Halide electrolyte material, method of making and solid-state battery

Abstract

This invention discloses a halide electrolyte material, its preparation method, and a solid-state battery, relating to the field of halide electrolyte technology; the chemical formula of the halide electrolyte material is xLi. a Y b ·TaCl5·yLi c M d O e X f Wherein, Y is selected from at least one of the elements O, F, Cl, Br, I, S, and N; M is selected from at least one of the elements Al, Ga, In, Mo, and Ti; and X is selected from at least one of the elements F, Cl, Br, and I; 1 < a ≤ 4, 0 < b ≤ 3, 0 < c ≤ 3, 0 < d ≤ 2, 0 ≤ e ≤ 2, 0 < f ≤ 6, and x and y represent Li a Y b ·TaCl5 and Li c M d O e X f The molar ratio is 0 < x ≤ 2, 0 < y ≤ 1. The beneficial effect of this invention is that Li containing element M... c M d O e X f After the component is introduced, the content of Ta in the electrolyte is reduced, the cost of raw materials is reduced, and it has high ionic conductivity, which can form a good lithium-ion transport path on the surface of the active material, so that the capacity of the cathode material can be fully utilized. Its good viscosity can reduce the solid-solid contact resistance between the electrolyte material and the active cathode particles.

Description

Technical Field

[0001] This invention relates to the field of halide electrolyte technology, and in particular to a halide electrolyte material, its preparation method, and a solid-state battery. Background Technology

[0002] In solid-state batteries, the electrolyte not only performs ion transport but also acts as an electronic separator, forming a novel battery structure and working mechanism. Among them, halide solid-state electrolytes, with their unique chemical composition and crystal structure, exhibit significant advantages in several key performance indicators, especially in terms of compatibility with high-voltage cathodes and processability, making them a focus for industrial applications.

[0003] The solid electrolyte phase inside the positive electrode composite electrode must provide a continuous, low-resistance lithium-ion conduction path from the current collector / electrolyte layer interface to the surface of the active material particles, which requires the solid electrolyte material itself to have high ionic conductivity.

[0004] Tantalum-based halide electrolytes have high ionic conductivity, but the price of tantalum is expensive and fluctuates greatly, resulting in high material costs and hindering large-scale commercial applications. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a halide electrolyte material, a method for preparing the same, and a solid-state battery, so as to solve the above-mentioned technical problems.

[0006] This invention provides a halide electrolyte material, wherein the chemical formula of the halide electrolyte material is xLi. a Y b ·TaCl5·yLi c M d O e X f Wherein, Y is selected from at least one of the elements O, F, Cl, Br, I, S, and N; M is selected from at least one of the elements Al, Ga, In, Mo, and Ti; and X is selected from at least one of the elements F, Cl, Br, and I; 1 < a ≤ 4, 0 < b ≤ 3, 0 < c ≤ 3, 0 < d ≤ 2, 0 ≤ e ≤ 2, 0 < f ≤ 6, and x and y represent Li a Y b ·TaCl5 and Li c M d O e X f The molar ratio is 0 < x ≤ 2, 0 < y ≤ 1.

[0007] The halide electrolyte material xLi provided by this invention a Y b ·TaCl5·yLi c M dO e X f In the preparation process, Li containing the element M is introduced. c M d O e X f After componentization, the Ta content in the electrolyte is reduced, and the cost of the raw materials Al, Ga, In, Mo, and Ti used is lower than that of Ta, which can reduce the raw material cost of the electrolyte. Furthermore, in xLi a Y b • In TaCl5 electrolyte materials, Li is introduced c M d O e X f The components have good viscosity and ductility. When applied to composite cathodes, they can transform rigid point-to-point contact into flexible surface contact, reduce the interfacial resistance between solid-solid particles, improve ion transport capacity, enhance the densification of cathode sheets, and improve the electrochemical performance of all-solid-state batteries.

[0008] Optionally, the surface of the halide electrolyte material is further coated with a first coating layer Z, wherein Z is selected from at least one of Li3BO3 (lithium borate), Li3BN2 (lithium boron nitride), Li4SiO4 (lithium orthosilicate), and Li2SiO3 (lithium metasilicate).

[0009] By coating the surface of the halide electrolyte material with a first coating layer Z, which has a high redox potential, the electrochemical window of the halide electrolyte material is increased to above 4.5V, thus avoiding the problem of the halide electrolyte material being prone to decomposition under high voltage due to the electrochemical window being below 4V.

[0010] Optionally, the first coating layer Z is further coated with a second coating layer W, wherein W is selected from at least one of SiO2 (silicon dioxide), SeO2 (selenium dioxide), Bi2O3 (bismuth trioxide), and Sb2O3 (antimony trioxide).

[0011] By coating the surface of the halide electrolyte material with a second coating layer W, the second coating layer W can prevent the electrolyte material from direct contact with moisture in the air, and the second coating layer W does not react with H2O and O2 in the humid air, thereby improving the air stability of the halide electrolyte material, reducing the environmental requirements for the production of all-solid-state batteries, and improving production efficiency.

[0012] Optionally, the mass of the first coating layer Z is not greater than 20% of the mass of the halide electrolyte material, or the mass of the first coating layer Z is 1%-10% of the mass of the halide electrolyte material; the mass of the second coating layer W is not greater than 20% of the mass of the halide electrolyte material, or the mass of the second coating layer W is 1%-5% of the mass of the halide electrolyte material.

[0013] This invention also provides a method for preparing halide electrolyte materials, for preparing the halide electrolytes as described above, comprising the following steps: Weigh out the lithium source, tantalum source, M source, X source, and oxygen source, wherein the lithium source is one or more of LiCl (lithium chloride), LiOH (lithium hydroxide), Li2CO3 (lithium carbonate), Li2O (lithium oxide), Li2O2 (lithium peroxide), LiCl·H2O (lithium chloride-hydrate), and tert-butyllithium oxide; and the X source is LiX (lithium halide), AlX3 (aluminum trihalide), AlX3·6H2O (aluminum trihalide hexahydrate), GaX3 (gallium trihalide), InCl3 (indium trichloride), MoCl6 (molybdenum hexachloride), MoCl5 (molybdenum pentachloride), TiCl4 (titanium tetrachloride), and TiCl3 (trichloroethylene trichloride). The oxygen source is one or more of the following: lithium hydroxide (LiCl·H2O), wherein X is one of F, Cl, Br, and I; the tantalum source is one or more of TaCl5 (tantalum pentachloride) and Ta2O5 (tantalum pentoxide); the oxygen source is one or more of LiOH (lithium hydroxide), Li2O (lithium oxide), Li2O2 (lithium peroxide), LiCl·H2O (lithium chloride monohydrate), AlX3·6H2O (aluminum trihalide hexahydrate), Al(OH)3 (aluminum hydroxide), O2 (oxygen), and O3 (ozone); wherein X in AlX3·6H2O is one of F, Cl, Br, and I. The precursor was obtained by ball milling in an inert gas. The obtained precursor is annealed to obtain the halide electrolyte material xLi. a Y b ·TaCl5·yLi c M d O e X f .

[0014] Optionally, in the ball milling process, the milling time is 3h-20h, and the milling speed is 200rpm-800rpm.

[0015] Optionally, the annealing process includes the following steps: First, a first-stage annealing process is carried out at a temperature of 120℃-200℃ for 0.2h-5h; then, a second-stage annealing process is carried out at a temperature of 210℃-300℃ for 0.2h-8h.

[0016] Optionally, the following steps are also included: Before annealing the obtained precursor, a Z chemical raw material is added to mix and disperse the Z chemical raw material on the surface of the precursor; the Z chemical raw material is selected from one or more of Li3BO3 (lithium borate), B(C2H5)3 (triethylboron), B(CH3)3 (trimethylboron), Li3BN2 (lithium boron nitride), BN (boron nitride), Li4SiO4 (lithium orthosilicate), and Li2SiO3 (lithium metasilicate); Under a mixed gas atmosphere, the homogeneously mixed precursor and the Z chemical raw material are subjected to a first-stage annealing treatment to obtain xLi. a Y b ·TaCl5·yLi c M d O e X f @mZ, the mixed gas is nitrogen and oxygen, nitrogen and ozone, argon and oxygen, or argon and ozone, wherein the inert gas content is 80%-95%, m is the mass ratio of the Z chemical raw material to the halide electrolyte material, 0 < m ≤ 0.2, or 0.01 ≤ m ≤ 0.1.

[0017] Optionally, the following steps are also included: In the obtained xLi a Y b ·TaCl5·yLi c M d O e X f @mZ contains a W chemical raw material, wherein the W chemical raw material is selected from at least one of SiO2 (silicon dioxide), SeO2 (selenium dioxide), Bi2O3 (bismuth trioxide), and Sb2O3 (antimony trioxide); xLi under mixed gas conditions a Y b ·TaCl5·yLi c M d O e X f @mZ and the W chemical raw material are subjected to the two-stage annealing treatment to obtain xLi a Y b ·TaCl5·yLi c M d O e X f@mZ@nW, where n is the mass ratio of the W chemical raw material to the halide electrolyte material, 0 < n ≤ 0.2, or 0.01 ≤ n ≤ 0.05.

[0018] The present invention also provides a solid-state battery, comprising a halide electrolyte material prepared by the halide electrolyte material preparation method described above.

[0019] The beneficial effect of this invention is that it utilizes Li, which has high ionic conductivity. a Y b TaCl5 introduces viscoelastic Li c M d O e X f The composition can reduce the interfacial impedance between halide electrolyte materials and electrodes, and the M element can also replace the Ta element to reduce the raw material cost of halide electrolyte materials. Detailed Implementation

[0020] Specific embodiments of the present invention will now be described in detail. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of them. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0021] Example 1: The raw materials for synthesizing halide electrolyte materials, Li2O, TaCl5, and AlCl3, were weighed into a ball mill jar according to a stoichiometric ratio of 0.5Li2O·TaCl5·0.1Li2AlOCl3. The mixture was then ball-milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0022] The precursor was subjected to a first-stage annealing treatment under an inert gas atmosphere at a temperature of 230°C for 3 hours.

[0023] Then, a two-stage annealing treatment was performed at a temperature of 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂AlOCl₃.

[0024] Example 2: The raw materials for synthesizing halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, and AlCl3, were weighed into a ball mill jar according to the stoichiometric ratio of 0.5Li2O·TaCl5·0.1Li2AlCl4F. The mixture was then ball-milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0025] The precursor was subjected to a first-stage annealing treatment under an inert gas atmosphere at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed at a temperature of 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂AlCl₄F.

[0026] Example 3: The experimental preparation steps of Example 3 are the same as those of Example 2, but the stoichiometric ratios of the raw materials Li2O, TaCl5, LiCl, LiF and AlCl3 are different from those of Example 2. The halide electrolyte materials obtained are shown in Table 1.

[0027] Example 4: According to the stoichiometric ratio 0.5Li₂O·TaCl₅·0.1Li₂Al 0.9 Ga 0.1 Cl3F2: The raw materials for the synthesis of halide electrolytes, Li2O, TaCl5, LiCl, LiF, AlCl3, and GaF3, were weighed into a ball mill jar and ball milled in an inert gas at a speed of 750 rpm for 6 hours to obtain the precursor.

[0028] The precursor was subjected to a first-stage annealing treatment under an inert gas atmosphere at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed at 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.9 Ga 0.1 Cl3F2.

[0029] Examples 5 to 8 follow the same preparation steps as Example 4, but the stoichiometric ratios of the raw materials Li2O, TaCl5, LiCl, LiF, and AlCl3 are different from those in Example 4. The resulting halide electrolyte materials are shown in Table 1.

[0030] Example 9: According to the stoichiometric ratio 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.2 Ti 0.1 Cl 3.1 F2 weighed the raw materials for the synthesis of halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, and TiCl4, into a ball mill jar and ball-milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0031] The precursor was subjected to a first-stage annealing treatment under an inert gas atmosphere at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed at 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.2 Ti 0.1 Cl 3.1 F2.

[0032] Example 10: According to the stoichiometric ratio 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2 weighed the halide electrolyte synthesis raw materials Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5 into a ball mill jar and ball-milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0033] The precursor was subjected to a first-stage annealing treatment under an inert gas atmosphere at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed at 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2.

[0034] Example 11: According to the stoichiometric ratio 0.5Li₂O·TaCl₅·0.1Li₂Al 0.5 Ga 0.3 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.01Li3BO3 The raw materials for the synthesis of halide electrolytes, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0035] Triethylboron and lithium tert-butylol were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0036] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed in a nitrogen and oxygen mixture with an inert gas content of 92% at a temperature of 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.5 Ga 0.3 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.01Li3BO3.

[0037] Examples 12 to 17 follow the same preparation steps as Example 11, but the stoichiometric ratios of the raw materials Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5 differ from those in Example 11. The resulting halide electrolyte materials are shown in Table 1.

[0038] Example 18: According to the stoichiometric ratio of 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4 The raw materials for the synthesis of halide electrolytes, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0039] Triethylboron, lithium tert-butylol, and Li4SiO4 were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0040] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed in a mixture of nitrogen and oxygen with an inert gas content of 92% at a temperature of 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4.

[0041] Example 19: The preparation steps of Example 19 are the same as those of Example 18, but the stoichiometric ratios of the raw materials Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5 are different from those of Example 18. The halide electrolyte materials obtained are shown in Table 1.

[0042] Example 20: According to the stoichiometric ratio 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.3Li4SiO4 The raw materials for the synthesis of halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas at a speed of 750 rpm for 6 hours to obtain the precursor.

[0043] Li4SiO4 was added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0044] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. Then, a two-stage annealing treatment was performed in a mixture of nitrogen and oxygen with an inert gas content of 92% at a temperature of 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.3Li4SiO4.

[0045] Example 21: According to the stoichiometric ratio of 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.01SiO2 The raw materials for the synthesis of halide electrolytes, Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0046] Triethylboron, lithium tert-butylol, and Li4SiO4 were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0047] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 250°C for 5 hours. Subsequently, bis(diethylamino)silane was added to the mixture, followed by a two-stage annealing treatment in a nitrogen and oxygen mixture with an inert gas content of 92%. The two-stage annealing temperature was 260℃ for 2 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.01SiO2.

[0048] Examples 22 to 25 follow the same preparation steps as Example 21, but the stoichiometric ratios of the raw materials Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, MoCl5, and bis(diethylamino)silane differ from those in Example 21. The resulting halide electrolyte materials are shown in Table 1.

[0049] Example 26: According to the stoichiometric ratio of 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3F2@0.02Li3BO3·0.1Li4SiO4@0.02SeO2 The raw materials for the synthesis of halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0050] Triethylboron, lithium tert-butylol, and Li4SiO4 were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0051] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. SeO2 was then added to the mixture, followed by a two-stage annealing process in a nitrogen and oxygen mixture with an inert gas content of 92%. The two-stage annealing temperature was 250℃ for 5 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.02SeO2.

[0052] Example 27: According to the stoichiometric ratio of 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.02Bi2O3 The raw materials for the synthesis of halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0053] Triethylboron, lithium tert-butylol, and Li4SiO4 were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0054] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. Bi₂O₃ was then added to the mixture, followed by a two-stage annealing treatment in a nitrogen and oxygen mixture with an inert gas content of 92%. The two-stage annealing temperature was 260℃ for 2 hours. This yielded the halide electrolyte material 0.5Li₂O·TaCl₅·0.1Li₂Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.02Bi2O3.

[0055] Example 28: According to the stoichiometric ratio of 0.5Li₂O·TaCl₅·0.1Li₂Al 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.02Sb3O2 The raw materials for the synthesis of halide electrolyte materials, namely Li2O, TaCl5, LiCl, LiF, AlCl3, GaF3, TiCl4, and MoCl5, were weighed into a ball mill jar and ball milled in an inert gas atmosphere at a speed of 750 rpm for 6 hours to obtain the precursor.

[0056] Triethylboron, lithium tert-butylol, and Li4SiO4 were added to the precursor and mixed using a mixer at a speed of 25,000 rpm. Each mixing session lasted 30 seconds, with a 10-minute interval between each mixing session before the next mixing session. This process was repeated 6 times.

[0057] The mixture was subjected to a first-stage annealing treatment in a mixture of nitrogen and oxygen with an inert gas content of 92%. The first-stage annealing treatment was carried out at a temperature of 230°C for 3 hours. Sb3O2 was then added to the mixture, followed by a two-stage annealing process in a nitrogen and oxygen mixture with an inert gas content of 92%. The two-stage annealing temperature was 260℃ for 2 hours. This yielded the halide electrolyte material 0.5Li2O·TaCl5·0.1Li2Al. 0.7 Ga 0.1 Ti 0.1 Mo 0.1 Cl 3.3 F2@0.02Li3BO3·0.1Li4SiO4@0.02Sb3O2.

[0058] Comparative Example 1: The raw materials for the synthesis of halide electrolytes, Li2O and TaCl5, were weighed into a ball mill jar according to a stoichiometric ratio of 0.5Li2O·TaCl5. The ball milling speed was 750 rpm, the ball milling time was 6 h, the sintering temperature was 250℃, and the time was 5 h.

[0059] The preparation processes of Comparative Examples 2 to 4 were the same as those of Comparative Example 1, but the stoichiometric ratios of Li2O and TaCl5 were different from those in Comparative Example 1. The resulting halide electrolyte materials are shown in Table 1.

[0060] Table 1

[0061] The performance of the halide electrolyte materials obtained in the above embodiments and comparative examples was tested.

[0062] The halide electrolyte materials prepared in Examples 1 to 28 and the four comparative examples were subjected to tests for ionic conductivity and air stability. The specific steps included: After the halide electrolyte material was exposed to a low-humidity chamber with a dew point of -50°C for 4 hours, 150 mg of powder was weighed and placed in a battery mold (with an inner diameter of 10 mm). A pressure of 400 MPa was applied, and the AC impedance was tested using an electrochemical workstation with an applied voltage of 10 mV applied in the frequency range of 1 Hz to 1 MHz. The ionic conductivity of the halide electrolyte material after exposure was calculated, and the test results are shown in Table 2.

[0063] Table 2

[0064] As shown in Table 2: Example 2 shows higher ionic conductivity than Example 1. This is because the substitution of oxygen with halogen elements alters the structure of the electrolyte material. Compared to Example 2, Example 3 shows an increase in F content, resulting in a slight decrease in ionic conductivity, but improved oxidation potential and air stability.

[0065] The ionic conductivity of Example 4 is higher than that of Example 3. This is because GaF3 increases the viscosity of the electrolyte, and Ga... 3+ Ionic radius greater than Al 3+ It broadens the lithium-ion migration channels.

[0066] In Examples 4 to 8, the ionic conductivity showed a trend of first increasing and then decreasing, among which 0.5Li₂O·TaCl₅·0.1Li₂Al0.7 Ga 0.3 Cl3F2 has the highest ionic conductivity at 6.72 mS / cm. When the Ga content is greater than 0.4%, the ionic conductivity decreases because the excessive Ga content leads to structural distortion.

[0067] In Examples 9 to 11, Ga was used 3+ Ti with similar ionic radii but different valences (+4 and +5) 4+ and Mo 5 + Replace Ga 3+ Subsequently, the ionic conductivity of the electrolyte material was further improved.

[0068] In Examples 11 to 17, the oxidation potential of the electrolyte was significantly increased after the addition of Li3BO3.

[0069] In Examples 18 to 20, the addition of Li4SiO4 helps to further improve the oxidation potential of the electrolyte material. However, the ionic conductivity of Li4SiO4 is lower than that of Li3BO3. The oxidation potential, ionic conductivity, and ionic conductivity retention rate are better than those of Example 18.

[0070] Compared with the comparative examples, the air stability of the electrolyte material was significantly improved after the addition of SiO2 in Examples 21 to 25. In Example 22, the ionic conductivity was the highest after 4 hours of exposure to air when the SiO2 content was 2%.

[0071] Examples 26 to 28 involve surface coating with SeO2, Bi2O3, and Sb3O2. Their ionic conductivity and retention rate are lower than those of Example 22, but better than those of the comparative example.

[0072] Electrochemical window testing was performed on the halide electrolyte materials obtained in the above embodiments and comparative examples, including the following steps: In a battery mold with a diameter of 10 mm, halide electrolyte materials (halogen electrolyte materials from Examples 1 to 28 or the four comparative examples), Li 5.4 PS 4.4 Cl 1.6 The electrolyte is pressurized and molded at a pressure of 200 MPa in Li. 5.4 PS 4.4 Cl 1.6 A lithium foil is stacked on one side and pressurized to form a solid structure at 50 MPa. Stainless steel current collectors are placed on the top and bottom of the stack. Linear scanning voltammetry is then performed with a scanning range of 1.5–6.0 V and a scanning rate of 0.1 mV / s. The oxidation potential of the material is obtained by plotting the tangent line to the oxidation peak of the test curve and intersecting it with the horizontal axis.

[0073] The halide electrolyte materials obtained in the above embodiments and comparative examples were exposed for 4 hours and then added to the composite positive electrode to form a positive electrode layer. The corresponding electrolyte was used as the electrolyte layer, and lithium metal was used as the negative electrode to assemble an all-solid-state battery. Specifically, the following steps were included: A ternary cathode material, a halide electrolyte material exposed for 4 hours, a conductive agent (VGCF), and a binder (PTFE) were mixed in a mass ratio of 70:30:2:0.5 to prepare a cathode film. The cathode film was then combined with stainless steel to form a cathode electrode sheet. Lithium metal was used as the anode sheet.

[0074] Sulfide electrolyte Li 5.4 PS 4.4 Cl 1.6 After being thoroughly mixed with a binder (PTFE) at a mass ratio of 100:0.5, an electrolyte membrane is prepared.

[0075] Subsequently, the solid-state battery underwent electrochemical performance testing, including the following tests: First charge / discharge test: The solid-state battery was tested at 25℃ with a constant current charge / discharge of 0.1C for one cycle, with a voltage range of 2.7-4.3V.

[0076] Long-cycle testing: The solid-state battery was subjected to 300 cycles of constant current charge and discharge at 0.1C at 25℃, with a voltage range of 2.7-4.3V.

[0077] The test results are shown in Table 3 below.

[0078] Table 3

[0079] As shown in Table 3, compared with Examples 1 to 10 and the comparative examples, Example 10 has the best overall electrochemical performance.

[0080] Compared with Examples 11 to 20, Example 18 has the best overall performance.

[0081] Of all the embodiments, Embodiment 22 has the best discharge specific capacity, first coulomb efficiency, and rate performance.

[0082] In summary, the xLi provided by this invention a Y b ·TaCl5·yLi c M d O e X f@mZ@nW halide electrolyte materials can form a good ionic conductive network on the surface of the positive electrode active material, reducing the solid-solid interface contact impedance between the electrolyte material and the active positive electrode particles. Furthermore, the higher electrochemical window can prevent the oxidative decomposition of the electrolyte material under high voltage, improving its cycle performance. Simultaneously, improved air stability reduces the decomposition of the halide electrolyte, maintaining the structural stability of the electrolyte material. The introduction of Al, Ga, In, Mo, and Ti elements reduces raw material costs, and the adopted preparation method is low-cost and can be mass-produced, which is conducive to promoting the large-scale application of Ta-based halide electrolyte materials.

[0083] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A halide electrolyte material, characterized in that: The chemical formula of the halide electrolyte material is xLi a Y b ·TaCl5·yLi c M d O e X f Wherein, Y is selected from at least one of the elements O, F, Cl, Br, I, S, and N; M is selected from at least one of the elements Al, Ga, In, Mo, and Ti; and X is selected from at least one of the elements F, Cl, Br, and I; 1 < a ≤ 4, 0 < b ≤ 3, 0 < c ≤ 3, 0 < d ≤ 2, 0 ≤ e ≤ 2, 0 < f ≤ 6, and x and y represent Li a Y b ·TaCl5 and Li c M d O e X f The molar ratio is 0 < x ≤ 2, 0 < y ≤ 1.

2. The halide electrolyte material according to claim 1, characterized in that: The surface of the halide electrolyte material is further coated with a first coating layer Z, wherein Z is selected from at least one of Li3BO3, Li3BN2, Li4SiO4, and Li2SiO3.

3. The halide electrolyte material according to claim 2, characterized in that: The first coating layer Z is further coated with a second coating layer W, wherein W is selected from at least one of SiO2, SeO2, Bi2O3, and Sb2O3.

4. The halide electrolyte material according to claim 3, characterized in that: The mass of the first coating layer Z is no greater than 20% of the mass of the halide electrolyte, or the mass of the first coating layer Z is 1%-10% of the mass of the halide electrolyte; the mass of the second coating layer W is no greater than 20% of the mass of the halide electrolyte, or the mass of the second coating layer W is 1%-5% of the mass of the halide electrolyte.

5. A method for preparing a halide electrolyte material, used to prepare the halide electrolyte as described in claim 1, characterized in that, Includes the following steps: Weigh out a lithium source, a tantalum source, a M source, an X source, and an oxygen source, wherein the lithium source is one or more of LiCl, LiOH, Li2CO3, Li2O, Li2O2, LiCl·H2O, and lithium tert-butyloxide; the X source is one or more of LiX, AlX3, AlX3·6H2O, GaX3, InCl3, MoCl6, MoCl5, TiCl4, TiCl3, and LiCl·H2O, wherein X is one of F, Cl, Br, and I; the tantalum source is one or more of TaCl5 and Ta2O5; and the oxygen source is one or more of LiOH, Li2O, Li2O2, LiCl·H2O, AlX3·6H2O, Al(OH)3, O2, and O3. The precursor was obtained by ball milling in an inert gas. The obtained precursor is annealed to obtain the halide electrolyte material xLi. a Y b ·TaCl5·yLi c M d O e X f .

6. The method for preparing halide electrolyte materials according to claim 5, characterized in that: In the ball milling process, the milling time is 3h-20h, and the milling speed is 200rpm-800rpm.

7. The method for preparing halide electrolyte materials according to claim 5, characterized in that: The annealing process includes the following steps: First, a first-stage annealing process is carried out at a temperature of 120℃-200℃ for 0.2h-5h; then, a second-stage annealing process is carried out at a temperature of 210℃-300℃ for 0.2h-8h.

8. The method for preparing halide electrolyte materials according to claim 7, characterized in that, It also includes the following steps: Before annealing the obtained precursor, Z chemical raw material is added to mix and disperse the Z chemical raw material on the surface of the precursor. The Z chemical raw material is selected from one or more of Li3BO3, B(C2H5)3, B(CH3)3, Li3BN2, BN, Li4SiO4, and Li2SiO3; Under a mixed gas atmosphere, the homogeneously mixed precursor and the Z chemical raw material are subjected to a first-stage annealing treatment to obtain xLi. a Y b ·TaCl5·yLi c M d O e X f @mZ, where m is the mass ratio of the Z chemical raw material to the halide electrolyte material, 0 < m ≤ 0.2, or 0.01 ≤ m ≤ 0.1, the mixed gas is nitrogen and oxygen, nitrogen and ozone, argon and oxygen or argon and ozone, and the inert gas content is 80~95%.

9. The method for preparing halide electrolyte materials according to claim 8, characterized in that, It also includes the following steps: In the obtained xLi a Y b ·TaCl5·yLi c M d O e X f @mZ contains a W chemical raw material, wherein the W chemical raw material is selected from at least one of SiO2, SeO2, Bi2O3, and Sb2O3; xLi under the mixed gas a Y b ·TaCl5·yLi c M d O e X f @mZ and the W chemical raw material are subjected to the two-stage annealing treatment to obtain xLi a Y b ·TaCl5·yLi c M d O e X f @mZ@nW, where n is the mass ratio of the W chemical raw material to the halide electrolyte material, 0 < n ≤ 0.2, or 0.01 ≤ n ≤ 0.

05.

10. A solid-state battery, characterized in that: This includes halide electrolyte materials prepared by the method for preparing halide electrolyte materials as described in any one of claims 5-9.

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