WO2016148283A1

WO2016148283A1 - Manganese oxide and method for producing same, and lithium secondary battery using same

Info

Publication number: WO2016148283A1
Application number: PCT/JP2016/058736
Authority: WO
Inventors: 岡田昌樹
Original assignee: 東ソー株式会社
Priority date: 2015-03-19
Filing date: 2016-03-18
Publication date: 2016-09-22

Abstract

Provided are manganese oxide which is a positive electrode material for a new manganese-based lithium secondary battery capable of reconciling high energy density and low cost, a manganese oxide mixture, a mixed positive electrode active material, and a lithium secondary battery. This manganese oxide is represented by any of the general formula Ｌｉ_{（４／３）－（４Ｘ／５）－Ｙ}Ｍｎ_２／３Ｏ_{２－（２Ｘ／} _{５）－（Ｙ／２）}（In this formula, ０＜Ｘ＜１、０＜Ｙ＜（４／３）－（４Ｘ／５） are satisfied.), general formula ［Ｌｉ_２－ＡＭｎＯ_３－Ｂ］１－Ｅ・［Ｌｉ_４－ＣＭｎ_５Ｏ_１２－Ｄ］_Ｅ（In this formula, 0＜Ｅ＜１、０≤Ａ≤２、０≤Ｂ≤Ａ／２、０≤Ｃ≤４, and ０≤Ｄ≤Ｃ／２ are satisfied, but A=C=O is excluded.), or general formula Ｌｉ_{（４／３）－（４Ｘ／} _５）－ＹＭｎ_{（２／３）－Ｚ}Ｍ_ＺＯ_{２－（２Ｘ／５）－（Ｙ／２）}（In this formula, ０＜Ｘ＜１、０＜Ｙ＜（４／３）－（４Ｘ／５）、０＜Ｚ≤１／３ are satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.).

Description

Manganese oxide, method for producing the same, and lithium secondary battery using the same

The present invention relates to a manganese oxide, a method for producing the same, a lithium secondary battery using the same, a manganese oxide mixture, a mixed positive electrode active material, and a lithium secondary battery using the same.

Since lithium secondary batteries have higher energy density than other storage batteries, they have been widely used as storage batteries for mobile terminals. Recently, application to a large-sized application requiring a large capacity such as a stationary one and an in-vehicle one has been promoted.

Demand for high energy density is strong in applications that require large capacity, and the demand for cost reduction is particularly severe.

As the positive electrode material of the lithium secondary battery currently being developed with the aim of increasing the energy density, oxide materials containing a large amount of metal elements such as cobalt (Co) and nickel (Ni) are mainly studied. It is extremely difficult to reduce the cost of the positive electrode material containing a large amount of these rare metal elements. At present, there is no practical material that achieves both high energy density and low cost.

Manganese (Mn) is an inexpensive element with a large reserve in comparison with rare metal elements such as Co and Ni. Moreover, it is safer and less burden on the environment than Co and Ni.

・ Practical use of high-energy density manganese-based positive electrode materials will make it possible to achieve both cost and expansion of the large-capacity lithium secondary battery market. In particular, if a manganese-based positive electrode material that does not use any rare metal element can be developed, the lithium secondary battery market, especially for in-vehicle use, is expected to expand dramatically.

Manganese positive electrode materials that do not contain rare metal elements have been studied for some time. Typical examples include LiMn ₂ O _{4 having} a spinel structure that is easy to reversibly insert and desorb lithium (Li) and LiMnO ₂ having a layered rock salt structure.

Spinel-type LiMn ₂ O ₄ has been put into practical use as a positive electrode material for lithium secondary batteries. Because it is highly safe and has little impact on the environment, its use is spreading mainly for electric tools, electric bicycles, electric vehicles and the like.

In the spinel type LiMn ₂ O ₄ , the 8a site of the cubic space group Fd3-m is occupied by Li and the 16d site is occupied by Mn. The empty 16c site is located between the two lattices, which is one of the reasons for the high reversibility of Li insertion and desorption.

It is also possible to fill the empty 16c site with Li, and in principle it is possible to insert Li up to the Li ₂ Mn ₂ O ₄ composition. In this case, the usable electrochemical capacity is an oxide having a layered rock-salt structure containing Co or Ni, for example, LiCoO ₂ , Li (Ni _1-X · Al _X ) O ₂ , Li (Ni _1/3 Co _{1). / 3} Mn _1/3 ) O _{2, which} is about 285 mAh / g.

However, the insertion of Li into the 16c site leads to a change in crystal structure from cubic to tetragonal and a decrease in electronic conductivity, and as the charge / discharge cycle is repeated, microcrystallization and accompanying deactivation advance and charge / discharge capacity. Decreases. For this reason, it is difficult to insert Li into the reversible 16c site. In addition, in most of the existing lithium ion batteries, it is desirable to insert Li into the empty 16c site in advance because only Li contained in the positive electrode material is responsible for charge / discharge reaction. The Li ₂ Mn ₂ O ₄ composition easily reacts with water and easily returns to the LiMn ₂ O ₄ composition, and handling is extremely complicated. Therefore, the practical electrochemical capacity of LiMn ₂ O _{4 having} a spinel structure is limited to about 100 mAh / g, and is only applicable to some applications because of its small electrochemical capacity.

The electrochemical capacity of LiMnO ₂ is 285 mAh / g, which is larger than LiMn ₂ O ₄ .

There are _two types of LiMnO ₂ , orthorhombic crystals that can be represented by the space group Pmnm and monoclinic crystals that can be represented by the space group C2 / m. Among them, monoclinic LiMnO ₂ has a layered rock salt structure, Mn and Li are regularly arranged in the (111) direction of the cubic rock salt structure to form a two-dimensional plane, and Li in the Li layer diffuses two-dimensionally. As a result, the battery reaction proceeds.

A common feature of Li-containing transition metal oxides with a layered rock-salt structure is that the transition metal tends to be irregularly arranged in the Li layer and Li in the transition metal layer during synthesis, which makes the charge / discharge reaction reversible. The properties are greatly impaired. In addition, the irregular arrangement easily proceeds even in the process of repeating charge and discharge, and in LiMnO ₂ , a part of the crystal structure undergoes a phase transition to a spinel-like structure and changes to a LiMn ₂ O ₄ -like composition (Non-Patent Document 1). . As a result, the electrochemical capacity is greatly reduced to about half of the original capacity. If it is possible to suppress irregular arrangements, it is considered possible to prevent a decrease in capacity, but no method has been proposed at this time.

Recently, studies using Li ₂ MnO ₃ having a layered rock-salt structure are underway. Li ₂ MnO ₃ is a high-capacity positive electrode material that can obtain a discharge capacity of 250 mAh / g for the first time by charging up to 4.8 V, but it has been reported that a sudden capacity drop occurs as the charge / discharge cycle progresses. (Non-patent document 2).

Li ₂ MnO ₃ has a structure similar to that of monoclinic LiMnO ₂ , but has a Li-excess composition compared to LiMnO ₂ , and on that composition, Li already occupied 1/3 of the Mn sites of the Mn layer. Take. For this reason, irregular arrangement of constituent elements during synthesis hardly occurs, and synthesis is easy.

When Li ₂ MnO ₃ is used for the positive electrode of a lithium ion battery, its charging reaction is different from LiMn ₂ O ₄ and LiMnO ₂ .

Li ₂ MnO _{3 has} a Mn valence of +4, LiMn ₂ O _{4 has} a +3.5 valence (a state in which +3 and +4 valence coexist at a ratio of 1: 1), and LiMnO _{2 has} a +3 valence. Is not included. The valence of Mn, which can exist stably in the current lithium ion battery, is considered to be +4. Therefore, in materials containing +3 valence of Mn such as LiMn ₂ O ₄ and LiMnO ₂ , Mn is responsible for charge reaction, that is, oxidation reaction, whereas in Li ₂ MnO ₃ oxygen is considered to be responsible for oxidation reaction. Yes.

The inventor considers the oxidation reaction mode of Li ₂ MnO ₃ as follows. The electrochemical capacity of this reaction is 458 mAh / g, which is very large.

Li ₂ Mn ⁴⁺ O ₃ → Mn ⁴⁺ O ₂ + 2Li ⁺ + 2e ⁻ + 1 / 2O ₂ (Formula 1)
It is known that the oxygen ion O ²⁻ can be oxidized to O ₂ through the peroxidized state O ₂ ²⁻ , and the above equation 1 accompanied by desorption of oxygen is considered appropriate. Therefore, the more the oxygen is desorbed from Li ₂ MnO ₃ , the larger the charge capacity.

Since oxide ions are large in size, it is not difficult to imagine that oxygen desorption occurs more easily on the surface of the particles than from the inside of the Li ₂ MnO ₃ particles. Therefore, there is a tendency becomes different composition between the inside surface and the particles of the particle, the state of the MnO ₂ in the particle surface, possibly at the grain inside that there are many remains of Li ₂ MnO ₃ It is considered that the composition tends to be high and uneven.

It has also been clarified that oxygen desorption occurs selectively from oxygen in the vicinity of Mn atoms (Non-patent Documents 3 and 4). As the desorption of oxygen proceeds, it is expected that the Mn atoms in the Mn layer become unstable due to the simultaneous desorption of Li. In particular, it is considered that the structure of the particle surface is more likely to undergo structural change due to oxygen desorption than the interior of the particle, resulting in a non-uniform structure.

MnO ₂ produced by the oxidation reaction remains in the reduction to the LiMnO ₂ composition in the discharge reaction. The oxygen once desorbed is very unlikely to be taken into the crystal lattice as oxygen ions in the solid phase by the reduction reaction, and Mn is responsible for the reduction reaction as opposed to the oxidation reaction. Accordingly, the discharge capacity is smaller than the charge capacity.

Although details are unknown at the present time, the present inventor considers the reduction reaction mode of MnO ₂ as follows.

Mn ⁴⁺ O ₂ + Li ⁺ + e ⁻ → LiMn ³⁺ O ₂ (Formula 2)
It is difficult for LiMnO ₂ produced by the reduction reaction to have the same structure as the original layered rock salt structure Li ₂ MnO ₃ . While Mn moves to an empty Li site or an empty oxygen desorption site triggered by a change in the size of Mn accompanying a reduction reaction from Mn ⁴⁺ to Mn ³⁺ , the introduction of Li ⁺ to the oxygen desorption site occurs. It is thought that the reduction reaction proceeds. At this time, the crystal structure is likely to change.

Non-Patent Document 5 reports that a part of the crystal structure undergoes a phase transition to a spinel-like structure in the same manner as LiMnO ₂ described above to produce a composition similar to LiMn ₂ O ₄ . This means a reduction in capacity. In addition, the spinel structure-like composition produced has low crystallinity and low reversibility of the redox reaction, that is, the charge / discharge reaction.

As described above, since Li ₂ MnO ₃ causes desorption of oxygen necessary for high capacity development, 1) the discharge capacity is smaller than the charge capacity, and 2) the composition and structure are not uniform due to charge / discharge. 3) Since the crystallinity of a spinel structure-like composition that is newly generated is low, a decrease in capacity with respect to the charge / discharge cycle cannot be avoided, so that the original performance cannot be sufficiently exhibited.

As an approach for solving such a problem of Li ₂ MnO ₃ , a material in which Li (Co _1/3 Ni _1/3 Mn _1/3 ) O ₂ having the same layered rock salt structure is dissolved is proposed ( Patent Document 1, Non-Patent Document 6).

Li ₂ MnO ₃ can be expressed as Li [Li _1/3 Mn _2/3 ] O ₂ and has the same layered structure as described above. Therefore, Li (Co _1/3 Ni _{1 / 3} Mn _1/3 ) O ₂ can be dissolved.

It is a proposal aimed at a material with high reversibility of Li (Co _1/3 Ni _1/3 Mn _1/3 ) O ₂ while making use of the high capacity of Li ₂ MnO ₃ , but the first time close to 300 mAh / g Although a discharge capacity can be obtained, the capacity reduction with respect to the charge / discharge cycle is still large. In addition, since rare metal elements such as Co and Ni are included, it is not possible to take advantage of the low-cost characteristics inherent in Mn.

On the other hand, Li ₄ Mn ₅ O ₁₂ was restricted to use from a reduction reaction for inserting Li, that is, a discharge reaction, as described in Patent Document 2 and Non-Patent Document 7. This is because the valence of manganese is all +4 as described above, and it was thought that further oxidation, that is, charging could not be performed, so that the capacity obtained by discharging remained at about 140 mAh / g. It has been considered that charging and discharging can be repeated below this capacity.

On the other hand, a mixed cathode active material consisting of an oxide material rich in Co and Ni and a spinel-type lithium manganate oxide material (LiMn ₂ O ₄ ) is proposed as an effort to realize a cathode material that achieves both high energy density and low cost. And some have been put to practical use. The reason why the manganese (Mn) -based material is selected is based on the fact that it is an element that has a large reserve and is inexpensive and is safer and less burdened on the environment than Co and Ni.

In Patent Document 3, lithium cobaltate (LiCoO ₂ ), in Patent Document 4, nickel / lithium manganate (LiNi _1/2 · Mn _1/2 O ₂ ), and in Patent Document 5 nickel / cobalt acid to which aluminum (Al) is added. Lithium (LiNi _0.8 Co _0.15 Al _0.05 O ₂ ; abbreviated NCA), in Patent Document 6, solid solution material (Li ₂ MnO ₃ —LiMeO ₂ , Me = Ni, Mn, Co; abbreviated / Li ₂ MnO ₃ -NMC) and mixed cathode active materials have been proposed.

However, since the practical capacity of LiMn ₂ O ₄ is as small as about 100 mAh / g, the mixing ratio is suppressed to such an extent that the characteristics of high energy density are not impaired, and there is a limit to cost reduction with the conventional mixed positive electrode active material. there were.

In addition, in-vehicle storage batteries for hybrid vehicles, plug-in hybrid vehicles, and electric vehicles, it is essential to increase the energy density for the purpose of reducing the weight and extending the cruising distance. Recently, LiMn ₂ O _{4 in} exchange for the economics of the storage battery. The use of a mixed positive electrode active material with a reduced mixing ratio has been made to increase the energy density.

Realization of a mixed positive electrode active material with a high-capacity Mn-based positive electrode material instead of LiMn ₂ O ₄ has been desired.

Japanese National Special Publication 2004-528691 Japanese Unexamined Patent Publication No. 2000-243449 Japanese Patent No. 3754218 Japanese Unexamined Patent Publication No. 2003-168430 Japanese Unexamined Patent Publication No. 2010-262914 Japanese National Table 2013-520882

An object of the present invention is to provide a manganese oxide that is a novel positive electrode material for a manganese-based lithium secondary battery that can achieve both high energy density and low cost. An energy density lithium secondary battery is provided. Furthermore, an object of the present invention is to provide an unprecedented new manganese oxide mixture and mixed positive electrode active material that can achieve both high energy density and low cost, and further, it is excellent in economic efficiency using this as a positive electrode. A high energy density lithium secondary battery is provided.

The inventor has conducted intensive studies on manganese oxide, which is a positive electrode material for high-energy density manganese-based lithium secondary batteries. As a result, the lithium-containing manganese composition represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} (where 0 <X <1 is satisfied) things, the general formula _{_{_{_{[Li 2 MnO 3] 1-}}}} E · [Li 4 Mn 5 O 12] E ( where, 0 <E satisfy <1.) lithium-containing manganese composition represented by the general formula Li _{( 4/3)-(4X / 5)} Mn _{2 / 3-Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1/3 is satisfied, M is Li, It is one or more elements selected from elements other than Mn and O.) Manganese oxide obtained by electrochemically oxidizing is charged and discharged at a very high capacity compared to conventional manganese-based positive electrode materials. Can be used for the positive electrode of a lithium secondary battery. It found that the secondary battery can be constituted, and have completed the present invention.

Furthermore, the present inventor conducted extensive studies on a manganese oxide and a positive electrode active material that can achieve both high energy density and low cost. As a result, the lithium-containing manganese composition represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} (where 0 <X <1 is satisfied) things, the formula _{_{_{_{[Li 2 MnO 3] 1-}}}} E · [Li 4 Mn 5 O 12] E ( where, 0 <E satisfy <1.) lithium-containing manganese composition represented by the general formula Li _{( 4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1/3, where M is A manganese oxide mixture based on one or more elements selected from elements other than Li, Mn, and O) is used as a positive electrode material of a mixed positive electrode active material, thereby using conventional LiMn ₂ O ₄ . Compared to the mixed positive electrode active material, it becomes possible to charge and discharge at an extremely high capacity. Found that can be constructed a high energy density, low-cost lithium secondary battery by using the electrode, thereby completing the present invention.

That is, the gist of the present invention is as follows.
[1] General formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} (where 0 <X <1, 0 <Y <Manufactured by (4/3)-(4X / 5)).
[2] General formula [Li _2-A MnO _3-B ] _1-E · [Li _4-C Mn ₅ O _12-D ] _E (where 0 <E <1, 0 ≦ A ≦ 2, 0 ≦ B ≦ A / 2, 0 ≦ C ≦ 4 and 0 ≦ D ≦ C / 2, except A = C = 0.) Manganese oxides
[3] General formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} (where 0 <X <1, 0 <Y <(4/3) − (4X / 5), 0 <Z ≦ 1/3 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) The manganese oxide characterized by these.
[4] The manganese oxide as described in any one of [1] to [3] above, which has a layered rock salt structure and a spinel structure.
[5] Lithium-containing manganese composition represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} (where 0 <X <1 is satisfied) The method for producing a manganese oxide according to the above [1] or [4], wherein the product is electrochemically oxidized.
[6] A lithium-containing manganese composition represented by the general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E (where 0 <E <1 is satisfied) The method for producing a manganese oxide according to the above [2] or [4], wherein the manganese oxide is oxidized to.
[7] General formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1 / 3, and M is one or more elements selected from elements other than Li, Mn, and O.) The lithium-containing manganese composition represented by [3] is electrochemically oxidized [3 ] Or the manufacturing method of the manganese oxide as described in [4].
[8] The method for producing a manganese oxide according to any one of [5] to [7] above, wherein the lithium-containing manganese composition has a layered rock salt structure and a spinel structure.
[9] The method for producing a manganese oxide according to any one of [5] to [8] above, wherein the electrochemical oxidation is performed in the battery.
[10] Lithium-containing manganese composition represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} (where 0 <X <1 is satisfied) And a manganese oxide mixture containing a cathode material.
[11] A lithium-containing manganese composition represented by the general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E (where 0 <E <1 is satisfied) and a positive electrode material A manganese oxide mixture characterized by containing.
[12] General formula Li _{(4/3)-(4X / 5)} Mn _{2 / 3-Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1/3) M is one or more elements selected from elements other than Li, Mn, and O.) A manganese oxide mixture characterized by containing a lithium-containing manganese composition and a positive electrode material.
[13] The manganese oxide mixture as described in any one of [10] to [12] above, wherein the lithium-containing manganese composition has a layered rock salt structure and a spinel structure.
[14] A mixed positive electrode active material comprising the manganese oxide mixture according to any one of [10] to [13].
[15] A lithium secondary battery comprising a positive electrode containing the manganese oxide according to any one of [1] to [4] or the mixed positive electrode active material according to [14]. .

The manganese oxide of the present invention can be charged and discharged at a very high capacity compared to conventional manganese-based positive electrode materials, and by using this for the positive electrode of a lithium secondary battery, both high energy density and low cost are achieved. It is possible to provide a rechargeable lithium secondary battery. Furthermore, the manganese oxide mixture and the mixed positive electrode active material of the present invention can be charged and discharged at a very high capacity compared to the conventional mixed positive electrode active material, and this can be used for the positive electrode of a lithium secondary battery. It is possible to provide a lithium secondary battery that can achieve both high energy density and low cost.

2 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 1 to 11. FIG. 3 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Comparative Examples 1 and 2. FIG. It is an example (Example 1, comparative example 1) of the powder X-ray-diffraction pattern before and behind a charging / discharging test. 4 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 12 to 14. FIG. 3 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 15 to 18. FIG. 4 is a powder X-ray diffraction pattern of a lithium-containing manganese composition of Comparative Example 3. It is an example (Example 12, comparative example 3) of the powder X-ray-diffraction pattern before and behind a charging / discharging test. It is a powder X-ray-diffraction pattern of the lithium containing manganese composition used in Example 19 and Example 20. FIG. It is a powder X-ray-diffraction pattern of the lithium containing manganese composition used in Example 21 and Example 22. 4 is a powder X-ray diffraction pattern of NCA used in Example 19, Example 21, and Comparative Example 4. FIG. 4 is a powder X-ray diffraction pattern of NMC used in Example 20, Example 22, and Comparative Example 5. FIG. _{3 is} a powder X-ray diffraction pattern of LiMn ₂ O ₄ used in Comparative Examples 4 and 5. FIG. 3 is a powder X-ray diffraction pattern of the lithium-containing manganese composition used in Examples 23 to 28. FIG. It is a powder X-ray diffraction pattern of NCA used in Example 23 and Comparative Example 6. 4 is a powder X-ray diffraction pattern of NMC used in Example 24 and Comparative Example 7. FIG. _{3 is} a powder X-ray diffraction pattern of LiMn ₂ O ₄ used in Comparative Example 6 and Comparative Example 7. 3 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 29 to 31 and Comparative Example 11. FIG. 4 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 32 to 35. FIG. 3 is a powder X-ray diffraction pattern before and after the charge / discharge test of Examples 29 to 30. FIG. It is a charging / discharging profile of Example 31 and Comparative Example 11. 3 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 36 to 40 and Comparative Example 19. 4 is a powder X-ray diffraction pattern of lithium-containing manganese compositions of Examples 41 to 44. FIG. 3 is a powder X-ray diffraction pattern before and after the charge / discharge test of Examples 36 to 38. FIG. It is a charging / discharging profile of Example 38 and Comparative Example 19. 4 is a powder X-ray diffraction pattern of a lithium-containing manganese composition used in Examples 45 to 49. FIG. 3 is a powder X-ray diffraction pattern of the lithium-containing manganese composition used in Examples 50 to 54. FIG. 4 is a powder X-ray diffraction pattern of NMC used in Examples 45 to 49 and Comparative Example 24. FIG. 4 is an NCA powder X-ray diffraction pattern used in Examples 50 to 54 and Comparative Example 25. FIG. _{3 is} a powder X-ray diffraction pattern of LiMn ₂ O ₄ used in Comparative Example 24 and Comparative Example 25. FIG.

Hereinafter, the present invention will be described in more detail.

The manganese oxide of the present invention has the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} (where 0 <X < 1, 0 <Y <(4/3) − (4X / 5) is satisfied).

The manganese oxide of the present invention has a general formula [Li _2-A MnO _3-B ] _1-E. [Li _4-C Mn ₅ O _12-D ] _E (where 0 <E <1, 0 ≦ A ≦ 2, 0 ≦ B ≦ A / 2, 0 ≦ C ≦ 4 and 0 ≦ D ≦ C / 2, except A = C = 0.

The value of X in the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} , which is the manganese oxide of the present invention, It can be determined from a composition analysis of the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , which is a lithium-containing manganese composition.

The value of E in the general formula [Li _2-A MnO _3-B ] _1-E · [Li _4-C Mn ₅ O _12-D ] _E , which is the manganese oxide of the present invention, is the lithium-containing manganese composition of the present invention. It can be determined from the composition analysis of the general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E.

Examples of the method obtained from composition analysis include dielectric coupled plasma emission analysis and atomic absorption analysis.

The value of Y in the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention is Since it corresponds to the desorption of Li and O by chemical oxidation, it can be calculated from the quantity of electricity at the time of electrochemical oxidation using Coulomb's law.

The values of A, B, C, and D of the general formula [Li _2-A MnO _3-B ] _1-E · [Li _4-C Mn ₅ O _12-D ] _E , which is the manganese oxide of the present invention, Since it corresponds to chemical oxidation, that is, desorption of oxygen and Li due to charging, it can be calculated from the amount of charged electricity in the first cycle using Coulomb's law.

The manganese oxide of the present invention has the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} (here 0 <X <1, 0 <Y <(4/3) − (4X / 5), 0 <Z ≦ 1/3, and M is one or more elements selected from elements other than Li, Mn, and O It is an element.)

_X of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention From the composition analysis of the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is the lithium-containing manganese composition of the present invention. Can be sought.

_Z of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention From the composition analysis of the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is the lithium-containing manganese composition of the present invention. Can be sought.

_Y of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention Since this value corresponds to the desorption of Li and O by electrochemical oxidation, it can be calculated from the amount of electricity at the time of electrochemical oxidation, that is, the amount of charged electricity in the first cycle, using Coulomb's law. it can.

M of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention One or more elements selected from elements other than Li, Mn, and O can be used. Examples of one or more elements selected from elements other than Li, Mn, and O include, for example, H, Na, K, Rb, Cs, Ib group element Cu, Ag, Au, and IIa group element Be, Mg, Ca, Sr, Ba, IIb group element Zn, Cd, IIIa group element Sc, Y, IIIb group element B, Al, Ge, In, Mn transition metals other than Mn, the first transition except Mn Series elements Ti, V, Cr, Fe, Co, Ni, second and third transition series elements Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Pt, Au, etc. are illustrated. In order to maintain the capacity per weight as the positive electrode, H, Na, K, Mg, Ca, Al, Zn, Ga, Ti, V, Cr, Fe, Co, and Ni are preferable.

The Mn valence of the manganese composition of the present invention can be obtained by a general transition metal valence evaluation method. For example, a method of estimating from each spectrum obtained by XPS measurement (X-ray photoelectron spectroscopy), XAFS measurement (X-ray adsorption fine structure), PES measurement (Photoelectron spectroscopy), described in JIS (Japanese Industrial Standard) Although the method etc. which combined the analysis method (G1311-1) and the manganese dioxide analysis method (K1467) as described in JIS are illustrated, it is not restricted to these.

Since the manganese oxide of the present invention reversibly inserts and desorbs lithium, a two-phase coexistence state in which a layered rock salt structure and a spinel structure coexist is preferable, and in order to develop higher reversibility, these Are more preferably a twin structure in which a domain of a layered rock salt structure and a domain of a spinel structure are combined with a specific crystal plane or crystal axis in common in the same crystalline solid.

The inventor has the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} , which is the manganese oxide of the present invention. [Li _2-A MnO _3-B ] _1-E. [Li _4-C Mn ₅ O _12-D ] _E , general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) The} reason why _-Z M _Z O _{2- (2X / 5)-(Y / 2)} can be charged and discharged with a high capacity is considered as follows.

According to the study of the present inventors, when Li ₂ MnO ₃ is electrochemically oxidized and reduced, that is, charging and discharging are repeated, 1) a part of the crystal structure of Li ₂ MnO ₃ changes from a layered structure to a spinel-like structure. The generated spinel-like structure contributes to the charge / discharge reaction. 2) The crystallinity of the spinel-like structure produced by charging / discharging is low, and when the charge / discharge cycle is repeated, the crystallinity further decreases and the charge / discharge capacity decreases. I know that.

Therefore, it was considered that if a spinel structure with good crystallinity can coexist in advance with the layered rock salt structure of Li ₂ MnO _3, the capacity decrease can be suppressed and high capacity can be maintained even after repeated charge and discharge.

By the way, Li ₂ MnO ₃ releases oxygen and Li by charging as shown in Formula 1. It is thought that oxygen is responsible for the oxidation reaction, and the valence of Mn remains +4, and the valence does not change. In the process in which oxidation proceeds to the MnO ₂ composition while the valence of Mn remains +4, there is a possibility that the composition passes through the composition of Li ₄ Mn ₅ O ₁₂ or Li ₂ Mn ₄ O ₉ . These all have a spinel structure.

In particular, Li ₄ Mn ₅ O ₁₂ is similar in composition to Li ₂ MnO ₃ compared to Li ₂ Mn ₄ O ₉ , and as represented by Li [Li _1/3 Mn _5/3 ] O ₄ , It can be regarded as a layered structure in which 1/3 of Mn is replaced with Li, and although the arrangement pattern of oxygen is slightly different, it can be regarded as a composition having a crystal structure similar to Li ₂ MnO ₃ .

Due to the difference in crystal structure, it is difficult to prepare a solid solution of Li ₂ MnO ₃ and Li ₄ Mn ₅ O ₁₂ , but it is easy to make it coexist in a very small state, not just a mixed state it is conceivable that. Furthermore, it is considered that it is easy to create a twin structure state in which the domain of Li ₂ MnO _{3 and} the domain of Li ₄ Mn ₅ O ₁₂ are combined in the same crystalline solid with a specific crystal plane and crystal axis in common. It is done.

Further, Li ₄ Mn ₅ O ₁₂ having a spinel structure can be regarded as a composition obtained by removing a part of Li and oxygen from Li ₂ MnO ₃ . Therefore, it has a structure with a movement path of Li and oxygen from the beginning. Therefore, when the _Li 2 MnO ₃ and _Li 4 _Mn 5 _{O 12} coexist in the same particle, the diffusion of oxygen and Li is easier as compared to _Li 2 MnO _{_3,} the composition in a prone particles with Li 2 MnO ₃ It is considered that non-uniformity of the structure is difficult to occur. In addition, since Li ₄ Mn ₅ O ₁₂ has better crystallinity than a composition produced by charging and discharging Li ₂ MnO ₃ , it is considered that a decrease in capacity associated with charging and discharging cycles is suppressed.

Further, the present inventor considers the reason why charging and discharging can be performed with a high capacity by substituting a part of Mn with an element other than Li, Mn, and O as follows.

Li ₂ MnO ₃ has a part of the crystal structure that changes from a layered structure to a spinel-like structure due to charge / discharge, but the present inventors have a structure triggered by the elimination of Li, which accounts for 1/3 of the Mn layer. We believe that changes are likely to occur. When Li is desorbed from Li ₂ MnO ₃ , O is also desorbed at the same time, but it is considered that O in the vicinity of Mn is preferentially desorbed in order to maintain the valence of Mn at +4. It is done. Mn moves from an Mn site to an empty Li site generated by Li desorption through an oxygen vacancy site generated by O desorption, and Mn moves to another adjacent empty Li site to spinel. It changes to a similar structure. If a part of Mn is replaced with other elements, O desorption in the vicinity of Mn is suppressed, and although the amount of Li that can be removed, that is, the capacity is reduced, the structure change suppressing effect is obtained, which is superior to that, and charge / discharge It is thought that high capacity can be maintained even if the above is repeated.

The manganese oxide of the present invention is represented by the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} (where 0 <X < 1, 0 <Y <(4/3)-(4X / 5) is satisfied.) Is represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} ( Here, the lithium-containing manganese composition represented by 0 <X <1 is satisfied) by electrochemical oxidation.

The manganese oxide of the present invention is represented by the general formula [Li _2-A MnO _3-B ] _1-E. [Li _4-C Mn ₅ O _12-D ] _E (where 0 <E <1, 0 ≦ A ≦ 2, 0 ≦ B ≦ A / 2, 0 ≦ C ≦ 4 and 0 ≦ D ≦ C / 2, except A = C = 0.) Is represented by the general formula [Li ₂ MnO ₃ ] _1-E * Obtained by electrochemically oxidizing a lithium-containing manganese composition represented by [Li ₄ Mn ₅ O ₁₂ ] _E (where 0 <E <1 is satisfied).

The manganese oxide of the present invention is represented by the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} (here 0 <X <1, 0 <Y <(4/3) − (4X / 5), 0 <Z ≦ 1/3, and M is one or more elements selected from elements other than Li, Mn, and O Is an element of the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1/3 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) obtained by electrochemically oxidizing a lithium-containing manganese composition represented by: .

The reason for electrochemical oxidation is to remove Li ₂ O from the lithium-containing manganese composition. By methods other than electrochemical oxidation, Li and O cannot be removed at the same time while the valence of Mn remains +4.

Examples of the electrochemical oxidation method include a method of producing a battery and charging in the battery, a method of using an oxidizing agent, and the like.

As a method for producing a battery and charging in the battery, a general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} which is the lithium-containing manganese composition of the present invention is used. _, [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E , or general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2 -A} method of producing a lithium battery using _{(2X / 5)} as a positive electrode material and charging in the battery is exemplified. For example, for the positive electrode, the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , which is the lithium-containing manganese composition of the present invention, the general formula [Li ₂ MnO ₃ ] _{1 -E.} [Li ₄ Mn ₅ O ₁₂ ] _E or lithium using the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} Examples of the method include charging a battery by constituting a constant current, a constant voltage, or a combination of a constant current and a constant voltage. As a structure of a lithium battery, the structure which can be used as a lithium secondary battery as it is is preferable.

As a method of using an oxidizing agent, for example, in a solution of an oxidizing agent NO ₂ BF ₄ dissolved in a solvent acetonitrile, the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E , or general formula Li _{(4/3)-(4X / 5)} A method of stirring Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} is exemplified. The oxidation potential of the oxidant NO ₂ BF ₄ is 5.1 V on the basis of lithium, and Li and O can be removed while maintaining the valence of Mn at +4.

Since it can be used as a battery as it is, the method of electrochemical oxidation is preferably a method of producing a battery and charging it in the battery.

The manganese oxide of the present invention having a layered rock salt structure and a spinel structure can be obtained by electrochemically oxidizing a lithium-containing manganese composition having a layered rock salt type structure and a spinel type structure.

Lithium-containing manganese used in the production of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention The value of X in the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , which is the composition, can be determined from the composition analysis of the lithium-containing manganese composition. .

Lithium-containing manganese composition used in the production of the general formula [Li _2-A MnO _3-B ] _1-E · [Li _4-C Mn ₅ O _12-D ] _E which is the manganese oxide of the present invention The value of E in the formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E can be determined from composition analysis of the lithium-containing manganese composition.

Lithium-containing manganese used in the production of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _2/3 O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention The composition represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , the manganese oxide of the present invention represented by the general formula [Li _2-A MnO _3-B _{_{_{] 1-E · [Li 4}}} -C Mn 5 O 12-D] formula is a lithium-containing manganese composition used in the production of _{_{_{_{E [Li 2 MnO 3] 1}}}} -E · [Li 4 Mn 5 O 12] _E : Mn raw material and Li raw material molar ratio (Li / Mn ratio) is 0.8 <Li / Mn ratio <2.0, Mn raw material and Li raw material are solid phase, liquid phase, or a combination of both Can be prepared by firing the mixture. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

Production of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention The value of X in the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is a lithium-containing manganese composition used in It can obtain | require from a composition analysis of a containing manganese composition.

Production of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention The value of Z in the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is a lithium-containing manganese composition used in It can obtain | require from a composition analysis of a containing manganese composition.

Production of the general formula Li _{(4/3)-(4X / 5) -Y} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)-(Y / 2)} which is the manganese oxide of the present invention Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is a lithium-containing manganese composition used in (Mn raw material + M raw material) And the molar ratio of Li raw material [Li / (Mn + M) ratio] is 0.8 <Li / (Mn + M) ratio <2.0, and the molar ratio of Mn raw material to M raw material [M / (Mn + M) ratio] is 0 <M. It can be prepared by firing a mixture of a Mn raw material, an M raw material, and a Li raw material in a solid phase, a liquid phase, or a combination of both at a / (Mn + M) ratio ≦ 1/2. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

There is no particular limitation on the Mn raw material used in the production of the lithium-containing manganese composition, but in order to contain a layered rock salt type structure and a spinel type structure, a manganese raw material containing + 2-valent manganese and / or a monoclinic manganese raw material Is preferably used. Examples of manganese raw materials containing divalent manganese include manganese sulfate, manganese carbonate, manganese nitrate, manganese chloride, trimanganese tetraoxide (Mn ₃ O ₄ ), MnO, Mn (OH) ₂ , and acids of these manganese raw materials Although a processed material etc. are illustrated, it is not restrict | limited to these. Examples of the monoclinic manganese raw material include, but are not limited to, birnessite, hollandite, manganite, romanite, todokeite, manganese oxides having similar structures to these, and acid-treated products of these manganese raw materials. . The Li raw material used in the production of the lithium-containing manganese composition is not particularly limited, and examples include lithium carbonate, lithium hydroxide, lithium nitrate, lithium chloride, lithium iodide, lithium oxalate, lithium sulfate, and lithium oxide. However, it is not limited to these.

Although there is no restriction | limiting in the M raw material used by manufacture of a lithium containing manganese composition, Although the carbonate, nitrate, oxalate, chloride, oxide, etc. of M element to be used are illustrated, it is not restrict | limited to these.

</ RTI> By using the manganese oxide of the present invention for the positive electrode of a lithium secondary battery, it becomes possible to constitute a high-capacity lithium secondary battery that could not be obtained conventionally.

The configuration of the lithium secondary battery other than the positive electrode is not particularly limited, but the negative electrode is a material that occludes and releases Li, for example, a carbon-based material, a tin oxide-based material, Li ₄ Ti ₅ O ₁₂ , SiO, Li, and the like. Examples of the material that forms an alloy include Li-based alloys, and examples of the material that forms an alloy with Li include silicon-based materials and aluminum-based materials. Examples of the electrolyte include an organic electrolytic solution in which a Li salt and various additives are dissolved in an organic solvent, a Li ion conductive solid electrolyte, and a combination thereof.

Next, the manganese oxide mixture and mixed cathode active material of the present invention will be described.

The manganese oxide mixture of the present invention is represented by the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} (where 0 <X <1 is satisfied). The lithium-containing manganese composition and the positive electrode material are contained.

Further, the manganese oxide mixture of the present invention is a lithium represented by the general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E (where 0 <E <1 is satisfied). It contains a manganese composition and a positive electrode material.

Further, the manganese oxide mixture of the present invention has the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} (where 0 <X <1, 0 <Z ≦ 1/3 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) It is.

The lithium-containing manganese composition contained in the manganese oxide mixture of the present invention has a higher capacity than LiMn ₂ O ₄ , and its capacity is 130 to 170 mAh / g. LiCoO ₂ , LiNi _1/2 · Mn _{1 /} Compared with ₂ O ₂ , NCA (lithium / nickel / cobalt / aluminum composite oxide) and NMC (lithium / nickel / manganese / cobalt composite oxide), it has the characteristics of high energy density regardless of the mixing ratio. There is no loss. For this reason, in the mixed positive electrode active material, both high energy density and low cost can be achieved.

The value of X in the general formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5)} , which is a lithium-containing manganese composition, is determined from the composition analysis of the lithium-containing manganese composition. be able to.

The value of E in the general formula [Li ₂ MnO ₃ ] _1-E · [Li ₄ Mn ₅ O ₁₂ ] _E , which is a lithium-containing manganese composition, can be determined from the composition analysis of the lithium-containing manganese composition.

The value of X in the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is a lithium-containing manganese composition, It can obtain | require from the composition analysis of a thing.

The value of Z in the general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5)} , which is a lithium-containing manganese composition, It can obtain | require from the composition analysis of a thing.

The Mn valence of the lithium-containing manganese composition can be obtained by a general transition metal valence evaluation method. For example, a method of estimating from each spectrum obtained by XPS measurement (X-ray photoelectron spectroscopy), XAFS measurement (X-ray adsorption fine structure), PES measurement (Photoelectron spectroscopy), described in JIS (Japanese Industrial Standard) Although the method etc. which combined the analysis method (G1311-1) and the manganese dioxide analysis method (K1467) as described in JIS are illustrated, it is not restricted to these.

Since the lithium-containing manganese composition reversibly inserts and desorbs lithium, a two-phase coexistence state in which a layered rock salt type structure and a spinel type structure coexist is preferable. A twin structure in which a domain of a layered rock salt structure and a domain of a spinel structure are combined with a specific crystal plane or crystal axis in common in the same crystal solid is more preferable.

General formula Li _{(4/3)-(4X / 5)} Mn _2/3 O _{2- (2X / 5) which is} a lithium-containing manganese composition, general formula [Li ₂ MnO ₃ ] ₁ which is a lithium-containing manganese composition _-E · [Li ₄ Mn ₅ O ₁₂ ] _E is a molar ratio of Mn raw material to Li raw material (Li / Mn ratio) with 0.8 <Li / Mn ratio <2.0. Can be prepared by baking a solid phase, a liquid phase, or a combination of both. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

The general formula Li _{(4/3)-(4X / 5)} Mn _{(2/3) -Z} M _Z O _{2- (2X / 5) which} is a lithium-containing manganese composition is (Mn raw material + M raw material) and Li raw material The molar ratio [Li / (Mn + M) ratio] of 0.8 <Li / (Mn + M) ratio <2.0, and the molar ratio [M / (Mn + M) ratio] of Mn raw material to M raw material is 0 <M / (Mn + M). It can be prepared by firing a mixture of a Mn raw material, an M raw material and a Li raw material in a solid phase, a liquid phase, or a combination of both at a ratio ≦ 1/2. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

The positive electrode material contained in the manganese oxide mixture of the present invention is not particularly limited as long as it contains lithium and the lithium can be released by electrochemical oxidation. For example, NCA (lithium / nickel) Cobalt / aluminum composite oxide), NMC (lithium / nickel / manganese / cobalt composite oxide), lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium / nickel / manganese composite oxide (LiNi _{1) /} 2Mn _1/2 O ₂ ), lithium / nickel / manganese spinel composite oxide (LiNi _1/2 · Mn _3/2 O ₄ ), solid solution material, olivine type LiMnPO ₄ , olivine type LiFePO _{4 and the} like. .

The manganese oxide mixture of the present invention can be produced by mixing a lithium-containing manganese composition and a positive electrode material. The mixing method is not limited as long as it can be uniformly mixed. For example, mixing with a mortar, mixing with a mixer, etc. are illustrated.

By using the manganese oxide mixture of the present invention as a mixed positive electrode active material, it is possible to provide a high-capacity and low-cost lithium secondary battery that could not be obtained conventionally.

A positive electrode can be obtained by mixing the mixed positive electrode active material with a conductive additive, a binder, and the like.

The configuration of the lithium secondary battery other than the positive electrode is not particularly limited, but the negative electrode is a material that occludes and releases Li, for example, a carbon-based material, a tin oxide-based material, Li ₄ Ti ₅ O ₁₂ , SiO, Li Examples of the material that forms an alloy include Li-based alloys, and examples of the material that forms an alloy with Li include silicon-based materials and aluminum-based materials. Examples of the electrolyte include an organic electrolytic solution in which a Li salt and various additives are dissolved in an organic solvent, a Li ion conductive solid electrolyte, and a combination thereof.

Next, another manganese oxide will be described.

The manganese oxide of the present invention has a general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} (where 0 <X ≦ _8/9 , 0 ≦ Z ≦ 8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.

The value of X in the general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, is determined by the electrochemical oxidation of Li and O. Can be calculated from the quantity of electricity during electrochemical oxidation using Coulomb's law.

The value of Z in the general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, is the lithium-containing manganese composition of the present invention. It can be determined from the composition analysis of the general formula Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ . Examples of the method obtained from the composition analysis include dielectric coupling plasma emission analysis and atomic absorption analysis.

The manganese oxide of the present invention has a general formula of Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} (where 0 <X ≦ _4/3 , 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.)

The value of X in the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, is determined by the electrochemical oxidation of Li and O. Can be calculated from the quantity of electricity during electrochemical oxidation using Coulomb's law.

The value of Z in the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, is the lithium-containing manganese composition of the present invention. It can be determined from the composition analysis of the general formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ . Examples of the method obtained from the composition analysis include dielectric coupling plasma emission analysis and atomic absorption analysis.

The general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} , the general formula Li _{(4/3) -X} Mn _{(5 / 3)} One or more elements selected from elements other than Li, Mn, and O can be used for M in _—Z M _Z O _{4- (X / 2)} . Examples of one or more elements selected from elements other than Li, Mn, and O include, for example, H, Na, K, Rb, Cs, Ib group element Cu, Ag, Au, and IIa group element Be, Mg, Ca, Sr, Ba, IIb group element Zn, Cd, IIIa group element Sc, Y, IIIb group element B, Al, Ge, In, Mn transition metals other than Mn, the first transition except Mn Series elements Ti, V, Cr, Fe, Co, Ni, second and third transition series elements Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Pt, Au, etc. are illustrated. In order to maintain the capacity per weight as the positive electrode, H, Na, K, Mg, Ca, Al, Zn, Ga, Ti, V, Cr, Fe, Co, and Ni are preferable.

The manganese oxide of the present invention preferably has a spinel structure in order to reversibly insert and desorb lithium. The spinel structure has a structure having a Li movement path. Therefore, it is considered that the composition and structure non-uniformity within the particles hardly occur, and it is considered that the decrease in capacity accompanying the charge / discharge cycle is suppressed.

The general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention (where 0 <X ≦ _8/9 , 0 ≦ Z ≦ _8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) is represented by the general formula Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ ( Here, 0 ≦ Z ≦ 8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O). Can be obtained.

Further, the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention (where 0 <X ≦ _4/3 , 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) is represented by the general formula Li _4/3 Mn _(5/3 ) _—Z M _Z O ₄ (where 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O). Obtained by oxidation.

The reason for electrochemical oxidation is to remove Li ₂ O from the lithium-containing manganese composition. By methods other than electrochemical oxidation, Li and O cannot be removed at the same time while the valence of Mn remains +4. By simultaneously removing Li and O electrochemically, the manganese oxide of the present invention can maintain the spinel structure of the lithium-containing manganese composition.

As a method for producing a battery and charging in the battery, a general formula Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ (where 0 <Z ≦ 8/9, where M is one or more elements selected from elements other than Li, Mn, and O), or the general formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6, and M is one or more elements selected from elements other than Li, Mn, and O.) is used as a positive electrode material, and a lithium battery is manufactured and charged in the battery A method is illustrated. For example, for the positive electrode, the general formula Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ or the general formula Li _4/3 Mn _{(5/3) -Z} M _Z which is the lithium-containing manganese composition of the present invention is used. Examples include a method in which a lithium battery using O ₄ is configured and charged with a constant current, a constant voltage, or a combination of a constant current and a constant voltage. As a structure of a lithium battery, the structure which can be used as a lithium secondary battery as it is is preferable.

As a method of using an oxidizing agent, for example, in a solution in which NO ₂ BF ₄ as an oxidizing agent is dissolved in acetonitrile as a solvent, the general formula Li _8/9 Mn _(16/9 ) that is the lithium-containing manganese composition of the present invention is _{used. )} -Z _M Z _{O 4,} or the general _formula _{_{Li 4/3 Mn (5/3) -Z M}} Z O 4 method of stirring and the like. The oxidation potential of the oxidant NO ₂ BF ₄ is 5.1 V on the basis of lithium, and Li and O can be removed while maintaining the valence of Mn at +4.

The manganese oxide of the present invention having a spinel structure can be obtained by electrochemically oxidizing a lithium-containing manganese composition having a spinel structure.

The general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, where 0 <X ≦ _8/9 , 0 < Z ≦ _8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn and O. General formula Li _8/9 Mn _{(16 / 9) -Z} M _Z O ₄ (where 0 <Z ≦ 8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O) is (□ _1/9 Li _8/9 ) _8a [□ _2/9 Mn _{(16/9) -Z} M _Z ] _16d (O ₄ ) _32e (where □ represents an empty site), and LiMn ₂ O ₄ 8a 1/9 of the site Li and 2/9 of the 16d site Mn have an empty spinel structure.

Lithium-containing manganese composition used in the production of the general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention The composition of Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ can be determined from composition analysis. Examples of the method obtained from the composition analysis include dielectric coupling plasma emission analysis and atomic absorption analysis.

Further, the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention (where 0 <X ≦ _4/3 , 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) General formula Li _4/3 Mn _{( 5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn and O) is LiMn ₂ O (Li) _8a [Li _1/3 Mn _5/3 ] _16d (O ₄ ) _{32e, in} which 1/3 of ₄ Mn is replaced by Li, has a spinel crystal structure.

The lithium-containing manganese composition used in the production of the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention The composition of Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ can be determined from composition analysis. Examples of the method obtained from the composition analysis include dielectric coupling plasma emission analysis and atomic absorption analysis.

The general formula Li _{(8/9) -X} Mn _{(16/9) -Z} M _Z O _{4- (X / 2)} , which is the manganese oxide of the present invention, where 0 <X ≦ _8/9 , 0 < Z ≦ _8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) General formula Li _8/9 Mn _{(16 / 9) -Z} M _Z O ₄ (where 0 <Z ≦ 8/9 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O) is (Mn raw material + M The molar ratio of the raw material) to the Li raw material [Li / (Mn + M) ratio] is 1/2, and the molar ratio of the Mn raw material to the M raw material [M / (Mn + M) ratio] is 0 ≦ M / (Mn + M) ratio ≦ 1/2. Mn raw material and Li raw material, or Mn raw material and M raw material and Li raw material are mixed in solid phase, liquid phase, or a combination of both. It can be prepared by firing. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

Further, the general formula Li _{(4/3) -X} Mn _{(5/3) -Z} M _Z O _{4- (X / 2)} which is the manganese oxide of the present invention (where 0 <X ≦ _4/3 , 0 ≦ Z ≦ 5/6 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O.) General formula Li _4/3 Mn _{( 5/3) -Z} M _Z O ₄ has a molar ratio (Li / (Mn + M) ratio) of (Mn raw material + M raw material) to Li raw material of 4/5, and a molar ratio of Mn raw material to M raw material [M / (Mn + M ) Ratio] is 0 ≦ M / (Mn + M) ratio ≦ 1/2, and Mn raw material and Li raw material, or Mn raw material and M raw material and Li raw material are mixed in solid phase, liquid phase, or a combination of both. Can be prepared by firing. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

There is no particular limitation on the Mn raw material used in the production of the lithium-containing manganese composition. Is preferably used. Examples of manganese raw materials containing divalent manganese include manganese sulfate, manganese carbonate, manganese nitrate, manganese chloride, trimanganese tetraoxide (Mn ₃ O ₄ ), MnO, Mn (OH) ₂ , and acids of these manganese raw materials Although a processed material etc. are illustrated, it is not restrict | limited to these. Examples of the monoclinic manganese raw material include, but are not limited to, birnessite, hollandite, manganite, romanite, todokeite, manganese oxides having similar structures to these, and acid-treated products of these manganese raw materials. . The Li raw material used in the production of the lithium-containing manganese composition is not particularly limited, and examples include lithium carbonate, lithium hydroxide, lithium nitrate, lithium chloride, lithium iodide, lithium oxalate, lithium sulfate, and lithium oxide. However, it is not limited to these.

Next, another manganese oxide mixture and mixed cathode active material will be described.

The manganese oxide mixture of the present invention has the general formula Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ (where 0 ≦ Z ≦ _8/9 is satisfied, and M is other than Li, Mn, and O). One or more elements selected from the elements)) and a lithium-containing manganese composition and a positive electrode material.

Further, the manganese oxide mixture of the present invention has the general formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6, where M is Li, Mn, O One or more elements selected from the other elements.) And a positive electrode material.

Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ (where 0 ≦ Z ≦ _8/9 is satisfied, and M is an element other than Li, Mn, and O, which is a lithium-containing manganese composition One or more elements selected.), General formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6, where M is Li, Mn, O The value of Z of the lithium-containing manganese composition represented by the above can be determined from the composition analysis of the lithium-containing manganese composition. Examples of the method obtained from the composition analysis include dielectric coupling plasma emission analysis and atomic absorption analysis.

Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ (where 0 ≦ Z ≦ _8/9 is satisfied, and M is an element other than Li, Mn, and O, which is a lithium-containing manganese composition One or more elements selected.), General formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6, where M is Li, Mn, O One or more elements selected from elements other than Li, Mn, and O can be used for M in the lithium-containing manganese composition represented by: Examples of one or more elements selected from elements other than Li, Mn, and O include, for example, H, Na, K, Rb, Cs, Ib group element Cu, Ag, Au, and IIa group element Be, Mg, Ca, Sr, Ba, IIb group element Zn, Cd, IIIa group element Sc, Y, IIIb group element B, Al, Ge, In, Mn transition metals other than Mn, the first transition except Mn Series elements Ti, V, Cr, Fe, Co, Ni, second and third transition series elements Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Pt, Au, etc. are illustrated. In order to maintain the capacity per weight as the positive electrode, H, Na, K, Mg, Ca, Al, Zn, Ga, Ti, V, Cr, Fe, Co, and Ni are preferable.

The Mn valence of the lithium-containing manganese composition of the present invention can be determined by a general transition metal valence evaluation method. For example, a method of estimating from each spectrum obtained by XPS measurement (X-ray photoelectron spectroscopy), XAFS measurement (X-ray adsorption fine structure), PES measurement (Photoelectron spectroscopy), described in JIS (Japanese Industrial Standard) Although the method etc. which combined the analysis method (G1311-1) and the manganese dioxide analysis method (K1467) as described in JIS are illustrated, it is not restricted to these.

Li _8/9 Mn _{(16/9) -Z} M _Z O ₄ (where 0 <Z ≦ _8/9 is satisfied, and M is an element other than Li, Mn, and O, which is a lithium-containing manganese composition Is one or more elements selected.) Is (Mn raw material + M raw material) and Li raw material molar ratio [Li / (Mn + M) ratio] 1/2, Mn raw material and M raw material molar ratio [M / (Mn + M ) Ratio] is 0 ≦ M / (Mn + M) ratio ≦ 1/2, and Mn raw material and Li raw material, or Mn raw material and M raw material and Li raw material are mixed in solid phase, liquid phase, or a combination of both. Can be prepared by firing. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

General formula Li _4/3 Mn _{(5/3) -Z} M _Z O ₄ (where 0 ≦ Z ≦ 5/6 is satisfied, and M is an element other than Li, Mn, and O, which is a lithium-containing manganese composition Is one or more elements selected.) Is a molar ratio of [Mn raw material + M raw material] to Li raw material [Li / (Mn + M) ratio] of 4/5, and a molar ratio of Mn raw material to M raw material [M / (Mn + M). ) Ratio] is 0 ≦ M / (Mn + M) ratio ≦ 1/2, and Mn raw material and Li raw material, or Mn raw material and M raw material and Li raw material are mixed in solid phase, liquid phase, or a combination of both. Can be prepared by firing. In order to make the valence of Mn +4, it is preferably fired at 300 to 800 ° C. in an air circulation or an atmosphere having an oxygen content higher than the air. Examples of the temperature increase and temperature decrease conditions during firing include, but are not limited to, temperature increase and decrease at a constant rate and stepwise temperature increase and decrease.

Next, the present invention will be described with specific examples, but the present invention is not limited to these examples.

<Production of battery>
Obtained lithium-containing manganese composition and conductive binder (trade name: TAB-2, manufactured by Hosen Co., Ltd.), or obtained manganese oxide mixture (mixed positive electrode active material) and conductive binder (trade name: TAB) -2, manufactured by Hosen Co., Ltd.) using an agate mortar at a weight ratio of 2: 1, uniaxially pressed into a 13 mmφ SUS mesh (SUS316) at 1 ton / cm ² and then pelletized. It dried under reduced pressure at 2 degreeC for 2 hours, and was set as the positive electrode.

Metallic lithium for the negative electrode, 1 mol / dm ³ of LiPF ₆ dissolved in a 1: 2 volume ratio solvent of ethylene carbonate and dimethyl carbonate in the electrolyte, polyethylene sheet in the separator (trade name: Celgard, manufactured by Polypore Corporation) A 2032 type coin cell was prepared using

<Charge / discharge test>
1) Test conditions of Examples 1 to 54, Comparative Example 11 and Comparative Example 19 Using the produced coin cells, the cell voltage was 4.8 V at room temperature (22 to 27 ° C.) and a constant current of 10 mA / g. Between 1 and 2.0 V, charge first, then discharge, and then repeat charge and discharge, charge capacity at the first cycle (mAh / g), discharge capacity at the first cycle (mAh / g) The discharge capacity (mAh / g) at the 10th cycle was measured. Further, the discharge capacity (mAh / g) at the 50th cycle was measured, and the capacity retention rate (ratio (%) of the discharge capacity at the 10th cycle to the discharge capacity at the 1st cycle) was determined.

2) Test conditions of Comparative Examples 8 to 10, Comparative Examples 12 to 18, and Comparative Examples 20 to 23 Using the produced coin cells, room temperature conditions (22 to 27 ° C.) at a constant current of 10 mA / g When the cell voltage is between 2.0 V and 3.3 V, discharge is performed first, then charging is performed, and then the discharge and charging are repeated, so that the discharge capacity (mAh / g) in the first cycle and the first cycle The charge capacity (mAh / g) and the discharge capacity (mAh / g) at the 10th cycle were measured, and the capacity retention ratio (ratio (%) of the discharge capacity at the 10th cycle to the discharge capacity at the 1st cycle) was determined.

<Composition analysis>
The composition of lithium and manganese in the prepared lithium-containing manganese composition, or the composition of lithium, manganese and M (one or more elements selected from elements other than lithium, manganese and oxygen) in the prepared lithium-containing manganese composition is dielectric. Analysis was performed with a coupled plasma emission analyzer (trade name: ICP-AES, manufactured by PerkinElmer Japan Co., Ltd.).

<Evaluation of crystallinity>
The crystal structure of the prepared lithium-containing manganese composition was identified with a powder X-ray diffraction measurement device (trade name: MXP3, manufactured by Mac Science).

The measurement conditions were as follows.

Target: Cu
Output: 1.2kW (30mA-40kV)
Step scan: 0.04 ° (2θ / θ)
Measurement time: 3 seconds <Change in crystallinity before and after the charge / discharge test>
The coin cell after the charge / discharge test was disassembled, the positive electrode was taken out, and the crystallinity of the manganese oxide was evaluated with a powder X-ray diffractometer (trade name: MXP3, manufactured by Mac Science).

The measurement conditions were as follows.

Target: Cu
Output: 1.2kW (30mA-40kV)
Step scan: 0.04 ° (2θ / θ)
Measurement time: 3 seconds Example 1
Manganese carbonate 0.5 hydrate (special grade reagent) 12.35 g and lithium hydroxide monohydrate (special grade reagent) 6.66 g (Li / Mn ratio = 11/7) using a mortar 30 After dry-mixing for a minute, the mixture was pulverized until it passed through a mesh having a mesh size of 150 μm.

2 g of the obtained mixed powder was put in a baking dish, subjected to heat treatment at 400 ° C. for 32 hours under an air aeration condition of 1 liter per minute in a tubular furnace, cooled to room temperature, and a sample was taken out. The temperature increase rate and the temperature decrease rate were 50 ° C./hr and 100 ° C./hr, respectively. When the temperature was lowered, the furnace was cooled at 150 ° C. or lower.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 11/7. From this value, it was found that the value of X was 0.36, and a lithium-containing manganese composition of Li _1.05 Mn _2/3 O _1.86 was obtained. The value of E was 0.10, and it was found to be a lithium-containing manganese composition of [Li ₂ MnO ₃ ] _0.90 · [Li ₄ Mn ₅ O ₁₂ ] _0.10 .

The results of the charge / discharge test are shown in Table 1. From the result, it was found that the capacity retention rate was higher than that of Li _4/3 Mn _2/3 O _{2 of} the comparative example.

The value of Y obtained from the charge capacity at the first cycle was 0.66, and it was found that a manganese oxide of Li _0.56 Mn _2/3 O _1.61 was obtained.

Regarding the change in crystallinity before and after the charge / discharge test, it was found from the comparison of the X-ray diffraction patterns before and after the charge / discharge test that the crystallinity of the lithium-containing manganese composition and the manganese oxide was not changed.

Example 2
A lithium-containing manganese composition was prepared in the same manner as in Example 1 except that the preparation temperature was 375 ° C.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 11/7. From this value, it was found that the value of X was 0.36, and a lithium-containing manganese composition of Li _1.05 Mn _2/3 O _1.86 was obtained. Moreover, the value of E was 0.10, and it was found to be a lithium-containing manganese composition of [Li ₂ MnO ₃ ] _0.90 · [Li ₄ Mn ₅ O ₁₂ ] _0.10 .

The value of Y obtained from the charge capacity at the first cycle was 0.60, and it was found that a manganese oxide of Li _0.45 Mn _2/3 O _1.56 was obtained.

Example 3
A lithium-containing manganese composition was prepared in the same manner as in Example 1 except that 7.42 g of lithium hydroxide monohydrate (special grade reagent) and the preparation temperature were 600 ° C. (Li / Mn ratio = 7/4). ).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 7/4. From this value, it was found that the value of X was 0.21, and a lithium-containing manganese composition of Li _1.17 Mn _2/3 O _1.92 was obtained. The value of E is _0.05, it was found that a lithium-containing manganese composition _{_{_{[Li 2 MnO 3] 0.95 ·}}} [Li 4 Mn 5 O 12] 0.05.

The value of Y obtained from the charge capacity at the first cycle was 0.61, and it was found that a manganese oxide of Li _0.39 Mn _2/3 O _1.53 was obtained.

Example 4
A lithium-containing manganese composition was prepared in the same manner as in Example 2 except that the preparation temperature was 550 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.50, and it was found that a manganese oxide of Li _0.55 Mn _2/3 O _1.61 was obtained.

Example 5
A lithium-containing manganese composition was prepared in the same manner as in Example 3 except that 5.65 g of lithium hydroxide monohydrate (special grade reagent) and the preparation temperature were 375 ° C. (Li / Mn ratio = 4/3). ).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 4/3. From this value, it was found that the value of X was 0.56, and a lithium-containing manganese composition of Li _0.89 Mn _2/3 O _1.78 was obtained. The value of E was 0.20, and it was found to be a lithium-containing manganese composition having [Li ₂ MnO ₃ ] _0.80 · [Li ₄ Mn ₅ O ₁₂ ] _0.20 .

The value of Y obtained from the charge capacity at the first cycle was 0.53, and it was found that a manganese oxide of Li _0.36 Mn _2/3 O _1.51 was obtained.

Example 6
A lithium-containing manganese composition was prepared in the same manner as in Example 5 except that the preparation temperature was 400 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.50, and it was found that a manganese oxide of Li _0.39 Mn _2/3 O _1.53 was obtained.

Example 7
A lithium-containing manganese composition was prepared in the same manner as in Example 5 except that the preparation temperature was 450 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.41, and it was found that a manganese oxide of Li _0.48 Mn _2/3 O _1.57 was obtained.

Example 8
A lithium-containing manganese composition was prepared in the same manner as in Example 5 except that the preparation temperature was 500 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.33, and it was found that a manganese oxide of Li _0.56 Mn _2/3 O _1.61 was obtained.

Example 9
10. Manganese dioxide (Mn content: 60.3 wt%) obtained by treating sulfuric acid with trimanganese tetroxide <chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) A lithium-containing manganese composition was prepared in the same manner as in Example 7 except that 4.66 g of monohydrate (special grade reagent) of 0 g and lithium hydroxide was used (Li / Mn ratio = 1/1).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 1/1. From this value, it was found that the value of X was 0.83, and a lithium-containing manganese composition of Li _0.67 Mn _2/3 O _1.67 was obtained. The value of E was 0.50, which was found to be a lithium-containing manganese composition having [Li ₂ MnO ₃ ] _0.50 · [Li ₄ Mn ₅ O ₁₂ ] _0.50 .

The results of the charge / discharge test are shown in Table 1. From the results, it was found that both the first cycle and the tenth cycle were larger than the discharge capacity of Li _4/3 Mn _2/3 O ₂ of the comparative example.

The value of Y obtained from the charge capacity at the first cycle was 0.59, and it was found that a manganese oxide of Li _0.08 Mn _2/3 O _1.38 was obtained.

Example 10
A lithium-containing manganese composition was prepared in the same manner as in Example 9 except that 5.10 g of lithium hydroxide monohydrate (special grade reagent) was used (Li / Mn ratio = 13/11).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition had a layered rock salt structure and a spinel structure, and the Li / Mn ratio was 13/11. From this value, it was found that the value of X was 0.68, and a lithium-containing manganese composition of Li _0.79 Mn _2/3 O _1.73 was obtained. The value of E was 0.30, and it was found to be a lithium-containing manganese composition having [Li ₂ MnO ₃ ] _0.70 · [Li ₄ Mn ₅ O ₁₂ ] _0.30 .

The value of Y obtained from the charge capacity at the first cycle was 0.56, and it was found that a manganese oxide of Li _0.23 Mn _2/3 O _1.45 was obtained.

Example 11
A lithium-containing manganese composition was prepared in the same manner as in Example 9 except that the firing temperature was 500 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.57, and it was found that a manganese oxide of Li _0.10 Mn _2/3 O _1.39 was obtained.

Comparative Example 1
A lithium-containing manganese composition was prepared in the same manner as in Example 1 except that 7.81 g of lithium hydroxide monohydrate (special grade reagent) was used (Li / Mn ratio = 2/1).

From the composition analysis of the prepared sample and the evaluation of crystallinity, the obtained lithium-containing manganese composition had only a layered rock salt structure, and the Li / Mn ratio was 2/1. From this value, it was found that a lithium-containing manganese composition of Li _4/3 Mn _2/3 O ₂ was obtained with both the value of X and the value of E being 0.

Table 1 shows the results of the charge / discharge test. From the result, it was found that the capacity retention rate was lower than that of the manganese oxide of the example.

The value of Y obtained from the charge capacity at the first cycle was 0.94, and it was found that a manganese oxide of Li _0.39 Mn _2/3 O _1.53 was obtained.

Regarding the change in crystallinity before and after the charge / discharge test, it was found from the comparison of X-ray diffraction patterns before and after the charge / discharge test that the crystallinity of the manganese oxide was lower than that of the lithium-containing manganese composition.

Comparative Example 2
A lithium-containing manganese composition was prepared in the same manner as in Example 3 except that 7.81 g of lithium hydroxide monohydrate (special grade reagent) was used (Li / Mn ratio = 2/1).

The value of Y obtained from the charge capacity at the first cycle was 0.97, and it was found that a manganese oxide of Li _0.36 Mn _2/3 O _1.52 was obtained.

Example 12
Manganese carbonate hemihydrate (special grade reagent) 5.87 g, magnesium hydroxide (special grade reagent) 0.16 g and lithium hydroxide monohydrate (special grade reagent) 3.33 g (Li / (Mn + Mg) ratio) = 11/7, Mg / (Mn + Mg) ratio = 0.05) using a mortar for 30 minutes, and then pulverized until all of the mesh passed through a 150 µm mesh.

2 g of the obtained mixed powder was put in a baking dish, subjected to heat treatment at 450 ° C. for 32 hours under a 1-liter air aeration condition in a tubular furnace, cooled to room temperature, and a sample was taken out. The temperature increase rate and the temperature decrease rate were 50 ° C./hr and 100 ° C./hr, respectively. When the temperature was lowered, the furnace was cooled at 150 ° C. or lower.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, and the Li / (Mn + Mg) ratio is 11/7. The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of X was 0.36, the value of Z was 1/30, and a lithium-containing manganese composition of Li _1.05 Mn _19/30 Mg _1/30 O _1.86 was obtained. It was.

Table 2 shows the results of the charge / discharge test. From the result, it was found that both the first cycle and the tenth cycle were larger than the discharge capacity of Li _4/3 Mn _2/3 O ₂ of Comparative Example 3.

The value of Y obtained from the charge capacity at the first cycle was 0.70, and it was found that a manganese oxide of Li _0.35 Mn _19/30 Mg _1/30 O _1.51 was obtained.

Example 13
A lithium-containing manganese composition was prepared in the same manner as in Example 12 except that the preparation temperature was 500 ° C.

The value of Y obtained from the charge capacity at the first cycle was 0.65, and it was found that a manganese oxide of Li _0.40 Mn _19/30 Mg _1/30 O _1.53 was obtained.

Example 14
Manganese carbonate hemihydrate (special grade reagent) 5.87 g, magnesium hydroxide (special grade reagent) 0.15 g and lithium hydroxide monohydrate (special grade reagent) 2.83 g (Li / (Mn + Mg) ratio) = 4/3, Mg / (Mn + Mg) ratio = 0.05), and a lithium-containing manganese composition was prepared in the same manner as in Example 12 except that the preparation temperature was 400 ° C.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, and the Li / (Mn + Mg) ratio is 4/3. The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of X was 0.56, the value of Z was 1/30, and a lithium-containing manganese composition of Li _0.89 Mn _19/30 Mg _1/30 O _1.78 was obtained. It was.

The value of Y obtained from the charge capacity at the first cycle was 0.58, and it was found that a manganese oxide of Li _0.31 Mn _19/30 Mg _1/30 O _1.49 was obtained.

Example 15
Example except that 2.85 g of manganese carbonate 0.5 hydrate (special grade reagent), 0.12 g of magnesium hydroxide (special grade reagent) and 1.73 g of lithium hydroxide monohydrate (special grade reagent) were used. In the same manner as in No. 12, a lithium-containing manganese composition was prepared.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, and the Li / (Mn + Mg) ratio is 18/11. The (Mn + Mg) ratio was 0.08. From this value, it was found that the value of X was 0.30, the value of Z was 4/75, and a lithium-containing manganese composition of Li _1.09 Mn _46/75 Mg _4/75 O _1.88 was obtained. It was.

The value of Y obtained from the charge capacity at the first cycle was 0.57, and it was found that a manganese oxide of Li _0.52 Mn _46/75 Mg _4/75 O _1.60 was obtained.

Example 16
Using manganese carbonate 0.5 hydrate (special grade reagent) 6.17 g, sodium carbonate (special grade reagent) 0.10 g and lithium hydroxide monohydrate (special grade reagent) 3.90 g, the preparation temperature was adjusted. A lithium-containing manganese composition was prepared in the same manner as in Example 12 except that the temperature was 600 ° C.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt structure and a spinel structure, and the Li / (Mn + Na) ratio is 47/25. The (Mn + Na) ratio was 0.04. From this value, it was found that the value of X was 0.10, the value of Z was 1/39, and a lithium-containing manganese composition of Li _1.25 Mn _25/39 Na _1/39 O _1.96 was obtained. It was.

The value of Y obtained from the charge capacity at the first cycle was 1.11. It was found that a manganese oxide of Li _0.14 Mn _25/39 Na _1/39 O _1.41 was obtained.

Example 17
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And magnesium hydroxide (special grade reagent) 0.34 g and lithium hydroxide monohydrate (special grade reagent) 4.91 g (Li / (Mn + Mg) ratio = 1/1, Mg / (Mn + Mg) ratio = 0.05) A lithium-containing manganese composition was prepared in the same manner as in Example 12 except that was used.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, the Li / (Mn + Mg) ratio is 1/1, and the Mg / The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of X was 0.83, the value of Z was 1/30, and a lithium-containing manganese composition of Li _0.67 Mn _19/30 Mg _1/30 O _1.67 was obtained. It was.

The value of Y obtained from the charge capacity at the first cycle was 0.46, and it was found that a manganese oxide of Li _0.21 Mn _19/30 Mg _1/30 O _1.44 was obtained.

Example 18
Manganese carbonate hemihydrate (special grade reagent) 5.87 g, magnesium hydroxide (special grade reagent) 0.29 g, sodium carbonate (special grade reagent) 0.45 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 12 except that 11.73 g was used and the preparation temperature was 600 ° C. (Li / (Mn + Mg + Na) ratio = 19/10, Mg / (Mn + Mg + Na) ratio) = 0.05, Na / (Mn + Mg + Na) = 0.02).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, and the Li / (Mn + Mg + Na) ratio is 19/10. The (Mn + Mg + Na) ratio was 0.05, and the Na / (Mn + Mg + Na) ratio was 0.02. From this value, the value of X is 0.08, the value of Z is 1/12, and a lithium-containing manganese composition of Li _1.27 Mn _179/300 Mg _1/20 Na _1/50 O _1.97 is obtained. I found out.

The value of Y obtained from the charge capacity at the first cycle was 0.82, and it was found that a manganese oxide of Li _0.45 Mn _179/300 Mg _1/20 Na _1/50 O _1.56 was obtained. .

Comparative Example 3
A lithium-containing manganese composition was prepared in the same manner as in Example 12 except that the monohydrate of lithium hydroxide (special grade reagent) was 7.81 g and magnesium hydroxide (special grade reagent) was not used (Li / Mn ratio = 2/1).

From the composition analysis of the prepared sample and the evaluation of crystallinity, the obtained lithium-containing manganese composition had only a layered rock salt structure, and the Li / Mn ratio was 2/1. From this value, it was found that the value of X was 0, and a lithium-containing manganese composition of Li _4/3 Mn _2/3 O ₂ was obtained.

Table 2 shows the results of the charge / discharge test. From the results, it was found that both the first cycle and the tenth cycle were smaller than the discharge capacities of the manganese oxides of Examples 12 to 18.

Regarding the change in crystallinity before and after the charge / discharge test, the crystallinity of the manganese oxide is reduced as compared with the lithium-containing manganese composition of Example 12 from the comparison of the X-ray diffraction patterns before and after the charge / discharge test. I understood.

Example 19
Manganese carbonate 0.5 hydrate (special grade reagent) 12.35 g and lithium hydroxide monohydrate (special grade reagent) 6.66 g (Li / Mn ratio = 11/7) using a mortar 30 After dry-mixing for a minute, the mixture was pulverized until it passed through a mesh having a mesh size of 150 μm.

The obtained lithium-containing manganese composition and the positive electrode material (NCA: LiNi _0.8 Co _0.15 Al _0.05 O ₂ , manufactured by Toshima Seisakusho Co., Ltd.) were mixed at a weight ratio of 1: 1 using an agate mortar. And a manganese oxide mixture (mixed cathode active material) was prepared.

Table 3 shows the results of the charge / discharge test. From the result, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NCA of Comparative Example 4 and the same performance as that of NCA alone was exhibited.

Example 20
A manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 19 except that NMC (111) (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , manufactured by Toyoshima Seisakusho Co., Ltd.) was used as the positive electrode material. Material) was prepared.

Table 3 shows the results of the charge / discharge test. From the result, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NMC (111) of Comparative Example 5, and the same performance as that of only NMC (111) was exhibited.

Example 21
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name; CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment A lithium-containing manganese composition was prepared in the same manner as in Example 19 except that 4.66 g of monohydrate of lithium hydroxide (special grade reagent) was used.

Example 22
A manganese oxide mixture (mixed positive electrode active) was obtained in the same manner as in Example 21 except that NMC (111) (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , manufactured by Toyoshima Seisakusho Co., Ltd.) was used as the positive electrode material. Material) was prepared.

Comparative Example 4
A lithium-containing manganese composition was prepared in the same manner as in Example 19 except that 2.12 g of lithium hydroxide monohydrate (special grade reagent) and the heat treatment temperature were 800 ° C. (Li / Mn ratio = 1 / 2).

From the composition analysis and crystallinity evaluation of the prepared sample, it was found that the obtained lithium-containing manganese composition had a spinel structure and was LiMn ₂ O ₄ .

A manganese oxide mixture (mixed cathode active material) was prepared in the same manner as in Example 19 except that the obtained LiMn ₂ O ₄ was used as the lithium-containing manganese composition.

Table 3 shows the results of the charge / discharge test. From the result, it was found that the capacity was smaller than the manganese oxide mixture (mixed cathode active material) of Example 19 and Example 21.

Comparative Example 5
A manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 20 except that LiMn ₂ O ₄ obtained in Comparative Example 4 was used as the lithium-containing manganese composition.

Table 3 shows the results of the charge / discharge test. From the result, it was found that the capacity was smaller than the manganese oxide mixture (mixed positive electrode active material) of Example 20 and Example 22.

Example 23
Manganese carbonate hemihydrate (special grade reagent) 5.87 g, magnesium hydroxide (special grade reagent) 0.16 g and lithium hydroxide monohydrate (special grade reagent) 3.33 g (Li / (Mn + Mg) ratio) = 11/7, Mg / (Mn + Mg) ratio = 0.05) using a mortar for 30 minutes, and then pulverized until all of the mesh passed through a 150 µm mesh.

Table 4 shows the results of the charge / discharge test. From the result, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NCA of Comparative Example 6, and the same performance as that of NCA alone was exhibited.

Example 24
A manganese oxide mixture (mixed positive electrode active material) was obtained in the same manner as in Example 23 except that NMC (111) (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , manufactured by Toyoshima Seisakusho Co., Ltd.) was used as the positive electrode material. Material) was prepared.

Table 4 shows the results of the charge / discharge test. From the result, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NMC (111) of Comparative Example 7, and the same performance as that of only NMC (111) was exhibited.

Example 25
Example except that 2.85 g of manganese carbonate 0.5 hydrate (special grade reagent), 0.12 g of magnesium hydroxide (special grade reagent) and 1.73 g of lithium hydroxide monohydrate (special grade reagent) were used. In the same manner as in No. 23, a lithium-containing manganese composition was prepared.

Using the obtained lithium-containing manganese composition, a manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 23, and the charge / discharge test was performed. As a result, LiMn ₂ O ₄ of Comparative Example 6 and It was found that the capacity was larger than that of the NCA mixed positive electrode, and the same performance as that of the NCA alone was exhibited.

Example 26
Using manganese carbonate 0.5 hydrate (special grade reagent) 6.17 g, sodium carbonate (special grade reagent) 0.10 g and lithium hydroxide monohydrate (special grade reagent) 3.90 g, the preparation temperature was adjusted. A lithium-containing manganese composition was prepared in the same manner as in Example 23 except that the temperature was 600 ° C.

Example 27
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And magnesium hydroxide (special grade reagent) 0.34 g and lithium hydroxide monohydrate (special grade reagent) 4.91 g (Li / (Mn + Mg) ratio = 1/1, Mg / (Mn + Mg) ratio = 0.05) A lithium-containing manganese composition was prepared in the same manner as in Example 23 except that was used.

Example 28
Manganese carbonate hemihydrate (special grade reagent) 5.87 g, magnesium hydroxide (special grade reagent) 0.29 g, sodium carbonate (special grade reagent) 0.45 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 23 except that 11.73 g was used and the preparation temperature was 600 ° C. (Li / (Mn + Mg + Na) ratio = 19/10, Mg / (Mn + Mg + Na) ratio) = 0.05, Na / (Mn + Mg + Na) = 0.02).

Using the obtained lithium-containing manganese composition, a manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 24, and a charge / discharge test was performed. As a result, LiMn ₂ O ₄ of Comparative Example 7 and It was found that the capacity was larger than that of the mixed positive electrode of NMC (111), and the same performance as that of NMC (111) alone was exhibited.

Comparative Example 6
A lithium-containing manganese composition was prepared in the same manner as in Example 23 except that 2.12 g of lithium hydroxide monohydrate (special grade reagent) and the heat treatment temperature were set to 800 ° C. (Li / Mn ratio = 1 / 2).

A manganese oxide mixture (mixed cathode active material) was prepared in the same manner as in Example 23 except that the obtained LiMn ₂ O ₄ was used as the lithium-containing manganese composition.

Table 4 shows the results of the charge / discharge test. From the results, it was found that the capacity was smaller than the manganese oxide mixtures (mixed positive electrode active materials) of Example 23 and Examples 25 to 27.

Comparative Example 7
A manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 24 except that LiMn ₂ O ₄ obtained in Comparative Example 6 was used as the lithium-containing manganese composition.

Table 4 shows the results of the charge / discharge test. From the result, it was found that the capacity was smaller than the manganese oxide mixture (mixed positive electrode active material) of Example 24 and Example 28.

Example 29
30 mg of manganese carbonate hemihydrate (special grade reagent) 6.05 g and lithium hydroxide monohydrate (special grade reagent) 1.06 g (Li / Mn ratio = 1/2) using a mortar After dry-mixing for a minute, it was pulverized until it passed through a mesh with a mesh size of 150 μm.

2 g of the obtained mixed powder was put in a baking dish, subjected to heat treatment at 400 ° C. for 32 hours under an air aeration condition of 1 liter per minute in a tubular furnace, cooled to room temperature, and a sample was taken out. The temperature increase rate and the temperature decrease rate were 50 ° C./hr and 100 ° C./hr, respectively. When the temperature was lowered, the furnace was cooled below 150 ° C.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 1/2, and Li _8/9 Mn _16/9 O _4. (Li ₂ Mn ₄ O ₉ ).

Table 5 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity was high and the capacity retention rate was also high.

The value of X calculated from the charge capacity at the first cycle was 0.70, and the composition of the manganese oxide was Li _0.19 Mn _16/9 O _3.65 .

Example 30
A lithium-containing manganese composition was prepared in the same manner as in Example 29 except that the preparation temperature was 600 ° C. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 1/2, and Li _8/9 Mn _16/9 O _4. (Li ₂ Mn ₄ O ₉ ).

The value of X calculated from the charge capacity at the first cycle was 0.81, and the composition of the manganese oxide was Li _0.08 Mn _16/9 O _3.60 .

Example 31
A lithium-containing manganese composition was prepared in the same manner as in Example 29 except that the preparation temperature was 800 ° C. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 1/2, and Li _8/9 Mn _16/9 O _4. (Li ₂ Mn ₄ O ₉ ).

The value of X calculated from the charge capacity at the first cycle was 0.88, and the composition of the manganese oxide was Li _0.01 Mn _16/9 O _3.56 .

Comparative Example 8
A coin cell was prepared using the sample prepared in Example 29, and charging and discharging were repeated at a constant current of 10 mA / g at room temperature (22 to 27 ° C.) and a battery voltage between 2.0 V and 3.3 V. A charge / discharge test was conducted.

Table 5 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 29 (the manganese oxide obtained in Example 29 had a larger discharge capacity).

Comparative Example 9
A coin cell was manufactured using the sample prepared in Example 30, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 30 (the manganese oxide obtained in Example 30 had a larger discharge capacity).

Comparative Example 10
A coin cell was prepared using the sample prepared in Example 31, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 31 (the manganese oxide obtained in Example 31 had a larger discharge capacity).

Comparative Example 11
20.00 g of electrolytic manganese dioxide (manufactured by Tosoh Hinata Co., Ltd.) and 4.58 g of lithium carbonate (special grade reagent) were dry-mixed for 30 minutes using a mortar, and then pulverized until all of the mesh passed through a 150 μm mesh .

A lithium-containing manganese composition was prepared under the same conditions as in Example 31 except that 2 g of the obtained mixed powder was put in a baking dish and an open air box furnace was used.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 2.81 / 5, and Li _1.08 Mn _1.92. It was O ₄ (Li _25/81 Mn _144/25 O ₁₂ ). The valence of Mn was +3.6.

Table 5 shows the results of the charge / discharge test. From the results, compared with Example 31 prepared under the same conditions, the discharge capacity is small and the capacity retention rate is also small (the manganese oxide obtained in Example 31 has both a large discharge capacity and capacity retention rate). I understood that.

Example 32
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And lithium hydroxide monohydrate (special grade reagent) 2.33 g (Li / Mn ratio = 1/2) was used to prepare a lithium-containing manganese composition in the same manner as in Example 29.

Example 33
Example except that 3.04 g of manganese carbonate hemihydrate (special grade reagent), 0.03 g of magnesium hydroxide (special grade reagent) and 0.53 g of monohydrate of lithium hydroxide (special grade reagent) were used. In the same manner as in Example 29, a lithium-containing manganese composition was prepared.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / (Mn + Mg) ratio is ½, and the Mg / (Mn + Mg) ratio is 0.02. From this value, it was found that the value of Z was 8/225, and a lithium-containing manganese composition of Li _8/9 Mn _392/225 Mg _8/225 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.81, and the composition of the manganese oxide was Li _0.08 Mn _392/225 Mg _8/225 O _3.60 .

Example 34
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment A lithium-containing manganese composition was prepared in the same manner as in Example 29 except that 0.34 g of magnesium hydroxide (special grade reagent) and 2.45 g of monohydrate of lithium hydroxide (special grade reagent) were used.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, the Li / (Mn + Mg) ratio is 1/2, and the Mg / The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of Z was 4/45, and a lithium-containing manganese composition of Li _8/9 Mn _76/45 Mg _4/45 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.80, and the composition of the manganese oxide was Li _0.09 Mn _76/45 Mg _4/45 O _3.60 .

Example 35
Manganese carbonate hemihydrate (special grade reagent) 5.76 g, magnesium hydroxide (special grade reagent) 0.15 g, sodium carbonate (special grade reagent) 0.11 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 29 using 1.06 g (Li / (Mn + Mg + Na) ratio = 1/2, Mg / (Mn + Mg + Na) ratio = 0.05, Na / (Mn + Mg + Na). ) = 0.02).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / (Mn + Mg + Na) ratio is 1/2, and the Mg / (Mn + Mg + Na) ratio is 0.05 and the Na / (Mn + Mg + Na) ratio was 0.02. From this value, it was found that the value of Z was 28/225, and a lithium-containing manganese composition of Li _8/9 Mn _372/225 Mg _4/45 Na _8/225 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.79, and the composition of the manganese oxide was Li _0.10 Mn _372/225 Mg _4/45 Na _8/225 O _3.61 .

Comparative Example 12
A coin cell was prepared using the sample prepared in Example 32, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 32 (the manganese oxide obtained in Example 32 had a larger discharge capacity).

Comparative Example 13
A coin cell was prepared using the sample prepared in Example 33, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 33 (the manganese oxide obtained in Example 33 had a larger discharge capacity).

Comparative Example 14
A coin cell was prepared using the sample prepared in Example 34, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 34 (the manganese oxide obtained in Example 34 had a larger discharge capacity).

Comparative Example 15
A coin cell was prepared using the sample prepared in Example 35, and a charge / discharge test was performed in the same manner as in Comparative Example 8.

Table 5 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 35 (the manganese oxide obtained in Example 35 had a higher discharge capacity).

Example 36
Manganese carbonate 0.5 hydrate (special grade reagent) 6.05 g and lithium hydroxide monohydrate (special grade reagent) 1.70 g (Li / Mn ratio = 4/5) using a mortar 30 After dry-mixing for a minute, the mixture was pulverized until it passed through a mesh having a mesh size of 150 μm.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

Table 6 shows the results of the charge / discharge test. From the results, it was found that the capacity retention rate was higher than that of the manganese oxides of Comparative Examples 16 to 18.

The value of X calculated from the charge capacity at the first cycle was 0.77, and the composition of the manganese oxide was Li _0.56 Mn _5/3 O _3.62 .

Example 37
A lithium-containing manganese composition was prepared in the same manner as in Example 36 except that the preparation temperature was 600 ° C.

Table 6 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity and capacity retention ratio were higher, and the discharge capacity and capacity retention ratio were higher than those of the manganese oxides of Comparative Examples 16 to 18.

The value of X calculated from the charge capacity at the first cycle was 0.52, and the composition of the manganese oxide was Li _0.81 Mn _5/3 O _3.74 .

Example 38
A lithium-containing manganese composition was prepared in the same manner as in Example 36 except that the preparation temperature was 800 ° C. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

The value of X calculated from the charge capacity at the first cycle was 0.53, and the composition of the manganese oxide was Li _0.80 Mn _5/3 O _3.74 .

Example 39
A lithium-containing manganese composition was prepared in the same manner as in Example 36 except that the preparation temperature was 425 ° C. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

The value of X calculated from the charge capacity at the first cycle was 0.60, and the composition of the manganese oxide was Li _0.73 Mn _5/3 O _3.70 .

Example 40
A lithium-containing manganese composition was prepared in the same manner as in Example 36 except that the preparation temperature was 375 ° C. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

The value of X calculated from the charge capacity at the first cycle was 0.68, and the composition of the manganese oxide was Li _0.65 Mn _5/3 O _3.66 .

Comparative Example 16
A coin cell was prepared using the sample prepared in Example 36, and charging and discharging were repeated at a constant current of 10 mA / g at room temperature (22 to 27 ° C.) and a battery voltage of 2.0 V and 3.3 V. A charge / discharge test was conducted.

Table 6 shows the results of the charge / discharge test. As a result, both the discharge capacity and capacity retention rate were smaller than the manganese oxides of Examples 36 to 40 (the manganese oxides obtained in Examples 36 to 40 were both discharge capacity and capacity retention rates). It was great)

Comparative Example 17
A coin cell was prepared using the sample prepared in Example 37, and a charge / discharge test was performed in the same manner as in Comparative Example 16.

Comparative Example 18
A coin cell was produced using the sample prepared in Example 38, and a charge / discharge test was conducted in the same manner as in Comparative Example 16.

Comparative Example 19
20.00 g of electrolytic manganese dioxide (manufactured by Tosoh Hinata Co., Ltd.) and 4.58 g of lithium carbonate (special grade reagent) were dry-mixed for 30 minutes using a mortar, and then pulverized until all of the mesh passed through a 150 μm mesh .

2 g of the obtained mixed powder was put into a baking dish, and a lithium-containing manganese composition was prepared under the same conditions as in Example 38 except that an atmospheric open box furnace was used.

Table 6 shows the results of the charge / discharge test. From the results, compared with Example 38 prepared under the same conditions, although the charge / discharge capacity in the first cycle was large, the capacity retention rate was smaller (the manganese oxide obtained in Example 38 was the capacity retention rate). Is great).

Example 41
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And lithium hydroxide monohydrate (special grade reagent) 3.72 g (Li / Mn ratio = 4/5) was used to prepare a lithium-containing manganese composition in the same manner as in Example 36. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

Table 6 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity was high and the capacity retention rate was also high.

The value of X calculated from the charge capacity at the first cycle was 0.73, and the composition of the manganese oxide was Li _0.60 Mn _5/3 O _3.64 .

Example 42
Example except that 3.04 g of manganese carbonate 0.5 hydrate (special grade reagent), 0.03 g of magnesium hydroxide (special grade reagent) and 0.84 g of monohydrate of lithium hydroxide (special grade reagent) were used. In the same manner as in Example 36, a lithium-containing manganese composition was prepared.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / (Mn + Mg) ratio is 4/5, and the Mg / (Mn + Mg) ratio is 0.02. From this value, it was found that the value of Z was 1/30, and a lithium-containing manganese composition of Li _4/5 Mn _49/30 Mg _1/30 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.56, and the composition of the manganese oxide was Li _0.77 Mn _49/30 Mg _1/30 O _3.72 .

Example 43
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment A lithium-containing manganese composition was prepared in the same manner as in Example 36 except that 0.34 g of magnesium hydroxide (special grade reagent) and 3.92 g of monohydrate of lithium hydroxide (special grade reagent) were used.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt structure and a spinel structure, and the Li / (Mn + Mg) ratio is 4/5. The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of Z was 1/12, and a lithium-containing manganese composition of Li _4/5 Mn _95/60 Mg _1/12 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.52, and the composition of the manganese oxide was Li _0.81 Mn _95/60 Mg _1/12 O _3.74 .

Example 44
Manganese carbonate hemihydrate (special grade reagent) 5.76 g, magnesium hydroxide (special grade reagent) 0.15 g, sodium carbonate (special grade reagent) 0.11 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 36 using 1.70 g (Li / (Mn + Mg + Na) ratio = 4/5, Mg / (Mn + Mg + Na) ratio = 0.05, Na / (Mn + Mg + Na) ) = 0.02).

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / (Mn + Mg + Na) ratio is 4/5, and the Mg / (Mn + Mg + Na) ratio is 0.05 and the Na / (Mn + Mg + Na) ratio was 0.02. From this value, it was found that the value of Z was 7/60, and a lithium-containing manganese composition of Li _4/5 Mn _31/21 Mg _1/12 Na _1/30 O ₄ was obtained.

The value of X calculated from the charge capacity at the first cycle was 0.48, and the composition of the manganese oxide was Li _0.85 Mn _31/21 Mg _1/12 Na _1/30 O _3.76 .

Comparative Example 20
A coin cell was prepared using the sample prepared in Example 41, and a charge / discharge test was performed in the same manner as in Comparative Example 16.

Table 6 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than the manganese oxide of Example 41 (the manganese oxide obtained in Example 41 had a larger discharge capacity).

Comparative Example 21
A coin cell was prepared using the sample prepared in Example 42, and a charge / discharge test was performed in the same manner as in Comparative Example 16.

Table 6 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 42 (the manganese oxide obtained in Example 42 had a larger discharge capacity).

Comparative Example 22
A coin cell was prepared using the sample prepared in Example 43, and a charge / discharge test was performed in the same manner as in Comparative Example 16.

Table 6 shows the results of the charge / discharge test. From the result, it was found that the discharge capacity was smaller than that of the manganese oxide of Example 43 (the manganese oxide obtained in Example 43 had a larger discharge capacity).

Comparative Example 23
A coin cell was prepared using the sample prepared in Example 44, and a charge / discharge test was performed in the same manner as in Comparative Example 16.

Table 6 shows the results of the charge / discharge test. From the results, it was found that the discharge capacity was smaller than the manganese oxide of Example 44 (the manganese oxide obtained in Example 44 had a larger discharge capacity).

Example 45
30 mg of manganese carbonate hemihydrate (special grade reagent) 6.05 g and lithium hydroxide monohydrate (special grade reagent) 1.06 g (Li / Mn ratio = 1/2) using a mortar After dry-mixing for a minute, it was pulverized until it passed through a mesh with a mesh size of 150 μm.

The obtained lithium-containing manganese composition and the positive electrode material NMC (111) (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , manufactured by Toshima Seisakusho Co., Ltd.) were used in an agate mortar at a weight ratio of 1: 1. Then, a manganese oxide mixture (mixed cathode active material) was prepared.

Table 7 shows the results of the charge / discharge test. From the results, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NMC (111) of Comparative Example 24, and the same performance as that of NMC (111) alone was exhibited.

Example 46
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And lithium hydroxide monohydrate (special grade reagent) 2.33 g (Li / Mn ratio = 1/2) was used to prepare a lithium-containing manganese composition in the same manner as in Example 45. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 1/2, and Li _8/9 Mn _16/9 O _4. (Li ₂ Mn ₄ O ₉ ).

As a result of preparing a manganese oxide mixture (mixed cathode active material) in the same manner as in Example 45 using the obtained lithium-containing manganese composition and conducting a charge / discharge test, LiMn ₂ O ₄ and NMC (Comparative Example 24) It was found that the capacity was larger than that of the 111) mixed positive electrode, and the same performance as that of the NMC (111) alone was exhibited.

Example 47
Example except that 3.04 g of manganese carbonate hemihydrate (special grade reagent), 0.03 g of magnesium hydroxide (special grade reagent) and 0.53 g of monohydrate of lithium hydroxide (special grade reagent) were used. In the same manner as in No. 45, a lithium-containing manganese composition was prepared.

Example 48
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment A lithium-containing manganese composition was prepared in the same manner as in Example 45 except that 0.34 g of magnesium hydroxide (special grade reagent) and 2.45 g of monohydrate of lithium hydroxide (special grade reagent) were used.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a layered rock salt type structure and a spinel type structure, the Li / (Mn + Mg) ratio is 1/2, and the Mg / The (Mn + Mg) ratio was 0.05. From this value, it was found that the value of Z was 4/45, and a lithium-containing manganese composition of Li _8/9 Mn _380/225 Mg _4/45 O ₄ was obtained.

Example 49
Manganese carbonate hemihydrate (special grade reagent) 5.76 g, magnesium hydroxide (special grade reagent) 0.15 g, sodium carbonate (special grade reagent) 0.11 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 45 except that 1.06 g was used (Li / (Mn + Mg + Na) ratio = 1/2, Mg / (Mn + Mg + Na) ratio = 0.05, Na / (Mn + Mg + Na). ) = 0.02).

Example 50
Manganese carbonate 0.5 hydrate (special grade reagent) 6.05 g and lithium hydroxide monohydrate (special grade reagent) 1.70 g (Li / Mn ratio = 4/5) using a mortar 30 After dry-mixing for a minute, the mixture was pulverized until it passed through a mesh having a mesh size of 150 μm.

From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).
The obtained lithium-containing manganese composition and the positive electrode material NCA (LiNi _0.8 Co _0.15 Al _0.05 O ₂ , manufactured by Toshima Seisakusho Co., Ltd.) were mixed at a weight ratio of 1: 1 using an agate mortar. And a manganese oxide mixture (mixed cathode active material) was prepared.

Table 7 shows the results of the charge / discharge test. From the result, it was found that the capacity was larger than that of the mixed positive electrode of LiMn ₂ O ₄ and NCA of Comparative Example 25, and the same performance as that of the case of only NCA was exhibited.

Example 51
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment And lithium hydroxide monohydrate (special grade reagent) 3.72 g (Li / Mn ratio = 4/5) was used, and a lithium-containing manganese composition was prepared in the same manner as in Example 50. From the composition analysis and crystallinity evaluation of the prepared sample, the obtained lithium-containing manganese composition has a spinel structure, the Li / Mn ratio is 4/5, and Li _4/3 Mn _5/3 O _4. (Li ₄ Mn ₅ O ₁₂ ).

As a result of preparing a manganese oxide mixture (mixed positive electrode active material) in the same manner as in Example 50 using the obtained lithium-containing manganese composition and conducting a charge / discharge test, the results of LiMn ₂ O ₄ and NCA of Comparative Example 25 were obtained. It was found that the capacity was larger than that of the mixed positive electrode and the same performance as that of the NCA alone was exhibited.

Example 52
Example except that 3.04 g of manganese carbonate 0.5 hydrate (special grade reagent), 0.03 g of magnesium hydroxide (special grade reagent) and 0.84 g of monohydrate of lithium hydroxide (special grade reagent) were used. In the same manner as in No. 50, a lithium-containing manganese composition was prepared.

Example 53
Manganese tetraoxide <Chemical formula: Mn ₃ O ₄ > (trade name: CMO (registered trademark), manufactured by Tosoh Corporation) and 10.0 g of manganese dioxide (Mn content: 60.3 wt%) obtained by sulfuric acid treatment A lithium-containing manganese composition was prepared in the same manner as in Example 50 except that 0.34 g of magnesium hydroxide (special grade reagent) and 3.92 g of monohydrate of lithium hydroxide (special grade reagent) were used.

Example 54
Manganese carbonate hemihydrate (special grade reagent) 5.76 g, magnesium hydroxide (special grade reagent) 0.15 g, sodium carbonate (special grade reagent) 0.11 g and lithium hydroxide monohydrate (special grade reagent) A lithium-containing manganese composition was prepared in the same manner as in Example 50 using 1.70 g (Li / (Mn + Mg + Na) ratio = 4/5, Mg / (Mn + Mg + Na) ratio = 0.05, Na / (Mn + Mg + Na) ) = 0.02).

Comparative Example 24
A lithium-containing manganese composition was prepared in the same manner as in Example 45 except that 2.12 g of lithium hydroxide monohydrate (special grade reagent) and the heat treatment temperature were 800 ° C. (Li / Mn ratio = 1 / 2).

A manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 45 except that the obtained LiMn ₂ O ₄ was used as the lithium-containing manganese composition.

Table 7 shows the results of the charge / discharge test. From the results, it was found that the capacity was smaller than the manganese oxide mixtures (mixed positive electrode active materials) of Examples 45 to 49.

Comparative Example 25
A manganese oxide mixture (mixed positive electrode active material) was prepared in the same manner as in Example 50 except that LiMn ₂ O ₄ obtained in Comparative Example 24 was used as the lithium-containing manganese composition.

Table 7 shows the results of the charge / discharge test. From the results, it was found that the capacity was smaller than the manganese oxide mixtures (mixed positive electrode active materials) of Examples 50 to 54.

Note that Japanese Patent Application No. 2015-56647, Japanese Patent Application No. 2015-56648 and Japanese Patent Application No. 2015-56649 filed on March 19, 2015, Japanese Patent Application No. 2015 filed on March 30, 2015, are filed. -69564 and the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2016-41519 and Japanese Patent Application No. 2016-41520 filed on March 3, 2016 are cited herein. And as the disclosure of the specification of the present invention. Incorporated.

The manganese oxide, manganese oxide mixture, and mixed positive electrode active material of the present invention can be used for a positive electrode of a lithium secondary battery.

Claims

General formula Li (4/3)-(4X / 5) -Y Mn 2/3 O 2- (2X / 5)-(Y / 2) (where 0 <X <1, 0 <Y <(4 / 3)-(4X / 5))).
[Li 2-A MnO 3-B ] 1-E · [Li 4-C Mn 5 O 12-D ] E (where 0 <E <1, 0 ≦ A ≦ 2, 0 ≦ B ≦ A / 2, 0 ≦ C ≦ 4 and 0 ≦ D ≦ C / 2, except A = C = 0.)
General formula Li (4/3)-(4X / 5) -Y Mn (2/3) -Z M Z O 2- (2X / 5)-(Y / 2) (where 0 <X <1, 0 <Y <(4/3) − (4X / 5), 0 <Z ≦ 1/3 is satisfied, and M is one or more elements selected from elements other than Li, Mn, and O. Manganese oxide characterized by that.
The manganese oxide according to any one of claims 1 to 3, wherein the manganese oxide has a layered rock salt structure and a spinel structure.
The lithium-containing manganese composition represented by the general formula Li (4/3)-(4X / 5) Mn 2/3 O 2- (2X / 5) (where 0 <X <1 is satisfied) The method for producing manganese oxide according to claim 1 or 4, wherein the manganese oxide is chemically oxidized.
The lithium-containing manganese composition represented by the general formula [Li 2 MnO 3 ] 1-E · [Li 4 Mn 5 O 12 ] E (where 0 <E <1 is satisfied) is electrochemically oxidized. The manufacturing method of the manganese oxide of Claim 2 or Claim 4 characterized by the above-mentioned.
General formula Li (4/3)-(4X / 5) Mn (2/3) -Z M Z O 2- (2X / 5) (where 0 <X <1, 0 <Z ≦ 1/3 And M is one or more elements selected from elements other than Li, Mn, and O. The lithium-containing manganese composition represented by the following formula is electrochemically oxidized: 4. The method for producing manganese oxide according to 4.
The method for producing a manganese oxide according to any one of claims 5 to 7, wherein the lithium-containing manganese composition has a layered rock salt structure and a spinel structure.
The method for producing manganese oxide according to any one of claims 5 to 8, wherein the electrochemical oxidation is charged in the battery.
Lithium-containing manganese composition represented by the general formula Li (4/3)-(4X / 5) Mn 2/3 O 2- (2X / 5) (where 0 <X <1 is satisfied) and positive electrode A manganese oxide mixture comprising a material.
A lithium-containing manganese composition represented by the general formula [Li 2 MnO 3 ] 1-E · [Li 4 Mn 5 O 12 ] E (where 0 <E <1 is satisfied) and a positive electrode material. Manganese oxide mixture characterized by
General formula Li (4/3)-(4X / 5) Mn 2 / 3-Z M Z O 2- (2X / 5) (where 0 <X <1, 0 <Z ≦ 1/3 is satisfied, M is one or more elements selected from elements other than Li, Mn, and O.) A manganese oxide mixture comprising a lithium-containing manganese composition represented by the following formula: and a positive electrode material.
13. The manganese oxide mixture according to claim 10, wherein the lithium-containing manganese composition has a layered rock salt structure and a spinel structure.
A mixed positive electrode active material comprising the manganese oxide mixture according to any one of claims 10 to 13.
A lithium secondary battery comprising a positive electrode containing the manganese oxide according to any one of claims 1 to 4 or the mixed positive electrode active material according to claim 14.