KR20140100284A - Synthesis Method of Nano-Chemical Manganese Dioxide(CMD) by Epitaxial Growth for Cathode Material used in Secondary Battery - Google Patents

Abstract

The present invention relates to a method for manufacturing ultrafine chemical manganese dioxide (CMD) by epitaxial growth for a cathode material used in a secondary battery and to ultrafine CMD manufactured thereby. More specifically, the present invention relates to a method for manufacturing CMD by epitaxial growth for a cathode material used in a secondary battery and to CMD manufactured thereby, wherein the method includes producing chemical manganese dioxide seed (seed-MnO2) by heat-treating manganese carbonate (MnCO3); pulverizing the seed-MnO2 into nano-chemical manganese dioxide (CMD) in which the primary particles have nano sizes; making the CMD to have more homogeneous powder form by acid-treating; and easily manufacturing CMD used as a precursor of the cathode material used in a secondary battery.

Description

Technical Field [0001] The present invention relates to a method for manufacturing a nanodiamondite (CMD) for a cathode material for a secondary cell using homogeneous crystal growth and a method for producing a nanodiamondite (CMD)

The invention powder by heat-treating the ultrafine manganese dioxide (CMD) specifically, industrial manganese carbonate (MnCO ₃₎ than that of the manufacturing method of manufacturing a secondary battery positive electrode damper ultrafine manganese dioxide (CMD) with a homogeneous crystal growth, and use this to (Seed-MnO ₂ ), and the manganese dioxide seed is crushed with a manganese seed of a nano-sized nano-sized primary particle and subjected to an acid treatment to obtain a more homogeneous powdery form Of manganese dioxide and then used as a seed to easily prepare manganese dioxide used as a precursor of the cathode material of the secondary battery in the form of ultrafine powder and to mass-produce the manganese dioxide, A secondary battery cathode material using the same kind of crystal growth that can further improve the charge and discharge efficiency of a lithium secondary battery used as a material Second it relates to a particulate manganese dioxide (CMD) and a method for producing ultra fine manganese dioxide (CMD) prepared using them.

 In recent years, lithium manganese oxide (LMO) has attracted attention as a cathode material for a high output lithium secondary battery such as a hybrid electric vehicle and a power supply device for a heavy equipment. The lithium manganese oxide exhibits relatively good characteristics in terms of battery characteristics, stability, and economy. Therefore, although lithium manganese oxide has a relatively low battery capacity as compared with other materials such as lithium cobalt oxide and the like, As a good candidate for.

In addition, surface coating of lithium manganese oxide and addition of metal components have been devised in order to improve lifetime characteristics and electric storage characteristics at high temperatures of lithium manganese oxides, which have been pointed out as fatal defects when applied to batteries for hybrid electric vehicle power supply have. Many methods for improving the physical properties of the lithium manganese oxide include a method for improving the battery characteristics by using various lithium manganese oxide precursors.

 Most of commercially available lithium manganese oxides are prepared using Electrolytic Manganese Dioxide (EMD) obtained by electrochemical treatment as a precursor. Recently, however, attempts have been made to use a chemical manganese dioxide (CMD) obtained by chemical treatment as a precursor, and practically, a lithium manganese oxide produced using such manganese dioxide (CMD) has been used as a cathode material The battery characteristics of the lithium secondary battery tends to be improved. The feature of CMD is that it is easier to control particle size, particle shape, manganese purity and manganese oxidation than EMD.

Such CMD production methods include a solid phase method in which manganese carbonate is heat-treated and a liquid phase method in which oxidation-reduction reaction of various manganese salts such as sol-gel and precipitation method is used. However, the solid phase method has disadvantages that it is difficult to control the size and shape of the product particles and the oxidation number of manganese as in the EMD, and the liquid phase method takes a long reaction time and is not suitable for a mass production process.

In order to overcome this problem, CMD was prepared by using active manganese dioxide (Active-MnO ₂ ) as a catalyst for the reaction. By the catalytic action of active manganese dioxide, CMD can be produced at a relatively low acid concentration, a low reaction temperature and a short reaction time in the above reaction.

However, there is plenty of room for improving the production process of CMD more efficiently by the improvement of active manganese dioxide (active-MnO ₂ ) added in the above reaction process. Active manganese dioxide is obtained by heat treatment of manganese carbonate produced by precipitation method using manganese mass. In the conventional CMD manufacturing process, since the milling process is not included, the particle size is as large as several tens μm or more.

On the other hand, when the reagent manganese carbonate is heat-treated, the active manganese dioxide is obtained in a homogeneous and fine form. If the manganese carbonate is added to the CMD production reaction, the production rate of CMD is greatly accelerated as compared with the conventional process. However, the application of reagent grade manganese carbonate to commercial processes is not feasible in terms of the economics of the manufacturing process. Therefore, there is a need for a manufacturing process in which the final product can be used as an efficient secondary battery cathode material while lowering the production cost of CMD.

In the present invention, in order to complement the previously proposed CMD manufacturing process and to develop a process suitable for actual mass production process, a homogeneous CMD was synthesized in a short time using nano-sized manganese dioxide seeds.

In the previously proposed process, manganese carbonate is used as a catalyst by heat treatment. In the heat treated catalyst material, impurity Mn ²⁺ compounds exist. These impurities are eluted with MnSO ₄ (manganese sulfate) by sulfuric acid treatment, which is dissociated into Mn ²⁺ in the aqueous solution and oxidized to Mn ⁴⁺ by the added oxidizing agent. The resulting Mn ⁴⁺ is converted to manganese dioxide, and CMD of high purity is obtained.

In the process proposed in the present invention, the heat-treated manganese carbonate is pulverized to produce homogeneous nano-sized fine powder. As the particle size of the heat treated manganese carbonate decreases, the contact surface with the sulfuric acid solution increases, thereby increasing the rate at which the Mn ²⁺ compounds are eluted into manganese sulfate. Assuming that the rate-limiting step of the overall reaction is the rate at which the Mn ²⁺ compounds elute into manganese sulfate, the final rate of production of CMD increases.

On the other hand, a method for producing manganese dioxide by various electrolysis methods is known from U.S. Patent Nos. 3,535,217 and 4,048,027. When the lithium secondary battery is manufactured using the manganese dioxide produced by the above patent, the lifetime characteristics of the battery are remarkably lowered as compared with the battery currently used commercially, and the electrode density can not be applied to the size of a commercially used battery There is a problem.

The present invention relates to a method of producing ultrafine manganese dioxide (CMD) used for manufacturing a secondary battery cathode material using homogeneous crystal growth, and to ultra fine manganese dioxide (CMD) produced using the same, and more particularly, Of manganese dioxide seeds and the manganese seeds are ground to form manganese seeds of nanoparticles of nano size as primary particles and subjected to acid treatment to obtain a more homogeneous powder- Of manganese dioxide seeds and then using them as seeds to make it possible to easily produce ultrafine manganese dioxide (CMD) used as a precursor of a secondary battery cathode material, and to mass-produce the manganese dioxide, In order to improve the charge and discharge efficiency of the lithium secondary battery using the lithium secondary battery as a cathode material, One is to provide the ultrafine manganese dioxide (CMD) and a method for producing ultra fine manganese dioxide (CMD) prepared using this positive electrode material used in the secondary battery manufacturing.

Technical Solution In order to accomplish the above object, the present invention provides a method of manufacturing ultrafine manganese dioxide (CMD) for a secondary battery cathode material using the same kind of crystal growth,

a) maintaining manganese carbonate for industrial use (MnCO ₃ ) at a temperature of 300 to 450 ° C for 30 minutes to 15 hours under air atmosphere and then cooling to produce seeded manganese dioxide (Seed-MnO ₂ );

b) In the attrition mill pulverizer, the manganese dioxide seeds produced in the step a) are pulverized in the order of 10 to 13 wt% of manganese seeds, 67 wt% of zirconia balls for friction grinding and 10 to 20 wt% of distilled water %, And drying the pulverized material from which the ceramic balls have been removed to produce a powdery manganese seed having a nano-sized primary particle;

c) mixing the pulverized manganese dioxide seed with sulfuric acid (H ₂ SO ₄ ) using a stirrer and mixing the mixture at a constant temperature in a stirrer;

d) Mixing manganese sulfate (MnSO ₄ ) and distilled water using a stirrer and mixing at a constant temperature within the stirrer;

e) adding sodium chlorate (NaClO ₃ ) and distilled water using a stirrer, and mixing the mixture at a constant temperature in an agitator;

f) mixing the mixture of step c) and step d) at a constant temperature;

g) mixing the mixture of step f) and e) with the mixture of step f), stirring and drying at a constant temperature to prepare ultrafine mordanted manganese dioxide (CMD). A method for preparing ultrafine manganese dioxide (CMD) for a secondary battery cathode material is provided.

Further, in the step a) of the present invention, the MnCO ₃ for industrial use is gradually increased at a rate of 5 ° C / min. In the step b), the size of the ceramic ball for friction grinding is 2Φ, 3Φ, 10Φ And the ratio of the ceramic balls is 2?: 3?: 10? = 2.5: 2.5: 5.

In the step b), the manganese seeds are pulverized in an attrition mill pulverizer at 500 rpm for 12 hours, and in the step b), the manganese seed pulverized material is pulverized in an oven at 80 ° C Followed by drying at a temperature.

In the step c), the mixing ratio of the manganese seed and the sulfuric acid is 76 to 82 wt% of sulfuric acid with respect to 18 to 24 wt% of the pulverized manganese dioxide seed. In the step c), the temperature inside the stirrer is 95 And the manganese dioxide seed and sulfuric acid are mixed in a stirrer for 30 minutes.

In addition, in the step d) of the present invention, the mixing ratio of manganese sulfate and distilled water is 90 to 95 wt% of distilled water relative to 5 to 10 wt% of manganese sulfate. In the step d) The temperature of the solution is 95 ° C, and the manganese sulfate and distilled water are mixed in a stirrer for 10 minutes.

In step e), the mixing ratio of sodium chlorate and distilled water is 70 to 80 wt% of distilled water relative to 20 to 30 wt% of sodium chlorate. In step e), the temperature inside the stirrer is 95 And the sodium chlorate and distilled water are mixed in a stirrer for 10 minutes. In step (e), potassium chlorate (KClO ₃ ), potassium peroxide Any one of hydrogen (H ₂ O ₂ ), sodium persulfate (Na ₂ S ₂ O ₈ ), ammonium persulfate [(NH ₄ ) ₂ S ₂ O ₈ ], and potassium persulfate (K ₂ S ₂ O ₈ ) .

In the step f), the mixture of step c) and step d) is mixed at a temperature of 95 ° C .; the mixture of step f) contains particles of manganese dioxide seeds of nano size, Mn ²⁺ ions of manganese are present.

Also, the mixture which is mixed and stirred in the step g) is mixed with 46 wt% of manganese sulfate and distilled water mixture of step d) and 26 wt% of the mixture of manganese seed and sulfuric acid mixture of step c) Distilled water mixture is mixed at a ratio of 28wt%. The mixture of step g) is mixed at a temperature of 95 ° C for 1 minute. When the sodium chlorite mixture of step e) is added, sodium chlorate acts as an oxidant, As the Mn ²⁺ ions of the manganese sulfate present are oxidized, ultrafine manganese dioxide (CMD) is produced through homogeneous crystal growth on the surface of nano-sized manganese dioxide seeds. The yield of the ultrafine manganese dioxide (CMD) is 92 to 93% .

In addition, the present invention is characterized in that the ultrafine particulate manganese dioxide (CMD) produced as described above is in the form of a fine powder having a particle size of 0.1 to 0.2 μm and formed in the form of a rod on a manganese dioxide seed.

According to the method for manufacturing nanodiamondedium (CMD) for a secondary battery cathode material using the same kind of crystal growth of the present invention and the ultrafine particulate manganese dioxide (CMD) produced using the same, the manganese carbonate for industrial use can be heat treated to produce a powdery manganese dioxide seed, It is possible to produce more homogeneous nano powder type manganese dioxide seeds in which primary particles are nano-sized and impurities are removed by pulverizing and acid-treating seeds of manganese dioxide, and it is also possible to use them as seeds and to use them as precursors of cathode materials for secondary batteries The ultra-fine CMD can be manufactured easily and easily. In addition, it is possible to produce ultrafine manganese dioxide (CMD) in a short time, which is very advantageous for mass production. When the lithium manganese oxide synthesized using the lithium manganese oxide is used as a cathode material, the charging and discharging efficiency of the lithium secondary battery can be further improved.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be understood by those skilled in the art that it is easy to know.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart for explaining a method for producing ultrafine manganese dioxide (CMD) for a cathode material of a secondary battery using homogeneous crystal growth according to the present invention.
2A and 2B are electron micrographs of the manganese dioxide seeds prepared according to the present invention before and after grinding.
FIG. 3 is an electron micrograph of ultrafine manganese dioxide (CMD) prepared at a reaction time of 1 minute according to the present invention.
Figure 4 is an X-ray diffraction (XRD) graph of manganese dioxide seeds and ultrafine manganese dioxide (CMD) of the present invention.
FIGS. 5A and 5B are X-ray diffraction (XRD) graphs of lithium manganese oxide (LiMn ₂ O ₄ ) prepared using manganese dioxide seed and ultrafine manganese dioxide (CMD) of the present invention.
6 is a graph showing a high temperature lifetime characteristic curve showing discharge capacity according to the number of times of charging and discharging of a lithium secondary battery using lithium manganese oxide produced by using manganese seed and the ultrafine manganese dioxide (CMD) of the present invention as a cathode material. .
7A to 7B are graphs showing a specific capacity (specific capacity) of a lithium secondary battery using a lithium manganese oxide produced by using manganese dioxide seed and ultrafine manganese dioxide (CMD) of the present invention as a cathode material. graph.

Hereinafter, an embodiment of a method for producing ultrafine manganese dioxide (CMD) for a secondary battery cathode material using the same kind of crystal growth according to the present invention will be described in detail.

FIG. 1 is a flow chart for explaining a method for producing ultrafine manganese dioxide (CMD) for a secondary battery cathode material using the same kind of crystal growth according to the present invention, wherein a) manganese carbonate for industrial use is heated at 300 to 450 ° C. for 30 minutes To 15 hours and then cooled to produce manganese dioxide seeds; and b) the manganese dioxide seeds produced in step a) are pulverized in an abrasive mill to a number of ceramic balls for friction grinding Mixing the powdered mixture with 67wt% of distilled water and 10 to 20wt% of distilled water, and drying the powdered material from which the ceramic balls have been removed to prepare ultrafine particulate manganese dioxide powder having a nano-sized primary particle; c) Mixing manganese dioxide seed and sulfuric acid and mixing them at a constant temperature in an agitator, d) mixing manganese sulfate and distilled water using a stirrer, Mixing the mixture of step c) and step d) at a constant temperature, e) mixing sodium chlorate and distilled water using a stirrer, and mixing the mixture at a constant temperature in the stirrer, f) G) mixing the mixture of step f) with step e), stirring and drying at a constant temperature to prepare ultrafine manganese dioxide (CMD).

    The process for producing ultrafine manganese dioxide (CMD) for a secondary battery cathode material using the same kind of crystal growth as described above will be described in detail.

First, in step (a), manganese carbonate for industrial use is heated in an electric furnace from 300 to 450 ° C at a rate of 5 ° C / min under an air atmosphere, and then the temperature is maintained for 30 minutes to 15 hours. In this process, the carbonate of manganese carbonate is converted to carbon dioxide (CO ₂ ) and removed, and manganese is oxidized to form manganese dioxide. At this time, when the heating temperature of the industrial manganese carbonate is 300 ° C or less, it is difficult to remove the carbonate. When the heating temperature is 450 ° C or more, Mn ₃ O ₄ is produced at a high temperature. When this is made into a secondary battery, it causes a significant deterioration in the battery characteristics of the lithium manganese oxide. Therefore, when the manganese carbonate for industrial use is heated to produce manganese seed as in the present invention, it is most preferable to gradually raise the temperature of the manganese carbonate to 300 to 450 ° C at a rate of 5 ° C / min.

Next, the process of step b) of the present invention is a process of pulverizing the manganese dioxide seeds produced in the step a) into nano-sized particles. In the abrasive mill, 10 to 13 wt% of manganese seeds 67 wt% ceramic balls having a diameter of 10 to 20 wt%, and milled manganese seeds at 500 rpm for 12 hours. In order to increase the crushing effect of the mill, the ceramic balls were divided into ceramic balls having different diameters (2Φ, 3Φ, 10Φ), and the composition ratios of the ceramic balls were 2Φ, 3Φ, 10Φ = 2.5: 2.5 : 5, so that the manganese dioxide seed can be pulverized into a nano-sized powder state.

In this case, when the manganese seeds are mixed in the ceramic balls and the distilled water at a concentration of 10 wt% or less, the niobium seeds are not properly pulverized by the distilled water mixed with the manganese seeds, And 13 wt% or more of distilled water, it is preferable that 10 wt% to 13 wt% of the manganese seed is mixed with the ceramic balls and distilled water.

The pulverized manganese dioxide is separated from the ceramic ball and dried in an oven at a temperature of 80 ° C to obtain a nano-sized powdery manganese dioxide seed as a primary particle.

Meanwhile, in order to prepare the nano powder manganese seed as described above as a more homogeneous nano powder type manganese seed having impurities removed, in the process of step c), sulfuric acid is preferably added in an amount of 76 to 82 wt% based on 18-24 wt% % Is put into a stirrer and mixed at a speed of about 300 rpm for 30 minutes while maintaining the temperature inside the stirrer at 95 캜. When the pulverized manganese dioxide seeds are 18 wt% or less, the manganese dioxide seeds become too small in the reaction solution, and it takes a long time to produce ultrafine manganese dioxide (CMD) from which impurities are removed as described later. %, The impurity removal effect of the manganese dioxide seed by sulfuric acid becomes small, and it becomes difficult to produce homogeneous manganese seeds.

On the other hand, in step d), a reaction mother liquid containing manganese ions as a raw material of manganese oxide grown on manganese seeds is prepared. Using a stirrer, the mixture is diluted to a concentration of 90 to 95 wt% of distilled water with respect to 5 to 10 wt% of manganese sulfate, and the mixture is mixed at a rate of about 300 rpm for 10 minutes while maintaining the temperature inside the stirrer at 95 캜.

Also, in step e), an oxidant solution for oxidizing manganese ions present in the reaction mother liquor in step d) is prepared. Using a stirrer, 20 to 30 wt% of sodium chlorate is diluted with 70 to 80 wt% of distilled water, and the mixture is mixed at a rate of about 300 rpm for 10 minutes while maintaining the temperature inside the stirrer at 95 캜.

At this time, the temperature for mixing and stirring the manganese seeds and sulfuric acid, the temperature for mixing and stirring the distilled water with manganese sulfate, and the temperature for mixing and stirring the sodium chloride and the distilled water are kept at 95 ° C, In order to prepare ultrafine manganese dioxide (CMD), the temperature of the whole reaction system was controlled by maintaining a constant temperature of 95 ° C at all times even after the mixtures were mixed together.

(KClO ₃ ), hydrogen peroxide (H ₂ O ₂ ), and sodium persulfate (Na ₂ S ₂ O ₈ ) in place of sodium chlorate mixed with 70-80 wt% of distilled water by using an agitator in the step e) ), Ammonium persulfate [(NH ₄ ) ₂ S ₂ O ₈ ] and potassium persulfate (K ₂ S ₂ O ₈ ) may be mixed.

As described above, the mixture mixed in each of the steps c), d) and e) is a mixture of the manganese dioxide seeds and the sulfuric acid mixture produced in the steps c) and d) The mixture of manganese and distilled water is mixed in the mixer. At this time, nanosized manganese dioxide seed particles and Mn ²⁺ ions of manganese sulfate are present in the mixture produced in the steps of c) and d).

Therefore, in order to remove Mn ²⁺ ions such as the above-mentioned impurities, in the step g) of the last step of the present invention, the mixture mixed in the step f) is added with sodium chlorate mixed in the step e) And the mixture was stirred at a temperature of 95 캜 for 1 minute to produce ultrafine manganese dioxide (CMD) from which impurities were removed at a yield of about 92 to 93%.

At this time, the composition of the mixture to be mixed and agitated in the step g) is as follows: 26 wt% of the manganese seed and sulfuric acid mixture of step c), 46 wt% of the mixture of manganese sulfate and distilled water of step d) and sodium chlorate And 28 wt% of a distilled water mixture. In step g), sodium hypochlorite serves as an oxidant by adding a sodium chlorate mixture, which is a mixture of step e), and Mn ²⁺ of MnSO ₄ present in the reaction matrix is oxidized to Mn ⁴⁺ , Can be obtained.

On the other hand, when the particle size of the powdery ultrafine manganese dioxide (CMD) produced using the manganese dioxide seed obtained through the chemical treatment of industrial manganese carbonate as described above is measured using a nano particle sizer, It is formed into ultrafine powder having a size of 0.1 to 0.2 μm, and the yield is about 92 to 93%.

2A and 2B are electron micrographs of manganese dioxide seeds produced by the present invention. In the case of manganese dioxide seeds which are not subjected to the milling step after the heat treatment of industrial manganese carbonate, as shown in FIG. 2A, It can be confirmed that secondary particles having a size of several tens of micrometers are formed by agglomeration. On the other hand, in the case of manganese dioxide seeds obtained through the grinding process after the heat treatment, as shown in FIG. 2B, the nanocrystalline manganese seed crystals It can be confirmed that it is distributed.

Fig. 3 is an electron micrograph of ultrafine manganese dioxide (CMD) produced by the present invention, and is a sample collected at a reaction time of 1 minute. When the manganese seeds used in the reaction are made into nano-sized particles by pulverization and acid treatment, the final product, ultrafine manganese dioxide (CMD), has a nano-sized loading state even at a short reaction time of 1 minute on the surface of manganese dioxide seed It can be confirmed that it is generated evenly.

4 is an X-ray diffraction chart of the manganese dioxide seed and ultrafine manganese dioxide (CMD) of the present invention. The X-ray diffraction graph was measured using D / Max-2500 manufactured by Rigaku Corporation of Japan.

As can be seen from FIG. 4, it can be seen that both the manganese dioxide seed and the ultrafine manganese dioxide (CMD) of the present invention have the same crystal phase of MnO _{2. In} the case of the ultrafine manganese dioxide (CMD) - line diffraction angle 2 &thetas; of about 55.9 degrees, crystallinity is more developed than that of manganese dioxide seed.

5A and 5B are X-ray diffraction graphs of lithium manganese oxides prepared using manganese dioxide seeds and the ultrafine manganese dioxide (CMD) of the present invention. The X-ray diffraction patterns are shown in Rigaku ) ≪ / RTI > D / Max-2500.

5a and 5b, the lithium-manganese oxide prepared using the lithium-manganese oxide produced using the manganese seed and the ultrafine manganese dioxide (CMD) of the present invention are entirely the same lithium-manganese oxide In the case of the lithium-manganese oxide produced by using the manganese dioxide seeds having a crystal phase, a peak other than the lithium-manganese oxide to be produced was confirmed. In particular, as shown in FIG. 5A, a peak of Li ₂ MnO ₃ appears at about 18.5 ° and 44.9 ° of the X-ray diffraction angle 2θ, and a lot of impurities are contained therein. These impurities are factors that hinder the cell performance do.

FIG. 6 is a graph showing a lifetime characteristic of a lithium secondary battery according to the number of charging and discharging times of a lithium manganese dioxide seed and the inventive ultrafine manganese dioxide (CMD). FIG. CMD) was used, the charge / discharge test at a high temperature (55 ° C) showed a good 95 to 110 mAh / g even after 50 repetitive charge / discharge cycles, and the discharge capacity of the lithium secondary battery The reduction rate was about 88% as compared with the discharge capacity at the first charge / discharge, which was superior to the case using the cathode material made of manganese dioxide seed.

7A and 7B are graphs showing a specific capacity of the manganese dioxide seed and the ultrafine particulate manganese dioxide (CMD) of the present invention produced from a lithium battery according to a voltage. As shown in FIG. 7A, When the cathode active material made of the ultrafine particulate manganese dioxide (CMD) of the present invention is used as compared with the capacity and the output value by the charge and discharge test in the case of using the manganese dioxide seed as shown in Fig. 7B, In the test, the discharge capacity of the first charge / discharge cycle was 103 mAh / g, which was superior to the case of using the cathode active material made of manganese dioxide seed, and the output was also excellent at 98%.

① Manufacturing stage of manganese seed (before grinding)

The industrial manganese carbonate was heated in an electric furnace at a rate of 5 ° C / min from 300 ° C to 450 ° C in an air atmosphere, and then the temperature was maintained for 30 minutes to 15 hours. In this process, the carbonate of manganese carbonate was converted to carbon dioxide (CO ₂ ) and removed, and the manganese was oxidized.

(2) Production step (grinding) of manganese dioxide seeds in a nano powder state

In order to prepare the manganese dioxide seeds produced in the production step (before grinding) of the manganese seeds as nano-sized particles, 67 wt% of ceramic balls having diameters different from each other with respect to 10-13 wt% of manganese seeds in an induction mill, And 10 to 20 wt% of distilled water were mixed, and the manganese dioxide seeds were pulverized at 500 rpm for 12 hours. In order to increase the crushing effect of the mill, the ceramic balls were divided into ceramic balls having different diameters (2Φ, 3Φ, 10Φ), and the composition ratios of the ceramic balls were 2Φ, 3Φ, 10Φ = 2.5: 2.5 : 5.

The ground manganese dioxide seeds were separated from the ceramic balls and dried in an oven at a temperature of 80 ° C to recover primary particles of nanoparticles of manganese dioxide.

(3) Removal step of impurities present in nano powdery manganese seeds (liquid phase reaction)

To prepare manganese dioxide seeds of the nano powder type as a more homogeneous nano powder type manganese seeds having impurities removed, 76 to 82 wt% of sulfuric acid was added to 18-24 wt% of manganese seeds in a stirrer and the temperature inside the stirrer The mixture was mixed at a rate of about 300 rpm for 30 minutes while maintaining the temperature at 95 캜 to purify manganese dioxide seeds.

(4) Production step of reaction mother liquid containing manganese ions (liquid phase reaction)

Prior to the preparation of ultrafine manganese dioxide (CMD), a reaction mother liquor containing manganese ions as a raw material of manganese oxide grown on manganese seeds was prepared. Using a stirrer, the reaction mother liquor was diluted with 5 to 10 wt% of manganese sulfate at a ratio of 90 to 95 wt% of distilled water and mixed at a rate of about 300 rpm for 10 minutes while maintaining the temperature inside the stirrer at 95 캜.

(5) Step of preparing an oxidizing agent solution for oxidizing manganese ions (liquid phase reaction)

In the next step, an oxidant solution for oxidizing the manganese ions present in the reaction mother liquor was prepared. Using a stirrer, 20 to 30 wt% of sodium chlorate was diluted with 70 to 80 wt% of distilled water, and the mixture was mixed at a rate of about 300 rpm for 30 minutes while maintaining the temperature inside the stirrer at 95 캜.

At this time, the temperature at which the ③ manganese seed and sulfuric acid are mixed and stirred, the temperature at which the ④ manganese sulfate is mixed with the distilled water and stirred, and the temperature at which the ⑤ sodium chloride and distilled water are mixed and stirred is maintained at 95 ° C., In order to prepare ultrafine manganese dioxide (CMD), the temperature of the entire reaction system was controlled so that the temperature of the entire reaction solution was always maintained at a constant temperature of 95 ° C even after the above-mentioned mixtures were mixed together.

In the above procedure, potassium chlorate (KClO ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium persulfate (Na ₂ S ₂ O ₈ ), and sodium persulfate were mixed in place of sodium chlorate mixed with 70-80 wt% of distilled water using a stirrer. ammonium sulfate _{[(NH 4) 2 S 2} O 8], but may be mixed with any one of a potassium persulfate _{(K 2 S 2 O 8)} .

⑥ Production stage of superfine manganese dioxide (CMD) (liquid phase reaction)

A mixture of the manganese dioxide seed and the sulfuric acid mixture and the reaction mother liquor is injected into the reactor and mixed. At this time, nano-sized manganese dioxide seed particles and Mn ²⁺ ions of manganese sulfate are present in the reactor.

Therefore, in order to remove Mn ²⁺ ions such as the above-mentioned impurities, in a final step of the present invention, a mixture of sodium manganese seeds, sulfuric acid mixture and reaction mother liquor is added with a mixture of sodium chlorate and distilled water, Lt; / RTI > to produce ultrafine manganese dioxide (CMD) from which the impurities have been removed.

At this time, the composition of the mixture to be mixed and stirred at the final stage is composed of 46 wt% of manganese sulfate and distilled water mixture and 28 wt% of sodium chlorate and distilled water mixture with respect to 26 wt% of manganese seed and sulfuric acid mixture. The chlorate is sodium chlorate put give a mixture of sodium oxidant role in the process of the final stage, the Mn ²⁺ of MnSO ₄ in the reaction mother material can be obtained in high purity ultrafine manganese dioxide (CMD) as oxidation with Mn ⁴⁺ .

The shape of the powdery ultrafine manganese dioxide (CMD) particles prepared by using the manganese dioxide seeds obtained through the chemical treatment of the manganese carbonate for industrial use as described above is in the form of a rod, and when it is measured using a nano particle sizer, 0.1 to 0.2 mu m in size, and formed in rod form on manganese seeds. The yield of ultrafine manganese dioxide (CMD) at a reaction time of 1 minute is about 92 to 93%.

Claims (20)

A method for producing ultrafine manganese dioxide (CMD) for a secondary battery cathode material using homogeneous crystal growth,
a) maintaining manganese carbonate for industrial use at a temperature of 300 to 450 캜 for 30 minutes to 15 hours under an air atmosphere, and then cooling the manganese carbonate to produce manganese dioxide seed;
b) The manganese dioxide seeds produced in step a) are mixed with 10 to 20 wt% of ceramic ball for friction grinding and 10 to 20 wt% of ceramic balls for 10 to 13 wt% manganese seeds in an attrition mill, Pulverizing the powder into a powder, drying the pulverized product from which the ceramic ball has been removed, to produce a manganese dioxide seed in the form of a nano-sized powder;
c) mixing the pulverized manganese dioxide seed with sulfuric acid using an agitator and mixing the mixture at a constant temperature in an agitator;
d) Mixing manganese sulfate and distilled water using a stirrer and mixing at a constant temperature in the stirrer;
e) adding sodium chlorate and distilled water using a stirrer, and mixing the mixture at a constant temperature in an agitator;
f) mixing the mixture of step c) and step d) first and mixing at a constant temperature;
g) mixing the mixture of step f) and the mixture of step e), stirring and drying at a constant temperature to prepare an ultrafine manganese dioxide (CMD) from which the impurities have been removed. (Method for manufacturing ultrafine manganese dioxide (CMD) for cathode material of secondary battery using crystal growth.
The method according to claim 1, wherein the manganese carbonate for industrial use is gradually heated at a rate of 5 ° C / min during the step a), and the method for producing ultrafine manganese dioxide (CMD) for a cathode material for a secondary battery using the same kind of crystal growth.
The method according to claim 1, wherein the ceramic balls for friction grinding in the step b) have diameters different from each other in size 2Φ, 3Φ, and 10Φ. Manganese dioxide (CMD).
4. The method of claim 3, wherein the ratio of the ceramic balls having diameters of 2Φ, 3Φ, and 10Φ in the step b) is 2Φ: 3Φ: 10Φ = 2.5: 2.5: 5 (CMD) for a cathode material of a secondary battery using the same kind of crystal growth.
The method of claim 1, wherein the manganese seeds are pulverized in an attrition mill pulverizer at 500 rpm for 12 hours in the process of step b). CMD).
The method according to claim 1, wherein the manganese seed powder is dried in an oven at a temperature of 80 ° C in the process of b), and the method for producing ultrafine manganese dioxide (CMD) for a cathode active material of a secondary battery is provided.
[7] The method of claim 1, wherein, in the step c), the mixture ratio of nanoscale manganese dioxide seeds and sulfuric acid is 76 to 82 wt% sulfuric acid based on 18 to 24 wt% of pulverized nanoscale manganese dioxide seeds. (Method for manufacturing ultrafine manganese dioxide (CMD) for cathode material of secondary battery using crystal growth.
The method as claimed in claim 1, wherein the temperature of the inside of the agitator is 95 ° C in the step c), and the manganese dioxide seed and the sulfuric acid are mixed in a stirrer for 30 minutes. Process for the production of fine manganese dioxide (CMD).
The method of claim 1, wherein the mixing ratio of manganese sulfate and distilled water in the step d) is 90 to 95 wt% of distilled water relative to 5 to 10 wt% of manganese sulfate. A method for producing ultrafine manganese dioxide (CMD) for a cathode material.
The method of claim 1, wherein the temperature of the inside of the agitator is 95 ° C in the step d), and the manganese sulfate and distilled water are mixed in a stirrer for 10 minutes. Process for the production of fine manganese dioxide (CMD).
The method according to claim 1, wherein the mixing ratio of sodium chlorate and distilled water in the step (e) is in the range of 70 to 80 wt% of distilled water with respect to 20 to 30 wt% of sodium chlorate. (Method for producing ultrafine manganese dioxide (CMD) for battery anode material.
The method as claimed in claim 1, wherein the temperature of the inside of the stirrer is in a range of 95 ° C in the step e), and the sodium chlorate and distilled water are mixed in a stirrer for 10 minutes. Process for the production of fine manganese dioxide (CMD).
The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, and 9, wherein in step e), potassium chlorate (KClO ₃ ), hydrogen peroxide (H ₂ O ₂ ), sodium persulfate (Na ₂ S ₂ O ₈ ), ammonium persulfate [(NH ₄ ) ₂ S ₂ O ₈ ] and potassium persulfate (K ₂ S ₂ O ₈ ) (CMD) for a cathode material of a secondary battery using the same kind of crystal growth.
The method according to claim 1, wherein the mixture of step c) and step d) is mixed at a temperature of 95 캜 in step f), and the method for preparing ultrafine manganese dioxide (CMD) for a cathode material for a secondary battery using the same kind of crystal growth.
15. The method of claim 1 or 14, wherein in the dried mixture of step f), nanosized manganese dioxide seed particles and Mn ²⁺ ions of manganese sulfate are present. A method for producing ultra fine particulate manganese dioxide (CMD).
The method according to claim 1, wherein the mixed and stirred mixture in step g) comprises: 46 wt% of manganese sulfate and distilled water mixture in step d) for 26 wt% manganese seed and sulfuric acid mixture in step c) By weight of sodium chlorate and 28% by weight of a distilled water mixture. The method for producing ultrafine manganese dioxide (CMD) for a cathode material of a secondary battery using the same kind of crystal growth.
The method according to claim 1 or 16, wherein the mixture in step g) is a mixture of ultrafine manganese dioxide (CMD) for secondary battery cathode material using homogeneous crystal growth characterized by mixing at a temperature of 95 캜 and a reaction time of 1 minute Way.
The method according to claim 1, wherein sodium hypochlorite is used as an oxidizing agent when the sodium chlorite mixture in step g) is added, and Mn ²⁺ ions of manganese sulfate are oxidized to manganese dioxide, (CMD) for a cathode active material of a secondary battery using the same kind of crystal growth.
A micro-particulate manganese dioxide (CMD) produced through the process of claim 1.
The ultrafine manganese dioxide (CMD) according to claim 19, wherein the ultrafine particulate manganese dioxide (CMD) has a particle size of 0.1 to 0.2 μm and is formed in a rod shape on the manganese seed.

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