Preparation method of zirconium-based chloride solid electrolyte and lithium zirconium chloride solid electrolyte

Abstract

The invention relates to the technical field of electrolyte preparation, in particular to a preparation method of a zirconium-based chloride solid-state electrolyte and a lithium zirconium chloride solid-state electrolyte.The preparation method comprises the following steps that anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride and anhydrous zirconium chloride are dissolved in an absolute ethyl alcohol solvent according to the proportion and fully dissolved, and a chloride ethyl alcohol solution is obtained; the chloride ethanol solution is fully mixed and stirred, the mixture is sent into a closed inert atmosphere protection spray dryer to be rapidly dried, and the zirconium-based solid electrolyte Li2. 6Y0. 1La0. 1Zr0. 7Cl6 powder is obtained. The preparation method of the zirconium-based chloride solid electrolyte has the advantages of being short in process and high in efficiency, the quality uniformity is improved through mixing of liquid phase molecules of a product, and the product quality is improved. The ethanol solution can be recycled, the whole process cost is relatively low, the generated zirconium-based chloride solid electrolyte is uniform and stable in component, and the method has the advantage of industrialization cost.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolyte preparation, and specifically to a preparation method of zirconium-based chloride solid electrolyte and lithium zirconium chloride solid electrolyte. Background Art

[0002] All-solid-state batteries have become a promising next-generation energy storage technology due to their high safety and high energy density. Developing solid electrolytes with excellent chemical / electrochemical stability, high room-temperature ionic conductivity, good positive / negative electrode compatibility, and low manufacturing cost is the key to the practical application of all-solid-state batteries. Halide solid electrolytes have received extensive attention in the industry due to their high positive electrode stability, excellent electrochemical window, good mechanical ductility, acceptable room-temperature lithium-ion conductivity, and good interface stability. Among them, chloride solid electrolytes have a simple preparation process and are easy to scale up production, and have become one of the most powerful competitors in the commercialization technical route of all-solid-state batteries.

[0003] Chloride solid electrolytes have excellent performance in reducing interface impedance, increasing the positive electrode voltage window, and improving the antioxidant properties of electrolytes, and thus have important application value and practical prospects in constructing high-energy-density all-solid-state lithium batteries. The preparation process of chloride solid electrolytes has been a research hotspot in the industry in recent years. At present, the existing synthesis technical routes of chloride electrolytes mainly include high-energy ball milling method, interface reaction synthesis method of gaseous chloride and liquid chloride, and mixed collision reaction synthesis method of gaseous chloride and gaseous chloride. For example, the Chinese invention patent with the application number CN202010972122.2 discloses a preparation method of lithium zirconium chloride, in which zirconium chloride and lithium chloride are ball milled in a certain mass ratio to obtain lithium zirconium chloride. The Chinese invention patent with the application number CN202111656970.3 discloses a preparation method of solid electrolyte lithium zirconium chloride, in which molten lithium chloride is contacted with gaseous zirconium tetrachloride under the protection of an inert atmosphere, and the reaction generates lithium zirconium chloride, and after cooling, solid electrolyte lithium zirconium chloride is obtained. However, the above technical routes have problems such as low reaction efficiency, and the reaction adequacy and reaction uniformity need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of zirconium-based chloride solid electrolyte to solve the above technical problems.

[0005] To achieve the above purpose, the first technical solution provided by the present invention is: A preparation method of zirconium-based chloride solid electrolyte, comprising the following steps: S1. Dissolve anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride, and anhydrous zirconium chloride in an anhydrous ethanol solvent according to the ratio, and fully dissolve to obtain a chloride ethanol solution; S2. Thoroughly mix and stir the chloride ethanol solution, and feed it into a closed inert atmosphere protected spray dryer for rapid drying to obtain the zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

[0006] Preferably, in step S1, the raw material grades of anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride, and anhydrous zirconium chloride are all required to have W H2o ≤0.6%, the main component of the chloride is required to have W ZrCl4 ≥98.5%, W LaCl3 ≥99.9%, W YCl3 ≥99.9%, W LiCl ≥99.3%, and anhydrous ethanol is required to have W H2o ≤0.1%.

[0007] Preferably, the inlet liquid temperature of the dryer is set at 130 - 185 °C, and the end temperature of the dryer is set at 95 - 115 °C for spray drying.

[0008] Preferably, the circulating inert atmosphere in the dryer is argon or nitrogen.

[0009] Preferably, in step S1, the metering ratio of each raw material is anhydrous zirconium chloride: anhydrous lanthanum chloride: anhydrous yttrium chloride: anhydrous lithium chloride = 6.5 : 1.0 : 0.8 : 4.5.

[0010] The second technical solution provided by the present invention is: A lithium zirconium chloride solid electrolyte is prepared by using the preparation method of the zirconium-based chloride solid electrolyte.

[0011] Compared with the prior art, the beneficial effects of the present invention are: The preparation method of the zirconium-based chloride solid electrolyte of the present invention has the characteristics of a short process and high efficiency, and the quality uniformity is improved by the intermolecular mixing in the liquid phase of the product. The ethanol solution can be recycled, the overall process cost is relatively low, and the composition of the generated zirconium-based chloride solid electrolyte is uniform and stable, having an industrial cost advantage. Specific embodiments

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0013] A method for preparing a zirconium-based chloride solid electrolyte comprises the following steps: S1, dissolving anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride and anhydrous zirconium chloride in anhydrous ethanol solvent according to a proportion, and fully dissolving them to obtain a chloride ethanol solution; S2, the chloride ethanol solution is fully mixed and stirred, and sent into a closed inert atmosphere protection spray dryer for rapid drying to obtain a zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

[0014] From the above description, it can be seen that the preparation method of the zirconium-based chloride solid electrolyte of the present invention has the characteristics of short process and high efficiency, and the mixing between the liquid phase molecules of the product can achieve improved quality uniformity, the ethanol solution can be recycled and reused, the cost of the entire process is relatively low, and the generated zirconium-based chloride solid electrolyte has uniform and stable components, which has industrial cost advantages.

[0015] Among them, the preparation method of the present invention adopts liquid phase reaction technology, which is more conducive to the synthesis of materials with good component uniformity and stable electrochemical properties compared with traditional solid-solid high-energy ball milling, solid-liquid-gas phase interface reaction and other processes, and adopts liquid phase intermolecular mixing in organic solvent-spray drying powder making reaction technology, so that the electrolyte has better component uniformity and electrochemical properties. At the same time, the liquid phase solution reaction technology is adopted, the process flow is short, the reaction time is short, the reaction efficiency is high, the large-scale manufacturing process equipment is easy to implement, the output efficiency is high, and the comprehensive quality and cost considerations, the process has great advantages.

[0016] Furthermore, the raw material grades of anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride and anhydrous zirconium chloride in step S1 are all required to be W H2o ≤0.6%, the main component of chloride requires W ZrCl4 ≥98.5%, W LaCl3 ≥99.9%, W YCl3 ≥99.9%, W LiCl ≥99.3%, anhydrous ethanol requires W H2o ≤0.1%.

[0017] Furthermore, the temperature of the liquid inlet end of the dryer is set at 130-185° C., and the temperature of the terminal end of the dryer is set at 95-115° C. for spray drying, and the circulating inert atmosphere in the dryer is argon or nitrogen.

[0018] From the above description, it can be seen that the temperature of the liquid inlet end of the dryer is set at 130-185°C, and the temperature of the terminal end of the dryer is set at 95-115°C for spray drying. This is mainly because within this set temperature range, the ethanol solvent and the synthetic zirconium-based chloride electrolyte can be efficiently separated, and the ethanol solvent enters the condenser in a gaseous state and undergoes gas-liquid conversion, which is then recycled and reused.

[0019] Furthermore, the metering ratio of the raw materials in step S1 is anhydrous zirconium chloride: anhydrous lanthanum chloride: anhydrous yttrium chloride: anhydrous lithium chloride = 6.5:1.0:0.8:4.5.

[0020] It is worth noting that the reaction mechanism of the present invention is that anhydrous zirconium chloride (ZrCl4) will undergo a complex reaction after being dissolved in ethanol to generate a complex such as tetrachlorozirconium (IV) acid ethanol ([ZrCl2 (OC2H5)2]).

[0021] Reaction equation: ZrCl4 + 2C2H5OH → [ZrCl2(OC2H5)2] + 2HCl Heating at a certain temperature: [ZrCl2(OC2H5)2] + 2HCl → ZrCl4 + 2C2H5OH The dissolution of anhydrous lithium chloride and anhydrous rare earth chloride in ethanol is physical dissolution, which introduces chloride molecules into ethanol molecules through van der Waals force.

[0022] Embodiment 1 is: According to the raw material ratio W ZrCl4 :W LaCl3 :W YCl3 :W LiCl =6.5:1.0:0.8:4.5 Anhydrous lithium chloride, anhydrous zirconium chloride, anhydrous lanthanum chloride and anhydrous yttrium chloride are weighed in the drying room respectively, and the above anhydrous chlorides are added into anhydrous ethanol to fully dissolve. After being fully dissolved, the above chloride ethanol solutions are fully mixed and stirred, and sent into a closed inert atmosphere protection spray dryer for rapid drying. The temperature at the liquid inlet end of the drying tower is set at 155°C, and the temperature at the end of the drying tower is set at 112°C to obtain a zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

[0023] Embodiment 2 is: According to the raw material ratio W ZrCl4 :W LaCl3 :W YCl3 :W LiCl= 6.5:1.0:0.8:4.5, weigh lithium chloride anhydrous, zirconium chloride anhydrous, lanthanum chloride anhydrous and yttrium chloride anhydrous materials respectively in a drying chamber. Add the above anhydrous chlorides into absolute ethanol respectively and dissolve them fully. After full dissolution, fully mix and stir the above chloride ethanol solutions, and send them into a closed inert atmosphere protected spray dryer for rapid drying. Set the temperature at the liquid inlet end of the drying tower to 145 °C and the temperature at the end of the drying tower to 105 °C to obtain zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

[0024] Example three is as follows: According to the raw material ratio of W ZrCl4 : W LaCl3 : W YCl3 : W LiCl = 6.5:1.0:0.8:4.5, weigh lithium chloride anhydrous, zirconium chloride anhydrous, lanthanum chloride anhydrous and yttrium chloride anhydrous materials respectively in a drying chamber. Add the above anhydrous chlorides into absolute ethanol respectively and dissolve them fully. After full dissolution, fully mix and stir the above chloride ethanol solutions, and send them into a closed inert atmosphere protected spray dryer for rapid drying. Set the temperature at the liquid inlet end of the drying tower to 135 °C and the temperature at the end of the drying tower to 100 °C to obtain zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

[0025] Comparative example one: Take solid lithium chloride and zirconium chloride particles with a purity ≥ 98% and a particle size of 3 mm in a drying chamber, put them into a planetary ball mill tank, use zirconia balls as grinding media, and grind lithium chloride and zirconium chloride to 400-mesh fineness respectively. Weigh lithium chloride, yttrium chloride and zirconium chloride powders according to the set molar ratio and add them into a zirconia grinding tank. At the same time, add 6-mm zirconia beads to the grinding tank according to the ball-to-material mass ratio of 45:1. Set the high-energy ball milling speed to 600 r / min, and set the mechanical ball milling synthesis program to rotate forward for 5 min, pause for 5 min, rotate backward for 5 min, pause for 5 min, and cycle the ball milling according to the above program cycle. The effective grinding time is 45 h to obtain lithium zirconium chloride solid electrolyte powder. The lithium zirconium chloride solid electrolyte powder is superfine ground in a dry inert atmosphere environment and filtered through a 400-mesh sieve to obtain solid lithium zirconium chloride electrolyte powder.

[0026] The zirconium-based solid electrolytes Li 2.6 Y 0.1 La 0.1 Zr 0.7The Cl6 powder was respectively added into a cylindrical mold (Φ12 mm), and a pressure of 380 MPa was applied using a manual tablet press. After cold pressing for 5 minutes and demolding, electrolyte sheets were obtained. Then, the average ionic conductivity of the electrolyte sheets was measured at room temperature, and the results are shown in Table 1 below: Table 1

[0027] Conclusion: From the above experimental results, it can be seen that the zirconium-based solid electrolytes prepared by the present invention have higher homogeneity, which helps to optimize the lithium ion transmission environment, reduce the transmission resistance, and thus improve the conductivity.

[0028] In summary, the preparation method provided by the present invention has the characteristics of short process and high efficiency. The quality homogeneity is improved by the intermolecular mixing in the liquid phase of the product, and the ethanol solution can be recycled and reused. The overall process cost is relatively low, and the zirconium-based chloride solid electrolyte produced has uniform and stable composition, with industrial cost advantages.

[0029] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent transformation made using the description of the present invention, directly or indirectly applied in the relevant technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for preparing a zirconium-based chloride solid electrolyte, characterized in that: It includes the following steps: S1. Dissolve anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride, and anhydrous zirconium chloride in an anhydrous ethanol solvent respectively according to the ratio, and fully dissolve to obtain a chloride ethanol solution; S2. Thoroughly mix and stir the chloride ethanol solution, and feed it into a closed inert atmosphere-protected spray dryer for rapid drying to obtain a zirconium-based solid electrolyte Li 2.6 Y 0.1 La 0.1 Zr 0.7 Cl6 powder.

2. The preparation method of a zirconium-based chloride solid electrolyte according to claim 1, characterized in that: In the step S1, the raw material grades of anhydrous lithium chloride, anhydrous yttrium chloride, anhydrous lanthanum chloride, and anhydrous zirconium chloride are all required to be W H2o ≤ 0.6%, and the main component of the chloride is required to be W ZrCl4 ≥ 98.5%, W LaCl3 ≥ 99.9%, W YCl3 ≥ 99.9%, W LiCl ≥ 99.3%, and the anhydrous ethanol is required to be W H2o ≤ 0.1%.

3. The preparation method of a zirconium-based chloride solid electrolyte according to claim 1, wherein: Set the temperature at the liquid inlet end of the dryer to 130 - 185 °C, and set the temperature at the end of the dryer to 95 - 115 °C for spray drying in an environment.

4. The preparation method of a zirconium-based chloride solid electrolyte according to claim 1, characterized in that: The circulating inert atmosphere in the dryer is argon or nitrogen.

5. The preparation method of a zirconium-based chloride solid electrolyte according to claim 1, characterized in that: The metering ratio of each raw material in step S1 is anhydrous zirconium chloride: anhydrous lanthanum chloride: anhydrous yttrium chloride: anhydrous lithium chloride = 6.5: 1.0: 0.8: 4.

5.

6. A lithium zirconium chloride solid electrolyte, characterized in that: Prepare by using the preparation method of the zirconium-based chloride solid electrolyte described in any one of claims 1 - 5.

Images