxygen even at high temperatures, has excellent thermal stability, and is applied to a high-power, large-capacity secondary battery electrode active material. Suitable for Further, since 0.5 lithium contained per Mn atom can be inserted and removed by charging / discharging, it has been studied as a positive electrode active material for a new lithium secondary battery replacing lithium cobalt oxide. For example, Patent Document 1 discloses a lithium manganese oxide in which all primary particles are less than 1 μm and a BET specific surface area of 1 m ² / g or more, and Patent Document 2 discloses an average of lithium manganese oxide. A positive electrode active material having a particle size of 5 μm or more and 30 μm or less and a particle size distribution width with respect to the average particle size of ± 20% or less is disclosed, and Patent Document 3 discloses a primary particle having an average particle size of 0.01 to 3 μm. A lithium manganese oxide composed of secondary particles having an average particle diameter of 20 to 100 μm formed by agglomerating particles is disclosed.

  Patent Document 4 discloses a lithium transition metal composite oxide for a lithium ion secondary battery positive electrode active material having a silicon atom content of 100 to 1000 ppm and a fluorine atom content of 300 to 900 ppm. Yes.

The spinel lithium manganese composite oxide proposed in Patent Document 5 describes that synthesis is performed using LiF and MnF ₂ as raw materials.

  In the spinel lithium manganese composite oxide proposed in Patent Document 6, it is described that LiF can be cited as a raw material candidate for the synthesis.

  Patent Document 7 describes that lithium fluoride is detected in the surface layer, but the potential is limited to 4.5 V or more, and the content thereof is not particularly limited.

  Patent Document 8 describes that the lithium fluoride is detected on the surface using TOF-SIMS (time-of-flight secondary ion mass spectrometry) or the like, but the content thereof is not particularly limited.

  Patent Document 9 discloses a spinel lithium manganese composite oxide coated with a fluorine compound.

Japanese Patent Laid-Open No. 9-086933 Japanese Patent Laid-Open No. 10-162826 Japanese Patent Laid-Open No. 10-172569 JP 2008-277265 A JP 2012-074390 A Special table 2012-529752 gazette JP 2013-066942 A Japanese Patent No. 3141858 Special table 2008-536285 gazette

Spinel lithium manganese (LiMn ₂ O ₄ ) produced by a conventional method is prone to oxygen deficiency, and in order to synthesize a uniform compound, it is necessary to use a method of repeating firing, etc. It took time and effort. Considering this, in order to synthesize inexpensive spinel lithium manganese, it is preferable to regenerate used spinel lithium manganese. However, when the regenerated spinel lithium manganese is used, there is a problem that the resistance of the powder increases and a sufficient charge / discharge capacity cannot be obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a spinel lithium manganese composite oxide capable of obtaining high charge / discharge capacity when used as a positive electrode active material of an electrochemical device. And

To achieve the above object, the present invention provides a spinel lithium manganese composite oxide used as an active material for a positive electrode of an electrochemical device, wherein the spinel lithium manganese composite oxide is dispersed in ultrapure water. Fluorine ions eluted in the liquid are in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide, and the composition of the spinel lithium manganese is represented by the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
The present invention provides a spinel lithium-manganese composite oxide characterized by:

  With such a spinel lithium manganese composite oxide, when it is used as an active material for the positive electrode of an electrochemical device, lithium ions can be smoothly inserted and removed, and powder resistance is reduced, thereby stabilizing lithium ions. Thus, the charge / discharge capacity can be increased.

  At this time, it is preferable that the lithium ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is 500 ppm or more and 5000 ppm or less in a mass ratio with respect to the spinel lithium manganese composite oxide.

  If the lithium ions eluted in the eluate when dispersed with ultrapure water are in the above range in terms of the mass ratio to the spinel lithium manganese composite oxide, charge and discharge when used as the positive electrode active material of an electrochemical device The capacity can be increased more effectively.

  At this time, the mass ratio (the mass of fluorine ions / the mass of lithium ions) of lithium ions and fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is 0.1 or more. It is preferable that it is 10 or less.

  When the mass ratio of eluted lithium ions to fluorine ions (fluorine ion mass / lithium ion mass) is within the above range, the charge / discharge capacity is more reliably obtained when used as an active material for the positive electrode of an electrochemical device. Can be high.

  At this time, according to the X-ray diffraction measurement of the spinel lithium manganese composite oxide, a peak corresponding to lithium fluoride is observed in the range where the value of 2θ is 43 ° to 46 ° and / or the value of 2θ is 23. It is preferable that a peak corresponding to lithium phosphate fluoride is observed in the range of from 0 ° to 26 °.

  If the spinel lithium manganese composite oxide having such an X-ray diffraction pattern is used as an active material for the positive electrode of an electrochemical device, the charge / discharge capacity can be increased more reliably. It can use suitably for a positive electrode active material.

  At this time, it is preferable that the average particle diameter of a spinel lithium manganese complex oxide is 0.5 micrometer or more and 40.0 micrometers or less.

  When the average particle size of the spinel lithium manganese composite oxide is in the above range, the charge / discharge capacity can be increased more effectively when used as the active material of the positive electrode of the electrochemical device.

In this case, it is preferable BET specific surface area of the spinel lithium-manganese composite oxide is less than 0.05 m ² / g or more 5.0 m ² / g.

  When the BET specific surface area of the spinel lithium manganese composite oxide is in the above range, the charge / discharge capacity can be increased more effectively when used as the active material of the positive electrode of the electrochemical device.

The composition of the present invention has the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
A process for producing a spinel lithium manganese composite oxide represented by:
The composition is represented by the following general formula (2):
_{Li 1-y Mn 2-z} M z O 4-b F b (x <y <1,0 ≦ z <2,0 ≦ b ≦ 4) ··· (2)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
A process of mixing and reacting a spinel lithium manganese precursor from which lithium represented by
Fluorine that elutes into the eluate when the spinel lithium manganese composite oxide produced is dispersed in ultrapure water by using the spinel lithium manganese precursor or the lithium compound containing fluorine. Provided is a method for producing a spinel lithium manganese composite oxide, characterized in that ions are contained in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide.

  In such a manufacturing method, the spinel lithium manganese composite oxide in which the fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is in a predetermined range by mass ratio to the spinel lithium manganese composite oxide. An oxide can be produced reliably.

  At this time, it is preferable that lithium is extracted electrochemically from the spinel lithium manganese precursor.

  Such a method can be suitably used as a method for extracting lithium.

  At this time, it is preferable that lithium is extracted electrochemically after the spinel lithium manganese precursor is molded with a thickness of 1.0 mm or more.

  If the spinel lithium manganese precursor is molded with the above thickness, handling can be easily performed.

At this time, the lithium compound preferably contains lithium hexafluorophosphate (LiPF ₆ ).

  By using a lithium compound containing lithium hexafluorophosphate as a lithium compound to be reacted with the spinel lithium manganese precursor, fluorine can be contained in the spinel lithium manganese composite oxide.

At this time, the lithium compound preferably contains lithium tetrafluoroborate (LiBF ₄ ).

  By using a lithium compound containing lithium tetrafluoroborate as the lithium compound to be reacted with the spinel lithium manganese precursor, fluorine can be contained in the spinel lithium manganese composite oxide.

  At this time, the step of reacting includes a stage of firing, and in the stage of firing, the firing temperature is preferably 700 ° C. or higher and 900 ° C. or lower.

  As a method of reacting the spinel lithium manganese precursor and the lithium compound, a method of firing in the above temperature range can be suitably used.

  At this time, it is preferable that the reacting step includes a firing step, and in the firing step, firing is performed in an oxygen-containing atmosphere.

  By performing firing in an oxygen-containing atmosphere, oxygen vacancies in the spinel lithium manganese composite oxide can be suppressed.

  At this time, it is preferable that the reacting step includes a firing step, and in the firing step, firing is performed in an air atmosphere.

  By firing in the air atmosphere, oxygen deficiency of the spinel lithium manganese composite oxide can be prevented, and the spinel lithium manganese composite oxide can be synthesized at a lower cost.

  Furthermore, the present invention provides a negative electrode including a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material for an electrochemical device, and the above spinel lithium manganese composite oxidation There is provided an electrochemical device comprising a positive electrode including a positive electrode active material layer containing a product.

  Such an electrochemical device can have a high charge / discharge capacity.

In addition, the present invention provides a negative electrode including a negative electrode active material layer containing negative electrode active material particles containing silicon oxide whose composition formula is represented by SiO _x (0.5 ≦ x <1.6), and the above spinel There is provided an electrochemical device comprising a positive electrode including a positive electrode active material layer containing a lithium manganese composite oxide.

  Such an electrochemical device can have a high charge / discharge capacity.

  The present invention also provides a negative electrode including a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material of a lithium ion secondary battery, and the above spinel lithium manganese A lithium ion secondary battery comprising a positive electrode including a positive electrode active material layer containing a composite oxide is provided.

  Such a lithium ion secondary battery can have a high charge / discharge capacity.

In addition, the present invention provides a negative electrode including a negative electrode active material layer containing negative electrode active material particles containing silicon oxide whose composition formula is represented by SiO _x (0.5 ≦ x <1.6), and the above spinel A lithium ion secondary battery comprising a positive electrode including a positive electrode active material layer containing a lithium manganese composite oxide is provided.

  Such a lithium ion secondary battery can have a high charge / discharge capacity.

  As described above, when the spinel lithium manganese composite oxide of the present invention is used as an active material for the positive electrode of an electrochemical device, lithium ion can be smoothly inserted and removed and the powder resistance can be reduced. Therefore, lithium ions can be supplied stably and appropriately, so that the charge / discharge capacity can be increased. Further, according to the method for producing the spinel lithium manganese composite oxide of the present invention, the fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water are in a mass ratio with respect to the spinel lithium manganese composite oxide. A spinel lithium manganese composite oxide having a predetermined range can be reliably produced. Furthermore, the electrochemical device of the present invention can have a high charge / discharge capacity. Moreover, if it is the lithium ion secondary battery of this invention, it can have a high charging / discharging capacity | capacitance.

2 is a diagram showing an X-ray diffraction pattern of a spinel lithium manganese composite oxide of Example 1. FIG. It is the figure which expanded the area | region A of FIG. It is the figure which expanded the area | region B of FIG.

As described above, spinel lithium manganese (LiMn ₂ O ₄ ) produced by a conventional method is likely to be oxygen deficient, and in order to synthesize a uniform compound, it is necessary to use a method of repeating firing, etc. For this reason, since the synthesis has been time-consuming, it is preferable to regenerate used spinel lithium manganese in order to synthesize inexpensive spinel lithium manganese. However, when the regenerated spinel lithium manganese is used as the positive electrode active material of the electrochemical device, there is a problem that the resistance of the powder is increased and a sufficient charge / discharge capacity cannot be obtained.

  Therefore, the present inventors have made extensive studies on a spinel lithium manganese composite oxide that can provide a high charge / discharge capacity when used as a positive electrode active material for an electrochemical device. As a result, the spinel lithium manganese composite oxide in which the fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed in ultrapure water is 500 ppm or more and 15000 ppm or less by mass ratio with respect to the spinel lithium manganese composite oxide. Then, even if the raw material of spinel lithium manganese composite oxide (spinel lithium manganese precursor) from which lithium is extracted is used, lithium ion can be smoothly inserted and removed when used as a positive electrode active material of an electrochemical device. At the same time, it was found that the powder resistance decreased, whereby lithium ions could be supplied stably and appropriately, and a high charge / discharge capacity could be obtained, and the present invention was made.

  Hereinafter, although this invention is demonstrated in detail as an example of an embodiment, this invention is not limited to this.

  First, the spinel lithium manganese composite oxide of the present invention will be described.

The spinel lithium manganese composite oxide of the present invention is a spinel lithium manganese composite oxide used as an active material for a positive electrode of an electrochemical device, and fluorine ions eluted in an eluate dispersed in ultrapure water are spinel lithium manganese The weight ratio with respect to the composite oxide is 500 ppm or more and 15000 ppm or less, more preferably 1000 ppm or more and 15000 ppm or less, and further preferably 1500 ppm or more and 15000 ppm or less, and the composition of spinel lithium manganese is represented by the following general formula (1):
The composition of the present invention has the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
It is a spinel lithium manganese complex oxide represented by these. Here, x is more preferably 0 ≦ x <1.0, and further preferably 0 ≦ x <0.8. Further, z is more preferably 0 ≦ z <0.8, and further preferably 0 ≦ z <0.4.

  With such a spinel lithium manganese composite oxide, when it is used as an active material for the positive electrode of an electrochemical device, lithium ions can be smoothly inserted and removed, and powder resistance is reduced, thereby stabilizing lithium ions. Thus, the charge / discharge capacity can be increased. The eluted fluorine ions are considered to be contained in the form of LiF on the composite surface. However, what is important in the present invention is that the amount when fluorine ions are eluted as described above is within the specified range. Fluorine may be dissolved in the base material. The amount of each ion eluted in the eluate can be measured using a solution in which the spinel lithium manganese composite oxide is dispersed with ultrapure water and then the solid content is filtered.

  The spinel lithium manganese composite oxide is preferably such that the lithium ions eluted in the eluate dispersed with ultrapure water are in a mass ratio of 500 ppm to 5000 ppm with respect to the spinel lithium manganese composite oxide, and 600 ppm or more. More preferably, it is 5000 ppm or less, and more preferably 1000 ppm or more and 5000 ppm or less.

  If the lithium ions eluted in the eluate dispersed with ultrapure water are in the above range in terms of mass ratio to the spinel lithium manganese composite oxide, the charge / discharge capacity will be reduced when used as the active material for the positive electrode of an electrochemical device. It can be increased more effectively.

  In the above spinel lithium manganese composite oxide, the mass ratio of lithium ions to fluorine ions (the mass of fluorine ions / the mass of lithium ions) eluted in the eluate dispersed with ultrapure water is 0.1 or more and 10 or less. It is preferable that it is 0.5 or more and 8 or less.

  When the mass ratio of eluted lithium ions to fluorine ions (fluorine ion mass / lithium ion mass) is within the above range, the charge / discharge capacity is more reliably obtained when used as an active material for the positive electrode of an electrochemical device. Can be high. Here, the elution amount of fluorine ions can be controlled, for example, by controlling the amount of the electrolyte solution containing fluorine when the spinel lithium manganese precursor and the lithium compound are reacted. That is, when the fluorine is insufficient, the electrolytic solution is added and regenerated. When the fluorine is excessive, the amount of fluorine ions eluted can be controlled by discharging the electrolytic solution by centrifugation or the like. The elution amount of lithium ions can be controlled by, for example, the amount of lithium source other than the electrolyte, the firing temperature, etc., if the elution amount of fluorine ions is determined.

  The above spinel lithium manganese composite oxide preferably has a peak corresponding to lithium fluoride in the range of 2θ of 43 ° to 46 ° by X-ray diffraction measurement. More preferably, the peak intensity corresponding to lithium fluoride is small. The above spinel lithium manganese composite oxide is also preferably such that a peak corresponding to lithium phosphate is observed in the range of 2θ of 23 ° or more and 26 ° or less by X-ray diffraction measurement. More preferably, the peak intensity corresponding to the obtained lithium phosphate is small.

  If the spinel lithium manganese composite oxide having such an X-ray diffraction pattern is used as an active material for the positive electrode of an electrochemical device, the charge / discharge capacity can be increased more reliably. If it can be used suitably for a positive electrode active material and the peak intensity corresponding to the obtained lithium fluoride is as small as the detection limit, a reduction in charge / discharge capacity can be prevented.

  The average particle diameter (median diameter) of the spinel lithium manganese composite oxide is preferably 0.5 μm or more and 40 μm or less, and more preferably 0.5 μm or more and 20 μm or less. Here, the standard of the average particle diameter is a volume standard.

  When the average particle size of the spinel lithium manganese composite oxide is within the above range, the charge / discharge capacity can be increased more effectively when used as an active material for the positive electrode of an electrochemical device.

That BET specific surface area of the spinel lithium-manganese composite oxide is less than 0.05 m ² / g or more 5.0 m ² / g is preferably 0.1 m ² / g or more 5.0 m ² / g or less more preferably, it is more preferably not more than 0.1 m ² / g or more 4.0 m ² / g. Here, the BET specific surface area means a surface area per unit mass determined by the BET method (a method in which gas particles such as nitrogen are adsorbed on solid particles and the surface area is measured from the adsorbed amount).

  When the BET specific surface area of the above spinel lithium manganese composite oxide is in the above range, the charge / discharge capacity can be increased more effectively when used as an active material for the positive electrode of an electrochemical device.

  If the spinel lithium manganese composite oxide described above is used as an active material for the positive electrode of an electrochemical device, the lithium ion can be smoothly inserted and removed, and the powder resistance can be reduced. Since it can be supplied stably and appropriately, the charge / discharge capacity can be increased.

  Next, the manufacturing method of the spinel lithium manganese complex oxide of this invention is demonstrated.

The method for producing the spinel lithium manganese composite oxide of the present invention has the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
In which the composition is represented by the following general formula (2):
_{Li 1-y Mn 2-z} M z O 4-b F b (x <y <1,0 ≦ z <2,0 ≦ b ≦ 4) ··· (2)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
The spinel lithium manganese precursor from which lithium represented by the formula is extracted is mixed with a lithium compound and reacted, and the spinel lithium manganese precursor or the lithium compound containing fluorine is used. The spinel lithium manganese composite oxide produced is a method in which the fluorine ions eluted in the eluate when dispersed with ultrapure water are in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide. . Here, x is more preferably 0 ≦ x <1.0, and x is more preferably 0 ≦ x <0.8. Further, y is more preferably x <y <0.8. Furthermore, z is more preferably 0 ≦ z <0.8, and further preferably 0 ≦ z <0.4.

  In such a production method, the spinel lithium in which the fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is in the above-described predetermined range in terms of the mass ratio with respect to the spinel lithium manganese composite oxide. Manganese composite oxide can be produced reliably. In addition, if spinel lithium manganese composite precursor from which lithium is extracted is used as a raw material, spinel lithium manganese used electrochemically can be regenerated, the amount of lithium added can be reduced, and spinel lithium manganese is cost competitive. Composite oxides can be produced. Furthermore, with such a production method, the amount of the lithium compound used can be reduced, so that the spinel lithium manganese composite oxide can be produced at a low cost.

In the method for producing the spinel lithium manganese composite oxide, the spinel lithium manganese precursor from which lithium has been extracted is, for example, one obtained by dissolving and using an organic solvent from the used electrode after charge and discharge, The lithium is extracted, the state in which lithium ions are scattered by baking at a high temperature, the state after lithium is extracted from the powder or pellets by charging and discharging, and the like. If a spinel lithium manganese precursor from which lithium is partially removed is used, since some lithium remains, it is easier to produce a spinel lithium manganese composite oxide than when a coprecipitate raw material is used. The amount of the lithium compound used can be reduced, and the spinel lithium manganese composite oxide can be produced at a low cost. Spinel lithium manganese precursor _{Li 1-y Mn 2-z} M z O 4-b F b by charge and discharge, the state returns to the original state _{Li 1-y Mn 2-z} MzO 4-b F b (y = Playback may be started from the state 0).

  In the above method for producing a spinel lithium manganese composite oxide, it is preferable that lithium is extracted from the spinel lithium manganese precursor electrochemically (specifically, by charge / discharge).

  Such a method can be suitably used as a method for extracting lithium. This is because lithium can be easily extracted. Further, by extracting lithium, a spinel lithium manganese precursor suitable for regeneration of the positive electrode active material can be produced.

  In the above method for producing a spinel lithium manganese composite oxide, the spinel lithium manganese precursor is formed with a thickness of 1.0 mm or more, more preferably 5.0 mm or more, and then lithium is extracted electrochemically. It is preferable.

  If the spinel lithium manganese precursor is molded with the above thickness, handling can be easily performed.

  In the above spinel lithium manganese composite oxide production method, the lithium compound used is, for example, lithium carbonate, lithium hydroxide, lithium oxide, lithium oxalate, lithium phosphate, lithium hexafluorophosphate, boron tetrafluoride. Lithium oxide or lithium carbonate, preferably lithium hydroxide or a mixture of lithium carbonate and lithium hexafluorophosphate, or lithium hydroxide or lithium carbonate and boron tetrafluoride. It is a mixture of lithium acid.

  Lithium hydroxide and lithium carbonate are particularly preferable because they are easily available industrially, have high reactivity, and are inexpensive. Moreover, it is a good lithium conductor contained as an electrolyte in lithium hexafluorophosphate and lithium tetrafluoroborate electrolytes, and is an ideal lithium compound for obtaining an excellent charge / discharge capacity.

  In the method for producing the spinel lithium manganese composite oxide, the step of reacting includes a stage of firing, and in the stage of firing, the firing temperature is preferably 700 ° C. or higher and 900 ° C. or lower, and preferably 750 ° C. or higher and 850 ° C. or lower. It is more preferable that

  As a method of reacting the spinel lithium manganese precursor and the lithium compound, a method of firing in the above temperature range can be suitably used. The firing time is preferably 1 hour to 50 hours, more preferably 2 hours to 15 hours, and further preferably 2 hours to 8 hours. Furthermore, it is preferable to perform a calcining step before firing, the calcining temperature is preferably 150 ° C. or higher and 450 ° C. or lower, more preferably 200 ° C. or higher and 300 ° C. or lower, and the calcining time is 30 minutes. It is preferably 5 hours or less and more preferably 2 hours or more and 5 hours or less.

  In the method for producing the spinel lithium manganese composite oxide, it is preferable to perform the firing in an air atmosphere or an oxygen-containing atmosphere. Here, the oxygen-containing atmosphere means an atmosphere containing 10% or more of oxygen gas. By performing firing in an atmosphere containing a large amount of oxygen in this manner, oxygen deficiency in the spinel lithium manganese composite oxide can be prevented. As the oxygen-containing atmosphere, for example, a mixed gas of 30% oxygen and 70% nitrogen can be used. In particular, if firing is performed in an air atmosphere, a spinel lithium manganese composite oxide can be synthesized at a lower cost.

In the manufacturing method of said spinel lithium manganese complex oxide, it can also calcinate together with another lithium containing compound with a spinel lithium manganese precursor. Examples of the lithium-containing compound include a composite oxide composed of lithium and a transition metal element, or a phosphate compound having lithium and a transition metal element. Among these lithium-containing compounds, compounds having at least one of nickel, iron, manganese, and cobalt are preferable. These chemical formulas are represented by, for example, Li _c M1O ₂ or Li _d M2PO ₄ . In the formula, M1 and M2 represent at least one or more transition metal elements, and the values of c and d vary depending on the battery charge / discharge state, but generally 0.05 ≦ c ≦ 1.1, 0.05 ≦ d ≦ 1.1. Examples of the composite oxide having lithium and a transition metal element include lithium cobalt composite oxide (Li _c CoO ₂ ) and lithium nickel composite oxide (Li _c NiO ₂ ). Examples of the phosphoric acid compound having the bets, for example, lithium-iron phosphate compound _(Li d FePO _4), or lithium-iron-manganese phosphate compound _{(Li d Fe 1-e Mn} e PO 4 (0 <e <1)) , Etc. This is because a high battery capacity can be obtained and excellent cycle characteristics can be obtained.

  In the above method for producing a spinel lithium manganese composite oxide, when a spinel lithium manganese precursor is mixed with a lithium compound and reacted, a method other than firing may be used, or firing and other methods may be used in combination. May be. For example, when the reaction is performed, hydrothermal treatment may be performed, the number of firings may be increased, pellet molding may be performed, and firing may be performed.

  According to the method for producing the spinel lithium manganese composite oxide described above, the fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water are described above in a mass ratio with respect to the spinel lithium manganese composite oxide. Thus, a spinel lithium manganese composite oxide having a predetermined range can be reliably produced.

  Said spinel lithium manganese complex oxide can be utilized as a positive electrode active material of various electrochemical devices (for example, a battery, a sensor, an electrolytic cell, etc.). Here, the term “electrochemical device” refers to a device including an electrode plate material through which an electric current flows, that is, a device that can extract electric energy in general, and includes an electrolytic cell, a primary battery, and a secondary battery. It is a concept that includes. The “secondary battery” is a concept including so-called storage batteries such as lithium ion secondary batteries, nickel hydride batteries, nickel cadmium batteries, and power storage elements such as electric double layer capacitors. The lithium composite oxide is particularly suitable as an electrode material for lithium ion secondary batteries and electrolytic cells. The shape of the electrolytic cell may be any shape as long as it contains an electrode plate material that allows current to flow. The shape of the lithium ion secondary battery can be applied to any of coins, buttons, sheets, cylinders, and square shapes. The use of the lithium ion secondary battery to which the spinel lithium manganese composite oxide of the present invention is applied is not particularly limited. For example, a notebook computer, a laptop computer, a pocket word processor, a mobile phone, a cordless phone, a portable CD, a radio Electronic devices such as automobiles, electric vehicles, and consumer electronic devices such as game machines.

  Hereinafter, components of an electrochemical device and a lithium ion secondary battery to which the above spinel lithium manganese composite oxide is applied will be described.

[Positive electrode active material layer]
The positive electrode active material layer can contain 50 to 100% by mass of the spinel lithium manganese composite oxide of the present invention. Further, it contains any one or more of positive electrode active materials capable of occluding and releasing lithium ions, and may contain other materials such as binders, conductive assistants, and dispersants depending on the design. Good.

[Positive electrode]
The positive electrode has, for example, a positive electrode active material layer on both sides or one side of the current collector. The current collector may be formed of a conductive material such as aluminum, for example.

[Negative electrode active material layer]
The negative electrode active material is preferably any one of silicon oxides represented by the general formula SiO _x (0.5 ≦ x <1.6), or a mixture of two or more thereof. The negative electrode active material layer contains the above negative electrode active material, and may contain other materials such as a binder, a conductive additive, and a dispersant depending on the design.

[Negative electrode]
The negative electrode has the same configuration as the positive electrode described above, and has, for example, a negative electrode active material layer on one side or both sides of a current collector. It is preferable that the negative electrode has a larger negative electrode charge capacity than the electric capacity (charge capacity as a battery) obtained from the lithium composite oxide active material agent. This is for suppressing the deposition of lithium metal on the negative electrode.

[Binder]
As the binder, for example, any one or more of a polymer material and a synthetic rubber can be used. Examples of the polymer material include polyvinylidene fluoride, polyimide, polyamideimide, aramid, polyacrylic acid, lithium polyacrylate, and carboxymethylcellulose. The synthetic rubber is, for example, styrene butadiene rubber, fluorine rubber, ethylene propylene diene, or the like.

[Conductive aid]
As the lithium composite oxide conductive auxiliary agent and the negative electrode conductive auxiliary agent, for example, any one or more of carbon materials such as carbon black, acetylene black, graphite, ketjen black, carbon nanotube, and carbon nanofiber can be used. .

[Electrolyte]
At least a part of the active material layer or the separator is impregnated with a liquid electrolyte (electrolytic solution). This electrolytic solution has an electrolyte salt dissolved in a solvent, and may contain other materials such as additives. Examples of the solvent include non-aqueous solvents. Examples of the non-aqueous solvent include the following materials. Ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, 1,2-dimethoxyethane or tetrahydrofuran. Among these, at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate is desirable. This is because better characteristics can be obtained. In this case, more advantageous characteristics can be obtained by combining a high viscosity solvent such as ethylene carbonate or propylene carbonate and a low viscosity solvent such as dimethyl carbonate, ethyl methyl carbonate or diethyl carbonate. This is because the dissociation property and ion mobility of the electrolyte salt are improved.

  In particular, the solvent preferably contains at least one of a halogenated chain carbonate or a halogenated cyclic carbonate. This is because a stable film is formed on the surface of the negative electrode active material during charging / discharging, particularly during charging. The halogenated chain carbonate is a chain carbonate having halogen as a constituent element (at least one hydrogen is replaced by a halogen). The halogenated cyclic carbonate is a cyclic carbonate having halogen as a constituent element (at least one hydrogen is replaced by halogen).

  The type of halogen is not particularly limited, but fluorine is more preferable. This is because a film having a higher quality than other halogens is formed. Further, the larger the number of halogens, the more desirable, because the resulting coating is more stable and the decomposition reaction of the electrolyte is reduced. Examples of the halogenated chain carbonate include fluoromethyl methyl carbonate and difluoromethyl methyl carbonate. Examples of the halogenated cyclic carbonate include 4-fluoro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolan-2-one.

  The solvent additive preferably contains an unsaturated carbon bond cyclic carbonate. This is because a stable film is formed on the surface of the negative electrode during charging and discharging, and the decomposition reaction of the electrolytic solution can be suppressed. Examples of the unsaturated carbon bond cyclic ester carbonate include vinylene carbonate and vinyl ethylene carbonate. Moreover, it is also preferable that sultone (cyclic sulfonate ester) is included as a solvent additive. This is because the chemical stability of the battery is improved. Examples of sultone include propane sultone and propene sultone.

  Furthermore, it is preferable that the solvent contains an acid anhydride. This is because the chemical stability of the electrolytic solution is improved. Examples of the acid anhydride include propanedisulfonic acid anhydride.

The electrolyte salt can contain, for example, any one or more of light metal salts such as lithium salts. Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ) and lithium tetrafluoroborate (LiBF ₄ ). The content of the electrolyte salt is preferably 0.5 mol / kg or more and 2.5 mol / kg or less with respect to the solvent. This is because high ionic conductivity is obtained.

[Current collector]
The current collector of the electrode is not particularly limited as long as it is an electronic conductor that does not cause a chemical change in the configured lithium ion secondary battery and electrochemical device, but for example, stainless steel, nickel, aluminum, titanium, The surface of calcined carbon, aluminum or stainless steel is surface-treated with carbon, nickel, copper, titanium or silver. The negative electrode is made of copper, in addition to stainless steel, nickel, copper, titanium, aluminum, calcined carbon, etc. Or a surface of stainless steel treated with carbon, nickel, titanium, silver, or the like, or an Al—Cd alloy is used.

[Separator]
The separator separates the positive electrode and the negative electrode and allows lithium ions to pass through while preventing current short-circuiting due to both-pole contact. This separator is formed of, for example, a porous film made of synthetic resin or ceramic, and may have a laminated structure in which two or more kinds of porous films are laminated. Examples of the synthetic resin include polytetrafluoroethylene, polypropylene, and polyethylene.

  Next, the electrochemical device of the present invention will be described.

The electrochemical device of the present invention comprises a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material of an electrochemical device, and a negative electrode current collector, An electrochemical device comprising a positive electrode active material layer containing the above spinel lithium manganese composite oxide and a positive electrode comprising a positive electrode current collector. The electrochemical device of the present invention includes a negative electrode active material layer containing negative electrode active material particles containing silicon oxide represented by a composition formula of SiO _x (0.5 ≦ x <1.6) and a negative electrode current collector. It may be an electrochemical device having a negative electrode composed of a body, a positive electrode composed of a positive electrode active material layer containing the above spinel lithium manganese composite oxide, and a positive electrode current collector. Note that the negative electrode and the positive electrode may not include a current collector.

  Such an electrochemical device can have a high charge / discharge capacity.

  Note that the regenerated spinel lithium manganese composite oxide tends to increase the powder resistance. When the powder resistance increases, the charge / discharge efficiency decreases. Therefore, the negative electrode active material particles having a charge / discharge efficiency of 90% or less are used. When used, it is sufficient in terms of the balance between the charge and discharge efficiency of the positive electrode and the negative electrode, and a stable charge and discharge current is obtained, which is preferable.

  Next, the lithium secondary battery of the present invention will be described.

The lithium secondary battery of the present invention comprises a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material of a lithium ion secondary battery, and a negative electrode current collector. And a positive electrode composed of a positive electrode active material layer containing the above spinel lithium manganese composite oxide and a positive electrode current collector. Further, the lithium secondary battery of the present invention includes a negative electrode active material layer containing negative electrode active material particles containing silicon oxide represented by a composition formula of SiO _x (0.5 ≦ x <1.6), and a negative electrode It may be a lithium ion secondary battery having a negative electrode comprising a current collector, and a positive electrode comprising a positive electrode active material layer containing the above spinel lithium manganese composite oxide and a positive electrode current collector. Note that the negative electrode and the positive electrode may not include a current collector.

  Such a lithium secondary battery can have a high charge / discharge capacity.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.

(Example 1-4)
Li _0.5 Mn ₂ O ₄ obtained by extracting lithium from pellet-molded LiMn ₂ O ₄ to 50% at a constant current is dried while containing an electrolytic solution containing lithium hexafluorophosphate (LiPF ₆₎ as an electrolyte. Then, lithium hydroxide (LiOH.H ₂ O) was mixed with the lightly pulverized powder so that the equivalent ratio of Li / Mn was 0.55 / 1.00. The mixture was fired in the air, then cooled and finely pulverized. Then classified with a sieve having a mesh opening 75 [mu] m, to prepare a spinel lithium-manganese composite oxide having the composition LiMn 2 O _4-a F _a having a peak corresponding to lithium fluoride. However, the firing conditions were 800 ° C. for 2 hours in Example 1, 750 ° C. for 4 hours in Example 2, 750 ° C. for 3 hours in Example 3, and 800 ° C. for 3 hours in Example 4. The powder obtained in Example 1 was subjected to X-ray diffraction measurement. The obtained X-ray diffraction pattern is shown in FIG. An enlarged view of region A in FIG. 1 is shown in FIG. 2, and an enlarged view of region B in FIG. 1 is shown in FIG. In the spinel lithium manganese composite oxide obtained in Example 1 from FIG. 3, the peak corresponding to lithium fluoride (peak marked in FIG. 3) is in the range of 2θ of 43 ° to 46 °. In the spinel lithium manganese composite oxide obtained in Example 1 from FIG. 2, it was confirmed that a peak corresponding to lithium fluoride in the range of 2θ of 23 ° or more and 26 ° or less (in FIG. 2) It was confirmed that a marked peak) was observed. For Example 2-4, X-ray diffraction measurement was performed in the same manner as in Example 1, and it was confirmed that a peak corresponding to lithium fluoride was observed.

(Example 5-8)
Li _0.5 Mn ₂ O ₄ obtained by extracting lithium from pellet-molded LiMn ₂ O ₄ to 50% at a constant current was washed with DMC (dimethyl carbonate), filtered, dried, and lightly pulverized into lithium carbonate ( Li ₂ CO ₃ ) and lithium hexafluorophosphate (LiPF ₆ , 5% of the total lithium added) were mixed so that the equivalent ratio of Li / Mn was 0.55 / 1.00. The mixture was fired in a mixed gas of 30% oxygen and 70% nitrogen, cooled, and finely pulverized. Then classified with a sieve having a mesh opening 75 [mu] m, to prepare a spinel lithium-manganese composite oxide having the composition _{LiMn 2 O 4-a F a} . However, the firing conditions were 820 ° C. for 4 hours in Example 5, 770 ° C. for 2 hours in Example 6, 750 ° C. for 6 hours in Example 7, and 780 ° C. for 3 hours in Example 8. Also in Example 5-8, X-ray diffraction measurement was performed in the same manner as in Example 1, and it was confirmed that the sample had a peak corresponding to lithium fluoride.

(Example 9-11)
Li _0.5 Mn ₂ O ₄ obtained by extracting lithium from pellet-molded LiMn ₂ O ₄ to 50% at a constant current is dried while containing an electrolyte containing lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte. Then, lithium hydroxide (LiOH.H ₂ O) and lithium tetrafluoroborate (LiBF ₄ , 5% of the total lithium added) were added to the lightly pulverized powder so that the equivalent ratio of Li / Mn was 0.55 / 1. It was mixed so that it might become 00. The mixture was fired in the air, then cooled and finely pulverized. Then classified with a sieve having a mesh opening 75 [mu] m, to prepare a spinel lithium-manganese composite oxide having the composition _{LiMn 2 O 4-a F a} . However, the firing conditions were 750 ° C. for 7 hours in Example 9, 770 ° C. for 0.5 hour in Example 10, and 780 ° C. for 1 hour in Example 11. For Example 9-11, X-ray diffraction measurement was performed in the same manner as in Example 1, and it was confirmed that a peak corresponding to lithium fluoride was observed.

(Example 12)
A spinel lithium manganese composite oxide having _a composition of LiMn ₂ O _{4 -a} Fa was produced under the same conditions as in Example 9 except that the electrolytic solution contained lithium tetrafluoroborate. Also in Example 12, X-ray diffraction measurement was performed in the same manner as in Example 1, and it was confirmed that a peak corresponding to lithium fluoride was observed.

(Comparative Example 1-5)
Li _0.5 Mn ₂ O ₄ obtained by extracting lithium from pellet-molded LiMn ₂ O ₄ to 50% at a constant current is dried while containing an electrolyte containing lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte. Then, lithium hydroxide (LiOH.H ₂ O) was mixed with the lightly pulverized powder so that the equivalent ratio of Li / Mn was 0.55 / 1.00. The mixture was fired in the air, then cooled and finely pulverized. Then classified with a sieve having a mesh opening 75 [mu] m, to prepare a spinel lithium-manganese composite oxide having the composition _{LiMn 2 O 4-a F a} . However, the firing conditions were 730 ° C. for 5 hours in Comparative Example 1, 850 ° C. for 5 hours in Comparative Example 2, and 780 ° C. for 5 hours in Comparative Examples 3-5. In Comparative Examples 1 and 5, when X-ray diffraction measurement was performed in the same manner as in Example 1, a peak corresponding to lithium fluoride was observed. About Comparative Examples 2-4, the X-ray-diffraction measurement was performed like Example 1, but the peak corresponded to lithium fluoride was not seen.

(Measurement of average particle diameter (median diameter))
The measurement of the particle size distribution of the spinel lithium manganese composite oxide of Example 1-11 and Comparative Example 1-5 was performed using ion-exchanged water as a dispersion medium and Microtrac MK-II (SRA) (LEED & NORTHHRUP, laser scattered light detection type). It was performed using.
In addition, the dispersing agent, ring flow rate, and ultrasonic output in the measurement of particle size distribution are shown below.
Dispersant: 2 ml of 10% sodium hexametaphosphate aqueous solution
Ring flow rate: 40 ml / sec
Ultrasonic output: 40 W 60 seconds Table 1 shows the measurement results of the average particle diameter.

(Measurement of BET specific surface area)
The BET specific surface areas of the spinel lithium manganese composite oxides of Example 1-11 and Comparative Example 1-5 were measured using Flowsorb 2300 type (manufactured by Shimadzu Corporation).
Table 1 shows the measurement results of the BET specific surface area.

(Measurement of mass of eluted fluorine ions)
The mass of the fluorine ions eluted in the eluate obtained by dispersing the spinel lithium manganese composite oxide of Example 1-11 and Comparative Example 1-5 with ultrapure water was measured by ion chromatography, and the spinel lithium manganese composite oxide was measured. The mass ratio was calculated. The obtained mass ratio is shown in Table 1.

(Measurement of mass of eluted lithium ions)
The mass of lithium ions eluted in the eluate obtained by dispersing the spinel lithium manganese composite oxide of Example 1-11 and Comparative Example 1-5 with ultrapure water was measured, and the mass ratio with respect to the spinel lithium manganese composite oxide was determined as ICP. It was calculated by the method (high frequency inductively coupled plasma method). The obtained mass ratio is shown in Table 1. Further, Table 1 also shows the mass ratio of the eluted fluorine ions to the eluted lithium ions (the mass of fluorine ions / the mass of lithium ions).

<Battery performance test>
(Preparation of positive electrode)
A positive electrode was produced using the spinel lithium manganese composite oxides of Example 1-11 and Comparative Example 1-5 produced as described above. The produced spinel lithium manganese composite oxide 88% by mass, graphite powder 4.0% by mass, and polyvinylidene fluoride 8.0% by mass were mixed to obtain a positive electrode material, which was used as N-methyl-2-pyrrolidinone (hereinafter, A kneaded paste was prepared by dispersing in NMP). The kneaded paste was applied to an aluminum foil (current collector), dried, pressed and punched into a disk having a diameter of 15 mm to obtain a positive electrode plate.

(Preparation of negative electrode)
Next, a SiO negative electrode was prepared. For the SiO negative electrode, a raw material in which metallic silicon and silicon dioxide were mixed was placed in a reactor, deposited in a vacuum of 10 Pa, cooled sufficiently, and the deposit was taken out and pulverized by a ball mill. After adjusting the particle diameter, a carbon layer was obtained by performing thermal decomposition CVD as necessary. The prepared powder was subjected to bulk modification using an electrochemical method in a 1: 1 mixed solvent of propylene carbonate and ethylene carbonate (electrolyte salt 1.3 mol / kg). The obtained material is subjected to a drying treatment in a carbon dioxide atmosphere as necessary. Subsequently, the negative electrode active material particles, the precursor of the negative electrode binder, the conductive additive 1 (Ketjen black), and the conductive auxiliary agent 2 (acetylene black) are in a dry weight ratio of 80: 8: 10: 2. Were mixed to obtain a negative electrode agent, and diluted with NMP to obtain a paste-like negative electrode mixture slurry. In this case, NMP was used as a solvent for the polyamic acid. Subsequently, the negative electrode mixture slurry was applied to the negative electrode current collector with a coating apparatus and then dried. As this negative electrode current collector, an electrolytic copper foil (thickness = 15 μm) was used. Finally, baking was performed at 400 ° C. for 1 hour in a vacuum atmosphere. By this firing, a negative electrode binder (polyimide) was formed. A negative electrode plate was obtained by pressing and punching into a disk having a diameter of 16 mm.

(Production of coin-type non-aqueous electrolyte secondary battery)
A non-aqueous electrolyte secondary coin battery was manufactured using each member such as the prepared positive electrode plate and negative electrode plate, separator, mounting bracket, external terminal, and electrolytic solution. Among these, as the electrolytic solution, one obtained by dissolving 1 mol of LiPF _{6 in} 1 liter of a 2: 7: 1 kneaded solution of ethylene carbonate, didiethyl carbonate, and fluoroethylene carbonate was used.

(Measurement of positive electrode discharge capacity)
The coin-type lithium ion secondary battery manufactured as described above is charged at a constant current / constant voltage for 5 hours at a current corresponding to 0.5 C, and then up to 2.5 V at a current corresponding to 0.1 C. A charge / discharge test was performed to measure the initial positive electrode discharge capacity (mAh / g). The measurement results are shown in Table 1.

  As can be seen from Table 1, the spinel lithium manganese composite oxide of Example 1-12 in which the fluorine ions eluted in the eluate dispersed with ultrapure water are in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide. In the non-aqueous electrolyte secondary coin battery manufactured using the above, a comparative example in which the fluorine ions eluted in the eluate dispersed with ultrapure water are less than 500 ppm or more than 15000 ppm in terms of mass ratio to the spinel lithium manganese composite oxide Compared with a non-aqueous electrolyte secondary coin battery manufactured using 1-5 spinel lithium manganese composite oxide, a high discharge capacity is obtained.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Claims (18)

A spinel lithium manganese composite oxide used as an active material for a positive electrode of an electrochemical device,
Fluorine ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water are in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide,
The composition of the spinel lithium manganese has the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
A spinel lithium manganese composite oxide characterized by being represented by the formula:   2. The lithium ion eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is 500 ppm to 5000 ppm in mass ratio with respect to the spinel lithium manganese composite oxide. Spinel lithium manganese composite oxide.   The mass ratio (the mass of fluorine ions / the mass of lithium ions) of lithium ions eluted in the eluate in which the spinel lithium manganese composite oxide is dispersed with ultrapure water is 0.1 or more and 10 or less. The spinel lithium manganese composite oxide according to claim 1, wherein the spinel lithium manganese composite oxide is present.   According to the X-ray diffraction measurement, a peak corresponding to lithium fluoride is observed in the range of 2θ of 43 ° to 46 ° and / or phosphoric acid in the range of 2θ of 23 ° to 26 °. The peak corresponding to lithium is seen, The spinel lithium manganese composite oxide of any one of Claims 1-3 characterized by the above-mentioned.   The spinel lithium manganese composite oxide according to any one of claims 1 to 4, wherein an average particle diameter is 0.5 µm or more and 40.0 µm or less. Spinel lithium manganese oxide as claimed in claim 1, a BET specific surface area is equal to or less than 0.05 m ² / g or more 5.0 m ² / g to any one of claims 5. The composition is the following general formula (1):
_{Li 1-x Mn 2-z} M z O 4-a F a (-0.1 ≦ x <1,0 ≦ z <2,0 ≦ a ≦ 4) ··· (1)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
A process for producing a spinel lithium manganese composite oxide represented by:
The composition is represented by the following general formula (2):
_{Li 1-y Mn 2-z} M z O 4-b F b (x <y <1,0 ≦ z <2,0 ≦ b ≦ 4) ··· (2)
(In the formula, M represents one or more metal elements selected from the group consisting of V, Ni, Co, Fe, Cr, Al, Nb, Ti, Cu, and Zn.)
A process of mixing and reacting a spinel lithium manganese precursor from which lithium represented by
Fluorine that elutes into the eluate when the spinel lithium manganese composite oxide produced is dispersed in ultrapure water by using the spinel lithium manganese precursor or the lithium compound containing fluorine. A method for producing a spinel lithium manganese composite oxide, characterized in that ions are contained in a mass ratio of 500 ppm to 15000 ppm with respect to the spinel lithium manganese composite oxide.   The method for producing a spinel lithium manganese composite oxide according to claim 7, wherein lithium is extracted from the spinel lithium manganese precursor electrochemically.   8. The method for producing a spinel lithium manganese composite oxide according to claim 7, wherein the spinel lithium manganese precursor is molded with a thickness of 1.0 mm or more and then lithium is electrochemically extracted. . 10. The method for producing a spinel lithium manganese composite oxide according to claim 7, wherein the lithium compound contains lithium hexafluorophosphate (LiPF ₆ ). 11. 11. The method for producing a spinel lithium manganese composite oxide according to claim 7, wherein the lithium compound includes lithium tetrafluoroborate (LiBF ₄ ). 11. The step of reacting includes a step of firing;
The method for producing a spinel lithium manganese composite oxide according to any one of claims 7 to 11, wherein, in the firing step, a firing temperature is 700 ° C or higher and 900 ° C or lower. The step of reacting includes a step of firing;
The method for producing a spinel lithium manganese composite oxide according to any one of claims 7 to 12, wherein the firing is performed in an oxygen-containing atmosphere. The step of reacting includes a step of firing;
The method for producing a spinel lithium manganese composite oxide according to any one of claims 7 to 12, wherein the firing is performed in an air atmosphere. A negative electrode including a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material of an electrochemical device;
It has a positive electrode containing the positive electrode active material layer containing the spinel lithium manganese complex oxide of any one of Claims 1-6, The electrochemical device characterized by the above-mentioned. A negative electrode including a negative electrode active material layer containing negative electrode active material particles containing silicon oxide whose composition formula is represented by SiO _x (0.5 ≦ x <1.6);
It has a positive electrode containing the positive electrode active material layer containing the spinel lithium manganese complex oxide of any one of Claims 1-6, The electrochemical device characterized by the above-mentioned. A negative electrode including a negative electrode active material layer containing negative electrode active material particles having a charge / discharge efficiency of 90% or less when used as a negative electrode active material of a lithium ion secondary battery;
It has a positive electrode containing the positive electrode active material layer containing the spinel lithium manganese complex oxide of any one of Claims 1-6, The lithium ion secondary battery characterized by the above-mentioned. A negative electrode including a negative electrode active material layer containing negative electrode active material particles containing silicon oxide whose composition formula is represented by SiO _x (0.5 ≦ x <1.6);
It has a positive electrode containing the positive electrode active material layer containing the spinel lithium manganese complex oxide of any one of Claims 1-6, The lithium ion secondary battery characterized by the above-mentioned.

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