KR101905702B1 - Hierarchically porous inorganic oxide, method for preparing the same, and lithium-ion battery comprising the same - Google Patents

Abstract

The present invention relates to a hierarchically porous inorganic oxide which comprises: a meso-pore inorganic oxide including a plurality of meso-pores; and one macro-pore or a plurality of macro-pores surrounded by the meso-porous inorganic oxide. The hierarchically porous inorganic oxide has various macro-pore structures by controlling a use of nitric acid and a rate of evaporation. Also, the hierarchically porous inorganic oxide is applied to a cathode of a lithium secondary battery, thereby improving efficiency of the lithium secondary battery.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a layered porous inorganic oxide, a method of manufacturing the same, and a lithium secondary battery including the porous oxide layer,

The present invention relates to a layered porous inorganic oxide, a method for producing the same, and a lithium secondary battery comprising the layered porous inorganic oxide. More particularly, the present invention relates to a layered porous inorganic oxide which can be used as a carrier, a drug delivery or an anode active material for a catalyst, And a lithium secondary battery comprising the same as a negative electrode material.

The hierarchical porous structure refers to a porous structure having two or more pores having different sizes at the same time. The layered porous material has a high surface area, size selectivity and wide active site from micropores (<2 nm), mesopores (2 to 50 nm), while macropores (&Gt; 50 nm). Particularly, inorganic oxide materials having a hierarchical porous structure are widely used in applications such as catalysts, separation, drug delivery, and energy devices.

Previously, hierarchical porous structures have been synthesized by simultaneously mixing templates with different length scales. In this case, however, it is difficult to control the mixing behavior between the different templates, and each template works competitively, resulting in a material having irregular pore structure or only one pore.

In order to overcome these disadvantages, a method of sequentially applying each template was used. A three-dimensionally packed colloidal crystal having a size of several hundreds of nanometers is first impregnated into a small space between the packed colloidal crystals and the block copolymer-material precursor mixture is impregnated into a small space between packed colloidal crystals, To obtain a layered porous structure. However, this method is difficult to mass-synthesize colloidal crystals, requires a lot of time and effort to uniformly pack the synthesized colloids, and precipitates and agglomerates of precursors in the process of impregnating the precursor between empty spaces of the colloid sequentially But also has a disadvantage that the wall thickness is thinned and the mechanical strength is weakened and the stability is lowered.

The block copolymer can self-assemble into various structures ranging from 2 to 50 nm in size through microphase separation. Using the properties of these block copolymers, mixtures of block copolymers - organic (inorganic) precursors have been made to make mesoporous materials of various compositions and structures. However, such block copolymer-multicomponent mixtures exhibit complex phase behavior and macroscale (> 50 nm) macrophase separation can occur during self-assembly. This macrophase separation may occur mainly when the precursor is too large to stabilize within the block copolymer, is low in solubility, or is difficult to control due to the high reactivity of the precursor. When the object separation occurs, the mesoporous structure is deformed and irregular amorphous nanostructures are generated.

The object of the present invention is to provide a hierarchically porous porous inorganic oxide having various structures by controlling the use and evaporation rate of nitric acid.

Still another object of the present invention is to provide a lithium secondary battery with high efficiency by applying such a hierarchically-porous porous inorganic oxide to a cathode of a lithium secondary battery.

According to an aspect of the present invention, there is provided a mesoporous inorganic oxide comprising a plurality of meso-pores; And a single or multiple macro-pores surrounded by the mesoporous inorganic oxide.

The shape of the macropores may be any one selected from the group consisting of spherical, tunnel, and matirix types.

The macropores can be uniformly distributed in the layered porous inorganic oxide.

The mesopores may be uniformly distributed in the mesoporous inorganic oxide.

Wherein the mesoporous inorganic oxide is selected from the group consisting of titanium dioxide (TiO ₂ ), titanium dioxide-carbon composite (TiO ₂ -C), niobium-titanium composite oxide (TiNb ₂ O ₇ ), tungsten trioxide (WO ₃ ) And may be at least one selected from the group consisting of titanium oxide-carbon composite oxide, niobium oxide, titania, tungsten oxide, niobium oxide, zirconium oxide, alumina, aluminosilicate, germania, tantalum oxide, tin oxide, manganese oxide and vanadium oxide.

The diameter of the mesopores may be between 2 and 50 nm.

The diameter of the macropores may be greater than 50 nm and less than or equal to 3,000 nm.

According to another aspect of the present invention, there is provided a cathode comprising the layered porous inorganic oxide.

According to another aspect of the present invention, there is provided a lithium secondary battery including the negative electrode.

According to another aspect of the present invention, there is provided a process for preparing a mixed solution comprising: (a) preparing a mixed solution by mixing an amphiphilic block copolymer, an inorganic precursor, a carbon precursor, an acid, and an organic solvent; (B) preparing a complex comprising an amphiphilic block copolymer-inorganic oxide-carbon precursor by evaporation-induced self-assembly (EISA) of the mixed solution; And (c) heat treating the composite to produce a layered porous inorganic oxide; Wherein the porous inorganic oxide is a porous inorganic oxide.

The macropore structure of the layered porous inorganic oxide can be controlled by controlling the mass ratio of the mass of the amphiphilic block copolymer and the inorganic precursor to the mass of the acid.

The mass ratio of the mass of the amphiphilic block copolymer and the inorganic precursor to the mass of the acid may be 1: 3 to 1: 5.

The morphology of macropores of the layered porous inorganic oxide can be controlled by controlling the evaporation rate of the organic solvent in the evaporation-induced self-assembly.

The step (b) may be carried out at 20 to 80 &lt; 0 &gt; C.

The step (b) may be carried out under atmospheric pressure.

Wherein the amphiphilic block copolymer is selected from the group consisting of a polyethylene oxide-block-polystyrene block copolymer (poly (ethylene oxide) -b-poly (styrene)), a polyethylene oxide-block-polymethyl methacrylate block copolymer ) -b-poly (methylmethacrylate)), polyisoprene-block-polyethylene oxide

Poly (isoprene) -b-poly (ethylene oxide), polyisoprene-block-polystyrene-block-polyethylene oxide block copolymer (polye (isoprene) ), Poly (4-tert-butyl) styrene-block-polyethyleneoxide and Pluronic-type commercial block copolymers (P123, F127, F108) . &Lt; / RTI &gt;

The inorganic precursor may include at least one of a metal precursor and a non-metal inorganic precursor.

The metal precursor may include at least one of a metal alkoxide and a metal chloride.

The metal precursor may include at least one selected from the group consisting of titanium isopropoxide, Niobium chloride, and tungsten isopropoxide.

The non-metallic inorganic precursor may include at least one selected from the group consisting of alkyl silicate, sodium silicate, silicon alkoxide, aluminum alkoxide and aluminosilicate.

Wherein the carbon precursor is selected from the group consisting of resol, phenol-formaldehyde resin, resorcinol-formaldehyde resin, phloroglucinol-formaldehyde resin, Formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin, and furfuryl alcohol.

The organic solvent may include at least one selected from the group consisting of chloroform, tetrahydrofuran, and dioxane.

The step (c) may be calcined in air at a temperature of 400 to 1200 ° C.

(D) removing the non-metal oxide from the inorganic oxide by etching after the step (c) to produce a layered porous inorganic oxide containing a metal oxide.

The present invention can improve the efficiency of a lithium secondary battery by providing a layered porous inorganic oxide having various macro-pore structures by controlling the use and evaporation rate of nitric acid and applying it to a cathode of a lithium secondary battery.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow diagram illustrating the structure and method of manufacturing a hierarchically-porous inorganic oxide of the present invention.
2 (a), 2 (b) and 2 (c) are SEM images of Example 1, and FIGS. 2 i) shows an SEM image of Example 3. Fig.
3 (a) and 3 (b) are SEM images of Example 7, and FIGS. 3 (c) and 3 (d) are SEM images of Example 8.
FIGS. 4 (a) and 4 (b) are SEM side and top view images of the cmm-TNOS-500 prepared according to Example 4 by cutting out the focused ion beam (FIB) (c) is a 3D image obtained by visualizing the cmm-TNOS-500 prepared according to Example 4 using a nanoscale X-49-23ray computed tomography, (d) a 3D image obtained by enlarging a part of (c) ) Is reconstructed by a strut-thinning algorithm to show a simplified skeletal structure (e) and macro pores (f). Fig. 4 (g) shows quantitative structure analysis in the macro pore region of (f), showing the distance g between nodes and the distribution h of struts per node.
5 (a) is a SEM image of cmm-TNOS-900 prepared according to Example 5, (b) and (c) are SEM images of cmm- TNO-900 prepared according to Example 7 and m-TNO-900 prepared according to Comparative Example 1, (e) shows the result of analysis according to the nitrogen adsorption / desorption analysis curve, (G) and (h) show X-ray diffraction pattern analysis results of cmm-TNO-900 prepared in Example 7 and m-TNO-900 prepared in Comparative Example 1, (1 C = 167.5 mA g ^-1 ) at a current density of 0.2 to 10 C (1 C = 167.5 mA g ^-1 ).

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

It is to be understood, however, that the following description is not intended to limit the invention to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Furthermore, terms including an ordinal number such as first, second, etc. to be used below can be used to describe various elements, but the constituent elements are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Also, when an element is referred to as being "formed" or "laminated" on another element, it may be directly attached or laminated to the front surface or one surface of the other element, It will be appreciated that other components may be present in the &lt; / RTI &gt;

The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow diagram illustrating the structure and method of manufacturing a hierarchically-porous inorganic oxide of the present invention.

Hereinafter, the hierarchically-porous inorganic oxide of the present invention will be described with reference to FIG.

The present invention relates to a mesoporous inorganic oxide comprising a plurality of meso-pores; And one or more macro-pores surrounded by the mesoporous inorganic oxide; Porous porous inorganic oxide.

The shape of the macropores may be any one selected from the group consisting of spherical, tunnel, and matirix types.

The macropores can be uniformly distributed in the layered porous inorganic oxide.

The mesopores may be uniformly distributed in the mesoporous inorganic oxide.

Specifically, the hierarchical porous structure means a porous structure in which two groups of pores having different pore sizes coexist. Preferably, the two types of pores, mesopores and macropores, form a uniform distribution . Accordingly, the metal oxide component included in the layered porous inorganic oxide can form a three-dimensional connection structure. The macropores can be connected to each other or independently. The macro pores may be connected to each other to form enlarged macro pores, or they may exist separately from other macro pores.

Wherein the mesoporous inorganic oxide is selected from the group consisting of titanium dioxide (TiO ₂ ), titanium dioxide-carbon composite (TiO ₂ -C), niobium-titanium composite oxide (TiNb ₂ O ₇ ), tungsten trioxide (WO ₃ ) And may include at least one selected from the group consisting of titanium oxide-carbon composite oxide, niobium oxide, titania, tungsten oxide, niobium oxide, zirconium oxide, alumina, aluminosilicate, germania, tantalum oxide, tin oxide, manganese oxide and vanadium oxide .

The mesopores may have a diameter of 1 to 50 nm.

The macropore diameter may be greater than 50 nm and less than or equal to 3,000 nm.

However, the scope of the present invention is not limited, and the appropriate range may vary depending on the device to which it is applied. The diameter of the pores means the shortest distance between the wall surface of the formed pores and the wall surface.

The present invention provides an anode comprising the layered porous inorganic oxide.

The present invention provides a lithium secondary battery including the negative electrode.

The hierarchically-porous inorganic oxide of the present invention provides a porous inorganic oxide which can be used as a carrier of a catalyst and an electrode active material of a lithium secondary battery. By effectively controlling the separation of a block copolymer, A hierarchical porous inorganic oxide having mesopores and a plurality of macropores coexisted is manufactured to manufacture an energy storage device having improved charge / discharge rate characteristics and cycle characteristics, or used as a carrier in a catalytic reaction, Can facilitate access to the catalyst and facilitate the diffusion and transport of the material under conditions that include bulky reactants and products.

The present invention also provides a method for producing a layered porous inorganic oxide.

Specifically, the method of producing the layered porous inorganic oxide may be performed as follows.

first, Amphibian Block copolymer , Inorganic precursors, carbon precursors, acids and Organic solvent  And mixed to prepare a mixed solution. (Step a)

The macropore structure of the layered porous inorganic oxide can be controlled by controlling the mass ratio of the mass of the amphiphilic block copolymer and the inorganic precursor to the mass of the acid.

The mass ratio of the mass of the amphiphilic block copolymer and the inorganic precursor to the mass of the acid may be 1: 3 to 1: 5.

Wherein the amphiphilic block copolymer is a block copolymer comprising a hydrophobic block and a hydrophilic block, wherein the amphiphilic block copolymer is a poly (ethylene oxide) -b-poly (styrene) block copolymer, ), Poly (ethylene oxide) -b-poly (methylmethacrylate), polyisoprene-block-polyethylene oxide block copolymer (poly (isoprene) -b-poly (ethylene oxide)), polyisoprene-block-polystyrene-block-polyethyleneoxide block copolymer (polye (isoprene) -b-poly (styrene) -bpoly (P123, F127, F108), preferably polyethylene oxide-poly (ethylene oxide) -based styrene-block-polyethyleneoxide and Pluronic- Block-polystyrene block aerial Poly (ethylene oxide) -b-poly (styrene)] may be used. However, the scope of the present invention is not limited thereto.

The inorganic precursor may include at least one of a metal precursor and a non-metal inorganic precursor.

The metal precursor may include at least one of a metal alkoxide and a metal chloride.

The non-metallic inorganic precursor may include at least one selected from the group consisting of alkyl silicate, sodium silicate, silicon alkoxide, aluminum alkoxide and aluminosilicate.

Wherein the carbon precursor is selected from the group consisting of resol, phenol-formaldehyde resin, resorcinol-formaldehyde resin, phloroglucinol-formaldehyde resin, Formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin, and furfuryl alcohol.

The acid may be hydrochloric acid (HCL), nitric acid (HNO ₃ ), phosphoric acid (H ₃ PO ₄ ), perchloric acid (HClO ₄ ) or sulfuric acid (H ₂ SO ₄ ).

The organic solvent may include at least one selected from the group consisting of chloroform, tetrahydrofuran, and dioxane.

Next, the mixed solution was subjected to evaporation-induced self-assembly (EISA) Amphibian Block copolymer - inorganic oxide - carbon precursor. (Step b)

The mixed solution may be subjected to evaporation-induced self-assembly (EISA) to prepare a composite containing an amphiphilic block copolymer-inorganic oxide-carbon precursor.

The morphology of macropores of the layered porous inorganic oxide can be controlled by controlling the evaporation rate of the organic solvent in the evaporation-induced self-assembly.

The step (b) may be carried out at 20 to 80 캜, preferably 20 to 70 캜, more preferably 20 to 60 캜.

The step (b) may be carried out under atmospheric pressure.

Finally, the composite is heat treated to produce a layered porous inorganic oxide. (Step c)

The step (c) may be performed in air at 400 to 1200 ° C, preferably 400 to 1100 ° C, and more preferably 400 to 1000 ° C.

Removing the non-metallic oxide from the inorganic oxide by etching after step (c) to produce a layered porous inorganic oxide containing the metal oxide.

Step (d) may be performed a plurality of times to effectively remove the nonmetal oxide by the etching.

The etching may be performed by a basic solution, and the basic solution may be sodium hydroxide (NaOH) or potassium hydroxide (KOH).

In some cases, the etching may be performed by an acidic solution, and the acidic solution may be hydrofluoric acid (HF).

The hierarchical porous inorganic oxide of the present invention can control the macropore shape of the layered porous inorganic oxide by controlling the rate of evaporation of the organic solvent in the evaporation-induced self-assembly, and the unique macropore And can be used as a negative electrode material of a lithium secondary battery to improve charge / discharge rate characteristics, cycle characteristics, and the like. In addition, the layered porous inorganic oxide of the present invention can be used as a carrier in a catalytic reaction to enhance accessibility to a catalyst and facilitate diffusion and transport of the catalyst under conditions of high viscosity or high volume of reactants and products .

[Example]

Hereinafter, preferred embodiments of the present invention will be described. However, this is for illustrative purposes only, and thus the scope of the present invention is not limited thereto.

The chemicals used in the following examples are as follows, and the names are abbreviated as parentheses.

(Formalin, 36.5-38% in H ₂ O), sodium hydroxide (NaOH), THF (formaldehyde) solution, , and hydrochloric acid (HCl, 35 wt% in H ₂ O) were purchased from Sigma-Aldrich. Nitric acid (68 wt% in H ₂ O) was obtained from Matsunoen Chem. Ltd, and Tungsten (VI) isopropoxide 5% w / v in isopropanol was purchased from Alfa Aeasar. All materials were used immediately after purchase without purification. The polyethylene oxide-polystyrene block copolymer (PEO- b- PS) was synthesized by atomic transfer radical polymerization (ATRP) method (Mn = 34 kg mol ^-1 , 15 wt% PEO, PDI = 1.3), resole was synthesized by basic polymerization synthesis method. Polyvinylidene difluoride (PVDF) was purchased from Alfa Aesar, and N-methyl-2-pyrrolidone (NMP) was purchased from Aldrich. Super-P conductive carbon was purchased from TIMCAL Graphite & Carbon Inc., and 1.0 M lithium hexafluorophosphate (LiPF ₆ ) in ethylene carbonate / dimethyl carbonate (EC / DMC, 1: 1 volume ratio) was purchased from Panaxetec Co. Were used.

Manufacturing example  One: ( Polyethylene oxide -block- Polystyrene Block copolymer ) PEO Preparation of -b-PS

Polyethylene oxide - polystyrene block copolymer was prepared by atomic transfer radical polymerization method. To make PEO-Br, 20 g of poly (ethylene oxide) polymer (mPEO-OH) is dissolved in CH ₂ Cl ₂ (100 ml) and 5 ml of TEA is added. After stirring at 0 ° C, 1.48 ml of 2-bromoisobutylbromide is added dropwise. The reaction is then maintained at room temperature for 8 hours. The resultant is extracted / purified with DI water and ether and then dried in vacuum (PEO-Br).

20 g (192 mmol) of styrene, 0.071 g (0.5 mmol) of CuBr and 0.085 g (0.5 mmol) of PMDETA are added to 2.539 g (0.5 mmol) of PEO-Br. After making the vacuum atmosphere, the temperature of the reactor is increased to 110 ° C and maintained for 12 hours. The resultant is dissolved in THF and then passed through an alumina column to remove the copper catalyst (PEO-b-PS).

Preparation Example 2: Preparation of resole (phenol formaldehyde resin)

Phenol formaldehyde resin was prepared by basic polymerization method. 12.2 g (130 mmol) of phenol are placed in a flask and dissolved at 42 DEG C, and then 2.6 g (13 mmol) of 20 wt% NaOH is slowly added thereto. Then 21 g of 37 wt% formalin solution is added. The temperature of the reactor is then maintained at 70 DEG C for one hour and then cooled. To prevent further polymerization, titrate with HCl until a neutral solution is obtained. After drying in a vacuum oven at 50 ° C to remove moisture, THF solution is added to precipitate NaCl salt, and THF is dried.

Example 1: Preparation of mim-TNO-500 with a hierarchical porous structure

0.15 g of PEO-b-PS (Mn = 34 kg mol ^-1 , 15 wt% PEO, PDI = 1.3) was dissolved in THF to prepare a 5 wt% polymer solution. Then, 0.06 g of resole (in 0.24 g of THF) and 0.015 g of HNO ₃ (68% in H ₂ O) were added in this order to obtain a mixture of PEO-b-PS / THF / niobium chloride / titanium tetraisopropoxide / HNO ₃ was added so that the mass ratio of the components was 1: 23: 2.56: 1.33: 0.4, and the mass ratio of each component of PEO-b-PS: HNO ₃ was 1: 0.1. The mixed solution was stirred for 1 hour and then put into a flat glass dish having a diameter of 140 mm. With the glass lid open, THF and HNO ₃ evaporated rapidly in the hood at 30 ° C. Thereafter, the glass plate was placed in an oven at 100 캜 for 12 hours for thermal curing. The product thus prepared was calcined in air at 500 &lt; 0 &gt; C for 4 hours, at a heating rate of 1 [deg.] C / min. The mim-TNO-500, a hierarchical porous structure consisting of independently isolated macro-pores of 300 nm and mesopores of 43 nm, was prepared. The mim refers to mesoporous TNO containing isolated macropores.

Example 2: Preparation of cmm-TNO-500 of a hierarchical porous structure

HNO 1 mass ratio of each component of the _3: Example 1 PEO-b-PS in the set at 0.1 with PEO-b-PS, instead of preparing a mixed solution by the addition of HNO _3: mass ratio of the components of HNO ₃ 1: 2.8, and HNO ₃ was added to prepare a mixed solution. Cmm-TNO-500 having a hierarchical porous structure having macropores of 50 to 3000 nm and mesopores of 32 nm in tunnel form was prepared. The relative mass of the resol and nitric acid (HNO ₃ ) relative to the mass of the synthesized inorganic precursors (Niobium chloride (NbCl ₅ ) and Titanium isopropoxide (TTIP) Mesozoic and macroscopic tunnel-like pores can be formed with good connectivity. Cmm means co-continuous macro / mesoporous.

Example 3: Preparation of sm-TNO-500 with hierarchical porous structure

HNO 1 mass ratio of each component of the _3: Example 1 PEO-b-PS in the set at 0.1 with PEO-b-PS, instead of preparing a mixed solution by the addition of HNO _3: mass ratio of the components of HNO ₃ 1: 3.2, and HNO ₃ was added thereto to prepare a mixed solution. A sm-TNO-500 with a hierarchical porous structure consisting of macro-pores of 200-1000 nm and mesopores of 45 nm was prepared. The relative mass of the resol and nitric acid (HNO ₃ ) relative to the mass of the synthesized inorganic precursors (Niobium chloride (NbCl ₅ ) and Titanium isopropoxide (TTIP)) increased to be greater than that of cmm-TNO-500 Meso and macros can form spherical pores. The term &quot; sm &quot; means spherical mesoporous.

Example 4: Preparation of cmm-TNOS-500 with hierarchical porous structure

A 5 wt% polymer solution was prepared by dissolving 0.25 g of PEO-b-PS (Mn = 34 kg mol ^-1 , 15 wt% PEO, PDI = 1.3) in THF. Then, PEO-b-PS / niobium chloride / titanium tetraisopropoxide / tetraethyl orthosilicate (TEOS) (0.24 g), resole (0.06 g) and concentrated HNO ₃ (68% in H ₂ O, 0.42 g) ) / resol / HNO ₃ was 1: 2.84: 1.48: 0.96: 0.6: 2.8. The mixed solution was stirred for 1 hour and then put into a flat glass dish having a diameter of 70 mm. With the glass lid open, THF and HNO ₃ evaporated rapidly in the hood at 50 ° C.

Thereafter, the glass plate was placed in an oven at 100 DEG C for 12 hours to be thermally cured. The product thus prepared was calcined in air at 500 &lt; 0 &gt; C for 4 hours, at a heating rate of 1 [deg.] C / min.

Example 5: Preparation of cmm-TNOS-900 with a hierarchical porous structure

Example 4 was prepared in the same manner as in Example 4, except that calcination was carried out in air at 900 ° C for 4 hours instead of calcination in air at 500 ° C for 4 hours. As the temperature of the calcination increases, the pore size of meso and macro is larger than that of the cmm-TNOS-500 prepared according to Example 4, and the phase separation has a monoclinic form.

Example 6: Preparation of m-TNOS-900 of hierarchical porous structure

Example 4 at 500 ℃ in a state in which the calcination (calcination) in air for 4 hours, and opening the glass lid THF and HNO ₃ was calcined at 900 ℃ instead of rapidly evaporated within 50 ℃ hood for 4 hours in air was prepared in the same manner as in Example 4 except that THF and HNO ₃ were rapidly evaporated in a hood at 50 ° C with calcination and closing of the glass lid. M-TNOS-900 of a hierarchical porous structure composed of one mesopore was prepared. M means monolithic mesoporous.

Example 7: Preparation of cmm-TNO-900 of hierarchical porous structure

The hierarchical porous structure cmm-TNO-900 was prepared by etching the cmm-TNOS-900 of the hierarchical porous structure of Example 5 with 1M NaOH to remove the silica.

Example  8: cmm-WO of hierarchical porous structure ₃ -400 manufacture

0.15 g of PEO-b-PS (Mn = 34 kg mol ^-1 , 15 wt% PEO, PDI = 1.3) was dissolved in THF to prepare a 5 wt% polymer solution. Then, 0.426 g of concentrated HNO ₃ (68% in water) was added in order to make the mass ratio of each component of PEO-b-PS / THF / HNO ₃ 1: 23: 2.84, / v, 1 ml of tungsten (Ⅵ) isopropoxide was added to prepare a mixed solution. The mixed solution was stirred for 1 hour and then put into a flat glass dish having a diameter of 100 mm. With the glass lid open, THF and HNO ₃ were rapidly evaporated in the hood at 50 ° C. Thereafter, the glass plate was placed in an oven at 100 캜 for 12 hours for thermal curing. The product thus prepared was calcined in air at 400 &lt; 0 &gt; C for 3 hours, at a heating rate of 1 [deg.] C / min. Cmm-WO ₃ -400, a hierarchical porous structure composed of macropores and mesopores, was prepared.

Example  9: The hierarchical porous structure of cmm- TiO ₂ -C-700 manufacture

0.15 g of PEO-b-PS (Mn = 34 kg mol ^-1 , 15 wt% PEO, PDI = 1.3) was dissolved in THF to prepare a 5 wt% polymer solution. The mass ratio of each component of PEO-b-PS / THF / titanium tetraisopropoxide / resol / HNO ₃ was adjusted to 1:33 (molar ratio) by adding Resol (0.03 g) and concentrated HNO ₃ : 4.3: 0.2: 2.84. The mixed solution was stirred for 1 hour and then put into a flat glass dish having a diameter of 140 mm. With the glass lid open, THF and HNO ₃ evaporated rapidly in the hood at 40 ° C. Thereafter, the glass plate was placed in an oven at 100 캜 for 12 hours for thermal curing. The product thus prepared was calcined at 700 &lt; 0 &gt; C for 3 hours under an argon atmosphere at a heating rate of 1 [deg.] C / min. Cmm-TiO ₂ -C-700, a hierarchical porous structure composed of macropores and mesopores, was prepared.

Comparative Example 1: Preparation of m-TNO-900

M-TNO-900 of the hierarchical porous structure was prepared by etching the m-TNOS-900 of Example 6 with 1M NaOH to remove the silica.

The physicochemical properties of the layered porous inorganic oxides prepared according to Examples 1 to 9 and Comparative Example 1 were compared and summarized in Table 1 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Comparative Example 1 matter mim-TNO-500 cmm-TNO-500 sm-TNO-500 cmm-TNOS-500 cmm-TNOS-900 m-TNOS-900 cmm-TNO-900 cmm-WO ₃ -400 cmm-TiO ₂ -C-700 m-
TNO-900 PEO- b- PS (g) 0.15 0.15 0.15 0.25 0.25 0.25 0.25 0.15 0.15 0.25 Niobium chloride 2.56 2.56 2.56 2.84 2.84 2.84 0.71 0 0 0.71 Titanium tetraisopropoxide 1.33 1.33 1.33 1.48 1.48 1.48 0.37 0 4.3 0.37 tungsten (VI) isopropoxide 0 0 0 0 0 0 0 0.3 0 0 Resol 0.4 0.4 0.4 0.6 0.6 0.6 0.15 0 0.2 0.15 Tetraethyl orthosilicate 0 0 0 0.96 0.96 0.96 0.24 0 0 0.24 HNO ₃ (68% in water) 0.1 2.8 3.2 2.8 2.8 2.8 0.7 2.84 2.84 0.7 Diameter of dish (mm) 140 140 140 70 70 70 70 100 140 70 Glass lid off off off off off on off off off on NICE temperature (° C) 30 30 30 50 50 50 50 100 100 50 Calcination temperature (° C) 500 500 500 500 900 900 900 400 700 900

Device Example  1: cmm- TNO Containing -900 as the cathode The lithium secondary battery  Produce

C-TNO-900 prepared in Example 7 was used as an anode active material, carbon black (super P) as a carbon additive for increasing conductivity, polyvinylidene difluoride (PVDF) as a polymer binder, N-methyl-2-pyrrolidone NMP) as a solvent, and the mass ratio of each component of cmm-TNO-900 / Super P / PVDF in the slurry was 7: 2: 1. The prepared slurry was coated on a Cu film, dried at 60 캜 for 12 hours in air, and dried in a vacuum oven at 110 캜 for 12 hours. The prepared negative electrode was squeezed and cut into a circular shape corresponding to the size of the half cell. The mass load of the electrode is in the range of 1.1 to 1.4 mg cm &lt;&quot; ^{2 &} gt ;. The half cell is made of two electrode system (CR2032 type). The cmm-TNO-900 thus prepared was used as an anode and a lithium metal foil as a counter electrode. A half-cell of cmm-TNO-900 / Li was prepared using 1.0 M LiPF ₆ in ethylene carbonate / dimethyl carbonate (EC / DMC, 1: 1 volume ratio, Panaxetec Co., Korea) as an electrolyte. The cell was assembled in a glove box filled with Ar.

Device comparison example  1: m- TNO Containing -900 as the cathode The lithium secondary battery  Produce

TNO-900 prepared in accordance with Comparative Example 1 was used as a negative electrode active material instead of using cmm-TNO-900 prepared in Example 7 as a negative electrode active material, .

[Test Example]

Test Example 1: SEM image analysis of hierarchical porous inorganic oxide 1

2 (a), 2 (b) and 2 (c) are SEM images of Example 1, and FIGS. 2 i) shows an SEM image of Example 3. Fig.

According to FIGS. 2 (a), 2 (b) and 2 (c), the mim-TNO-500 prepared according to Example 1 has a structure in which PEO- Macroscopic pores of about 300 nm, which are independent of the mesopores of the mesopores, were formed, and the mesopores were uniformly distributed in the mesopores.

According to (d), (e) and (f) of FIG. 2, the cmm-TNO-500 prepared according to Example 2 had the PEO-b-PS-rich phases removed by calcination at 500 ° C, Macroscopic pores of about several hundred nanometers, which are excellent in connectivity with the mesopores of the mesopores, were formed, and the mesopores were uniformly distributed in the mesopores.

According to (g), (h) and (i) of FIG. 2, sm-TNO-500 prepared according to Example 3 had HNO ₃ -rich phases removed by calcination at 500 ° C, And macroscopic pores of about 300-500 nm were formed, and a uniform distribution was observed in the structure.

Therefore, it can be seen that as the relative content of nitric acid increases, the structure changes to mim-TNO-500, cmm-TNO-500 and sm-TNO-500.

Test Example 2: SEM image analysis of layered porous inorganic oxide 2

3 (a) and 3 (b) are SEM images of Example 7, and FIGS. 3 (c) and 3 (d) are SEM images of Example 8.

According to FIGS. 3 (a) and 3 (b), cmm-WO ₃ -400 prepared according to Example 7 was produced by removing PEO-b-PS-rich phases by calcination at 400 ° C., And mesopores were formed, and it was confirmed that they exhibited a uniform distribution in the structure.

3 (c) and 3 (d), the cmm-TiO ₂ -C-700 prepared according to Example 8 had the PEO-b-PS-rich phases removed by calcination at 700 ° C, It was confirmed that these excellent macropores and mesopores were formed and exhibited a uniform distribution in the structure.

Test Example 3: Confirmation of the structure of cmm-TNOS-500

FIGS. 4 (a) and 4 (b) are SEM side and top view images of the cmm-TNOS-500 prepared according to Example 4 by cutting out the focused ion beam (FIB) (c) is a 3D image obtained by visualizing the cmm-TNOS-500 prepared according to Example 4 using a nanoscale X-49-23ray computed tomography, (d) a 3D image obtained by enlarging a part of (c) ) Is reconstructed by a strut-thinning algorithm to show a simplified skeletal structure (e) and macro pores (f). Fig. 4 (g) shows quantitative structure analysis in the macro pore region of (f), showing the distance g between nodes and the distribution h of struts per node.

4 (a) and 4 (b), it was confirmed that the macro-pores were formed as a whole in the cmm-TNOS-500 prepared in Example 4.

4 (c) to (f), the cmm-TNOS-500 prepared according to Example 4 confirmed the presence of successive interconnected macropores.

Also, according to (g) to (h) of FIG. 4, the distribution of the number of connections between the macro pore size distribution and the macro pore can be known. The size of the macropore was mainly less than 1 μm, and a part of the macro-domain was found to be in the range of 2-3 μm. In addition, three nodes were the most common and more complex nodes were observed. One strand or two strand nodes were also observed, but some of them were judged to be artificially formed errors in the process of reconstructing the structure with the strut-thinning algorithm, indicating that most mesostructure domains have a well-connected structure I could.

Test Example 4: SEM image analysis of cmm-TNOS-900 and cmm-TNO-900

5 (a) is an SEM image of cmm-TNOS-900 prepared according to Example 5, and (b) and (c) is an SEM image of cmm-TNO-900 prepared according to Example 7. Fig.

Referring to FIG. 5 (a), it was confirmed that the structure did not collapse despite the heat treatment at 900 ° C.

Referring to FIGS. 5 (b) and 5 (c), it was found that the macro pores were maintained and the size and shape of the mesopores were partially modified, but they had pores in the meso area.

Test Example 5: Nitrogen adsorption / desorption analysis of cmm-TNO-900 and m-TNO-900

FIG. 5 (d) is a nitrogen adsorption / desorption analysis curve of cmm-TNO-900 prepared in Example 7 and m-TNO-900 prepared in Comparative Example 1, and FIG.

According to Fig. 5 (d), Example 7, prepared according to the cmm-TNO-900 and Comparative Example 1 prepared in accordance with the m-TNO-900 are type-Ⅳ having a sharp absorption around 0.9 P / P ₀ curve , Indicating that homogeneous mesopores are predominant. The specific surface area, mesopore volume, and memo pore size of cmm-TNO-900 prepared according to Example 7 were 60 m ² g ^-1 , 0.23 cm ³ g ^-1 and 25 nm, respectively, The specific surface area, mesopore volume, and mesopore size of m-TNO-900 prepared according to the present invention were 57 m ² g ^-1 , 0.21 cm ³ g ^-1 and 28 nm, respectively.

Thus, it was confirmed that the cmm-TNO-900 prepared according to Example 7 and the m-TNO-900 prepared according to Comparative Example 1 had mesopores of the same size and specific surface area.

Test Example 6: X-ray diffraction pattern analysis of cmm-TNO-900 and m-TNO-900

FIG. 5 (f) shows the X-ray diffraction pattern analysis results of cmm-TNO-900 prepared according to Example 7 and m-TNO-900 prepared according to Comparative Example 1.

According to Fig. 5 (f), a monoclinic crystal structure (JCPDS #: 77-1374) and a similar crystal size were confirmed.

Test Example 7: Characterization of a cathode material of a lithium secondary battery

5 (g) and 5 (h) are graphs showing the electrical characteristics of the lithium secondary battery manufactured according to the device example 1 and the device comparative example 1 at a current density ranging from 0.2 to 10 C rate (1 C = 167.5 mA g ^-1 ) Chemical behavior. The test was conducted at 20 占 폚.

According to (g) and (h) 5, each naeteumyeo that the reversible capacity of 257mA and 190mA hg hg ^{-1 -1} at 0.2C-rate and 10C-rate that the lithium battery of the device of Example 1, comparing element example 0.2C-rate in the first and rate-10C the lithium secondary battery of each of 215mA and 145mA hg hg ^{-1 -} indicated by ^1, the reversible capacity of the lithium secondary battery of the device of example 1 is shown to a larger value. In addition, the reversible capacity of the electrode decreases as the C-rate increases. At the 60-rate, the lithium-ion secondary battery of Embodiment 1 retained 44% of the maximum capacity. However, the lithium secondary battery of Comparative Example 1 had 33% Respectively.

Therefore, it was found that the reversible capacity and the speed characteristic of the electrode were improved by the interconnected macro pores promoting the ion transport of the electrolyte.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (20)

A mesoporous inorganic oxide comprising a plurality of meso-pores; And
One or more macro-pores surrounded by the mesoporous inorganic oxide; / RTI &gt;
Wherein the mesoporous inorganic oxide comprises a niobium-titanium composite oxide (TiNb ₂ O ₇ ). The method according to claim 1,
Wherein the shape of the macropore is any one selected from the group consisting of a spherical shape, a tunnel shape, and a matirix shape. The method of claim 1, wherein
Wherein the macropores are uniformly distributed in the layered porous inorganic oxide. The method of claim 1, wherein
Wherein the mesopores are uniformly distributed in the mesoporous inorganic oxide. delete The method according to claim 1,
Wherein the mesopores have a diameter of 2 to 50 nm. The method of claim 1,
Wherein the macropore diameter is greater than 50 nm and less than or equal to 3,000 nm. An anode comprising the layered porous inorganic oxide of claim 1. A lithium secondary battery comprising the anode of claim 8. (A) preparing a mixed solution by mixing an amphiphilic block copolymer, an inorganic precursor, a carbon precursor, an acid, and an organic solvent;
(B) preparing a complex comprising an amphiphilic block copolymer-inorganic oxide-carbon precursor by evaporation-induced self-assembly (EISA) of the mixed solution; And
(C) heat treating the composite to produce a layered porous inorganic oxide; Lt; / RTI &gt;
Wherein the macropore of the layered porous inorganic oxide is controlled by adjusting mass of the amphiphilic block copolymer and inorganic precursor and mass ratio of the mass of the acid. delete 11. The method of claim 10,
Wherein the mass ratio of the mass of the amphiphilic block copolymer and the inorganic precursor to the mass of the acid is 1: 3 to 1: 5. 11. The method of claim 10,
Wherein the macropores of the layered porous inorganic oxide are controlled by adjusting the evaporation rate of the organic solvent in the evaporation-induced self-assembly. 11. The method of claim 10,
Wherein step (b) is carried out at 20 to &lt; RTI ID = 0.0 &gt; 80 C. &lt; / RTI &gt; 11. The method of claim 10,
Wherein step (b) is performed under atmospheric pressure. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; 11. The method of claim 10,
Wherein the amphiphilic block copolymer is selected from the group consisting of polyethylene oxide-block-polystyrene block copolymers (poly (ethylene oxide) -b-poly (styrene), polyethylene oxide-block-polymethyl methacrylate block copolymer poly (isoprene) -b-poly (ethylene oxide), polyisoprene-block-polystyrene-block-polyethylene oxide block copolymer isoprene-b-poly (styrene) -bpoly (ethylene oxide), poly (4-tert-butyl) styrene-block-polyethyleneoxide and pluronic (P123, F127, F108) based on the total weight of the porous inorganic oxide. 11. The method of claim 10,
Wherein the inorganic precursor comprises at least one of a metal precursor and a non-metal inorganic precursor. The method of claim 17, wherein
Wherein the metal precursor comprises at least one of a metal alkoxide and a metal chloride. 19. The method of claim 18,
Wherein the metal precursor comprises at least one selected from the group consisting of titanium isopropoxide, niobium chloride and tungsten isopropoxide. Way. 18. The method of claim 17,
Wherein the non-metallic inorganic precursor comprises at least one selected from the group consisting of alkyl silicate, sodium silicate, silicon alkoxide, aluminum alkoxide and aluminosilicate.

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