Oxide solid electrolyte, method for preparing same, and use thereof
Nano-oxide solid electrolytes were prepared by mixing, sintering, crushing, drying and air milling, which solved the problems of uneven particle size distribution and high water content in the existing technology, improved the preparation efficiency and powder output, reduced costs and improved the environment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JINLONGYU NEW ENERGY (SHENZHEN) CO LTD
- Filing Date
- 2026-02-04
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, nano-oxide solid electrolytes have uneven particle size distribution, high water content, and complex preparation processes, resulting in high production costs and serious environmental pollution.
Nano-oxide solid electrolytes were prepared by mixing, sintering, crushing, drying and air milling. The D50 and D100 of the powder material were controlled within a specific range. The moisture content was reduced and the particle uniformity was improved by air milling, avoiding the use of sand milling and drying processes.
This method achieves good particle size distribution uniformity, high dispersibility, and low water content in nano-oxide solid electrolytes, simplifying the preparation process, reducing costs, and improving the working environment.
Smart Images
Figure CN121662937B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of batteries, specifically relating to an oxide solid electrolyte, its preparation method, and its application. Background Technology
[0002] Nanoscale (1-1000 nm) oxide solid electrolytes can be applied to lithium battery separators, electrodes, and cathode co-doping to improve battery rate performance, safety performance, and low-temperature performance. Current technologies first prepare micron-sized oxide solid electrolyte powders using solid-state sintering, sol-gel methods, and co-precipitation, then use secondary processing techniques such as sand milling, drying, and crushing to prepare nanoscale oxide solid electrolyte powders. However, the nanoscale oxide solid electrolyte powders prepared by existing processes lack uniformity, exhibiting severe bimodal phenomena in their laser particle size distribution diagrams; furthermore, the obtained nanoparticles are prone to agglomeration, resulting in poor dispersion. Meanwhile, the secondary processing involves sand milling and drying. Since sand milling is a wet grinding method, the working environment is a slurry state requiring solvents. Therefore, a subsequent drying process is necessary. Both sand milling and drying release solvents and produce irritating odors, causing varying degrees of air pollution. Furthermore, the current process for preparing oxide solid electrolyte nanopowders is complex, involving numerous pieces of equipment, resulting in high processing and labor costs, long processing times, and low yields. In addition, the nano-oxide solid electrolyte powders prepared by existing technologies have high water content, requiring further, lengthy drying treatment before they can be used in batteries, further extending the production process and cycle time. Summary of the Invention
[0003] To address the problems of uneven particle size distribution and high water content in the preparation of nano-oxide solid electrolytes using the aforementioned existing technologies, this invention will provide an oxide solid electrolyte, its preparation method, and its applications.
[0004] To achieve the above objectives, the following technical solutions are specifically included:
[0005] In a first aspect, the present invention provides a method for preparing an oxide solid electrolyte.
[0006] (1) The raw materials of the oxide solid electrolyte are mixed and dried to obtain a mixture;
[0007] (2) The mixture is subjected to sintering, crushing, drying and sieving in sequence to obtain powder material; the D of the powder material 50 The particle size is 2.5-3.5 μm, and the D of the powder material is... 100 It is 8-12 μm;
[0008] (3) The powder material is passed through an air mill to obtain an oxide solid electrolyte.
[0009] This invention involves sequentially mixing, sintering, crushing, drying, and air milling raw materials to obtain nano-oxide solid electrolyte powder. It is crucial to control the density (D) of the powder material obtained after crushing and drying. 50 At 2.5-3.5μm and D 100 Within the range of 8-12 μm, to control its particle size and moisture content, and to adapt to subsequent two or more air milling processes, so that the obtained nano-oxide solid electrolyte powder has low moisture content and reaches nanoscale size. If the powder material D obtained after crushing and drying... 50 and D 100 Outside the aforementioned range, the particle size and moisture content are incompatible with two or more air milling processes, resulting in excessively large particle size or excessive water absorption in the obtained powder. The method of this invention can improve the uniformity of the obtained powder nanoparticles, reduce particle agglomeration, and result in a narrower particle size distribution, no significant particle agglomeration, good dispersibility, low moisture content, and high product consistency in the nano-oxide solid electrolyte powder. Furthermore, the method of this invention is simpler than existing processes, improves the efficiency of preparing nano-oxide solid electrolytes and the powder yield, and reduces costs. This method eliminates the need for sand milling and drying processes, therefore, it does not generate irritating gases, avoids environmental pollution, and improves the working environment.
[0010] Preferably, in step (1), the raw materials include a lithium source and at least one of the following: optional phosphorus source, optional aluminum source, optional titanium source, optional lanthanum source, optional niobium source, optional zirconium source, and optional tantalum source.
[0011] More preferably, the lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium dihydrogen phosphate, lithium oxalate, lithium acetate, and lithium phosphate.
[0012] More preferably, when the molar equivalent of lithium element obtained by stoichiometric calculation in the chemical formula of the oxide solid electrolyte is n1, in step (1), when the lithium source is added, the molar equivalent of lithium element in the lithium source is n2, satisfying the following relationship: n2=n1×(1+c), and 5%≤c≤15%.
[0013] More preferably, the phosphorus source includes at least one of ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and phosphoric acid.
[0014] More preferably, the aluminum source includes at least one of alumina, aluminum chloride, aluminum sulfate, aluminum phosphate, aluminum hydroxide, and aluminum nitrate.
[0015] More preferably, the titanium source includes titanium dioxide.
[0016] More preferably, the lanthanum source includes at least one of lanthanum oxide and lanthanum hydroxide.
[0017] More preferably, the niobium source includes at least one of niobium oxide and niobium hydroxide; the zirconium source includes at least one of zirconium oxide and zirconium hydroxide; and the tantalum source includes at least one of tantalum oxide and tantalum hydroxide.
[0018] Preferably, in step (1), the mixing method includes at least one of dry mixing and wet mixing, wherein the dry mixing includes at least one of star ball milling and drum ball milling, and the wet mixing includes at least one of vertical ball milling and dispersing disc stirring.
[0019] Preferably, in step (1), the drying temperature is 100-200℃ and the drying time is 1-15h.
[0020] Preferably, in step (1), the drying includes at least one of spray drying, freeze drying, and oven drying.
[0021] Preferably, in step (2), the sintering temperature is 800-1200℃ and the sintering time is 5-14h.
[0022] Preferably, in step (2), the crushing includes ball milling, in which zirconia balls with a diameter of 0.1-5 mm are used as steel balls, the ball-to-material ratio is (2-6):1, the ball milling speed is 200-1000 rpm, and the time is 1-10 h.
[0023] Preferably, in step (2), the mesh size of the sieve is 100-300 mesh.
[0024] Preferably, in step (2), the drying temperature is 100-200℃ and the drying time is 1-15h.
[0025] Preferably, in step (2), the drying includes at least one of spray drying, freeze drying, and oven drying.
[0026] Preferably, in step (3), the temperature of the hot air in the air mill is 100-200℃, and the air consumption is 1-60m³. 3 / min, staged power is 50-200Hz, induced draft power is 5-30Hz, and nozzle diameter is 0.5-2mm.
[0027] The high frequency of the classifying wheel in the air mill leads to a decrease in the material yield after air milling, but the particle size of the material after air milling is smaller.
[0028] Preferably, in step (3), the air milling is performed 2-3 times, and each time the process parameters are independently selected from the following parameters: hot air temperature of 100-200℃, and air consumption of 1-60m³. 3 / min, staged power is 50-200Hz, induced draft power is 5-30Hz, and nozzle diameter is 0.5-2mm.
[0029] Micron-sized powder materials can be broken down into smaller particles, reducing particle size and improving particle uniformity through high-energy airflow milling, thus mitigating the defect of powder agglomeration. Furthermore, increasing the number of milling cycles can further reduce the particle size. This invention utilizes air milling to break micron-sized powder materials down to the nanoscale. Compared to conventional sand milling, it requires no solvent, has a shorter cycle time, and eliminates the need for an additional drying step after air milling, resulting in a low-moisture product, reducing processing steps and shortening the production cycle.
[0030] Secondly, the present invention provides an oxide solid electrolyte prepared by the method described above.
[0031] Preferably, the oxide solid electrolyte comprises at least one of the compounds with the following chemical formulas: (1) Li 1+x Al x Ti 2-x (PO4)3, where x=0-2; (2) Li 7-y La3Zr 2-y Nb y O 12 , where y=0-7; (3) Li 7-z La3Zr 2- z Ta z O 12 , where z = 0-7.
[0032] Preferably, the D10 of the oxide solid electrolyte is 200-350nm, the D50 of the oxide solid electrolyte is 400-550nm, and the D90 of the oxide solid electrolyte is 700-1350nm.
[0033] In this invention, D10 represents the particle size corresponding to a sample when the cumulative particle size distribution reaches 10%, which means that 10% of the particles are smaller than D10. D50 represents the particle size corresponding to a sample when the cumulative particle size distribution reaches 50%, which means that 50% of the particles are larger than D50 and 50% are smaller than D50. D90 represents the particle size corresponding to a sample when the cumulative particle size distribution reaches 90%, which means that 90% of the particles are smaller than D90. D100 represents the particle size corresponding to a sample when the cumulative particle size distribution reaches 100%, which means that 100% of the particles are smaller than D100, i.e., the maximum particle size.
[0034] Thirdly, the present invention provides a lithium battery comprising the aforementioned oxide solid electrolyte. The oxide solid electrolyte of the present invention is a nano-sized powder, which, when mixed and doped into the separator, electrode, or positive electrode of a lithium battery, can further improve the battery's rate performance, safety performance, and low-temperature performance.
[0035] Compared to existing technologies, this invention offers the following advantages: This invention sequentially processes raw materials through mixing, sintering, crushing, drying, and air milling to obtain nano-oxide solid electrolyte powder. The method of this invention improves the uniformity of the obtained nanoparticles, reduces particle agglomeration, resulting in a narrower particle size distribution, no significant particle agglomeration, good dispersibility, low moisture content, and high product consistency. Furthermore, this method is simpler than existing processes, improving the efficiency and powder yield of nano-oxide solid electrolyte preparation while reducing costs. This method eliminates the need for sand milling and drying processes, thus avoiding the generation of irritating gases, preventing environmental pollution, and improving the working environment. Attached Figure Description
[0036] Figure 1 This is a particle size distribution diagram of the nano-oxide solid electrolyte material obtained after the first air milling in Example 1.
[0037] Figure 2 This is a particle size distribution diagram of the nano-oxide solid electrolyte material obtained after the second air milling in Example 1.
[0038] Figure 3 The image shows the XRD pattern of the nano-oxide solid electrolyte obtained after the second gas milling in Example 1.
[0039] Figure 4 This is a particle size distribution diagram of the nano-oxide solid electrolyte material obtained after the first air milling in Example 2.
[0040] Figure 5 This is a particle size distribution diagram of the nano-oxide solid electrolyte material obtained after the second air milling in Example 2.
[0041] Figure 6 The image shows the XRD pattern of the nano-oxide solid electrolyte obtained after the second gas milling in Example 2.
[0042] Figure 7 This is a particle size distribution diagram of the nano-oxide solid electrolyte material obtained after the first air milling in Example 3.
[0043] Figure 8 This is a particle size distribution diagram of the nano-oxide solid electrolyte obtained after the second air milling in Example 3.
[0044] Figure 9This is a particle size distribution diagram of the final oxide electrolyte powder obtained in Comparative Example 1.
[0045] Figure 10 This is a particle size distribution diagram of the final oxide electrolyte powder obtained in Comparative Example 2.
[0046] Figure 11 This is a particle size distribution diagram of the final oxide electrolyte powder obtained in Comparative Example 3. Detailed Implementation
[0047] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further explain the invention below. Unless otherwise specified, the test methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.
[0048] Example 1
[0049] A method for preparing an oxide solid electrolyte includes the following steps:
[0050] S1, according to Li 1.4 Al 0.4 Ti 1.6 P3O 12 According to the stoichiometric ratio, 15 kg of raw materials, including lithium carbonate (with a 10% molar excess of lithium source), alumina, titanium dioxide, and ammonium dihydrogen phosphate, were weighed and mixed with 20 kg of pure water. The mixture was then wet-milled vertically to obtain a slurry with a viscosity of 30 cps. The slurry was then added to a spray dryer with the inlet temperature set at 170℃, the outlet temperature at 110℃, and the slurry drying flow rate at 2000 ml / h to obtain a mixed material.
[0051] S2. The above mixture is placed in a muffle furnace and sintered at 1000℃ for 10 hours. The sintered product is then finely crushed, dried, and sieved through a 200-mesh sieve to obtain powder material. During the fine crushing process, a planetary ball mill is used with a ball-to-material ratio of 5:1. The powder is ball-milled until the particle size D50 is 3μm and D100 is 10μm to prevent the maximum particle size from being too large, which would result in large particles not being deagglomerated during subsequent air crushing. Although no additional solvent is added during the ball milling process, the ball-milled nanoparticles have a high specific surface area and the material itself absorbs water, so the powder needs to be dried after ball milling to remove water. The moisture content of the powder material is 400-600ppm.
[0052] S3. Place the powder material into a high-energy airflow mill for the first air milling. During the air milling process, the hot air blower temperature is set to 100℃, the nozzle diameter is 1mm, the classifying power is 150Hz, the induced draft fan power is 15Hz, and the air consumption of the compressor is 1m³ / min.3 The nano-oxide solid electrolyte material was obtained by [method / min]; its moisture content was tested to be 365 ppm, and the particle size distribution was as follows: Figure 1 As shown, D10 = 336nm, D50 = 897nm, and D90 = 1988nm;
[0053] S4. A second air milling process is performed on the nano-oxide solid electrolyte material. During the air milling process, the hot air blower temperature is set to 170℃, the nozzle diameter is 1mm, the stage power is 150Hz, the induced draft fan power is 20Hz, and the air consumption of the compressor is 1m³ / min. 3 / min, the particle size and moisture content of the powder after air milling were tested, and the particle size distribution of the obtained nano-oxide solid electrolyte was as follows. Figure 2 As shown, the water content is 256 ppm, D10=301 nm, D50=483 nm, and D90=786 nm.
[0054] Example 2
[0055] A method for preparing an oxide solid electrolyte includes the following steps:
[0056] S1. According to the stoichiometric ratio in Table 1, weigh 10 kg of raw materials including lanthanum oxide, lithium hydroxide (with a 10% excess of lithium source), zirconium oxide, and niobium oxide. Place the raw material powder into a ball mill jar containing zirconium oxide balls. The ball-to-material mass ratio is 5:1. Add ethanol as the ball milling medium. The ball milling speed is 400 rpm and the time is 25 h. Then dry the slurry after ball milling in a regular forced-air drying oven to obtain a mixture.
[0057] S2. The above mixture is placed in a muffle furnace and sintered at 1000℃ for 13 hours. The sintered product is then finely crushed, dried, and sieved through a 200-mesh sieve to obtain powder material. During the fine crushing process, a planetary ball mill is used with a ball-to-material ratio of 5:1. The powder is ball-milled until the particle size D50 is 3μm and D100 is 10μm to prevent the maximum particle size from being too large, which would result in large particles not being deagglomerated during subsequent air crushing. Although no additional solvent is added during the ball milling process, the ball-milled nanoparticles have a high specific surface area and the material itself absorbs water, resulting in the absorption of moisture from the air. Therefore, the powder after ball milling needs to be dried to remove water.
[0058] S3. Place the powder material into a high-energy airflow mill for the first air milling. During the air milling process, the hot air blower temperature is set to 130℃, the nozzle diameter is 1mm, the classifying power is 150Hz, the induced draft fan power is 15Hz, and the compressor air consumption is 1m³ / min. 3 The nano-oxide solid electrolyte material was obtained by [method / min]; its moisture content was tested to be 415 ppm, and the particle size distribution was as follows: Figure 4 As shown, D10 = 348nm, D50 = 728nm, and D90 = 1676nm;
[0059] S4. The nano-oxide solid electrolyte material is subjected to a second air milling process. During this process, the hot air blower temperature is set to 190℃, the nozzle diameter is 1mm, the grading power is 150Hz, the induced draft fan power is 25Hz, and the air consumption of the compressor is 1m³ / min. 3 / min, the particle size of the powder after air milling was tested, and the particle size distribution of the obtained nano-oxide solid electrolyte was as follows. Figure 5 As shown, D10 = 243nm, D50 = 407nm, and D90 = 836nm.
[0060] Example 3
[0061] A method for preparing an oxide solid electrolyte includes the following steps:
[0062] S1. Weigh 10 kg of raw materials, including lanthanum oxide, lithium hydroxide (with a 10% excess of lithium source), zirconium oxide, and tantalum oxide, according to the stoichiometric ratio. Place the raw material powder into a ball mill jar containing zirconium oxide balls. The ball-to-material mass ratio is 5:1. Add ethanol as the ball milling medium. The ball milling speed is 400 rpm and the time is 25 h. Then, dry the slurry after ball milling in a regular forced-air drying oven to obtain a mixture.
[0063] S2. The above mixture is placed in a muffle furnace and sintered at 1000℃ for 13 hours. The sintered product is then finely crushed, dried, and sieved through a 200-mesh sieve to obtain powder material. During the fine crushing process, a planetary ball mill is used with a ball-to-material ratio of 5:1. The powder is ball-milled until the particle size D50 is 3μm and D100 is 10μm to prevent the maximum particle size from being too large, which would result in large particles not being deagglomerated during subsequent air crushing. Although no additional solvent is added during the ball milling process, the ball-milled nanoparticles have a high specific surface area and the material itself absorbs water, resulting in the absorption of moisture from the air. Therefore, the powder after ball milling needs to be dried to remove water.
[0064] S3. Place the powder material into a high-energy airflow mill for the first air milling. During the air milling process, the hot air blower temperature is set to 130℃, the nozzle diameter is 1mm, the classifying power is 150Hz, the induced draft fan power is 15Hz, and the compressor air consumption is 1m³ / min. 3 The nano-oxide solid electrolyte material was obtained by [method / min]; its moisture content was tested to be 385 ppm, and the particle size distribution was as follows: Figure 7 As shown, D10 = 374nm, D50 = 733nm, and D90 = 2032nm;
[0065] S4. A second air milling process is performed on the nano-oxide solid electrolyte material. During the air milling process, the hot air blower temperature is set to 190℃, the nozzle diameter is 1mm, the stage power is 150Hz, the induced draft fan power is 25Hz, and the air consumption of the compressor is 1m³ / min. 3 / min, the particle size of the powder after air milling was tested, and the particle size distribution of the obtained nano-oxide solid electrolyte was as follows. Figure 8 As shown, D10 = 226nm, D50 = 504nm, and D90 = 1304nm.
[0066] Comparative Example 1
[0067] Compared with Example 1, this comparative example does not use air milling for the powder material, but sand milling, including the following steps:
[0068] S1. Weigh 20 kg of raw materials, including lithium carbonate (with a 10% excess of lithium source molar amount), alumina, titanium dioxide, and ammonium dihydrogen phosphate, according to the stoichiometric ratio. Mix these raw materials with 20 kg of pure water to obtain a slurry with a viscosity of 30 cps. Add the slurry to a spray dryer, set the inlet temperature to 170℃, the outlet temperature to 110℃, and the slurry drying flow rate to 2000 ml / h to obtain a mixed material.
[0069] S2. The above mixture is placed in a muffle furnace and sintered at 1000℃ for 10 hours. The sintered product is then finely crushed and sieved to obtain powder material. During the fine crushing process, a planetary ball mill is used with a ball-to-material ratio of 5:1. The powder is ball-milled until the particle size D50 is 3μm and D100 is 10μm. The ball-milled powder is then dried to remove water, and the moisture content of the powder material is 400-600ppm.
[0070] S3. The powder material is mixed and stirred with N-methyl-2-pyrrolidone (NMP) to form a slurry with a solid content of 45%. The slurry is then poured into a sand mill for sand milling at a speed of 1500 rpm for 4 hours. The slurry is then dried in a vacuum oven. The dried material is then finely crushed at a feed rate of 30 Hz and a classifying wheel frequency of 150 Hz. Subsequent sieving with a 200-mesh sieve yields oxide electrolyte powder with a moisture content of 815 ppm and a particle size distribution as shown. Figure 9 As shown, D10=195nm, D50=498nm, and D90=1006nm.
[0071] Comparative Example 2
[0072] Compared with Example 2, this comparative example does not use air milling for the powder material, but sand milling, including the following steps:
[0073] S1. Weigh 10 kg of raw materials, including lanthanum oxide, lithium hydroxide (with a 10% excess of lithium source molar amount), zirconium oxide, and niobium oxide, according to the stoichiometric ratio. Place the raw material powder into a ball mill jar containing zirconium oxide balls. The ball-to-material mass ratio is 5:1. Add ethanol as the ball milling medium. The ball milling speed is 400 rpm and the time is 25 h. Then dry the slurry after ball milling to obtain a mixture.
[0074] S2. The above mixture is placed in a muffle furnace and sintered at a temperature of 1000℃ for 13 hours. The sintered product is then screened through a 200-mesh sieve to obtain powder material.
[0075] S3. The powder material is mixed and stirred with N-methyl-2-pyrrolidone (NMP) to form a slurry with a solid content of 45%. The slurry is then poured into a sand mill for sand milling at a speed of 1500 rpm for 4 hours. The slurry is then dried in a vacuum oven. The dried material is then finely crushed at a feed rate of 30 Hz and a classifying wheel frequency of 150 Hz. Subsequent sieving with a 200-mesh sieve yields oxide electrolyte powder with a moisture content of 1006 ppm and a particle size distribution as shown. Figure 10 As shown, D10=243nm, D50=558nm, and D90=1291nm.
[0076] Comparative Example 3
[0077] Compared with Example 3, this comparative example does not use air milling for the powder material, but sand milling, including the following steps:
[0078] S1. Weigh 10 kg of raw materials, including lanthanum oxide, lithium hydroxide (with a 10% excess of lithium source), zirconium oxide, and tantalum oxide, according to the stoichiometric ratio. Place the raw material powder into a ball mill jar containing zirconium oxide balls. The ball-to-material mass ratio is 5:1. Add ethanol as the ball milling medium. The ball milling speed is 400 rpm and the time is 25 h. Then dry the slurry after ball milling to obtain a mixture.
[0079] S2. The above mixture is placed in a muffle furnace and sintered at a temperature of 1000℃ for 13 hours. The sintered product is then screened through a 200-mesh sieve to obtain powder material.
[0080] S3. The powder material is mixed with N-methyl-2-pyrrolidone (NMP) to form a slurry with a solid content of 45%. The slurry is then poured into a sand mill for sand milling at a speed of 1500 rpm for 4 hours. The slurry is then dried in a vacuum oven. The dried material is then finely crushed at a feed rate of 30 Hz and a classifying wheel frequency of 150 Hz. Subsequent sieving with a 200-mesh sieve yields oxide electrolyte powder with a moisture content of 948 ppm and a particle size distribution as shown. Figure 11 As shown, D10=194nm, D50=461nm, and D90=1107nm.
[0081] Table 1
[0082]
[0083] Continued from Table 1
[0084]
[0085] Table 2
[0086]
[0087] The water content of the oxide solid electrolytes in each embodiment and comparative example was tested. The particle size distribution of the oxide solid electrolytes was measured using a Malvern 3000 laser particle size analyzer. Before testing, each oxide solid electrolyte sample was dispersed in deionized water, and 0.5 wt% sodium hexametaphosphate dispersant was added under ultrasonic vibration for 2 minutes. XRD patterns of the oxide solid electrolytes in some embodiments were analyzed using an X-ray diffractometer.
[0088] Table 3
[0089]
[0090] XRD corresponding to Examples 1 and 2 ( Figure 3 and Figure 6 As can be seen from the spectrum, Example 1 successfully prepared LATP-type (Li 1+ x Al x Ti 2-x (PO4)3) oxide solid electrolyte, Example 2 successfully prepared LLZO type (Li) 7-y La3Zr 2-y Nb y O 12Oxide solid electrolyte. As shown in the examples, in the method of the present invention, after the first air milling, the water content of the oxide solid electrolyte is ≤800ppm, the D10 of the oxide solid electrolyte is 200-410nm, the D50 is 500-900nm, and the D90 is 1500-2100nm; the water content of the oxide solid electrolyte obtained by the second air milling is ≤400ppm, the D10 of the oxide solid electrolyte is 200-640nm, the D50 is 400-630nm, and the D90 is 700-1500nm.
[0091] Comparing Examples 1-3 with Comparative Examples 1-3, it can be seen that the oxide solid electrolytes prepared by conventional sintering followed by sand milling have a water content of over 800 ppm and a D90 greater than 3000 nm. The water content and particle size range are large. The method of the present invention, which involves two air millings after sintering, can significantly reduce the water content of the oxide solid electrolyte powder and make the particle size range of the powder narrower.
[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A method for preparing an oxide solid electrolyte, characterized in that, Includes the following steps: (1) The raw materials of the oxide solid electrolyte are mixed and dried to obtain a mixture; the raw materials include a lithium source and at least one of the following: optional phosphorus source, optional aluminum source, optional titanium source, optional lanthanum source, optional niobium source, optional zirconium source, optional tantalum source; (2) The mixture is subjected to sintering, ball milling, drying and sieving in sequence to obtain powder material; the D of the powder material 50 The particle size is 2.5-3.5 μm, and the D of the powder material is... 100 It is 8-12 μm; (3) The powder material is passed through an air mill to obtain an oxide solid electrolyte. The air milling is performed twice. In the air mill, the temperature of the hot air is 100-200℃ and the air consumption is 1-60m³. 3 / min, graded power of 50-200Hz, induced draft power of 5-30Hz, nozzle diameter of 0.5-2mm, the oxide solid electrolyte includes at least one of the compounds with the following chemical expressions: (1) Li 1+x Al x Ti 2-x (PO4)3, where x=0-2; (2) Li 7-y La3Zr 2-y Nb y O 12 , where y=0-7; (3) Li 7- z La3Zr 2-z Ta z O 12 , where z = 0-7.
2. The method for preparing the oxide solid electrolyte as described in claim 1, characterized in that, In step (2), the sintering temperature is 800-1200℃ and the sintering time is 5-14h.
3. The method for preparing the oxide solid electrolyte as described in claim 1, characterized in that, In step (2), in the ball milling crushing, zirconia balls with a diameter of 0.1-5mm are used as steel balls, the ball-to-material ratio is (2-6):1, the ball milling speed is 200-1000rpm, and the time is 1-10h; the sieve mesh size is 100-300 mesh.
4. The method for preparing the oxide solid electrolyte as described in claim 1, characterized in that, The phosphorus source includes at least one of ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and phosphoric acid. The lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium dihydrogen phosphate, lithium oxalate, lithium acetate, and lithium phosphate. The aluminum source includes at least one of aluminum oxide, aluminum chloride, aluminum sulfate, aluminum phosphate, aluminum hydroxide, and aluminum nitrate. The titanium source includes titanium dioxide; The lanthanum source includes at least one of lanthanum oxide and lanthanum hydroxide; The niobium source includes at least one of niobium oxide and niobium hydroxide; The zirconium source includes at least one of zirconium oxide and zirconium hydroxide; The tantalum source includes at least one of tantalum oxide and tantalum hydroxide.
5. The method for preparing the oxide solid electrolyte as described in claim 1, characterized in that, Step (1), the mixing method includes at least one of dry mixing and wet mixing, the dry mixing includes at least one of star ball mill and drum ball mill, the wet mixing includes at least one of vertical ball mill stirring and dispersion disc stirring; and / or, in step (1), the drying temperature is 100-200℃, and the drying time is 1-15h.
6. An oxide solid electrolyte, characterized in that, The oxide solid electrolyte is prepared by any one of claims 1-5; the water content of the oxide solid electrolyte is ≤400ppm.
7. The oxide solid electrolyte as described in claim 6, characterized in that, The oxide solid electrolyte includes at least one of the compounds with the following chemical formulas: (1) Li 1+x Al x Ti 2-x (PO4)3, where x=0-2; (2) Li 7- y La3Zr 2-y Nb y O 12 , where y=0-7; (3) Li 7-z La3Zr 2-z Ta z O 12 Where z = 0-7; and / or, the D10 of the oxide solid electrolyte is 200-350nm, the D50 of the oxide solid electrolyte is 400-550nm, and the D90 of the oxide solid electrolyte is 700-1350nm.
8. A lithium battery, characterized in that, Includes the oxide solid electrolyte as described in claim 6 or 7.