Hydrogenated titanium oxide, manufacturing method for the same and anode material having the same

Abstract

The present invention relates to H2Ti12O25, a method for manufacturing the same, and a negative electrode material for a secondary battery containing the same. H2Ti12O25 manufactured by the method of the present invention can be used as a negative electrode material for a high-potential secondary battery. A method for manufacturing H2Ti12O25 according to an embodiment of the present invention comprises the steps of: preparing Na2Ti3O7 by solid-state heat treatment of TiO2 nanoparticles; mixing the Na2Ti3O7 with a solvent to produce H2Ti3O7; and separating and heat-treating the H2Ti3O7. One embodiment may further include, after the step of preparing Na2Ti3O7, a step of cooling a mixture of heat-treated TiO2 nanoparticles and Na2CO3 and then heat-treating it again.

Description

Technology Field

[65535] This invention was devised as a result of the research on "Development of fuel cell manufacturing technology using platinum recovery and resynthesis Pt / C catalyst from degraded fuel cells," and comprises titanium hydride oxide (H2Ti 12 O 25 The present invention relates to a titanium oxide hydride (H2Ti) produced by the manufacturing method of the present invention, a method for manufacturing the same, and a negative electrode material for a secondary battery containing the same. 12 O 25 ) can be used as a negative electrode material for high-potential secondary batteries. Background Technology

[0002] The anode material of a secondary battery is a key component responsible for storing lithium ions during the charging process. Generally, such anode materials must possess high energy density, a long lifespan, and stability, while efficiency during charging and discharging is also critical. Currently, graphite is the widely used anode material in secondary batteries. Although graphite possesses a stable structure and relatively high lithium ion storage capacity, there are limitations in increasing energy density. Furthermore, graphite anode materials are vulnerable to fast charging and suffer from a decrease in charging capacity as charging cycles progress. To address these issues, materials with higher energy densities, such as silicon, lithium metal, and carbon nanotubes, are being researched; however, these materials still face challenges regarding volume expansion, manufacturing costs, and safety issues. Prior art literature

[0003] Korean Registered Patent Publication No. 10-1897895 The problem to be solved

[0004] The present invention relates to H2Ti that can be utilized as a negative electrode material for secondary batteries. 12 O 25 The purpose is to provide a method for manufacturing [the product].

[0005] In addition, the present invention can provide a negative electrode material for a secondary battery that has excellent efficiency at high potential.

[0006] In addition, the present invention can provide a negative electrode material for a secondary battery that has excellent stability even at high potential and low heat generation. means of solving the problem

[0007] H2Ti according to an embodiment of the present invention 12 O 25 A method for manufacturing the product comprises the steps of: preparing Na2Ti3O7 by solid-state heat treatment of TiO2 nanoparticles; mixing the Na2Ti3O7 with a solvent to produce H2Ti3O7; and separating and heat-treating the H2Ti3O7. One embodiment may further include, after the step of preparing Na2Ti3O7, a step of cooling a mixture of heat-treated TiO2 nanoparticles and Na2CO3 and then heat-treating it again.

[0008] The step of preparing the above Na2Ti3O7 may involve mixing TiO2 nanoparticles with Na2CO3 and heat-treating them.

[0009] The above TiO2 nanoparticles may be at least one of anatase, rutile, and a mixture of anatase and rutile.

[0010] The content of the above TiO2 nanoparticles and Na2CO3 may be TiO2:Na2CO3 in a molar ratio of 3:1.

[0011] The step of producing the above H2Ti3O7 may involve heating the mixture of the above Na2Ti3O7 and solvent to 50 to 70°C.

[0012] In the step of producing the above H2Ti3O7, the solvent may be acidic.

[0013] In the step of separating and heat-treating the above H2Ti3O7, the separation may be performed by a centrifugal separation process.

[0014] In the step of separating and heat-treating the above H2Ti3O7, the heat treatment can be performed at 250 to 270°C.

[0016] H2Ti according to an embodiment of the present invention 12 O 25 It is manufactured by the manufacturing method described above.

[0018] The negative electrode material for a secondary battery according to an embodiment of the present invention is H2Ti 12 O 25 Includes the above H2Ti 12 O 25 It is manufactured by the manufacturing method described above. Effects of the invention

[0019] The present invention relates to H2Ti that can be utilized as a negative electrode material for secondary batteries. 12 O 25 A method for manufacturing is provided.

[0020] In addition, the present invention can provide a negative electrode material for a secondary battery that has excellent efficiency at high potential.

[0021] In addition, the present invention can provide a negative electrode material for a secondary battery that has excellent stability even at high potential and low heat generation. Brief explanation of the drawing

[0022] FIG. 1 is H2Ti manufactured in an embodiment of the present invention 12 O 25 This is a TEM analysis image. FIG. 2 is H2Ti manufactured in an embodiment of the present invention 12 O 25 This is an SEM analysis image. FIG. 3 is H2Ti manufactured in an embodiment of the present invention 12 O 25 This is an EDS analysis image. FIG. 4 shows various current densities (10 to 1000 mA g -1 This shows the discharge capacity and Coulombic efficiency measured in ). Figure 5 shows the charge / discharge voltage in the first cycle. Specific details for implementing the invention

[0023] Hereinafter, preferred embodiments of the present invention are described as follows with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

[0025] H2Ti according to an embodiment of the present invention 12 O 25 A method for manufacturing the product comprises the steps of: preparing Na2Ti3O7 by solid-state heat treatment of TiO2 nanoparticles; mixing the Na2Ti3O7 with a solvent to produce H2Ti3O7; and separating and heat-treating the H2Ti3O7. One embodiment may further include, after the step of preparing Na2Ti3O7, a step of cooling a mixture of heat-treated TiO2 nanoparticles and Na2CO3 and then heat-treating it again.

[0027] The step of preparing the above Na2Ti3O7 may involve mixing TiO2 nanoparticles with Na2CO3 and heat-treating them.

[0028] The above TiO2 nanoparticles may be at least one of anatase, rutile, and a mixture of anatase and rutile, and may have an average particle size of tens of nanometers. The above Na2CO3 may be in powder form.

[0029] In this step, the content of the TiO2 nanoparticles and Na2CO3 may be TiO2:Na2CO3 in a molar ratio of 3:1.

[0030] This step can be performed by solid-state heat treatment of the TiO2 nanoparticles and Na2CO3. In one embodiment, the TiO2 nanoparticles and Na2CO3 can be heated in air at 500°C or higher, preferably 750 to 850°C, and the process can be performed for 15 to 25 hours.

[0031] In one embodiment, a step of grinding the TiO2 nanoparticles and Na2CO3 before the solid-state heat treatment may be performed. This allows for nano-sized H2Ti 12 O 25 It can manufacture.

[0033] One embodiment may further include a step of cooling a mixture of heat-treated TiO2 nanoparticles and Na2CO3 and then performing a secondary solid-state heat treatment after the step of preparing the Na2Ti3O7. After cooling the mixture, which has been heated to produce Na2Ti3O7 through the secondary solid-state heat treatment, to room temperature (20 to 30°C), it may be heated to 500°C or higher, preferably 750 to 850°C, and heat-treated for 15 to 25 hours. This allows for more effective production of Na2Ti3O7. One embodiment may perform a step of grinding the cooled mixture before the secondary solid-state heat treatment. This allows for nano-sized H2Ti 12 O 25 It can manufacture.

[0035] Next, the Na of the above Na2Ti3O7 + ul H + A step of producing H2Ti3O7 by ion exchange can be performed. This step can be carried out by mixing the Na2Ti3O7 and solvent, and heating and stirring.

[0036] In one embodiment, this step may be performed by heating the mixture of Na2Ti3O7 and the solvent to 50 to 70°C and for 4 to 6 days.

[0037] The above solvent may be acidic. In one embodiment, the solvent may be a mixture of deionized water and HCl.

[0039] Next, the step of separating and heat-treating the above H2Ti3O7 is performed.

[0040] The above separation can be carried out by a centrifugation process. The solvent and H2Ti3O7 are separated by centrifugation, and the separated H2Ti3O7 is washed with water and ethanol and then dried at 70°C. H2Ti3O7 can be obtained through this step.

[0041] The above heat treatment can be performed at 250 to 270°C for 4 to 6 hours. Through this step, H2Ti 12 O 25 You can obtain.

[0043] H2Ti according to an embodiment of the present invention 12 O 25 is manufactured by the manufacturing method described above. The above H2Ti 12 O 25 It is a nano-sized particle, and as shown in Fig. 2, it may have a shape in which a number of nanorods are clustered together.

[0045] The negative electrode material for a secondary battery according to an embodiment of the present invention is H2Ti 12 O 25 Includes the above H2Ti 12 O 25 It is manufactured by the manufacturing method described above.

[0047] Example: H 2 Ti 12 O 25 manufacturing

[0048] 1.2 g of TiO2 nanoparticles, in which anatase (COTIOX KA-100, Cosmo Chemical), rutile (Titanium(IV) oxide, rutile, Aldrich), and a mixed phase of anatase and rutile (Aeroxide TiO2P 25, Evonik) were mixed in equal weight ratios, and 0.53 g of Na2CO3 (≥99.0%, Sigma-Aldrich) was mixed. This mixture was ground and heated in air at 800°C for 20 hours. The heated mixture was cooled to room temperature, ground again, and heated in air at 800°C for 20 hours. Next, 0.75 g of the mixture (Na2Ti3O7) was added to 200 ml of a 0.1 M HCl solution and stirred at 60°C for 5 days. After completing stirring, the product (H2Ti3O7) was obtained by centrifugation, washed twice with water and ethanol, and dried at 70°C. The dried product was heat-treated at 260°C for 5 hours to obtain H2Ti 12 O 25 generated.

[0050] Experimental Example: TEM, SEM, and EDS imaging

[0051] H2Ti manufactured in the example 12 O 25 TEM, SEM, and EDS images were taken, and the results are shown in Figures 1 to 3, respectively. H2Ti 12 O 25 It has a bundle of multiple rods, and the diameter of each rod was 3 to 4 nm. In addition, the diameter of the bundle was 50 to 100 nm and the length was 250 to 350 nm. Referring to FIG. 3, the example is mainly composed of the elements Ti and O, and elements such as Na or C were not observed.

[0053] Manufacturing Example: Manufacturing of Coin Cells

[0054] H2Ti, an example, was used to measure electrochemical properties. 12 O 25A coin cell was manufactured using as the cathode material. Lithium foil was used as the counter electrode, and microporous polypropylene was used as the separator. The working electrode was the H2Ti prepared in the example. 12 O 25 , conductive carbon (Super P) and polyminylidene difluoride binder were mixed in a weight ratio of 8:1:1 to prepare a coin cell. This was assembled in a glove box filled with Ar to manufacture a coin cell.

[0056] Experimental Example: Galvanostatic charge / discharge analyses

[0057] This analysis was performed using an automatic battery cycler (WBCS3000, WonaTech) at 30℃.

[0058] FIG. 4 shows various current densities (10 to 1000 mA g -1 This plots the discharge capacity and Coulombic efficiency measured in ). In a coin cell (n-HTO) using the example as the working electrode, 10 to 1000 mA g -1 At current densities, it exhibited a Coulomb efficiency of nearly 100%, and 138 to 230 mAh g -1 It showed a discharge capacity of. This is micro-sized H2Ti 12 O 25 It was confirmed that it showed superior performance compared to a coin cell (μ-HTO) using as a working electrode.

[0060] Experimental Example: Electrochemical Impedance Spectroscopy (EIS) and Cyclic Volammetry (CV) Measurement

[0061] This analysis was performed using a computer-controlled potentiometer (ZIVE SP2, WonaTech). Measurements were taken at E=1.58V after 30 charge / discharge cycles. The frequency range was 100 mHz to 100 kHz in AC with an amplitude of 5 mV.

[0062] Figure 5 illustrates the charge / discharge voltages in the first cycle. From Figure 5, it can be seen that some of the Li stored during charging remains on the working electrode even during discharge. This indicates that H2Ti during the charging process12 O 25 H of + Ga Li + It means substituting with, and explains the reason why the specific capacity is high in the present invention.

[0064] The present invention is not limited by the embodiments described above and the attached drawings, but is intended to be limited by the appended claims. Accordingly, various substitutions, modifications, and changes may be made by those skilled in the art within the scope of the technical concept of the present invention as described in the claims, without departing from the technical spirit of the invention, and such are also to be considered to fall within the scope of the present invention.

Claims

Claim 1 The method comprises the steps of: preparing Na2Ti3O7 by solid-state heat treatment of TiO2 nanoparticles; mixing the Na2Ti3O7 with a solvent to produce H2Ti3O7; and separating and heat-treating the H2Ti3O7, wherein the TiO2 nanoparticles are a mixture of anatase and rutile in a weight ratio of 1:1, the step of preparing Na2Ti3O7 involves mixing the TiO2 nanoparticles with Na2CO3 and heat-treating them, and the content of the TiO2 nanoparticles and Na2CO3 is such that the molar ratio of TiO2:Na2CO3 is 3:1, H2Ti 12 O 25 Method of manufacturing. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 In claim 1, after the step of preparing the Na2Ti3O7, the H2Ti further comprises the step of cooling a mixture of heat-treated TiO2 nanoparticles and Na2CO3 and then heat-treating it again. 12 O 25 Method of manufacturing. Claim 6 In claim 1, the step of producing H2Ti3O7 is heating the mixture of Na2Ti3O7 and the solvent to 50 to 70°C, H2Ti 12 O 25 Method of manufacturing. Claim 7 In claim 1, in the step of producing H2Ti3O7, the solvent is acidic, H2Ti 12 O 25 Method of manufacturing. Claim 8 In claim 1, in the step of separating and heat-treating the H2Ti3O7, the separation is performed by a centrifugal separation process, H2Ti 12 O 25 Method of manufacturing. Claim 9 In claim 1, in the step of separating and heat-treating the H2Ti3O7, the heat treatment is performed at 250 to 270°C, H2Ti 12 O 25 Method of manufacturing. Claim 10 delete Claim 11 delete

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