KR20210068965A - Solid electrolyte, preparation method thereof, metal air battery including the solid electrolyte, and electrochemical device including the solid electrolyte - Google Patents

Abstract

The present invention relates to a solid electrolyte containing an oxide represented by the following chemical formula 1, a preparation method thereof, a metal air battery including the same, and an electrochemical device including the same. Chemical formula 1 is Li_(2+4x)M1_(1-x)O_3, wherein M1 and x are as defined in the detailed description. Chemical formula 2 is Li_(2-y(a-4))M1_(1-y)(M2^(a+))_yO_3, wherein M1, M2, a, and y are as defined in the detailed description. Chemical formula 3 is Li_(2-z)M1O_(3-z)X_z, wherein M1, X, and z are as defined in the detailed description.

Description

Solid electrolyte, preparation method thereof, and metal-air battery and electrochemical device including the same {Solid electrolyte, preparation method thereof, metal air battery including the solid electrolyte, and electrochemical device including the solid electrolyte}

It relates to a solid electrolyte, a method for manufacturing the same, and a metal-air battery and an electrochemical device including the same.

Lithium-air batteries use lithium itself as the negative electrode, and since there is no need to store air, which is the positive electrode active material, in the battery, a high-capacity battery is possible. The theoretical energy density per unit weight of a lithium-air battery is very high, over 3500Wh/kg.

The solid electrolyte of a lithium-air battery does not reach a satisfactory level of stability with respect to lithium hydroxide, a discharge product of a lithium-air battery, and the ionic conductivity is lowered in a strong base condition such as lithium hydroxide, and improvement is required.

One aspect is to provide a solid electrolyte stable to moisture and lithium and a method for preparing the same.

Another aspect is to provide a lithium-air battery including the solid electrolyte.

Another aspect is to provide an electrochemical device including the above-described solid electrolyte.

According to one aspect, there is provided a solid electrolyte comprising an oxide represented by the following Chemical Formula 1, 2 or 3 or a combination thereof.

<Formula 1>

Li _2+4x M1 _1-x O ₃

In Formula 1, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof, and 0<x<1;

<Formula 2>

Li _2-y(a-4) M1 _1-y M2 ^a+ _y O ₃

In Formula 2, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,

M2 is at least one selected from monovalent to hexavalent elements, a is the oxidation number of M2, and 0<y<1;

<Formula 3>

Li _2-z M1O _3-z X _z

chemical formula triple, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,

X is a halogen atom, pseudohalogen, or a combination thereof, and 0<z<2.

Anode according to another aspect; cathode anode; cathode; and an electrolyte disposed between the positive electrode and the negative electrode, wherein at least one selected from the positive electrode, the negative electrode and the electrolyte is provided, the metal-air battery including the above-described solid electrolyte.

According to another aspect, an electrochemical device including the above-described solid electrolyte is provided.

The electrochemical device includes at least one selected from a battery, a storage battery, a supercapacitor, a fuel cell, a sensor, and a color change device.

Preparing a precursor mixture by mixing a lithium precursor, an M1 precursor, an M2 precursor, and an X precursor according to another aspect; and a first heat treatment of the precursor mixture is provided.

The solid electrolyte according to one embodiment has improved ionic conductivity at room temperature, is stable to moisture and lithium in humidified or atmospheric conditions, maintains excellent ionic conductivity, and has excellent pellet density. By using such a solid electrolyte, it is possible to manufacture an electrochemical device in which deterioration is suppressed.

1 shows X-ray diffraction (XRD) spectra of the solid electrolytes of Examples 3-5, 7, 9, 12-13, Example 20 and Comparative Example 1. FIG.
2 is a graph showing the pellet density of the solid electrolytes of Examples 1 to 12 and the solid electrolyte of Comparative Example 1.
3 is a graph showing the ionic conductivity of the solid electrolytes of Examples 1 to 12 and the solid electrolyte of Comparative Example 1. FIG.
4 is a graph showing the ionic conductivity of the solid electrolytes of Examples 13 to 23 and the solid electrolyte of Comparative Example 2. FIG.
5 is a schematic diagram showing the structure of a lithium-air battery according to an embodiment.

Hereinafter, a solid electrolyte, a manufacturing method thereof, a metal-air battery including the same, and an electrochemical device including the solid electrolyte according to embodiments will be described in more detail.

A solid electrolyte comprising an oxide represented by the following Chemical Formula 1, 2 or 3 or a combination thereof is provided.

[Formula 1]

Li _2+4x M1 _1-x O ₃

In Formula 1, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof, and 0<x<1;

<Formula 2>

Li _2-y(a-4) M1 _1-y M2 ^a+ _y O ₃

In Formula 2, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,

M2 is at least one selected from monovalent to hexavalent elements, a is the oxidation number of M2, and 0<y<1;

<Formula 3>

Li _2-z M1O _3-z X _z

chemical formula triple, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,

X is a halogen atom, pseudohalogen, or a combination thereof, and 0<z<2.

In Formulas 1 to 3, M1 is, for example, hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof.

M2 is, for example, aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), scandium (Sc), Magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), vacancy or a combination thereof. .

In Formula 2, a is the oxidation number of M2, for example, 2, 3, 5, or 6.

In the formula (3), the halogen atom is, for example, Cl, Br, F, I, or a combination thereof.

The solid electrolyte satisfies the charge balance to have a neutral state.

The solid electrolyte of a lithium-air battery needs to have excellent stability to lithium and to ensure reversibility under humidified or air conditions. For this, stability by lithium hydroxide (LiOH) and moisture, which are discharge products, is very important.

However, the conventional solid electrolyte does not have sufficient stability to lithium, and the stability to strong bases such as lithium hydroxide and moisture is reduced, so that conductivity is lowered. Therefore, the need for a new solid electrolyte that can solve these problems is increasing.

Accordingly, the present inventors provide a solid electrolyte including oxides of Chemical Formulas 1 to 3 containing elements such as hafnium and zirconium, which are stable against both moisture and lithium, in order to solve the above problems.

The oxide is an ionic conductor having a thermothermally stable composition. The compound of Formula 1 improves ionic conductivity by introducing Li vacancies and excess lithium for lithium migration or doping other transition metals. The oxide of Formula 3 has excellent ionic conductivity by introducing one or more anions selected from halogen atoms and pseudohalogens.

The solid electrolyte contains oxides of Chemical Formulas 1 to 3 to improve phase stability. In particular, it is possible to maintain excellent ionic conductivity due to excellent stability under strong basic conditions, for example, pH 12 to 13 and moisture.

The oxides of Chemical Formulas 1 to 3 contain elements such as hafnium and zirconium that are not reduced by lithium, and thus have very high stability to lithium. Therefore, the interface between the solid electrolyte and the negative electrode is stabilized. In addition, the oxides of Chemical Formulas 1 to 3 have high stability against moisture and strong bases. Therefore, the interface between the positive electrode and the solid electrolyte may be stabilized.

The solid electrolyte according to one embodiment has excellent ionic conductivity at room temperature and excellent stability to lithium and moisture. Therefore, it is possible to manufacture a metal-air battery in which reversibility is secured in humidified or ambient air conditions.

The metal-air battery is, for example, a lithium-air battery using air as an anode and lithium as an anode.

In Formulas 1 to 3, M1 is a tetravalent cation element, for example, hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof.

In Formula 2, M2 may substitute some sites of M1. M2 is a monovalent element to a hexavalent element, or a combination thereof. In Formula 2, M2 is, for example, a divalent element, a trivalent element, a pentavalent element, a hexavalent element, a vacancy, or a combination thereof.

M2 is, for example, aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), scandium (Sc), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Zinc (Zn), Cadmium (Cd), Tungsten (W), Molybdenum (Mo), Vacancy or a combination thereof. .

In Formula 3, X may be a halogen atom, pseudohalogen, or a combination thereof, as described above.

As used herein, "pseudohalogen" is a molecule composed of atoms having two or more electronegativities resembling halogens in a free state, halide ions and Generates similar anions. Examples of pseudohalogens include cyanide, cyanate, and thiocyanate. azide or a combination thereof.

X may be, for example, two or more halogen atoms, for example, two halogen atoms and substituted some positions of oxygen in formula (1).

X is chlorine (Cl), bromine (Br), fluorine (F), cyanide (cyanide), cyanate (cyanate), thiocyanate (thiocyanate), azide (azide), or a combination thereof.

In Formula 1, x is, for example, 0.01 to 0.99, 0.01 to 0.97, 0.01 to 0.95, or 0.01 to 0.9.

In Formula 2, y is, for example, 0.01 to 0.8, 0.03 to 0.85, or 0.05 to 0.9.

In Formula 2, M2 is, for example, Y, Al, Ta, Mg, Zn, or a combination thereof.

In Formula 1, x is 0.01 to 0.9, 0.1 to 0.8, 0.1 to 0.6, or 0.1 to 0.5. and 2+4x is 2.05 to 5, 2.05 to 3, 2.1 to 2.5, 2.1 to 2.4, or 2.1 to 2.3. And in Formula 2, y is, for example, 0.05 to 0.9, 0.1 to 0.8, 0.1 to 0.5, 0.1 to 0.3, or 0.1 to 0.2. And in Formula 2, a is the oxidation number of M2, and is 1 to 6, for example, 2, 3, 5, or 6.

In addition, in Formula 3, z is 0.05 to 1, 0.1 to 0.9, 0.1 to 0.8, or 0.1 to 0.5.

The oxide represented by Chemical Formula 1 may include, for example, an oxide represented by the following Chemical Formula 4 and an oxide represented by the Chemical Formula 5.

<Formula 4>

Li _2+4x Hf _1-x O ₃

In Formula 4, 0.01≤x≤0.9,

<Formula 5>

Li _2+4x Zr _1-x O ₃

In formula (5), 0.01≤x≤0.9.

The oxide of Formula 2 may include, for example, an oxide represented by Formula 6 or an oxide represented by Formula 7 below.

<Formula 6>

Li _2-y(a-4) Hf _1-y M2 ^a+ _y O ₃

In Formula 6, M2 is aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), and scandium (Sc) , magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), or a combination thereof,

a is the oxidation number of M2, 0.05≤y≤0.9,

<Formula 7>

Li _2-y(a-4) Zr _1-y M2 ^a+ _y O ₃

In Formula 7, M2 is aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), scandium (Sc) , magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), or a combination thereof,

a is the oxidation number of M2, for example, 2, 3, 5, or 6, and 0.05≤y≤0.9.

The oxide of Formula 3 may include, for example, an oxide represented by the following Formula 8 or an oxide represented by the following Formula 9.

<Formula 8>

Li _2-z HfO _3-z X _z

chemical formula 8 in, X is a halogen atom, pseudohalogen, or a combination thereof, and 0.05≤z≤1,

<Formula 9>

Li _2-z ZrO _3-z X _z

chemical formula 9 in, X is a halogen atom, pseudohalogen, or a combination thereof, and 0.05≤z≤1.

In Formulas 4 and 5, x is 0.1 to 0.8, 0.1 to 0.6, or 0.1 to 0.5.

In Formulas 6 and 7, y is, for example, 0.1 to 0.8, 0.1 to 0.5, 0.1 to 0.3, or 0.1 to 0.2. And in Formulas 6 and 7, a is the oxidation number of M2, and is 1 to 6, for example 2, 3, 5, or 6.

In addition, in Formulas 8 and 9, z is 0.1 to 0.9, 0.1 to 0.8, or 0.1 to 0.5.

The solid electrolyte according to an embodiment has a phase having a rocksalt crystal structure. The solid electrolyte has, for example, a layered rock salt crystal structure and has a C2/c (space group No. 15) space group . These characteristics can be confirmed through XRD analysis.

결정면,

결정면 및

결정면과 관련된 회절 피크가 나타난다.In the solid electrolyte according to an embodiment, in the X-ray diffraction spectrum using CuKα,

crystal plane,

crystal plane and

A diffraction peak related to the crystal plane appears.

According to X-ray diffraction spectroscopy, in the oxide according to an embodiment, in the X-ray diffraction spectrum using CuKα _{, the diffraction peak 2θ is the peak of the Li 2 Hf0 3} series oxide, and the diffraction angle 2θ is 26.7±0.5°, 35±0.5° , a diffraction peak appears in the region of 39±0.5°.

결정면과 관련된 것이고, 회절각 2θ가 35±0.5°인 제2피크는 예를 들어 화학식 1의 산화물의

결정면과 관련된 것이다. 회절피크 2θ가 39±0.5°인 제3피크는 화학식 1의 산화물의

결정면과 관련된 것이다. Among the diffraction peaks, the first peak having a diffraction angle 2θ of 26.7±0.5° is, for example, that of the oxide of Formula 1

The second peak, which is related to the crystal plane and has a diffraction angle 2θ of 35±0.5°, is, for example, the

It is related to the crystal plane. The third peak with a diffraction peak 2θ of 39±0.5° is the

It is related to the crystal plane.

The oxide represented by Formula 1 is, for example, Li _2.2 Hf _0.95 O ₃ , Li _1.9 HfF _0.1 O _2.9 , Li _1.8 HfF _0.2 O _2.8 , Li _1.5 HfF _0.5 O _2.5 , Li _1.9 HfCl _0.1 O _2.9 , Li _1.8 HfCl _0.2 O _2.8 , Li _1.5 HfCl _0.5 O _2.5 , Li _1.9 HfF _0.05 Cl _0.05 O _2.9 , Li _1.8 HfF _0.1 Cl _0.1 O _2.8 , Li _1.8 HfBr _0.1 Cl _0.1 O _2.8 , Li _1.5 HfF _0.25 Cl _0.25 O _2.5 , Li _1.5 HfBr _0.25 Cl _0.25 O _2.5 , Li _2.2 Hf _0.8 Y _0.2 O ₃ , Li _2.2 Hf _0.8 La _0.2 O ₃ , Li _2.2 Hf _0.8 Sc _0.2 O ₃ , Li _2.2 Hf _0.8 Al _0.2 O ₃ , Li _2.2 Hf _0.8 Ta _0.2 O ₃ , Li _2.2 Hf _0.8 Nb _0.2 O ₃ , Li _2.2 Hf _0.8 V _0.2 O ₃ , Li _2.2 Hf _0.9 Mg _0.1 O ₃ , Li _2.2 Hf _0.9 Ca _0.1 O ₃ , Li _2.2 Hf _0.9 Sr _0.1 O ₃ , Li _2.2 Hf _0.9 Ba _0.1 O ₃ , Li _2.2 Hf _0.9 Zn _0.1 O ₃ , Li _2.2 Hf _0.9 Cd _0.1 O ₃ , Li _2.2 Zr _0.95 O ₃ , Li _1.9 ZrF _0.1 O _2.9 , Li _1.8 ZrF _0.2 O _2.8 , Li _1.5 ZrF _0.5 O _2.5 , Li _1.9 ZrCl _0.1 O _2.9 , Li _1.8 ZrCl _0.2 O _2.8 , Li _1.5 ZrCl _0.5 O _2.5 , Li _1.9 ZrF _0.05 Cl _0.05 O _2.9 , Li _1.9 ZrBr _0.05 Cl _0.05 O _2.9 , Li _1.8 ZrF _0.1 Cl _0.1 O _2.8 , Li _1.8 ZrBr _0.1 Cl _0.1 O _2.8 , Li _1.5 ZrF _0.25 Cl _{0 .25} O _2.5 , Li _1.5 ZrBr _0.25 Cl _0.25 O _2.5 , Li _2.2 Zr _0.8 Y _0.2 O ₃ , Li _2.2 Zr _0.8 La _0.2 O ₃ , Li _2.2 Zr _0.8 Sc _0.2 O ₃ , Li _2.2 Zr _0.8 Al _0.2 O ₃ , Li _2.2 Zr _0.8 Ta _0.2 O ₃ , Li _2.2 Zr _0.8 Nb _0.2 O ₃ , Li _2.2 Zr _0.8 V _0.2 O ₃ , Li _2.2 Zr _0.9 Mg _0.1 O ₃ , Li _2.2 Zr _0.9 Ca _0.1 O ₃ , Li _2.2 Zr _0.9 Sr _0.1 O ₃ , Li _2.2 Zr _0.9 Ba _0.1 O ₃ , Li _2.2 Zr _0.9 Mg _0.1 O ₃ , Li _2.2 Zr _0.9 Zn _0.1 O ₃ , Li _2.2 Zr _0.9 Cd _0.1 O ₃ , or a combination thereof.

The solid electrolyte according to an embodiment has an ionic conductivity at room temperature (25° C.), for example, 1.0×10 ^-5 S/cm or more, 3.0×10 ^-5 S/cm or more, or 3.0×10 ^-5 S/cm to 20×10 ^-5 S/cm. Since the solid electrolyte has such high ionic conductivity, the internal resistance of a lithium-air battery containing such a solid electrolyte is further reduced.

The solid electrolyte may exist in a particle state. The solid electrolyte particles have an average particle diameter of 5 nm to 500 μm, for example 100 to 15 μm, for example 300 nm to 10 μm, and a specific surface area of 0.01 to 1000 m ² /g, for example 0.5 to 100 m ² /g to be.

The pellet density of the solid electrolyte according to an embodiment is 2.6 g/cc to 5.10 g/cc, 2.8 g/cc to 5.1 g/cc, 3.0 g/cc to 5.0 g/cc, 4.00 g/cc to 5.1 g/cc , 4.3 g/cc to 5.0 g/cc, 4.4 g/cc to 4.99 g/cc, or 4.5 g/cc to 4.85 g/cc. When a solid electrolyte having the above-mentioned pellet density is used, the result obtained after the pressurization process for preparing the solid electrolyte is dense, and when a membrane-type solid electrolyte is prepared using the solid electrolyte, water or air does not pass through it, so the physical properties of the solid electrolyte are very excellent. .

The pressing process is performed, for example, at 1 MPa to 200 MPa, 5 MPa to 150 MPa, or 10 MPa to 120 MPa.

A method of manufacturing a solid electrolyte according to an embodiment will be described as follows.

A precursor mixture is prepared by mixing the lithium precursor, the M1 precursor, the M2 precursor, and the X precursor.

Subsequently, a solid electrolyte including the oxide represented by Chemical Formulas 1 to 3 or a combination thereof may be prepared, including the first heat treatment of the precursor mixture. The M1 precursor is as defined in Formulas 1 to 3, the M2 precursor is as defined in Formula 2, and the X precursor is as defined in Formula 3.

If necessary, a solvent may be added to the mixture.

The solvent may be any solvent capable of dissolving or dispersing the lithium compound, the M1 precursor, the M2 precursor, and the X precursor. The solvent may be, for example, ethanol, water, ethylene glycol, isopropanol, or a combination thereof.

The mixing may be carried out according to methods known in the art, such as milling, blending and stirring. Milling may use, for example, a ball mill, an air jet mill, a bead mill, a roll mill, and the like.

Then, the first heat treatment is performed on the mixture.

The temperature increase rate during the primary heat treatment for the mixture is 1 ℃ / min to 10 ℃ / min, the first heat treatment temperature is carried out in the range of 400 ℃ to 950 ℃, for example, 600 ℃ to 900 ℃. In the first heat treatment step, when the temperature increase rate is within the above range, the heat treatment is sufficiently performed to obtain a solid electrolyte having a desired crystal structure after the second heat treatment process to be described later.

The primary heat treatment may be performed in an oxidizing gas atmosphere. An oxidizing gas atmosphere is created using, for example, air or oxygen. And the first heat treatment time varies depending on the first heat treatment temperature, for example, 1 to 20 hours, for example, 4 to 15 hours, for example, 9 to 13 hours range.

wherein the M1 precursor, the M2 precursor is each M1, or M2 containing oxide, M1, or M2 containing carbonate, M1, or M2 containing chloride, M1, or M2 phosphate, M1, or M2 hydroxide, M1, or M2 nitrate, or combinations thereof, for example, hafnium oxide, zirconium oxide, yttrium oxide, hafnium nitrate, hafnium sulfate, zirconium nitrate, zirconium sulfate, aluminum oxide, tantalum oxide, magnesium oxide, zinc oxide, gallium oxide, indium oxide, niobium oxide, at least one selected from tantalum oxide, vanadium oxide, lanthanum oxide, scandium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, zinc oxide, and cadmium oxide.

The X precursor is, for example, lithium chloride, lithium fluoride, lithium bromide, or a combination thereof. And the lithium precursor may be, for example, at least one selected from lithium oxide, lithium carbonate, lithium chloride, lithium sulfide, lithium nitrate, lithium phosphate, and lithium hydroxide.

Contents of the lithium precursor, the M1 precursor, the M2 precursor, and the X precursor are stoichiometrically controlled so that the oxides represented by Chemical Formulas 1 to 3 can be obtained.

Then, the primary heat-treated product is pulverized to obtain a molded body. The compact is, for example, a powder particle. The size of the compact (powder particle) obtained by pulverization is 10 µm or less. When the pulverized particle size is within the above range, the particle size is small and the pulverization and mixing are sufficiently performed to smoothly form the Nasicon crystal phase. In the present specification, "size" may indicate an average diameter when the particles are spherical, and may mean a long axis length when the particles are non-spherical. The size can be measured using a scanning electron microscope or a particle size analyzer.

Then, secondary heat treatment is performed on the molded body. During the secondary heat treatment, the temperature increase rate is 1°C/min to 10°C/min. The secondary heat treatment may be performed at 500°C to 1300°C, for example, 700°C to 1200°C.

According to one embodiment, the second heat treatment temperature may be performed at a higher temperature than the first heat treatment temperature. As described above, before the second heat treatment of the molded body, the molded body may be pressed to form a pellet. The pressure during pressurization is performed in the range of 1 MPa to 200 MPa, 5 MPa to 150 MPa, or 10 MPa to 120 MPa. Since the solid electrolyte according to one embodiment has a pellet density in the range of 2.6 g/cc to 5.1 g/cc, when it is made in the form of pellets under the pressure condition, the solid electrolyte in the form of a membrane obtained from the pellets has excellent impermeability to air or water Do.

As described above, when the secondary heat treatment is performed in the form of pellets, the diffusion distance of the material to be heat treated is shortened, so that a desired solid electrolyte can be easily manufactured. When the secondary heat treatment proceeds in the form of powder particles instead of the above-mentioned pellet form, the oxides of Chemical Formulas 1 to 3 can be made, but compared to the case of the secondary heat treatment in the form of pellets, the diffusion distance is long, resulting in a longer heat treatment time and higher Temperature may be required.

The secondary heat treatment is finally determined by the desired valences or oxidation numbers of M1 and M2, and can be performed, for example, in an oxidizing gas atmosphere, a reducing gas atmosphere, or an inert gas atmosphere. The oxidizing gas atmosphere may be created using, for example, air or oxygen, and the reducing gas atmosphere may be created using a reducing gas such as hydrogen and an inert gas atmosphere such as nitrogen, argon, or helium.

The second heat treatment time varies depending on the second heat treatment temperature, for example, 1 to 50 hours, for example, 6 to 48 hours range.

After the secondary heat treatment, oxides of Chemical Formulas 1 to 3 are formed. When the temperature increase rate during the first and second heat treatment is within the above range, the heat treatment proceeds sufficiently to form the desired crystal structure, and the synthesis time is short, which is economical.

The solid electrolyte according to an embodiment may be used in, for example, a metal-air battery electrolyte, for example, a lithium-air battery. Also, the solid electrolyte can be used as an electrolyte for a lithium battery such as an all-solid-state battery. The solid electrolyte can be used in the manufacture of a positive electrode and a negative electrode of a battery, and can also be used in coating the surface of the positive electrode and the negative electrode.

According to another aspect, an electrochemical device containing a solid electrolyte according to an embodiment is provided. The solid electrolyte is chemically stable, has excellent ionic conductivity, and has improved stability against moisture and strong bases, so that an electrochemical device in which deterioration is effectively suppressed can be obtained.

The electrochemical device is, for example, at least one selected from a battery, an accumulator, a supercapacitor, a fuel cell, a sensor, and an electrochromic device, but must be composed of these It is not limited and any one used as an electrochemical device in the art is possible.

The battery is, for example, a primary battery or a secondary battery. The battery is, for example, a lithium battery, a sodium battery, etc., but is not limited thereto, and any battery used as a battery in the art may be used. The lithium battery includes, for example, a lithium ion battery, a lithium-air battery, etc., but is not necessarily limited thereto, and any lithium battery used in the art may be used. The color-changing element is an electrochemical mirror, a window, a screen, etc., but is not necessarily limited thereto, and any color-changing element used in the art may be used.

The electrochemical device is, for example, a lithium metal battery using a metal such as lithium, zinc, or the like as an anode, for example, a lithium air battery using lithium as an anode. These lithium-air batteries have an improved lifespan.

The anode is, for example, porous. Since the anode is porous, diffusion of air, oxygen, etc. into the anode is easy.

A metal-air battery according to another embodiment includes the above-described positive electrode; cathode; and an electrolyte disposed between the positive electrode and the negative electrode, and at least one selected from the positive electrode, the negative electrode, and the electrolyte may include the solid electrolyte according to an embodiment.

The electrolyte may contain a solid electrolyte according to an embodiment.

At least one selected from the negative electrode and the positive electrode may contain the solid electrolyte according to an embodiment. The negative electrode may include lithium.

By adopting the above-described solid electrolyte in the lithium-air battery, stability against moisture and strong base is improved, and reversibility is ensured in humidified or air conditions, thereby enabling smooth operation. In addition, the structural stability of the lithium-air battery is improved and deterioration is suppressed.

The lithium-air battery includes a positive electrode, and the positive electrode is disposed on, for example, a positive electrode current collector.

The positive electrode may contain the above-described solid electrolyte. The content of the solid electrolyte is, for example, 1 to 100 parts by weight, for example, 10 to 100 parts by weight, for example, 50 to 100 parts by weight, for example, 60 to 100 parts by weight, for example, based on 100 parts by weight of the positive electrode. 80 to 100 parts by weight, for example 90 to 100 parts by weight.

It is also possible to introduce pores into the anode by introducing a pore-forming agent during the manufacture of the cathode. The positive electrode has, for example, a form of a porous pellet, a porous sheet, etc., but is not necessarily limited to such a form and is formed according to a required battery type.

The anode is permeable to, for example, a gas such as oxygen or air. Therefore, it is substantially impermeable to gases such as oxygen and air, and is distinguished from a conventional anode that conducts only ions. Oxygen, air, etc. are easily diffused into the inside of the positive electrode because the positive electrode is porous and/or gas permeable, and lithium ions and/or electrons easily move through the solid electrolyte included in the positive electrode, so that oxygen, Electrochemical reaction by lithium ions and electrons proceeds easily.

Electronic conductivity and ionic conductivity may be further increased by adding a general conductive material in addition to the solid electrolyte during the manufacture of the positive electrode. The conductive material may be porous, for example. Since the conductive material has porosity, air permeation is easy. The conductive material may be any material used in the art as a material having porosity and/or conductivity, for example, a carbon-based material having porosity. Carbon-based materials are, for example, carbon blacks, graphites, graphenes, activated carbons, carbon fibers, etc., but are not limited thereto, and any carbon-based material used in the art may be used. The conductive material is, for example, a metallic material. The metallic material is, for example, a metal fiber, a metal mesh, a metal powder, and the like. The metal powder is, for example, copper, silver, nickel, aluminum or the like. The conductive material is, for example, an organic conductive material. The organic conductive material is, for example, a polyribenylene derivative, a polythiophene derivative, or the like. The conductive materials are used alone or in combination, for example. The anode may include a composite conductor as a conductive material, and the anode may further include the conductive material described above in addition to the composite conductor.

The anode further comprises, for example, a catalyst for oxidation/reduction of oxygen. The catalyst is, for example, a noble metal-based catalyst such as platinum, gold, silver, palladium, ruthenium, rhodium, or osmium, an oxide-based catalyst such as manganese oxide, iron oxide, cobalt oxide, nickel oxide, or an organometallic catalyst such as cobalt phthalocyanine, etc. However, it is not necessarily limited thereto, and any one used as an oxidation/reduction catalyst of oxygen in the art is possible.

The catalyst is supported on a carrier, for example. The carrier is, for example, an oxide carrier, a zeolite carrier, a clay-based mineral carrier, a carbon carrier, and the like. Oxide carriers include, for example, Al, Si, Zr, Ti, Ce, Pr, Sm, Eu, Tb, Tm, Yb, Sb, Bi, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo and It is a metal oxide support containing one or more metals selected from W. Oxide carriers include, for example, alumina, silica, zirconium oxide, titanium dioxide, and the like. Carbon carriers include, but are not limited to, carbon blacks such as Ketjen Black, Acetylene Black, Tunnel Black, Lamp Black, Natural Graphite, Artificial Graphite, and Expanded Graphite, Activated Carbon, Carbon Fiber, and the like. Any use is possible as long as it is used as a carrier in

The positive electrode further includes, for example, a binder. The binder includes, for example, a thermoplastic resin or a thermosetting resin. The binder is, for example, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, vinylidene fluoride. - Hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetra fluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethylvinyl ether-tetrafluoroethylene copolymer; Single or mixture of ethylene-acrylic acid copolymer, etc., but is not necessarily limited thereto, and any one used as a binder in the art is possible.

The positive electrode is, for example, mixed with a conductive material, an oxygen oxidation/reduction catalyst, and a binder and then an appropriate solvent is added to prepare a positive electrode slurry, then applied and dried on the surface of the substrate, or compression molded on the substrate to improve the electrode density. manufacture The substrate is, for example, a positive electrode current collector, a separator, or a solid electrolyte film. The positive electrode current collector is, for example, a gas diffusion layer. The conductive material includes a composite conductor, and the oxygen oxidation/reduction catalyst and the binder in the anode may be omitted depending on the type of the anode required.

A lithium-air battery includes an anode. The negative electrode may contain the solid electrolyte according to an embodiment.

The negative electrode contains lithium.

The negative electrode is, for example, a lithium metal thin film or a lithium-based alloy thin film. The lithium-based alloy is, for example, an alloy of lithium with aluminum, tin, magnesium, indium, calcium, titanium, vanadium, and the like.

A lithium-air battery includes an electrolyte disposed between a positive electrode and a negative electrode.

The electrolyte may be, for example, a solid electrolyte including an oxide represented by Chemical Formulas 1 to 3.

The electrolyte may further include one or more electrolytes selected from general solid electrolytes, gel electrolytes, and liquid electrolytes in addition to the solid electrolyte according to an embodiment. The solid electrolyte, the gel electrolyte, and the liquid electrolyte are not particularly limited, and any electrolyte used in the art may be used.

The solid electrolyte includes a solid electrolyte containing an ion conductive inorganic material, a solid electrolyte containing a polymeric ionic liquid (PIL) and a lithium salt, a solid electrolyte containing an ionically conducting polymer and a lithium salt, and At least one selected from a solid electrolyte including an electron conductive polymer is not necessarily limited thereto, and any solid electrolyte used in the art may be used.

The ion conductive inorganic material includes, but is not limited to, at least one selected from glass or amorphous metal ion conductor, ceramic active metal ion conductor, and glass ceramic active metal ion conductor, as long as it is used as an ion conductive inorganic material in the art All is possible. The ion conductive inorganic material is, for example, an ion conductive inorganic particle or a molded article in the form of a sheet thereof.

The ion conductive inorganic material is, for example, BaTiO ₃ , Pb(Zr,Ti)O ₃ (PZT), Pb _1-x La _x Zr _1-y Ti _y O ₃ (PLZT) (0≤x<1, 0≤y< 1), Pb(Mg ₃ Nb _2/3 )O ₃ -PbTiO ₃ (PMN-PT), HfO ₂ , SrTiO ₃ , SnO ₂ , CeO ₂ , Na ₂ O, MgO, NiO, CaO, BaO, ZnO, ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , SiC, lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0<x<2, 0 <y<3), lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0<x<2, 0<y<1, 0<z<3), Li _1+x+y (Al , Ga) _x (Ti, Ge) _2-x Si _y P _3-y O ₁₂ (0≤x≤1, 0≤y≤1), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0<x< 2, 0<y<3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , 0<x<4, 0<y<1, 0<z<1, 0<w<5), lithium nitrite Ride (Li _x N _y , 0<x<4, 0<y<2), SiS ₂ (Li _x Si _y S _z , 0<x<3,0<y<2, 0<z<4) series glass , P ₂ S ₅ (Li _x P _y S _z , 0<x<3, 0<y<3, 0<z<7) based glass, Li ₂ O, LiF, LiOH, Li ₂ CO ₃ , LiAlO ₂ , Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ Ceramics, Garnet Ceramics (Li _3+x La ₃ M ₂ O ₁₂ (M = Te, Nb, Zr) )) at least one selected from or a combination thereof.

The ionic liquid polymer (polymeric ionic liquid, PIL) is, for example, i) ammonium-based, pyrrolidinium-based, pyridinium-based, pyrimidinium-based, imidazolium-based, piperidinium-based, pyrazolium-based, oxazolium-based, or pyridinium-based At least one cation selected from the group consisting of dazinium, phosphonium, sulfonium, triazolium, and mixtures thereof, and ii) BF ₄ ^- , PF ₆ ^- , AsF ₆ ^- _{, SbF 6} ^- , AlCl ₄ ^- , HSO ₄ ^- , ClO ₄ ^- , CH ₃ SO ₃ -, CF ₃ CO ₂ ^- , (CF ₃ SO ₂ ) ₂ N ^- , Cl ^- , Br ^- , I-, SO ₄ ^- , CF ₃ SO ₃ ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ )(CF ₃ SO ₂ )N ^- , NO ₃ ^- , Al ₂ Cl ₇ ^- , CH ₃ COO ^- , (CF ₃ SO ₂ ) ₃ C ^- , (CF ₃ CF ₂ SO ₂ ) ₂ N ^- _, (CF ₃ ) ₂ PF ₄ ^- , (CF ₃ ) ₃ PF ₃ ^- , (CF ₃ ) ₄ PF ₂ ^- , (CF ₃ ) ₅ PF ^- , (CF ₃ ) ₆ P ^- , SF ₅ CF ₂ SO ₃ ^- , SF ₅ CHFCF ₂ SO ₃ ^- , CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- , (CF ₃ SO ₂ ) ₂ CH ^- , (SF ₅ ) ₃ C ^- , and (O(CF ₃ ) ₂ C ₂ (CF ₃ ) ₂ O) ₂ PO ⁻ at least one anion. The ionic liquid polymer is, for example, poly(diallyldimethylammonium)TFSI, poly(1-allyl-3-methylimidazolium trifluoromethanesulfonyl). imide) and poly(N-methyl-N-propylpiperidinium bistrifluoromethanesulfonylimide) (poly((N-Methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide))).

The ion conductive polymer includes, for example, one or more ion conductive repeating units selected from ether-based, acrylic-based, methacrylic-based and siloxane-based monomers.

The ion conductive polymer is, for example, polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyvinylsulfone, polypropylene oxide (PPO), polymethylmethacrylate, polyethyl Methacrylate, polydimethylsiloxane, polyacrylic acid, polymethacrylic acid, polymethylacrylate, polyethylacrylate, poly2-ethylhexyl acrylate, polybutyl methacrylate, poly2-ethylhexyl methacrylate, poly Decyl acrylate and polyethylene vinyl acetate, phosphoric acid ester polymer, polyester sulfide, polyvinylidene fluoride (PVdF), Li-substituted Nafion (Nafion), etc., including but not necessarily limited thereto, and ion conductive polymers in the art Anything is possible if you use it as

The electron-conducting polymer is, for example, a polyribenylene derivative, a polythiophene derivative, etc., but is not necessarily limited thereto, and any electron-conducting polymer used in the art may be used.

The gel electrolyte is obtained, for example, by further adding a low molecular weight solvent to a solid electrolyte disposed between the positive electrode and the negative electrode. The gel electrolyte is, for example, a gel electrolyte obtained by additionally adding a solvent, an oligomer, and the like, which are low molecular weight organic compounds, to a polymer. The gel electrolyte is, for example, a gel electrolyte obtained by additionally adding a solvent, an oligomer, and the like, which are low molecular weight organic compounds, to the above-described polymer electrolyte.

The liquid electrolyte includes a solvent and a lithium salt.

The solvent includes at least one selected from an organic solvent, an ionic liquid, and an oligomer, but is not necessarily limited thereto, and any solvent that is liquid at room temperature (25° C.) and can be used as a solvent may be used.

The organic solvent includes, for example, at least one selected from an ether-based solvent, a carbonate-based solvent, an ester-based solvent, and a ketone-based solvent. The organic solvent is, for example, propylene carbonate, ethylene carbonate, fluoroethylene carbonate, vinyl ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl isopropyl carbonate, dipropyl Carbonate, dibutyl carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxolane, 4-methyldioxolane, dimethylacetamide, dimethyl sulfoxide, dioxane , 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, succinonitrile, diethylene glycol dimethyl ether (DEGDME), tetraethylene glycol dimethyl ether (TEGDME), polyethylene glycol dimethyl ether (PEGDME) , Mn=~500), dimethyl ether, diethyl ether, dibutyl ether, dimethoxyethane, 2-methyltetrahydrofuran, and at least one selected from tetrahydrofuran, but is not necessarily limited thereto. Any organic solvent that is liquid at room temperature is possible.

The ionic liquid (IL) is, for example, i) ammonium-based, pyrrolidinium-based, pyridinium-based, pyrimidinium-based, imidazolium-based, piperidinium-based, pyrazolium-based, oxazolium-based, pyridazinium-based , phosphonium-based, sulfonium-based, triazolium-based and at least one cation selected from mixtures thereof, and ii) BF ₄ ^- , PF ₆ ^- , AsF ₆ ^- , SbF ₆ ^- , AlCl ₄ ^- , HSO ₄ ^- , ClO ₄ ^- , CH ₃ SO ₃ -, CF ₃ CO ₂ ^- , (CF ₃ SO ₂ ) ₂ N ^- , Cl ^- , Br ^- , I-, SO ₄ ^- , CF ₃ SO ₃ -, (C ₂ F ₅ SO ₂ ) ₂ N-, (C ₂ F ₅ SO ₂ )(CF ₃ SO ₂ )N-, NO ₃ ^- , Al ₂ Cl ₇ ^- , CH ₃ COO ^- , (CF ₃ SO ₂ ) ₃ C ^- , (CF ₃ CF ₂ SO ₂ ) ₂ N ^- _, (CF ₃ ) ₂ PF ₄ ^- , (CF ₃ ) ₃ PF ₃ ^- , (CF ₃ ) ₄ PF ₂ ^- , (CF ₃ ) ₅ PF ^- , (CF ₃ ) ₆ P ^- , SF ₅ CF ₂ SO ₃ ^- , SF ₅ CHFCF ₂ SO ₃ ^- , CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- , (CF ₃ SO ₂ ) ₂ CH ^- , (SF ₅ ) ₃ C ^- , and (O (CF ₃ ) ₂ C ₂ (CF ₃ ) ₂ O) ₂ PO ⁻ at least one anion.

Lithium salts are LiTFSI, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiNO ₃ , (lithium bis(oxalato) borate(LiBOB), LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiN(SO ₂ C) ₂ F ₅ ) ₂ , LiN(SO ₂ F) ₂ , LiC(SO ₂ CF ₃ ) ₃ , LiN(SO ₃ CF ₃ ) ₂ , LiC ₄ F ₉ SO ₃ , LiAlCl ₄ and CF ₃ SO ₃ Li The lithium salt includes, but is not limited to, any lithium salt that can be used in the art. The concentration of the lithium salt is, for example, 0.01 to 5.0M.

The lithium-air battery further includes, for example, a separator between the positive electrode and the negative electrode.

The separator is not limited as long as it has a composition that can withstand the use range of the lithium-air battery. The separator includes, for example, a nonwoven fabric made of polypropylene or a nonwoven fabric made of polyphenylene sulfide, a polymer nonwoven fabric such as a nonwoven fabric made of polyphenylene sulfide, a porous film made of an olefin resin such as polyethylene or polypropylene, and glass fiber, and these two types It is also possible to include in combination with the above.

The electrolyte has, for example, a structure in which a separator is impregnated with a solid polymer electrolyte or a structure in which a separator liquid electrolyte is impregnated. The electrolyte in which the solid polymer electrolyte is impregnated in the separator is prepared, for example, by disposing a solid polymer electrolyte film on one side and both sides of the separator and then rolling them simultaneously. The electrolyte in which the liquid electrolyte is impregnated into the separator is prepared by injecting the liquid electrolyte containing lithium salt into the separator.

A lithium-air battery is arranged on one side of the case in a negative electrode, an electrolyte layer on the negative electrode, a positive electrode on the electrolyte, a porous positive electrode current collector on the positive electrode, and air on the porous positive electrode current collector It is completed by arranging a pressing member that can be delivered and pressing to fix the cell. The case may be divided into an upper portion in contact with the negative electrode and a lower portion in contact with the cathode, and an insulating resin is interposed between the upper portion and the lower portion to electrically insulate the positive electrode and the negative electrode.

Lithium-air batteries can be used for both primary and secondary batteries. The shape of the lithium-air battery is not particularly limited, and for example, a coin type, a button type, a sheet type, a laminate type, a cylinder type, a flat type, a cone type, and the like. Lithium-air batteries can also be applied to medium and large-sized batteries for electric vehicles.

5 schematically shows the structure of a lithium-air battery according to an embodiment.

Referring to FIG. 5 , the lithium-air battery 500 uses oxygen as an active material adjacent to the first current collector 210 , and a negative electrode 300 containing lithium adjacent to the positive electrode 200 and the second current collector 310 . It has a structure in which the first electrolyte 400 is interposed between the fruits. The first electrolyte 400 is a separator impregnated with a liquid electrolyte.

A second electrolyte 450 may be disposed between the positive electrode 200 and the first electrolyte 400 . The second electrolyte 450 is a lithium ion conductive solid electrolyte membrane, and a solid electrolyte according to an embodiment may be used. The first current collector 210 is porous and may also serve as a gas diffusion layer capable of air diffusion. A pressing member 220 through which air can be delivered to the positive electrode is disposed on the first current collector 210 .

A case 320 made of an insulating resin is interposed between the positive electrode 200 and the negative electrode 300 to electrically separate the positive electrode 200 and the negative electrode 300 . Air is supplied to the air inlet (230a) and discharged to the air outlet (230b). The lithium-air battery 500 may be accommodated in a stainless steel container.

"Air" of the lithium-air battery is not limited to atmospheric air, and may include a combination of gases including oxygen, or pure oxygen gas. This broad definition of the term "air" applies to all uses, eg, air cells, air cathodes, and the like.

It will be described in more detail through the following examples and comparative examples. However, the examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

(Preparation of solid electrolyte containing oxide)

Comparative Example 1: Li ₂ Hf0 ₃

Lithium precursor of Li ₂ CO _3, M1 precursor of HfO ₂ mixed according to the composition ratio of Li ₂ Hf0 ₃ and to obtain a precursor mixture by adding and mixing in ethanol here. The precursor mixture was put into a ball-milling device and pulverized and mixed for 4 hours. After drying the mixed product, it was heated to 650°C at a temperature increase rate of about 5°C/min, and the primary heat treatment was performed in an air atmosphere for 12 hours.

After grinding the powder obtained by the primary heat treatment, the powder was pressurized by about 100 MPa to prepare pellets having a diameter of about 1 cm and a height of about 0.1 cm. The pellets were subjected to secondary heat treatment in air or oxygen atmosphere at a temperature of 700° C. for 12 hours to obtain a solid electrolyte containing an oxide. When the temperature was raised to 700 °C for the secondary heat treatment, the temperature increase rate was about 5 °C/min.

Example 1

When preparing the precursor mixture, more lithium chloride (LiCl) is added _{, and the contents of Li 2} CO _{3 as a lithium precursor, HfO 2 as} M1 precursor, and lithium chloride are stoichiometrically controlled to obtain _{Li 1.5} HfCl _0.5 O _{2.5 and 1} A solid electrolyte including an oxide was obtained in the same manner as in Comparative Example 1, except that the primary heat treatment was performed at 650° C. for 12 hours and the secondary heat treatment was performed at 700° C. for 12 hours.

Example 2 and Example 6

A solid electrolyte was obtained in the same manner as in Example 1, except that the contents _{of Li 2} CO _{3 as a lithium precursor, HfO 2 as} M1 precursor, and lithium chloride were controlled to obtain the target material shown in Table 1.

Examples 3, 9 and 10

When the precursor mixture was prepared, lithium fluoride (LiF) was further added _{, and the contents of Li 2} CO _{3 as a lithium precursor, HfO 2 as} M1 precursor, and lithium fluoride were stoichiometrically controlled to obtain a target product having the composition of Table 1. Except that, the same procedure as in Comparative Example 1 was carried out to obtain a solid electrolyte.

Example 4

A solid electrolyte was obtained in the same manner as in Comparative Example 1, except that the content _{of Li 2} CO ₃ , which is a lithium precursor, and _{HfO 2} , which is an M1 precursor, were stoichiometrically controlled to obtain a target product when the precursor mixture was prepared.

Example 5

When preparing the precursor mixture, Al ₂ O _{3 as an Al precursor is further added, and the content of Li 2} CO ₃ which is a lithium precursor _{, HfO 2} which is an M1 precursor, and Al ₂ O _{3 which} is an Al precursor is stoichiometric to obtain a target product having a composition. A solid electrolyte was obtained in the same manner as in Comparative Example 1, except that it was controlled as .

Example 7

When the precursor mixture is prepared, magnesium oxide (MgO), which is a Mg precursor, is further added _{, and the content of Li 2} CO _{3 as} a lithium precursor, HfO _{2 as an} M1 precursor, and magnesium oxide as a Mg precursor are stoichiometrically to obtain a target product having a composition. A solid electrolyte was obtained in the same manner as in Comparative Example 1 except for the control.

Example 8

When the precursor mixture is prepared, tantalum oxide (Ta ₂ O ₅ ), which is a Ta precursor, is further added, and the content of Li ₂ CO _{3 as} a lithium precursor, HfO _{2 as an} M1 precursor, and tantalum oxide (Ta ₂ O ₅ ) as a Ta precursor is added. A solid electrolyte was obtained in the same manner as in Comparative Example 1, except that it was stoichiometrically controlled to obtain the target product.

Examples 11 and 12

When preparing the precursor mixture, yttrium oxide (Y ₂ O ₃ ) as a _{Y precursor is further added, and the content of Li 2} CO _{3 as} a lithium precursor, HfO _{2 as an} M1 precursor, and yttrium oxide as a Y precursor to obtain a target product having a composition A solid electrolyte was obtained in the same manner as in Comparative Example 1 except for stoichiometric control.

division Furtherance Comparative Example 1 Li ₂ Hf0 ₃ Example 1 Li _1.5 HfCl _0.5 O _2.5 Example 2 Li _1.8 HfCl _0.2 O _2.8 Example 3 Li _1.5 HfF _0.5 O _2.5 Example 4 Li _2.2 Hf _0.95 O ₃ Example 5 Li _2.2 Hf _0.8 Al _0.2 O ₃ Example 6 Li _1.9 HfCl _0.1 O ₃ Example 7 Li _2.2 Hf _0.9 Mg _0.1 O ₃ Example 8 Li _1.8 Hf _0.8 Ta _0.2 O ₃ Example 9 Li _1.9 HfF _0.1 O _2.9 Example 10 Li _1.8 HfF _0.2 O _2.8 Example 11 Li _2.2 Hf _0.8 Y _0.2 O ₃ Example 12 Li _2.2 Hf _0.9 Y _0.1 O ₃

Comparative Example 2: Li ₂ Zr0 ₃

Lithium precursor of Li ₂ CO _3, M1 precursor of ZrO ₂ mixed according to the composition ratio of Li ₂ Zr0 ₃ and to obtain a precursor mixture by adding and mixing in ethanol here. The precursor mixture was put into a ball-milling device and pulverized and mixed for 4 hours. After drying the mixed product, it was heated to 650°C at a temperature increase rate of about 5°C/min, and the primary heat treatment was performed in an air atmosphere for 12 hours.

After grinding the powder obtained by the primary heat treatment, the powder was pressed to prepare pellets having a diameter of about 1 cm and a height of about 0.1 cm. The pellets were subjected to secondary heat treatment at a temperature of 700° C. in air or oxygen atmosphere for 12 hours to obtain a target product. When the temperature was raised to 700 °C for the secondary heat treatment, the temperature increase rate was about 5 °C/min.

Example 13

When preparing the precursor mixture, aluminum oxide (Al ₂ O _{3 ), which is an Al precursor, is further added, and the content of Li 2} CO ₃ which is a lithium _{precursor, ZrO 2} which is an M1 precursor, and aluminum oxide which is an Al precursor can be added to obtain a target product having a composition A solid electrolyte was obtained in the same manner as in Comparative Example 2 except for stoichiometric control.

Examples 14 and 16

When preparing the precursor mixture, lithium chloride (LiCl) was further added _{, and the contents of Li 2} CO _{3 as a lithium precursor, ZrO 2 as} M1 precursor, and lithium chloride were stoichiometrically controlled to obtain a target product having the composition of Table 1. Except that, the same procedure as in Comparative Example 2 was carried out to obtain a solid electrolyte.

Example 15

When preparing the precursor mixture, yttrium oxide (Y ₂ O ₃ ) as a yttrium precursor is further added, and Li ₂ CO _{3 as} a lithium precursor, ZrO _{2 as an} M1 precursor, and yttrium oxide as a yttrium precursor (Y ₂ O ₃ ) having a composition having a composition A solid electrolyte was obtained in the same manner as in Comparative Example 2, except that it was stoichiometrically controlled to obtain the target product.

Example 17

When the precursor mixture is prepared, magnesium oxide (MgO), which is an Mg precursor, is further added _{, and the contents of Li 2} CO _{3 as} a lithium precursor, ZrO _{2 as an} M1 precursor, and MgO as Mg precursor are measured in a chemical amount to obtain a target product having the composition shown in Table 1. A solid electrolyte was obtained in the same manner as in Comparative Example 2, except for theoretical control.

Example 18

When the precursor mixture is prepared, zinc oxide (ZnO), which is a Zn precursor, is further added _{, and the contents of Li 2} CO _{3 as} a lithium precursor, ZrO _{2 as an} M1 precursor, and ZnO as a Zn precursor are measured in chemical amounts to obtain the target product having the composition shown in Table 1. A solid electrolyte was obtained in the same manner as in Comparative Example 2, except for theoretical control.

Example 19

When preparing the precursor mixture, tantalum oxide (Ta ₂ O ₅ ), which is a Ta precursor, is further added _{, and the contents of Li 2} CO _{3 as} a lithium precursor, ZrO _{2 as an} M1 precursor, and tantalum oxide (Ta ₂ O ₅ ) as a Ta precursor are shown in Table 1 A solid electrolyte was obtained in the same manner as in Comparative Example 2, except that it was stoichiometrically controlled to obtain a target product having a composition of .

Example 20

A solid electrolyte was obtained in the same manner as in Comparative Example 1, except that the lithium precursor Li ₂ CO ₃ and the M1 precursor ZrO ₂ content were _{controlled according to the composition ratio of Li 2.2} Zr _0.95 0 _{3 .}

Examples 21-23

When the precursor mixture was prepared, lithium fluoride (LiF) was further added and _{the contents of Li 2} CO _{3 as a lithium precursor, ZrO 2 as an} M1 precursor, and lithium fluoride were stoichiometrically controlled so as to obtain a target product having the composition shown in Table 1. Except that, the same procedure as in Comparative Example 1 was carried out to obtain a solid electrolyte.

division Furtherance Comparative Example 2 Li ₂ Zr0 ₃ Example 13 Li _2.2 Zr _0.8 Al _0.2 O ₃ Example 14 Li _1.8 ZrCl _0.2 O _2.8 Example 15 Li _2.2 Zr _0.8 Y _0.2 O ₃ Example 16 Li _1.9 ZrCl _0.1 O _2.9 Example 17 Li _2.2 Zr _0.9 Mg _0.1 O ₃ Example 18 Li _2.2 Zr _0.9 Zn _0.1 O ₃ Example 19 Li _1.8 Zr _0.8 Ta _0.2 O ₃ Example 20 Li _2.2 Zr _0.95 O ₃ Example 21 Li _1.5 ZrF _0.5 O _2.5 Example 22 Li _1.8 ZrF _0.2 O _2.8 Example 23 Li _1.9 ZrF _0.1 O _2.9

The solid electrolyte of Example 4 contains an oxide containing cation vacancies, and the solid electrolyte of Examples 3, 9 and 10 contains an oxide doped with an anion F. And the solid electrolytes of Examples 1, 2 and 6 were oxides doped with anion Cl, and the solid electrolytes of Examples 5 and 11 contained oxides doped with trivalent cations.

Further, the solid electrolyte of Example 8 contains an oxide doped with a pentavalent cation, and the solid electrolyte of Example 7 contains an oxide doped with a divalent cation. The solid electrolyte of Example 12 includes an oxide doped with divalent cations.

Preparation Example 1: Preparation of Lithium Air Battery (Anode/Solid Electrolyte/PEO/Li Anode)

After mixing 40 parts by weight of carbon (Super-P), 10 parts by weight of polytetrafluoroethylene (PTFE), and 50 parts by weight of NMP (N-methylpyrrolidone) to prepare a positive electrode slurry, the slurry was coated and rolled Thus, a positive electrode composite sheet was obtained. The positive electrode composite sheet was pressed onto a stainless mesh and vacuum dried in an oven at 100° C. for 120 minutes to obtain a positive electrode.

Punch 1 cmХ1 cm in the center of a 5 cmХ5 cm aluminum film (Polypropylene coated aluminum film, 200 μm) and use an adhesive to close the hole with the 1.4 cmХ1.4 cm solid electrolyte of Example 1, so that some A first aluminum film made of the solid electrolyte of Example 1 was prepared. Next, a new 2nd aluminum film with a size of 5 cmХ5 cm, a copper current collector (thickness 20 μm), lithium foil (1.4 cmХ1.4 cm, thickness 100 μm), and an electrolyte solution that is a mixture of 1M LiTFSI and PC A Celgard-3501 separator of 25 μm in thickness, which is an impregnated polypropylene material, and the prepared first aluminum film were laminated and vacuum heat-bonded to obtain an aluminum pouch-type protected lithium anode.

The protected lithium negative electrode was installed in a stainless case, and a positive electrode having a 25 μm-thick Celgard Celgard separator made of polypropylene was set on the side opposite to the negative electrode. Next, a porous gas diffusion layer made of carbon fiber is placed on the positive electrode, and a foamed nickel plate is placed thereon, and the lithium air battery is pressed by a pressing member on which air can be delivered to the positive electrode. prepared.

Preparation Example 2-23: Preparation of lithium-air battery

A lithium-air battery was manufactured in the same manner as in Preparation Example 1, except that the solid electrolytes of Examples 2 to 23 were respectively used instead of the solid electrolyte of Example 1.

Comparative Preparation Example 1-2: Preparation of Lithium Air Battery

A lithium-air battery was manufactured in the same manner as in Example 1, except that the solid electrolyte of Comparative Example 1 and the solid electrolyte of Comparative Example 2 were respectively used instead of the solid electrolyte of Example 1.

Evaluation Example 1 XRD spectrum

XRD spectra of the solid electrolytes of Examples 3 to 5, Example 7, Example 9, Example 12, Example 13, Example 20 and Comparative Example 1 were measured, and the results are shown in FIG. 1 . X-ray diffraction analysis was performed using Bruker's D8 Advance, and Cu Kα radiation was used for XRD spectrum measurement.

As shown in FIG. 1 , in the solid electrolytes of Examples 3-5, 7, 9, 12-13, and Example 20, peaks appear in the diffraction angle 2θ of 26.7±0.5°, 35±0.5°, and 39±0.5°, but , The above-mentioned peak was not observed in the solid electrolyte of Comparative Example 1.

Evaluation Example 2: Ion conductivity

Gold (Au) was coated (deposition) by sputtering on the upper and lower surfaces of the ion conductor pellets prepared in Examples 1 to 12 and Comparative Example 1, and a 2-probe method using an impedance analyzer. Impedance was measured. The frequency range was 1 Hz to 1 MHz, and the amplitude voltage was 100 mV. Measurements were made at 30° C. in an air atmosphere. The resistance value was obtained from the arc of the Nyguist plot for the impedance measurement result, and the ionic conductivity was calculated therefrom.

As shown in FIG. 3 , the solid electrolytes of Examples 1 to 12 exhibited higher ionic conductivity retention compared to the solid electrolyte of Comparative Example 1. From these results, it was confirmed that the ionic conductivity was improved by introducing anions such as fluorine and chlorine and introducing yttrium, aluminum, tantalum, magnesium or zinc into the solid electrolyte.

In addition, the solid electrolytes of Examples 11 and 12 contained yttrium and zinc, respectively, in addition to hafnium, and thus the weight was reduced compared to the electrolyte of Comparative Example 1, and thus a lightweight lithium-air battery could be manufactured.

Evaluation Example 3: Ion Conductivity

Gold (Au) was coated (deposition) by sputtering on the upper and lower surfaces of the ion conductor pellets prepared in Examples 13 to 23 and Comparative Example 2, and the sample was measured by a two-probe method using an impedance analyzer. Impedance was measured. The frequency range was 1 Hz to 1 MHz, and the amplitude voltage was 100 mV. Measurements were made at 30° C. in an air atmosphere. The resistance value was obtained from the arc of the Nyguist plot for the impedance measurement result, and the ionic conductivity was calculated therefrom.

As shown in FIG. 4 , the solid electrolytes of Examples 13 to 23 exhibited equal or improved ionic conductivity compared to the solid electrolyte of Comparative Example 2. From these results, it was confirmed that the ionic conductivity was improved by introducing anions such as fluorine and chlorine and introducing yttrium, aluminum, tantalum, magnesium or zinc into the solid electrolyte. In particular, the solid electrolytes of Examples 20 to 23 exhibited an equivalent level of ionic conductivity compared to the solid electrolyte of Comparative Example 2, but increased pellet density as shown in Table 4 below. When a solid electrolyte with increased pellet density is used as described above, the result obtained after the pressurization process for the production of the solid electrolyte is dense. did.

Evaluation Example 4: Pellet Density

(1) Examples 1-12 and Comparative Example 1

The diameter, height, and weight of the ion conductor pellets obtained according to Examples 1-12 and Comparative Example 1 were measured to measure the pellet density. The pellet density evaluation results are shown in Table 3 and FIG. 2 below.

division Pellet density (g/cc) Example 1 4.42 Example 2 4.31 Example 3 4.60 Example 4 4.00 Example 5 4.99 Example 6 4.24 Example 7 5.10 Example 8 4.37 Example 9 4.42 Example 10 4.41 Example 11 4.96 Example 12 4.92 Comparative Example 1 3.97

As shown in Table 3 and FIG. 2, it was found that the pellets of Examples 1 to 12 had improved pellet density compared to the pellets of Comparative Example 1.

(2) Examples 13-23 and Comparative Example 2

The diameter, height, and weight of the pellets obtained according to Examples 13-23 and Comparative Example 2 were measured

The pellet density was measured by measuring, and the pellet density evaluation results are shown in Table 4 below.

division Pellet density (g/cc) Example 13 3.42 Example 14 2.60 Example 15 2.94 Example 16 2.79 Example 17 2.85 Example 18 3.33 Example 19 3.18 Example 20 3.04 Example 21 3.09 Example 22 2.99 Example 23 2.87 Comparative Example 2 2.62

As can be seen from Table 4, the ion conductor pellets of Examples 13 and 15 to 23 had improved pellet density compared to the pellets of Comparative Example 2. The ion conductor pellet of Example 14 had a smaller pellet density than the pellet of Comparative Example 2, but the conductivity was greatly increased as shown in FIG. 4 .

Evaluation Example 5: Electrochemical stability evaluation

After the solid electrolyte of Example 1 was pulverized to a size of about 1 μm, 85 wt% of the pulverized compound, 10 wt% of a carbon black conductive material, and 5 wt% of a PVDF (Polyvinylidene fluoride) binder were mixed with N-methyl-2-pyrrolidone. to prepare a slurry. The prepared slurry was coated on aluminum foil and dried to prepare a working electrode. A half-cell was completed by using a lithium metal foil as a counter electrode, and placing a separator impregnated with a liquid electrolyte (1M LiTFSI in propylene carbonate (PC)) between the working electrode and the counter electrode. .

Electrochemical stability of the layered structure compound disposed on lithium metal for a voltage range of 2-4V (vs. Li) at a scan rate of 0.1 mV/sec by Cyclic Voltammetry (CV) for the prepared half-cell was evaluated.

As a result of the evaluation, the solid electrolyte of Example 1 was electrochemically stable without overcurrent due to side reactions during one scan, 80 scans, or 100 scans.

Evaluation Example 6: Lithium-air battery charge/discharge characteristic evaluation

^{The lithium-air battery prepared according to Preparation Example 1 was discharged to 2.0 V (vs. Li) with a constant current of 0.01 mA/cm 2 in} an oxygen atmosphere at 60° C. and 1 atm oxygen, and then charged to 4.25 V with the same current. A charge/discharge cycle was performed. carried out. The results of the charge/discharge test in the first cycle of each lithium-air battery were examined.

As a result of the charge/discharge test, it was confirmed that the lithium-air battery of Preparation Example 1 employing the solid electrolyte of Example 1 was stably driven.

The lithium-air batteries of Preparation Examples 2 to 23 were evaluated for charging and discharging characteristics in the same manner as in the evaluation method of the charging and discharging characteristics of the lithium-air battery of Preparation Example 1.

As a result of the evaluation, it was found that the lithium-air batteries of Preparation Examples 2 to 23 were stably operated in the same manner as the lithium-air batteries of Preparation Example 1.

200: positive electrode 210: first current collector
220: pressing member 230a: air inlet
230b: air outlet 300: cathode
310: second current collector 320: insulating case
400: electrolyte membrane 450: solid electrolyte membrane
500: lithium air battery

Claims (26)

A solid electrolyte comprising an oxide represented by Formula 1, 2 or 3 or a combination thereof:
<Formula 1>
Li _2+4x M1 _1-x O ₃
In Formula 1, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof, and 0<x<1;
<Formula 2>
Li _2-y(a-4) M1 _1-y M2 ^a+ _y O ₃
In Formula 2, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,
M2 is at least one selected from monovalent to hexavalent elements, a is the oxidation number of M2, and 0<y<1;
<Formula 3>
Li _2-z M1O _3-z X _z
chemical formula triple, M1 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof,
X is a halogen atom, pseudohalogen, or a combination thereof, and 0<z<2. The solid electrolyte of claim 1, wherein M1 in Formulas 1 to 3 is hafnium (Hf), titanium (Ti), zirconium (Zr), or a combination thereof. According to claim 1, wherein M2 in Formula 2 is aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La) ), scandium (Sc), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), vacancies (Vacancy) or a combination of solid electrolytes. According to claim 1, wherein X in Formula 3 is fluorine (F), chlorine (Cl), bromine (Br), cyanide (cyanide), cyanate (cyanate), thiocyanate (thiocyanate), azide (azide) ) or a combination thereof. The solid electrolyte of claim 1, wherein x in Formula 1 is 0.01 to 0.9. The solid electrolyte of claim 1, wherein y in Formula 2 is 0.05 to 0.9. The solid electrolyte of claim 1, wherein a in Formula 2 is 2, 3, 5, or 6. The solid electrolyte of claim 1, wherein z in Formula 3 is 0.05 to 1. The solid electrolyte of claim 1 , wherein the oxide of Formula 1 is an oxide represented by Formula 4 or an oxide represented by Formula 5:
<Formula 4>
Li _2+4x Hf _1-x O ₃
In Formula 4, 0.01≤x≤0.9,
<Formula 5>
Li _2+4x Zr _1-x O ₃
In formula (5), 0.01≤x≤0.9. The solid electrolyte according to claim 1, wherein the oxide of Formula 2 is an oxide represented by Formula 6 or an oxide represented by Formula 7:
<Formula 6>
Li _2-y(a-4) Hf _1-y M2 ^a+ _y O ₃
In Formula 6, M2 is aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), and scandium (Sc) , magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), or a combination thereof,
a is the oxidation number of M2, 0.05≤y≤0.9,
<Formula 7>
Li _2-y(a-4) Zr _1-y M2 ^a+ _y O ₃
In Formula 7, M2 is aluminum (Al), gallium (Ga), indium (In), niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), lanthanum (La), scandium (Sc) , magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), cadmium (Cd), tungsten (W), molybdenum (Mo), or a combination thereof,
a is the oxidation number of M2, and 0.05≤y≤0.9. The solid electrolyte according to claim 1, wherein the oxide of Formula 3 is an oxide represented by the following Formula 8 or an oxide represented by the following Formula 9:
<Formula 8>
Li _2-z HfO _3-z X _z
chemical formula 8 in, X is a halogen atom, pseudohalogen, or a combination thereof, and 0.05≤z≤1,
0.05 to 1
<Formula 9>
Li _2-z ZrO _3-z X _z
chemical formula 9 in, X is a halogen atom, pseudohalogen, or a combination thereof, and 0.05≤z≤1. The solid electrolyte according to claim 1, wherein the oxide has a rock salt crystal structure. The solid electrolyte according to claim 1, wherein the oxide has a C2/c (space group No. 15) space group. According to claim 1, wherein the oxide is Li _2.2 Hf _0.95 O ₃ , Li _1.9 HfF _0.1 O _2.9 , Li _1.8 HfF _0.2 O _2.8 , Li _1.5 HfF _0.5 O _2.5 , Li _1.9 HfCl _0.1 O _2.9 , Li _1.8 HfCl _0.2 O _2.8 , Li _1.5 HfCl _0.5 O _2.5 , Li _1.9 HfF _0.05 Cl _0.05 O _2.9 , Li _1.8 HfF _0.1 Cl _0.1 O _2.8 , Li _1.8 HfBr _0.1 Cl _0.1 O _2.8 , Li _1.5 HfF _0.25 Cl _0.25 O _2.5 , Li _1.5 HfBr _0.25 Cl _0.25 O _2.5 , Li _2.2 Hf _0.8 Y _0.2 O ₃ , Li _2.2 Hf _0.8 La _0.2 O ₃ , Li _2.2 Hf _0.8 Sc _0.2 O ₃ , Li _2.2 Hf _0.8 Al _0.2 O ₃ , Li _2.2 Hf _0.8 Ta _0.2 O ₃ , Li _2.2 Hf _0.8 Nb _0.2 O ₃ , Li _2.2 Hf _0.8 V _0.2 O ₃ , Li _2.2 Hf _0.9 Mg _0.1 O ₃ , Li _2.2 Hf _0.9 Ca _0.1 O ₃ , Li _2.2 Hf _0.9 Sr _0.1 O ₃ , Li _2.2 Hf _0.9 Ba _0.1 O ₃ , Li _2.2 Hf _0.9 Zn _0.1 O ₃ , Li _2.2 Hf _0.9 Cd _0.1 O ₃ , Li _2.2 Zr _0.95 O ₃ , Li _1.9 ZrF _0.1 O _2.9 , Li _1.8 ZrF _0.2 O _2.8 , Li _1.5 ZrF _0.5 O _2.5 , Li _1.9 ZrCl _0.1 O _2.9 , Li _1.8 ZrCl _0.2 O _2.8 , Li _1.5 ZrCl _0.5 O _2.5 , Li _1.9 ZrF _0.05 Cl _0.05 O _2.9 , Li _1.9 ZrBr _0.05 Cl _0.05 O _2.9 , Li _1.8 ZrF _0.1 Cl _0.1 O _2.8 , Li _1.8 ZrBr _0.1 Cl _0.1 O _2.8 , Li _1.5 ZrF _0.25 Cl _0.25 O _2.5 , Li _1.5 ZrBr _0.25 Cl _0.25 O _2.5 , Li _2.2 Zr _0.8 Y _0.2 O ₃ , Li _2.2 Zr _0.8 La _0.2 O ₃ , Li _2.2 Zr _0.8 Sc _0.2 O ₃ , Li _2.2 Zr _0.8 Al _0.2 O ₃ , Li _2.2 Zr _0.8 Ta _0.2 O ₃ , Li _2.2 Zr _0.8 Nb _0.2 O ₃ , Li _2.2 Zr _0.8 V _0.2 O ₃ , Li _2.2 Zr _0.9 Mg _0.1 O ₃ , Li _2.2 Zr _0.9 Ca _0.1 O ₃ , Li _2.2 Zr _0.9 Sr _0.1 O ₃ , Li _2.2 Zr _0.9 Ba _0.1 O ₃ , Li _2.2 Zr _0.9 Mg _0.1 O ₃ , Li _2.2 Zr _0.9 Zn _0.1 O ₃ , Li _2.2 Zr _0.9 Cd _0.1 O ₃ , or a combination thereof. The solid electrolyte according to claim 1, wherein the solid electrolyte has an ionic conductivity of 1X10 ^-5 S/cm or more at room temperature (25° C.). The method of claim 1, wherein the solid electrolyte is an X-ray diffraction spectrum using CuKα.
oxide

crystal plane,

crystal plane and

A solid electrolyte with diffraction peaks related to the crystal plane. The solid electrolyte according to claim 1, wherein the solid electrolyte exhibits diffraction peaks in the regions where the diffraction angles 2θ are 26.7±0.5°, 35±0.5°, and 39±0.5° in an X-ray diffraction spectrum using CuKα. The solid electrolyte according to claim 1, wherein the pellet density of the solid electrolyte is 2.6 g/cc to 5.10 g/cc. anode; cathode; and an electrolyte disposed between the positive electrode and the negative electrode; and
At least one selected from the positive electrode, the negative electrode and the electrolyte is a metal-air battery comprising the solid electrolyte of any one of claims 1 to 18. The metal-air battery according to claim 19, wherein the metal-air battery is a lithium-air battery comprising a negative electrode containing lithium and a positive electrode using air as an active material. An electrochemical device comprising the solid electrolyte of any one of claims 1 to 18. The electrochemical device according to claim 21, wherein the electrochemical device is at least one selected from a battery, a storage battery, a supercapacitor, a fuel cell, a sensor, and a color change device. preparing a precursor mixture by mixing the lithium precursor, the M1 precursor, the M2 precursor, and the X precursor; and
19. A method for producing a solid electrolyte comprising the step of preparing the solid electrolyte of any one of claims 1 to 18, including the step of first heat-treating the precursor mixture. The method of claim 23, wherein the primary heat treatment is performed at 400 to 950°C. 24. The method of claim 23, wherein the manufacturing method comprises: pulverizing the first heat-treated product to obtain a compact; and subjecting the molded body to secondary heat treatment. The method of claim 25, wherein the secondary heat treatment is performed at 500°C to 1300°C.

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