KR101847763B1 - Ultrafast auto flame synthesis method for the electrode material - Google Patents

Abstract

The present invention relates to a method for mass production of electrode materials using an ultrafast automatic flame synthesis method, wherein the method for producing electrode materials according to the present invention dissolves raw material in an alcohol solvent without any special equipment and mixes the raw material with the alcohol solvent at the temperature of 80 to 150 deg. C for a short time, thereby immediately producing the electrode materials with a very high exothermic flame reaction. The process takes about 11 to 60 minutes, which is a remarkably short period of time compared to a conventional solid-phase preparation method requiring 40 to 48 hours or a wet solution method requiring 30 to 42 hours. Therefore, the method for producing electrode materials according to the present invention, as compared to the conventional methods, has the effects of process simplification, high efficiency, low costs, energy saving, and mass production.

Description

[0001] The present invention relates to a method for manufacturing an electrode material using an ultra-high speed auto flame synthesis method,

FIELD OF THE INVENTION The present invention relates to a method for mass production of an electrode material using an ultra-high speed automatic flame synthesis method.

Recently, in response to the rapid development of the communication industry such as electronic industry and various information communication including mobile communication, in order to meet the demand of light and short life of electronic devices, a variety of products such as notebooks, netbooks, tablet PCs, mobile phones, smart phones, PDAs, Portable electronic products, and communication terminals have been widely popularized, and development of a battery that is a driving power source for these devices is also increasing.

In addition, with the development of electric vehicles such as hydrogen electric vehicles, hybrid electric vehicles and fuel cell vehicles, great attention has been paid to the development of batteries having high performance, large capacity, high density, high output and high stability, The development of batteries is also a big issue.

Batteries that convert chemical energy into electrical energy are divided into primary cells, secondary cells, fuel cells, and solar cells depending on the type and characteristics of basic materials.

The dual primary cells produce energy through irreversible reactions such as manganese batteries, alkaline batteries, and mercury batteries. However, they have a disadvantage in that they are large in capacity but can not be recycled, and thus have various problems such as energy inefficiency and environmental pollution.

The secondary battery includes a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lithium ion battery, a lithium polymer battery, and a lithium metal battery and repeats charge and discharge using reversible mutual conversion of chemical energy and electric energy. As a chemical cell that can be operated by reversible reaction, it has advantages of recycling and environment-friendly.

The secondary cell has four basic components: a positive electrode and a negative electrode, a separator and an electrolyte.

The positive and negative electrodes have positive and negative potentials, respectively, as electrodes for conversion and storage of energy such as oxidation / reduction. The separator is positioned between the anode and the cathode to maintain electrical insulation and provide a path for charge transport. In addition, the electrolyte acts as an intermediary for charge transfer.

Each of the electrodes includes each of the electrode active materials. Each of the active materials used in a lithium secondary battery, which is currently the most popular among the secondary batteries, is as follows.

Lithium cobalt oxide (Li _x CoO ₂ ), lithium nickel oxide (Li _x NiO ₂ ), lithium nickel cobalt oxide (Li _x (NiCo) O ₂ ), and the like are used as the cathode active material. Oxides such as lithium nickel cobalt manganese oxide (Li _x (NiCoMn) O ₂ ), spinel type lithium manganese oxide (Li _x Mn ₂ O ₄ ), manganese dioxide (MnO ₂ ), or lithium iron phosphate (Li _x FePO ₄ ) Olivine type or NASICON type phosphates, silicates, sulfates or polymer materials such as manganese phosphate (Li _x MnPO ₄ ) and the like can be used.

As the negative electrode active material, a compound capable of intercalating lithium metal, its alloy or lithium ion can be used. A polymer material or a carbon material can be used, and a graphite system such as artificial or natural graphite, Carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon nanotubes (CNTs), carbon nanotubes (CNTs), graphite- Carbon based materials such as carbon nonawall (CNW), etc. may be used.

Although a solid phase production method, a wet solution method, a microwave production method, a polymer pyrolysis method and a flame spray pyrolysis method have been developed as methods for producing an electrode active material, an economical method capable of mass production with less energy in a short time has not been developed.

For example, LiCoO ₂ is prepared using Li ₂ CO ₃ and Co ₃ O ₄ , and the mixture of the metal oxides is subjected to a pulverization process using a solution medium such as acetone and ethanol The sintering process is required for a long time at a high temperature. This makes it difficult to produce economically homogeneous LiCoO ₂ .

The wet solution method includes a sol-gel method, coprecipitation method, and a thermal method. In this method, compared with a solid-phase method, LiCoO₂ Powder can be produced. However, since the wet solution method has to be subjected to various steps, the manufacturing process is complicated and it is difficult to control the process conditions such as humidity, temperature and pH at each step.

In addition, since the microwave manufacturing method and the polymer pyrolysis method require several steps, the manufacturing process is complicated and a lot of energy is required.

In addition, pyrolytic spray pyrolysis requires special equipment equipped with special equipment such as ultrasonic atomizer, injection-type flame burner and particle collector. In order to produce precursor particles, it is necessary to precisely control process conditions such as heat of combustion and combustion conditions during manufacturing .

Therefore, there is a need for a technology capable of mass production of electrode material in a short time while saving energy with a simple manufacturing process.

Korea Patent Publication No. 2013-0127054

An object of the present invention is to provide a technique capable of mass-producing electrode materials in a short time while saving energy by using an ultra-high speed automatic flame synthesis method.

FIELD OF THE INVENTION The present invention relates to a method for mass production of an electrode material using an ultra-high speed automatic flame synthesis method. As an example of the method for producing the electrode material,

And a step of stirring a solution containing a lithium compound, a transition metal compound and an alcohol solvent at 80 to 150 占 폚.

The method of manufacturing an electrode material according to the present invention does not require special equipment and dissolves the raw material in an alcohol solvent and then mixes at a temperature of 80 to 150 ° C for a short period of time, Can be produced. This process takes about 11 to 60 minutes, which is remarkably short compared to the conventional solid-phase preparation method which takes 40 to 48 hours or the wet solution method which requires 30 to 42 hours.

Therefore, the method of manufacturing the electrode material according to the present invention has advantages of simplifying the process, high efficiency, low cost, energy saving, and mass production compared with the existing methods.

1 is a schematic view showing a method of manufacturing an electrode material according to the present invention.
2 shows XRD patterns of electrode materials according to Examples and Comparative Examples.
3 shows SEM, TEM and HRTEM images of electrode materials according to Examples and Comparative Examples.
FIG. 4 shows electrochemical characteristics of a coin cell manufactured using the electrode material according to Examples and Comparative Examples.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Of the existing secondary batteries, lithium cobalt oxide (Li _x CoO ₂ ), lithium nickel oxide (Li _x NiO ₂ ), lithium nickel cobalt oxide ( Oxides such as Li _x (NiCo) O ₂ , lithium nickel cobalt manganese oxide Li _x (NiCoMn) O ₂ , spinel type lithium manganese oxide Li _x Mn ₂ O ₄ , manganese dioxide MnO ₂ , Olivine type or NASICON type phosphates, silicates, sulfates or polymer materials such as phosphate (Li _x FePO ₄ ), lithium manganese phosphate (Li _x MnPO ₄ ) and the like can be used .

Although a solid phase production method, a wet solution method, a microwave production method, a polymer pyrolysis method and a flame spray pyrolysis method have been developed as methods for producing an electrode active material, an economical method capable of mass production with less energy in a short time has not been developed.

For example, LiCoO ₂ is prepared using Li ₂ CO ₃ and Co ₃ O ₄ , and the mixture of the metal oxides is subjected to a pulverization process using a solution medium such as acetone and ethanol The sintering process is required for a long time at a high temperature. This makes it difficult to produce economically homogeneous LiCoO ₂ .

The wet solution method includes a sol-gel method, coprecipitation method, and a thermal method. In this method, compared with a solid-phase method, LiCoO ₂ Powder can be produced. However, since the wet solution method has to be subjected to various steps, the manufacturing process is complicated and it is difficult to control the process conditions such as humidity, temperature and pH at each step.

In addition, since the microwave manufacturing method and the polymer pyrolysis method require several steps, the manufacturing process is complicated and a lot of energy is required.

In addition, pyrolytic spray pyrolysis requires special equipment equipped with special equipment such as ultrasonic atomizer, injection-type flame burner and particle collector. In order to produce precursor particles, it is necessary to precisely control process conditions such as heat of combustion and combustion conditions during manufacturing .

Therefore, there is a need for a technology capable of mass production of electrode material in a short time while saving energy with a simple manufacturing process.

Accordingly, the present invention does not require any special equipment, and dissolves the raw material in an alcohol solvent, and then mixes the mixture at a temperature of 80 to 150 ° C for a short period of time, so that a very high exothermic flame reaction occurs, To provide a method for producing a material. This process takes about 11 to 60 minutes, which is remarkably short compared to the conventional solid-phase preparation method which takes 40 to 48 hours or the wet solution method which requires 30 to 42 hours.

Therefore, the method of manufacturing the electrode material according to the present invention has advantages of simplifying the process, high efficiency, low cost, energy saving, and mass production compared with the existing methods.

A method of manufacturing an electrode material according to the present invention is a method of manufacturing an electrode material, comprising the steps of: preparing a lithium cobalt oxide (Li _x CoO ₂ ), lithium nickel oxide (Li _x NiO ₂ ), lithium nickel cobalt oxide (Li _x (NiCo) O ₂ ), lithium nickel cobalt manganese oxide (Li _x (NiCoMn) O ₂ ), lithium nickel cobalt aluminum oxide (Li _x (NiCoAl) O ₂ ), and the like.

Hereinafter, a method of manufacturing an electrode material according to the present invention will be described in more detail.

As one example of the method for producing the electrode material according to the present invention,

And a step of stirring a solution containing a lithium compound, a transition metal compound and an alcohol solvent at 80 to 150 占 폚.

Specifically, when a lithium compound and a transition metal compound are dissolved in an alcohol solvent, and then a solution containing a lithium compound, a transition metal compound and an alcohol solvent is stirred at a relatively low temperature ranging from 80 to 150 ° C, An electrode material is produced within about 1 to 30 seconds as an exothermic flame reaction occurs.

The temperature of the solution containing the lithium compound, the transition metal compound and the alcohol solvent may be, for example, 80 to 150 ° C, 90 to 150 ° C, 90 to 140 ° C, 90 to 130 ° C, 130 < 0 > C or 100-120 < 0 > C.

As described above, the present invention is a simple process, and no special equipment is required, and the electrode material can be mass-produced in a short time at a relatively low temperature.

The raw materials used in the present invention are as follows.

First, the lithium compound may include, for example, at least one of lithium acetate and lithium nitrate.

The transition metal compound may include at least one of Co, Mn, Ni, Cu, Zn and W, for example.

Specifically, the transition metal compound may be at least one selected from the group consisting of chloride, oxalate, acetate, sulfate, nitrate, hydroxide, ethylhexane salt, naphthenate, hexaate Or an organic acid metal salt (stearic acid, dimethyldithiocarbamic acid, acetylacetonate, oleic acid, linoleic acid, linolenic acid salt) and an oxide of a cyclopentadienyl compound, an alkoxide, an organic acid metal salt.

By using an alcohol solvent having a solubility parameter value within the above range, the lithium compound and the transition metal compound can be uniformly dissolved. Through this, an electrode material having a uniform crystal structure can be produced by heating and stirring a solution containing a lithium compound, a transition metal compound and an alcohol solvent to prepare an electrode material. Further, when this is used for a lithium ion battery, excellent non-discharge capacity can be realized.

The alcohol solvent may include, for example, at least one of 1-propanol, 2-methoxyethanol, ethylene glycol and tetraethylene glycol. Specifically, the alcohol solvent may be used for a monohydric alcohol. For example, the monohydric alcohol solvent may be 2-methoxyethanol. Thus, by using the alcohol solvent, the flame can be automatically formed in a short time at a relatively low temperature without a separate additive or a flame reaction.

The step of stirring the solution containing the lithium compound, the transition metal compound and the alcohol solvent at 80 to 150 DEG C may be performed for 10 to 45 minutes. For example, the stirring step may be performed for 10 to 40 minutes, 15 to 35 minutes, 20 to 35 minutes, or 25 to 30 minutes. As a result, it can be seen that the method for producing an electrode material according to the present invention can be produced by a simple method of heating and stirring at a low temperature for a short time.

The step of dissolving the lithium compound and the transition metal compound in the alcohol solvent for 1 to 15 minutes before the step of stirring the solution containing the lithium compound, the transition metal compound and the alcohol solvent at 80 to 150 캜.

Specifically, the uniformity of the solution can be further improved by mixing the lithium compound and the transition metal compound with an alcohol solvent and ultrasonic treatment. Here, the dissolving step may be performed, for example, for 3 to 12 minutes or 5 to 10 minutes.

As a result, it can be seen that when the electrode material is manufactured through the dissolving and heating and stirring steps in the method of manufacturing the electrode material according to the present invention, it takes about 11 to 60 minutes, that is, 1 hour or less.

And then sintering the solution containing the lithium compound, the transition metal compound and the alcohol solvent at a temperature of from 80 to 150 캜, followed by sintering at 600 to 1000 캜. For example, the sintering may be performed at 700 to 900 ° C or 750 to 850 ° C for 4 to 8 hours.

By performing the sintering step, the crystallinity of the electrode material produced by the method according to the present invention can be further improved.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.

Example

An electrode material was prepared by the same process as in the schematic diagram of Fig.

LiNO ₃ (98.0%, Junsei) and Co (NO ₃ ) ₂ .6H ₂ O (98.0%, Junsei) were dissolved in 2-methoxyethanol contained in a beaker and sonicated for about 10 to 15 minutes . Then, a magnetic stirrer was placed in a beaker containing the prepared solution of brown ions, and the solution was heated to 100 to 120 ° C using a hot plate (Stirring on hot plate) And the mixture was heated and stirred for about 25 to 30 minutes until the mixture was spontaneously ignited (Flame ignition of precursors). Then, the ignited flame was turned off within about 10 to 15 seconds to release a large amount of gas and to produce LiCoO ₂ powder (Burnt LiCoO ₂ powder). Then, the LiCoO ₂ powder was cooled in the air, and the cooled LiCoO ₂ powder was calcined at 800 ° C. for 6 hours to prepare LiCoO ₂ as an electrode material according to the present invention.

Comparative Example

LiCoO ₂ was purchased from Alfa Aesar (CAS No. 12190793).

Experimental Example  1: Structure verification

(One) XRD  Measure

X-ray diffraction (XRD, Rigaku Ultima IV, Japan) was measured to confirm the crystal structure of LiCoO ₂ according to the examples and the comparative examples. The results are shown in FIG. 2, it can be seen that the peak intensity of LiCoO ₂ according to the example (a) is stronger than that of LiCoO _{2 of the} comparative example (b). These results may indicate that the LiCoO ₂ produced by the ultra-high speed auto flame synthesis according to the present invention has a high crystallinity and uniformity as compared with commercially available LiCoO ₂ .

Specifically, the intensity ratio I ₍₀₀₃₎ / I ₍₁₀₄₎ of the peak of (003) and (104) of LiCoO ₂ according to the examples and the comparative examples was 1.69 and 1.40, respectively, and in the case of LiCoO ₂ according to the examples, appear. It can be seen that the cationic manipulation of Li / Co of LiCoO ₂ prepared by the process according to the present invention has a better crystal structure and thus can realize excellent electrochemical properties.

(2) SEM , TEM  shooting

SEM (scanning electron microscopy, JSM6500F, Jeol, Japan) and transmission electron microscopy (JEM-2100F, Jeol, Japan) were photographed to investigate the morphology of LiCoO ₂ according to the examples and the comparative examples. The results are shown in FIG.

3 (a) is a SEM photograph of LiCoO ₂ according to an embodiment, (b) is a SEM photograph of LiCoO ₂ according to a comparative example, and (c) is a TEM photograph of LiCoO ₂ according to an embodiment. (D) is a high-resolution TEM image of LiCoO ₂ according to an embodiment.

3 (a) and 3 (b), it can be seen that the LiCoO ₂ of the examples and the comparative examples are piled up in a plate shape and in a granular form. In addition, the average particle sizes of LiCoO ₂ according to Examples and Comparative Examples are in the range of 0.8 to 3.5 μm and 0.5 to 3 μm, respectively.

Referring to FIG. 3 (c), it can be seen that the particles of LiCoO ₂ according to the embodiment are nanocrystals having an average size of about 10 to 40 nm.

Also, FIG. 3 (d) shows that LiCoO ₂ according to the embodiment has a well-formed latex structure. Thus, it can be seen that the electrode material produced by the method according to the present invention has high crystallinity.

In addition, the crystal-to-planar distance (d-spacing) of the crystalline latex structure was confirmed to be about 0.205 Å corresponding to the (104) plane. This can support the accuracy of XRD data.

Experimental Example  2: Confirm electrochemical properties

Coin cells (2016 coin cells) were prepared using LiCoO ₂ according to the above Examples and Comparative Examples, and their electrochemical characteristics were confirmed. Specifically, each of the coin cells was operated at various C rate currents in a voltage range of 2 to 4.5V. The results are shown in FIG.

4 (a), the measurement result of the charge / discharge capacity of each cell can be confirmed. Specifically, when discharge at a 0.05 C rate current, in the case of a coin cell produced by using a LiCoO ₂ according to the embodiment the first non-discharge cycles the capacity is 191.7 mAh · g ^{- 1,} and if the comparative example 188.2 mAh · g ^-1 , It can be seen that the non-discharge capacity is excellent when the electrode material is manufactured by the method according to the present invention.

5 (b) and 5 (c), when the coin cell is discharged at 0.1, 0.2, 0.5, 1 and 2 C rate currents and the LiCoO ₂ according to the embodiment, 169, 169, 142, and 106 mAh · g ^-1 , respectively, and in the comparative examples, 183, 169, 139, 92, and 36 mAh · g ^-1 .

As a result, it can be seen that the electrode material produced by the method according to the present invention has excellent electrochemical characteristics, and is particularly superior at high current conditions.

Claims (7)

Dissolving a lithium compound and a transition metal compound in an alcohol solvent for 1 to 15 minutes;
Stirring the solution containing the lithium compound, the transition metal compound and the alcohol solvent through the dissolving step at 100 to 120 DEG C for 10 to 45 minutes; And
Said solution comprising a flame reaction for 1 to 30 seconds by spontaneous firing during the stirring step,
Wherein the alcohol solvent is at least one of 1-propanol, 2-methoxyethanol, ethylene glycol, and tetraethylene glycol.
The method according to claim 1,
Wherein the lithium compound comprises at least one of lithium acetate and lithium nitrate.
The method according to claim 1,
Wherein the transition metal compound comprises at least one of Co, Mn, Ni, Cu, Zn, and W.
3. The method of producing an electrode material according to claim 1, further comprising the step of sintering at 600 to 1000 DEG C after the step of passing through the flame reaction. delete delete delete

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