KR100668051B1 - Manganese Oxide Using Coprecipitation Method, Lithium Secondary Battery Spinel Type Cathode Active Material Using the Same and Manufacturing Method Thereof - Google Patents

Abstract

In the present invention, a spherical manganese oxide (Mn ₃ O ₄ ) having a high tap density is synthesized using the hydroxide coprecipitation method, and a spinel cathode active material having a high tap density and a low specific surface area is formed using Li _{1 + α} [Mn _{2 -α} ]. O ₄ (0≤α≤0.15) or _{Li 1 + α [Mn 2 -α} ] O 4 - provides a method for the synthesis of _{z F z (0≤α≤0.15, 0.01≤z≤0.15)} . According to the present invention, it is possible to obtain a spherical spinel type cathode active material having high structural stability at high temperature and having a high volumetric energy density according to an improvement in tap density.

Coprecipitation Method, Spinel Type Cathode Active Material

Description

Manganese Oxide by Coprecipitation Method, Spinel Type Cathode Active Material for Lithium Secondary Battery Active Material Using the Same and Preparation Method of the Same}

1 is a SEM photograph of a manganese oxide precursor synthesized by the method of Example 1 of the present invention,

2 is a SEM photograph of the positive electrode active material powder synthesized by the method of Example 1,

3 is an X-ray diffraction pattern of LiMn ₂ O ₄ synthesized in Examples 1, 3, and 4 and Comparative Example 1;

4 is an X-ray diffraction pattern of the trimanganese tetraoxide precursor commercialized with the manganese oxide precursor of Example 1,

5 is a SEM photograph of a manganese oxide precursor synthesized by the method of Example 2,

6 is a SEM photograph of a manganese oxide precursor synthesized by the method of Example 3,

7 is a SEM photograph of a manganese oxide precursor synthesized by the method of Example 4,

8 is a graph showing the life characteristics according to the charge and discharge cycles of LiMn ₂ O ₄ synthesized in Examples 1, 3, 4 and Comparative Example 1,

SEM photo of Fig. 9 Example 6 how a _{Li 1 .05 Mn 1 .95 O 3} .95 F 0.05 synthesized as,

SEM photograph of Fig. 10 Example 7 Method A _{Li 1 .05 Mn 1 .95 O 3} .95 F 0.05 synthesized as,

SEM photograph of Fig. 11 Example 8 Method A _{Li 1 .05 Mn 1 .95 O 3} .95 F 0.05 synthesized as,

12 is a graph showing life characteristics according to charge and discharge cycles of Li _1.05 Mn _1.95 O _3.95 F _0.05 synthesized at 750 ° C., 900 ° C. and 950 ° C. in Examples 5 to 7, respectively.

13 is a SEM photograph of the precursor synthesized by the method of Comparative Example 1,

14 is a SEM photograph of the LiMn ₂ O ₄ powder calcined by the method of Comparative Example 1,

15 is a SEM photograph of the precursor synthesized by the method of Comparative Example 2,

16 is a SEM photograph of the precursor synthesized by the method of Comparative Example 3,

17 is a SEM photograph of the precursor synthesized by the method of Comparative Example 4.

The present invention relates to a manganese oxide that can be used in the positive electrode active material for lithium secondary batteries.

Lithium secondary batteries have a high energy density and have a higher energy density of 1.5 to 2 times higher than Ni / Cd batteries, and are widely used in power supplies such as mobile phones and notebook computers. In addition, although it has a lower irreversible capacity (mh / g) than the existing LiCoO ₂ , due to the low price, low toxicity and high thermal stability, the 4V spinel type LiMn ₂ O ₄ is the next generation hybrid electric vehicle (HEV). Development as a positive electrode active material for is in progress.

In the case of the synthesis of LiMn ₂ O ₄ by the conventional solid phase reaction method, when lithium and manganese precursors are mixed and calcined, primary particles (0.5 to 5 μm) aggregate to form 4 V spinel having secondary particles of 5 to 30 μm. The type LiMn ₂ O ₄ can be obtained. When synthesized by the solid phase reaction method, it is difficult to uniformly control the size of the powder particles, so that it is difficult to obtain uniform particles having a narrow particle size distribution. In addition, due to agglomeration of non-uniform primary particles, the tap density (g / ml) is low, the specific surface area is high, the powder composition composed of single particles is difficult, and the particles are easily destroyed even at low pressure.

To compensate for this drawback, LiMn ₂ O ₄ is synthesized by the wet method, which is a mixture of manganese salt solution and lithium salt solution to evaporate the solvent to obtain a lithium manganese oxide precursor, and then heat treated to several micrometers ( Μm) to synthesize LiMn ₂ O ₄ with particles (Solid State Ionics, 100, 115 (1997)). LiMn ₂ O ₄ with a few micrometers and a large specific surface area shows a large discharge capacity, but due to its high reactivity with the electrolyte due to the large specific surface area, the amount of manganese elution increases in the electrolyte solution. The amount increased, resulting in a sharp decrease in capacity (Electrochemical and Solid-State Letters, 8 (3), A171 (2005)).

In order to solve the capacity reduction caused by manganese dissolution at high temperatures, many studies have been conducted to replace fluorine atoms in oxygen, but the manganese dissolution problem has not been solved (Journal of Power Sources 81-82 1999 458-462).

In recent years, a technique for preparing manganese oxide (Mn ₃ O ₄ ) through a synthetic process in the form of manganese hydroxide (Mn (OH) ₂ ) in an aqueous solution by wet synthesis method is known (JP2004-292264). However, the drawbacks of this synthesis method are the first reaction to make a suspension of manganese hydroxide, the step of heating the suspension to 90 ℃ under nitrogen atmosphere and the oxidation reaction at 60 ℃ again complicated manufacturing process, The particle shape of the powder is composed of triangles, squares and polyhedrons, and its particle distribution is not uniform. Since the positive electrode active material having such a polyhedral shape is attracted to one place of the powder particles during high-rate charging and discharging, heat is generated locally, which is a problem for battery safety.

Conventional solid-state and wet reaction methods, which are the spinel type LiMn ₂ O ₄ synthesis method, cannot control the particle size and shape and are difficult to synthesize powder composed of single particles. In other words, there is a need for a new synthesis method of a spinel type positive electrode active material that suppresses a small specific surface area and manganese dissolution reaction and has a high volumetric energy density.

The present invention is to solve the above problems, to provide a method for producing a spinel type positive electrode active material having a uniform particle size distribution of a single particle, excellent life characteristics having a high tap density and a high volume energy density. It is a technical task. In order to solve the above technical problem, the manganese hydroxide is continuously formed, and the manganese oxide is formed, and the particle growth reaction is realized that the present invention can provide a spherical manganese oxide precursor by a simple manufacturing process.

Therefore, according to the present invention, a manganese oxide using a coprecipitation method, which is composed of the composition formula Mn ₃ O ₄ and is a monodisperse spherical powder, is provided.

The manganese oxide is characterized in that the particle size of 5 to 15㎛ and tap density of 2.5 to 2.6g / cc.

In addition, the present invention provides a lithium secondary battery spinel-type positive electrode active material comprising a compositional formula Li _{1 + α} [Mn _{2 -α} ] O ₄ (0 ≦ _α ≦ 0.15) obtained by using the manganese oxide.

In the present invention, a lithium secondary battery comprising a composition formula Li _{1 + α} [Mn _{2 -α} ] O _4-z F _z (0 ≦ α ≦ 0.15, 0.01 ≦ _z ≦ 0.15) obtained by using the manganese oxide A spinel type positive electrode active material is provided.

In the present invention, to prepare the manganese oxide, manganese hydroxide by mixing at least one or more manganese solution of manganese sulfide, manganese nitrate, manganese chloride, manganese fluoride, aqueous ammonia solution as a complexing agent, alkali solution providing a hydroxyl group as a pH adjuster Forming step, by blowing air as an oxidizing agent to the mixed solution is provided a method for producing manganese oxide using a coprecipitation method comprising the step of converting the already formed manganese hydroxide to manganese oxide.

The concentration of the aqueous ammonia solution is characterized in that 30 to 60% of the aqueous solution of manganese.

The residence time of the manganese aqueous solution in the reactor is characterized in that 12 to 24 hours.

The alkaline aqueous solution is characterized in that the pH is added to 9.0 to 11.5 in the reactor.

In the present invention, the lithium mixture is mixed with the manganese oxide prepared by the above method, and preliminarily calcined at 450 to 600 ° C. for 5 to 10 hours, calcining at 10 to 20 hours at 750 to 1000 ° C., at 600 ° C. Provided is a method for manufacturing a lithium secondary battery spinel type cathode active material, further comprising annealing for 10 to 20 hours.

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

The manganese oxide provided by the present invention is a material that can be prepared as a cathode active material for a lithium secondary battery by mixing with a lithium compound. The manganese oxide provided by the present invention is composed of the compositional formula Mn ₃ O ₄ and characterized in that the monodisperse spherical powder. The manganese oxide is characterized in that the particle size of 5 to 15㎛ and tap density of 2.5 to 2.6g / cc. When the particle size is as described above, the particles are harder and have a heavier mass than the nano-sized particles, so they are easy to manufacture without breaking or deforming when manufacturing the electrode. In addition, the specific surface area is reduced, thereby further reducing side reactions with the electrolyte. In addition, if the tap density is increased, the amount that can be put in a unit volume increases, so it has a good property of increasing the capacity per volume.

The manganese oxide is pure crystal without generation of impurity phase, and has superior crystallinity as commercialized manganese oxide, and a lithium precursor mixture may be mixed with manganese oxide to prepare a cathode active material for a lithium secondary battery.

In the present invention, a lithium secondary battery spinel type cathode active material having a composition formula Li _{1 + α} [Mn _{2 -α} ] O ₄ (0 ≦ _α ≦ 0.15) may be provided using the manganese oxide. In addition, a lithium secondary battery spinel type cathode active material having a composition formula Li _{1 + α} [Mn _2-α ] O _4-z F _z (0 ≦ _α ≦ 0.15, 0.01 ≦ _z ≦ 0.15) may be provided.

As a manufacturing method for providing a cathode active material of the present invention, by mixing at least one or more manganese sulfide solution of manganese sulfide, manganese nitrate, manganese chloride, manganese fluoride, aqueous solution of ammonia as a complexing agent, alkaline aqueous solution providing a hydroxyl group as a pH regulator Forming the manganese hydroxide, blowing the air as an oxidant to the mixed solution is provided a method for producing a manganese oxide comprising the step of converting the already formed manganese hydroxide to manganese oxide.

The production method is a mixture of manganese sulfide, nickel sulfide, cobalt sulfide, magnesium sulfide, aluminum sulfide and at least one manganese solution, ammonia solution and alkaline aqueous solution simultaneously in a 4L coprecipitation reactor to spherical reaction after a predetermined time (12 ~ 24hr) Step 1 to obtain a transition metal hydroxide of. The transition metal hydroxide may be divided into two stages by blowing air as an oxidizing agent into manganese oxide.

In the first step, a manganese aqueous solution, that is, at least one or more manganese aqueous solutions of manganese sulfide, manganese nitrate, manganese chloride, and manganese fluoride, and the pH of the solution inside the reactor is adjusted to 9.0 to 11.5 for a predetermined time (12 to 24hr). It is preferable to make it. The aqueous solution is used that does not contain other metal salts except manganese. The concentration of ammonia is 0.07 to 0.1 M in the initial reactor, and the amount introduced from the outside of the reactor is 2.85 to 5.71 M. The concentration of the aqueous ammonia solution is preferably adjusted to be 30 to 60% of the concentration of aqueous manganese solution.

Blowing air as an oxidizing agent into the manganese hydroxide produced by the first step is converted to manganese oxide, washed with secondary distilled water, and dried at 110 ℃ for 24 hours to completely remove impurities.

According to the present invention, the lithium mixture is mixed with the manganese oxide and maintained at 450 to 600 ° C. for 5 to 10 hours, followed by pre-firing, firing at 750 to 1000 ° C. for 10 to 20 hours, and annealing at 600 ° C. for 10 to 20 hours. A method of manufacturing a lithium secondary battery spinel type positive electrode active material may further be provided. The lithium mixture is preferably used at least one mixture selected from the group consisting of lithium hydroxide, lithium fluoride, lithium nitrate and lithium carbonate.

The lower the calcination temperature, the higher the initial capacity but the poor service life characteristics, and the higher the calcination temperature, the lower the initial capacity due to the decrease of manganese elution due to the reduction of specific surface area, but the service life characteristics are increased. These excellent life characteristics are due to the improvement of crystal structure stability and surface properties by fluorine substitution, and it is considered that the lithium mixture is composed of single phase particles, so that the amount of manganese dissolved due to the reduction of specific surface area is reduced.

Hereinafter, the present invention will be described in detail with reference to Example 1, but the present invention is not limited thereto.

Example 1

4L of distilled water and 10 g of aqueous ammonia solution (30 wt%) were placed in a 4L reactor in a coprecipitation reactor (capacity 4L, output of more than 80W of a rotating motor), and air was supplied into the reactor at a rate of 1 L / min. The temperature in the reactor was stirred at a speed of 1100 rpm while maintaining at 50 ℃.

2 M manganese sulfide aqueous solution was 0.3 L / hr, 4.5 wt% aqueous ammonia solution was 0.03 L / hr was continuously introduced into the reactor using a metering pump. A 4 M sodium hydroxide solution acts as a pH adjuster, automatically supplied according to the defined pH. At this time, the pH was adjusted to 10.0, the average residence time of the solution was adjusted to a flow rate of about 6 hours, the air was blown for the oxidizing atmosphere, and after the reaction reached a steady state, the continuous manganese oxide was continuously passed through the overflow pipe. Got as. The obtained manganese oxide was dried at 110 ° C. for 24 hours to remove moisture in the oxide. A SEM (trade name: JSM 6400, company name: JEOL, Japan) photograph of the manganese oxide intermediate synthesized by the above method is shown in FIG. 1.

After mixing the manganese oxide and lithium hydroxide (LiOH) in a 1: 1.05 molar ratio, heated at a heating rate of 2 ℃ / min, and maintained at 500 ℃ for 10 hours and then mixed well and calcined at 750 ℃ for 12 hours to have a spinel structure LiMn ₂ O ₄ A positive electrode active material powder was obtained, and SEM photographs and X-ray diffraction patterns of the powder are shown in FIGS. 2 and 3, respectively.

In order to evaluate the properties of the LiMn ₂ O ₄ cathode active material prepared by the above method, using an electrochemical analyzer, a charge / discharger (Model No .: Toscat 3000U, Toyo, Japan), room temperature (30 ° C) and high temperature (60 ° C) ) Was tested at a current density of 0.4 mA / cm 2 at 3.4-4.3 V potential.

In the electrode preparation, a slurry was prepared by mixing the positive electrode active material and acetylene black as a conductive material and polyvinylidene fluoride (PVdF) as a binder in a weight ratio of 80:10:10. The slurry was uniformly applied to a 20 μm thick aluminum foil, and vacuum dried at 120 ° C. to prepare a positive electrode. The prepared anode and lithium foil were used as counter electrodes, and a porous polyethylene membrane (Celgard ELC, Celgard 2300, thickness: 25 μm) was used as a separator, and ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1. Using a liquid electrolyte in which LiPF ₆ was dissolved at a concentration of 1 M in a solvent, a coin battery was manufactured according to a commonly known manufacturing process to evaluate characteristics of a positive electrode active material.

The X-ray diffraction pattern of the manganese oxide synthesized in Example 1 and the commercialized manganese oxide powder is shown in FIG. 4. The manganese oxide powder synthesized by the method of Example 1 was pure crystal without impurity phase formation, and was superior in crystallinity to commercialized manganese oxide.

Example 2

Except for using 6 wt% concentration of aqueous ammonia solution supplied to the reactor was synthesized in the same manner as in Example 1 to evaluate the battery characteristics, SEM (manufactured name: JSM 6400, company name: JEOL of the synthesized manganese oxide intermediate) , Japan) The photograph is shown in FIG.

Example 3

Except that the calcination temperature was used at 850 ℃ synthesized in the same manner as in Example 1 to evaluate the battery characteristics, X-ray diffraction pattern and SEM image of the synthesized spinel type LiMn ₂ O ₄ in Figure 3 and 6 Respectively.

Example 4

Except that the calcination temperature was used at 900 ℃ was synthesized in the same manner as in Example 1 to evaluate the battery characteristics, X-ray diffraction pattern and SEM image of the synthesized spinel type LiMn ₂ O ₄ in Figure 3 and 7 Respectively.

The X-ray diffraction pattern of LiMn ₂ O ₄ synthesized at 750 ° C. in Example 1, 850 ° C. in Example 3, 900 ° C. in Example 4 and 750 ° C. in Comparative Example 1 is shown in FIG. Regardless of the type, all were well synthesized as a single-phase spinel compound without the formation of an impurity phase.

FIG. 2 shows SEM images of LiMn ₂ O ₄ of Example 1, FIG. 6, and FIG. 7, respectively. In Example 1, the primary particles of 2 to 4 ㎛ size are composed of agglomerated secondary particles, but as the sintering temperature increases, the size of the primary particles increases, and in the case of LiMn ₂ O ₄ powder of Example 4 Primary particles were grown completely into single particles of about 8 μm in size.

Table 2 shows the specific surface area and tap density of LiMn ₂ O ₄ synthesized in Examples 1, 3, Comparative Example 1 and Comparative Example 4. The specific surface area and tap density of LiMn ₂ O ₄ synthesized in Comparative Example 1 showed higher specific surface area and lower tap density than powders synthesized by the method of the present invention. The sample synthesized by the present invention has a small specific surface area and high tap density as the calcining temperature increases.

Figure 8 shows the discharge capacity according to the charge and discharge cycle of LiMn ₂ O ₄ calcined at 750 ℃ in Example 1, 850 ℃ in Example 3 and 900 ℃ in Example 4. The powder synthesized by Comparative Example 1 exhibited worse life characteristics than the powder synthesized in the present invention. As the calcination temperature increased, the manganese elution due to the decrease of specific surface area decreased, resulting in superior life characteristics.

Example 5

A manganese oxide precursor and a lithium precursor mixture (lithium hydroxide: lithium fluoride = 1: 0.05 molar ratio) synthesized in the same manner as in Example 1 were mixed well at a molar ratio of 1.95: 1.08, maintained at 450 to 550 ° C for 10 hours, and mixed well. After calcining at 750 ° C. for 12 hours, Li _1.05 Mn _1.95 O _3.95 F _0.05 was synthesized. Battery characteristic evaluation was performed by the method similar to Example 1.

Example 6

A manganese oxide precursor and a lithium precursor mixture (lithium hydroxide: lithium fluoride = 1: 0.05 molar ratio) synthesized in the same manner as in Example 1 were mixed well at a molar ratio of 1.95: 1.08, maintained at 450 to 550 ° C for 10 hours, and mixed well. After calcining at 900 ° C. for 12 hours, Li _1.05 Mn _1.95 O _3.95 F _0.05 was synthesized. Battery characteristic evaluation was performed by the method similar to Example 1.

Example 7

A manganese oxide precursor and a lithium precursor mixture (lithium hydroxide: lithium fluoride = 1: 0.05 molar ratio) synthesized in the same manner as in Example 1 were mixed well at a molar ratio of 1.95: 1.08, maintained at 450 to 550 ° C for 10 hours, and mixed well. After calcining at 950 ° C. for 12 hours, Li _1.05 Mn _1.95 O _3.95 F _0.05 was synthesized. Battery characteristic evaluation was performed by the method similar to Example 1.

Example 8

A manganese oxide precursor and a lithium precursor mixture (lithium hydroxide: lithium fluoride = 1: 0.05 molar ratio) synthesized in the same manner as in Example 1 were mixed well at a molar ratio of 1.95: 1.08, maintained at 450 to 550 ° C for 10 hours, and mixed well. After calcining at 1000 ° C. for 12 hours, Li _1.05 Mn _1.95 O _3.95 F _0.05 was synthesized. Battery characteristic evaluation was performed by the method similar to Example 1.

Example 6 to Example 8 were respectively indicate the SEM photograph of _{Li 1 .05 Mn 1 .95 O 3} .95 F 0.05 9 to 11 obtained in the. In the powder of Example 6 calcined at 900 ° C., secondary particles composed of primary particles and primary particles were completely grown and composed of single particles, and when calcined at a temperature of 950 ° C. or higher, the primary particles completely grew into single particles only. It was composed.

12 has shown the life characteristics of the charge-discharge cycle at 60 ℃ of Example 5 to Example 7 of the _{Li 1 .05 Mn 1 .95 O 3} .95 F 0.05. The lower the calcination temperature, the higher the initial capacity, but the poorer the life characteristics, but the higher the calcination temperature, the lower the initial capacity, but the longer the characteristics. Example 5 calcined at 750 ° C. showed a capacity retention rate of 89% compared to the initial capacity after 100 cycles, but the sample of Example 7 calcined at 950 ° C. showed excellent life characteristics of 97%. This excellent lifespan is due to the reduction of specific surface area and the decrease of manganese solubility due to the reduction of specific surface area because of fluorine substitution.

Comparative Example 1

The manganese oxide synthesized by the solid phase method was used as a manganese precursor, and it was quantitatively mixed with lithium hydroxide in a molar ratio of 1: 1.05, followed by induction, and calcined in the same manner as in Example 1 to evaluate battery characteristics. SEM photograph of the precursor is calcined in Figure 13, LiMn ₂ O ₄ SEM photographs of the powder are shown in FIG. 14, respectively. Also calcined LiMn ₂ O ₄ The X-ray diffraction pattern of the powder is shown in FIG. 3 together. Commercialized manganese oxide consisted of nanosized particles and had a low tap density of 1.02 g / cc.

Comparative Example 2

Except for using the gas supplied to the reactor was synthesized in the same manner as in Example 1 to evaluate the battery characteristics, and SEM (trade name: JSM 6400, company name: JEOL, Japan) of the synthesized manganese oxide intermediate 15 is shown.

Comparative Example 3

Except that the gas supplied to the reactor was used as oxygen and the pH of the reactor was adjusted to 7.0, the synthesis was performed in the same manner as in Example 1, and the battery characteristics were evaluated. SEM of the synthesized manganese oxide intermediate (trade name: JSM 6400, Company name: JEOL, Japan) Photograph is shown in FIG.

[Comparative Example 4]

Except for using the gas supplied to the reactor was synthesized in the same manner as in Example 1 to evaluate the battery characteristics, SEM (brand name: JSM 6400, company name: JEOL, Japan) of the synthesized manganese oxide intermediate 17 is shown.

Table 1 shows the synthesis conditions of the manganese precursors prepared in Examples 1 and 2 and Comparative Examples 2 to 4. In Example 1, Example 2, Comparative Example 2 and Comparative Example 3, the produced manganese hydroxide was converted to manganese oxide by the oxidation reaction, but in the case of Comparative Example 4 synthesized in a nitrogen gas atmosphere maintains the manganese hydroxide form And it was found.

In the case of Comparative Example 4 In the case of the synthesized powder (reaction in a nitrogen gas atmosphere), the manganese hydroxide shape was maintained and the porous structure was maintained, so that the tap density was the lowest as 1.12 g / cc as shown in Table 1. When the atmosphere of the reactor was adjusted with oxygen to oxidize the manganese hydroxide produced by the reaction (Comparative Examples 2 and 3), manganese oxide was formed, but the particle size thereof was reduced to 3 to 5 μm, and the tap density was Comparative Example 2 In the case of 1.8g / cc, Comparative Example 3 was 1.57g / cc slightly increased than that of manganese hydroxide. In the case of using the atmosphere of the reactor (Examples 1 and 2), the particle size of the powder was about 7 to 10 µm, similar to that of manganese hydroxide, due to the decrease in the rate of oxidation during the production of manganese oxide. Regardless, it showed a high tap density of about 2.5 to 2.6 g / cc.

Sample Name Furtherance Rpm Metal [mol / l] NaOH [mol / L] pH Internal NH ₄ OH Reactor internal temperature Reactor atmosphere Tap Density (g / cc) External NH ₄ OH Example 1 A Mn ₃ O ₄ 1100 2.0 4.0 10 3 g 50 ℃ air 2.6 1.35 g / hr Example 2 B Mn ₃ O ₄ 1100 2.0 4.0 10 3 g 50 ℃ air 2.5 1.8 g / hr Comparative Example 2 C Mn ₃ O ₄ 1100 2.0 4.0 10 3 g 50 ℃ Oxygen 1.8 1.35 g / hr Comparative Example 3 D Mn ₃ O ₄ 1100 2.0 4.0 7 3 g 50 ℃ Oxygen 1.57 1.35 g / hr Comparative Example 4 E Mn (OH) ₂ 1100 2.0 4.0 10 3 g 50 ℃ nitrogen 1.12 1.35 g / hr

Furtherance Legislation Sintering temperature Specific surface area (m ² / g) Tap density (g / cc) Example 1 LiMn ₂ O ₄ Copulation 750 ℃ 0.95 1.97 Example 3 LiMn ₂ O ₄ Copulation 900 ℃ 0.58 2.07 Comparative Example 1 LiMn ₂ O ₄ Solid state law 750 ℃ 4.32 0.8 Comparative Example 4 LiMn ₂ O ₄ Copulation 850 ℃ 0.78 2.0

Manganese oxide obtained in the present invention is a monodisperse spherical powder with a uniform particle size distribution, and has a high tap density of 2.5 to 2.6 g / cc. Spinel-type cathode active material Li _{1 + α} [Mn _2-α ] O _4-z F _z (0 ≦ _α ≦ 0.15, 0.01 ≦ _z ≦ 0.15) synthesized using this material has excellent crystallinity and Due to the low specific target, the manganese dissolution phenomenon was remarkably improved, resulting in excellent battery characteristics at high temperatures, that is, cycle characteristics and charge retention characteristics due to charge and discharge.

Claims (9)

Manganese oxide using coprecipitation method comprising a composition Mn ₃ O ₄ synthesized by coprecipitation method and is a monodisperse spherical powder . The manganese oxide according to claim 1, wherein the manganese oxide has a particle size of 5 to 15 µm and a tap density of 2.5 to 2.6 g / cc. A lithium secondary battery spinel type cathode active material, comprising a compositional formula Li _{1 + α} [Mn _2-α ] O ₄ (0 ≦ _α ≦ 0.15) obtained by using the manganese oxide according to claim 1. A composition formula Li _{1 + α} [Mn _2-α ] O _4-z F _z (0 ≦ _α ≦ 0.15, 0.01 ≦ _z ≦ 0.15) obtained using the manganese oxide of claim 1 or 2. A lithium secondary battery spinel type positive electrode active material. Manganese sulfide, manganese nitrate, manganese chloride, at least one or more of the manganese solution of manganese fluoride, ammonia solution serving as a complexing agent, an alkaline aqueous solution providing a hydroxyl group as a pH adjuster to form a manganese hydroxide, air as an oxidizing agent in the mixed solution Method of producing a manganese oxide using the co-precipitation method comprising the step of blowing the manganese hydroxide already formed by converting the manganese oxide. The method of claim 5, wherein the concentration of the aqueous ammonia solution is 30 to 60% of the concentration of aqueous manganese solution. The method of claim 5, wherein the residence time of the aqueous manganese solution in the reactor is 12 to 24 hours. The method of claim 5, wherein the alkaline aqueous solution is added so that the pH in the reactor is 9.0 to 11.5. The lithium mixture is mixed with the manganese oxide prepared by the method according to any one of claims 5 to 8, and then prebaked by maintaining at 5 to 10 hours at 450 to 600 ° C, 10 to 20 hours at 750 to 1000 ° C. A method of manufacturing a lithium secondary battery spinel type cathode active material, further comprising the step of firing, annealing at 600 ° C. for 10 to 20 hours.

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