Process for the preparation of a solid-state electrolyte lithium lanthanum zirconium oxide and the product obtained
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN CITY UNIV
- Filing Date
- 2026-03-06
- Publication Date
- 2026-05-29
Smart Images
Figure CN122102198A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of solid electrolyte technology, and in particular relates to a method for preparing solid electrolyte lithium lanthanum zirconium oxide and the resulting product. Background Technology
[0002] In recent years, with the rapid development of the new energy industry, traditional liquid lithium-ion batteries have gradually become insufficient to meet the requirements of high-energy, high-safety power batteries for electric vehicles. Therefore, the development of solid-state lithium metal batteries, which theoretically possess higher energy density and safety performance, has attracted considerable attention. The key to solid-state lithium metal battery technology lies in developing solid electrolytes with high ionic conductivity, stability at the lithium interface, and a wide electrochemical window. Currently developed solid electrolytes mainly include organic polymer solid electrolytes, inorganic solid electrolytes, and organic-inorganic composite solid electrolytes. Organic polymer solid electrolytes are mainly composed of a polymer matrix and an electrolyte lithium salt, exhibiting low ionic conductivity at room temperature. Inorganic solid electrolytes mainly include sulfide solid electrolytes and oxide solid electrolytes, which have slightly higher ionic conductivity than polymer electrolytes but poor contact with the electrode interface and high interfacial resistance. Organic-inorganic composite solid electrolytes are solid electrolytes composed of organic polymer solid electrolytes and inorganic solid electrolytes, combining the advantages of both. Among inorganic solid electrolytes, sulfide solid electrolytes possess advantages such as high room-temperature ionic conductivity, a wide electrochemical window, and low synthesis temperature; however, they are highly reactive with air and water, exhibiting poor chemical stability. Oxides, on the other hand, exhibit higher stability, particularly cubic LLZO, which serves as a novel high-energy, high-safety solid lithium-ion electrolyte, boasting advantages such as lithium interface stability, a wide electrochemical window, and high ionic conductivity. Furthermore, LLZO is frequently used to prepare high-performance organic-inorganic composite solid electrolytes, especially nanowire, sheet, and porous fillers, which significantly improve the ionic conductivity of composite solid electrolytes. Therefore, the production technology and commercial application of LLZO, particularly cubic LLZO with its unique morphology, are receiving increasing attention and importance.
[0003] High-temperature solid-state methods are simple and relatively low-cost, but require long ball milling times and high calcination temperatures, resulting in LLZO with sizes ranging from a few micrometers to tens of micrometers, making morphology difficult to control. Coprecipitation methods can achieve atomic-level mixing without prolonged ball milling, but differences in metal ion solubility products lead to uneven elemental distribution and difficulty in controlling stoichiometry, also making it challenging to produce LLZO with the desired morphology. Sol-gel methods can also achieve atomic-level mixing and prepare nanoscale materials. Low-temperature calcination significantly reduces production energy consumption, requiring lower calcination temperatures and shorter times. However, the aging time for precursor gel sol-gel preparation is long, the gel properties are unstable, and subsequent processes involve elemental segregation. Furthermore, irregular expansion during calcination affects the crystal purity of the material, thus impacting its performance. In general, conventional preparation techniques struggle to control the morphology of LLZO. While newer methods such as electrospinning can prepare LLZO nanofibers, their high equipment costs and low yields hinder large-scale production. Other methods also have their own advantages and disadvantages. Therefore, exploring a low-cost method for preparing LLZO with controllable morphology is of great significance for the commercial application of solid electrolyte LLZO and composite solid electrolyte materials filled with LLZO. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a method for preparing solid electrolyte lithium lanthanum zirconium oxide and the product obtained, in order to overcome the shortcomings of the prior art.
[0005] The technical solution adopted by this invention to solve its technical problem is:
[0006] A method for preparing a solid electrolyte lithium lanthanum zirconium oxide includes the following steps:
[0007] S1: Prepare a mixed solution by mixing soluble zirconium salt, lanthanum salt, doped element salt and solvent;
[0008] S2: Prepare an organic ligand solution from aromatic polycarboxylic acids or aromatic polybases;
[0009] S3: After uniformly mixing the mixed solution with the organic ligand solution, heat the reaction to obtain the MOF material slurry;
[0010] S4: Evaporate the solvent from the MOF material slurry, dry and grind to obtain lithium lanthanum zirconium oxide precursor material;
[0011] In step S1, a lithium source material is added to prepare a mixed solution, or in step S3, the lithium source material is mixed together with the mixed solution and the organic ligand solution.
[0012] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the soluble zirconium salt and lanthanum salt in step S1 are organic acid salts or organic salts, and the molar ratio of zirconium element to lanthanum element in the zirconium salt and lanthanum salt is 1:1-2.
[0013] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the doping element salt is a soluble salt of Na, Ca, Al, Ga, Ge, Y, Ti, Ce, Ta, Mo, Mn, Ni, Mo, Ru, Nb, Rh and elements of the same group.
[0014] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the solvent in step S1 is: deionized water, anhydrous ethanol, polyethylene glycol, N,N-dimethylformamide, or N,N-dimethylacetamide.
[0015] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, in step S2, the aromatic polycarboxylic acid is terephthalic acid, pyromellitic acid, pyromellitic tetracarboxylic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 1,3,6,7-naphthalitetraic acid, 4,4-biphenyl dicarboxylic acid, 3,3,4,4-biphenyltetracarboxylic acid, perylene-3,4,9,10-tetracarboxylic anhydride, or 3,3'4,4'-benzophenone tetracarboxylic acid.
[0016] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, in step S2, the aromatic polybase is imidazole, pyrazole, pyrimidine, 2,2'-dipyrrole, 2,2'-bipyridine, 2,2'-biimidazole, or 2,2'-bipyrimidine.
[0017] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the organic ligand solution further includes a pH buffer, wherein the pH buffer is ethanol, water, sodium carbonate solution, acetic acid solution, formic acid solution, methylamine solution or ammonium bicarbonate solution, and the pH value of the organic ligand solution is usually controlled at 6-8.
[0018] Preferably, in the method for preparing the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the lithium source is lithium oxide, lithium chloride, lithium hydroxide, lithium carbonate, lithium formate, lithium acetate and lithium nitrate, and the molar ratio of lithium element to lanthanum element added in step S1 in the lithium source is 2-3.5.
[0019] Preferably, in the preparation method of the solid electrolyte lithium lanthanum zirconium oxide of the present invention, the heating reaction in step S3 is carried out in a solvothermal reactor at a heating temperature of 100-200°C. When using a solvothermal reactor, a high-pressure environment is formed inside the reactor.
[0020] The drying temperature during drying and grinding in step S4 is 80-200℃.
[0021] Step S4 also includes the step of calcining the lithium lanthanum zirconium oxide precursor material.
[0022] The calcination atmosphere is oxygen or air;
[0023] The pre-firing temperature is 400-700℃, the pre-firing time is 1-12h, the calcination temperature is 700-1400℃, and the calcination time is 2-60h.
[0024] A solid electrolyte lithium lanthanum zirconium oxide is prepared by the above-described method for preparing solid electrolyte lithium lanthanum zirconium oxide.
[0025] The beneficial effects of this invention are:
[0026] The method for preparing the solid electrolyte lithium lanthanum zirconium oxide (LLZO) of this application utilizes the unique chelating effect of organic ligands to achieve atomic-level uniform dispersion of metal elements in the precursor MOF solid phase. During subsequent high-temperature decomposition, the metal elements are released simultaneously, and the rapid diffusion of lanthanum, zirconium, dopant elements, and lithium is observed, avoiding segregation caused by excessively high local element concentrations. This method facilitates the production of high-purity LLZO at relatively low temperatures and with short calcination times. The preparation process of this application is reliable, with simple equipment and no harmful gas generation. It effectively utilizes the stable chelating effect of polycarboxyl and polybase organic ligands on lanthanum, zirconium, dopant metal elements, or lithium ions. The resulting chelated MOFs effectively achieve uniform mixing of metal elements; or utilize the strong adsorption of lithium salts by the porous structure of the MOF material itself; combined with the shearing effect of high-temperature carbon decomposition of the organic framework on the production materials. This avoids elemental segregation caused by uneven local element distribution in the precursor, inhibits the generation of impurities and excessive grain growth during calcination, and ultimately achieves the preparation of a precursor with uniform element distribution. This allows for controllability of the material phase structure and particle morphology size during the calcination process, resulting in high-purity cubic LLZO micro / nano powders, which significantly improves the selectivity and efficiency of the reaction. Attached Figure Description
[0027] The technical solution of this application will be further described below with reference to the accompanying drawings and embodiments.
[0028] Figure 1 These are the XRD patterns of samples one to four in the embodiments of this application;
[0029] Figure 2 These are the XRD patterns of samples five to eight in the embodiments of this application;
[0030] Figure 3 These are the XRD patterns of samples nine and ten in the embodiments of this application;
[0031] Figure 4 These are the XRD patterns of samples eleven to thirteen in the embodiments of this application;
[0032] Figure 5 This is an SEM image of Sample 1 in the embodiments of this application;
[0033] Figure 6These are SEM images of samples two to thirteen in the embodiments of this application. Detailed Implementation
[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.
[0035] Example 1
[0036] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0037] S1: Weigh 5 mmol zirconium acetate, 5 mmol lanthanum nitrate and 2 mmol niobium chloride, add them to 30 ml ethylene glycol solution and stir to form a clear mixed solution (solution 1).
[0038] S2: Weigh 21.25 mmol of terephthalic acid and dissolve it in 85 ml of a mixture of ethanol and water to obtain an organic ligand solution (solution 2).
[0039] S3: Slowly add solution 2 to solution 1, and add 20 ml of a mixture of deionized water and ethanol. Stir continuously at 3000 r / min for 1 h and sonicate for 6 h. Transfer the mixture to a solvothermal reactor and react at 120℃ for 40 h. After cooling, add 17.5 mL of 1 mol / L lithium nitrate solution and stir for 6 h to obtain a uniform MOFs material slurry.
[0040] S4: While stirring, heat the slurry in a water bath at 60°C to evaporate it, and then dry it in an oven at 100°C for 30 hours. Grind the LLZO precursor material and name it Sample 1. Treat the precursor material (Sample 1) in an air atmosphere tube furnace at 400°C for 6 hours and then at 700°C for 30 hours to obtain niobium-doped LLZO nanopowder material, which is named Sample 2.
[0041] Example 2
[0042] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0043] S1: Weigh 5 mmol zirconium nitrate and 10 mmol lanthanum acetate, add them to 40 ml ethanol and 20 ml N,N-dimethylformamide solution, then add 2 mL 0.5 mol / L gallium nitrate solution and stir to form a clear mixed solution (solution 1).
[0044] S2: Weigh 16.67 mmol of pyromellitic acid (PMA), dissolve it in 50 ml of ethanol to obtain pyromellitic acid solution 2;
[0045] S3: Slowly add solution 2 to solution 1, and add 10 ml of a mixture of deionized water and ethanol. Stir continuously at 500 r / min for 18 h and sonicate for 2 h. Then transfer the mixture to a solvothermal reactor and react at 150 °C for 20 h. After cooling, take out the MOFs slurry, add 50 ml of 0.5 mol / L lithium hydroxide solution, and stir for 10 h to obtain a uniform slurry.
[0046] S4: The slurry was heated to dryness in a water bath at 80°C while stirring, and then dried at 150°C for 20 hours before grinding to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 300°C for 12 hours and at 800°C for 60 hours to obtain LLZO nanopowder material, named Sample 3.
[0047] Example 3
[0048] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0049] S1: Weigh 5 mmol zirconium acetate, 7.5 mmol lanthanum acetate, 0.5 mmol calcium nitrate and 0.5 mmol yttrium nitrate, add them to a mixture of 40 ml polyethylene glycol and 20 ml water, and stir to form a clear solution 1;
[0050] S2: Weigh 25 mmol of 1,4-naphthalenedicarboxylic acid and dissolve it in 25 ml of 1 mol / L sodium carbonate solution to obtain sodium 1,4-naphthalenedicarboxylic acid solution 2;
[0051] S3: Slowly add solution 2 to solution 1, and add 20 mL of a mixture of deionized water and ethanol. Stir continuously at 1000 r / min for 12 h and sonicate for 2 h. Then transfer the mixture to a solvothermal reactor and react at 200 °C for 1 h. After cooling, take out the MOFs slurry and add it to 250 mL of 0.1 mol / L lithium carbonate solution. Stir for 12 h to obtain a homogeneous slurry.
[0052] S4: The slurry was heated to dryness in a water bath at 100°C while stirring, and then dried at 200°C for 1 hour before grinding to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 700°C for 1 hour and then at 1000°C for 15 hours to obtain calcium-yttrium-doped LLZO nanopowder material, named Sample Four.
[0053] Example 4
[0054] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0055] S1: Weigh 5 mmol zirconium nitrate and 7.5 mmol lanthanum nitrate, add them to 40 ml ethanol and 20 ml N,N-dimethylacetamide solution, then add 3 mL 0.5 mol / L germanium nitrate solution and stir to form a clear solution 1;
[0056] S2: Weigh 21.25 mmol of 2,2'-biimidazole and dissolve it in 42.5 ml of 1 mol / L acetic acid solution to obtain solution 2;
[0057] S3: Slowly add solution 2 to solution 1, and add 20 ml of a mixture of deionized water and ethanol. Stir continuously at 2000 r / min for 6 h and sonicate for 10 h. Then transfer the mixture to a solvothermal reactor and react at 175 ℃ for 10 h. After cooling, take out the MOFs slurry and add 42 mL of 0.5 mol / L lithium nitrate solution. Stir for 1 h to obtain a homogeneous slurry.
[0058] S4: The slurry was heated to dryness in a water bath at 40°C while stirring, and then dried at 100°C for 25 hours before grinding to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 500°C for 1 hour and 1100°C for 2 hours to obtain LLZO nanopowder material, which was named Sample 5.
[0059] Example 5
[0060] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0061] S1: Weigh 5 mmol of zirconium acetate and 7.5 mmol of lanthanum acetate, add them to 40 ml of ethanol solution, then add 2 mL of 0.5 mol / L aluminum nitrate solution and stir to form a clear solution 1;
[0062] S2: Weigh 14.17 mmol of pyromellitic acid (TCA), dissolve it in 42.5 mL of deionized water to obtain pyromellitic acid solution 2;
[0063] S3: Slowly add solution 2 dropwise to solution 1, then add 40 ml of a mixture of deionized water and ethanol, stir continuously at 200 r / min for 24 h, and sonicate for 0.1 h; then transfer the mixture to a solvothermal reactor and react at 100 °C for 60 h. After cooling, take out the MOFs slurry and add 42 mL of 0.5 mol / L lithium acetate solution, stir for 4 h to obtain a uniform slurry;
[0064] S4: The slurry was heated to dryness in a water bath at 40°C while stirring, and then dried at 80°C for 40 hours before grinding to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 550°C for 3 hours and at 1000°C for 4 hours to obtain aluminum-doped LLZO nanopowder material, named Sample Six.
[0065] Example 6
[0066] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0067] S1: Weigh 10 mmol zirconium acetate, 17 mmol lanthanum sulfate and 1 mmol titanium tetrachloride, add them to 80 ml isopropanol and ethylene glycol solution, and stir to form a clear solution 1;
[0068] S2: Weigh 21.25 mmol of 3,3'4,4'-biphenyltetracarboxylic anhydride and dissolve it in 85 mL of 0.5 mol / L triethylamine solution to obtain 3,3'4,4'-biphenyltetracarboxylic acid salt solution 2;
[0069] S3: Slowly add solution 2 to solution 1, and add 40 mL of a mixture of deionized water and ethanol. Stir continuously at 2000 r / min for 6 h and sonicate for 4 h. Then transfer the mixture to a solvothermal reactor and react at 120 °C for 24 h. After cooling, add 100 mL of 0.5 mol / L lithium acetate solution and stir for 6 h to obtain a uniform slurry.
[0070] S4: The slurry was dried by heating in a water bath at 60°C while stirring, and then dried at 100°C for 20 hours before grinding to obtain the LLZO precursor material. The precursor material was then treated in a muffle furnace at 600°C for 2 hours and then at 1100°C for 3 hours to obtain titanium-doped LLZO nanopowder material, which was named Sample Seven.
[0071] Example 7
[0072] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0073] S1: Weigh 10 mmol zirconium oxynitrate, 15 mmol lanthanum formate and 0.75 mmol molybdenum nitrate, add them to 100 ml of ethanol and N,N-dimethylacetamide solution, and stir to form a clear solution 1;
[0074] S2: Weigh 32.5 mmol of 2,2'-bipyridine and dissolve it in 120.5 mL of 1 mol / L formic acid solution to obtain solution 2;
[0075] S3: Slowly add solution 2 to solution 1, and add 100 mL of a mixture of deionized water and ethanol. Stir continuously at 1200 r / min for 10 h and sonicate for 2 h. Then transfer the mixture to a solvothermal reactor and react at 140℃ for 20 h. After cooling, add 90 mL of 0.5 mol / L lithium acetate solution and stir for 2 h to obtain a uniform slurry.
[0076] S4: The slurry was dried by heating in a water bath at 80°C while stirring, and then ground at 80°C for 40 hours to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 400°C for 6 hours and at 1000°C for 10 hours to obtain molybdenum-doped LLZO nanopowder material, named Sample 8.
[0077] Example 8
[0078] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0079] S1: Weigh 20 mmol zirconium acetate and 32 mmol lanthanum acetate, add them to 160 ml of ethanol and methanol solution, then add 1 mL of 0.5 mol / L rhodium nitrate solution and stir to form a clear solution 1;
[0080] S2: Weigh 45 mmol of 3,3′,4,4′-diphenyl ether tetracarboxylic acid and dissolve it in 90 mL of 1 mol / L oxalic acid solution to obtain solution 2;
[0081] S3: Slowly add solution 2 to solution 1, and add 40 ml of a mixture of deionized water and ethanol. Stir continuously at 3000 r / min for 20 h and sonicate for 5 h. Then transfer the mixture to a solvothermal reactor and react at 100℃ for 40 h. After cooling, take out the MOFs slurry and add 40 mL of 2 mol / L lithium formate solution. Stir for 8 h to obtain a uniform slurry.
[0082] S4: The slurry was dried by heating in a water bath at 80°C while stirring, and then dried at 100°C for 50 hours before grinding to obtain LLZO precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 650°C for 4 hours and at 1400°C for 1 hour to obtain LLZO nanopowder material, which was named Sample Nine.
[0083] Example 9
[0084] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0085] S1: Weigh 10 mmol zirconium formate, 16 mol lanthanum chloride, 0.5 mmol nickel nitrate and 0.5 mmol manganese nitrate, add them to 80 mL of a mixed solution of deionized water and isopropanol, and stir to form a clear solution 1;
[0086] S2: Weigh 21.25 mmol of 2,2'-dipyrrole and dissolve it in 85 ml of 1 mol / L methylamine solution to obtain solution 2;
[0087] S3: Slowly add solution 2 dropwise to solution 1, and add 80 ml of a mixture of deionized water and ethanol. Stir continuously at 2000 r / min for 24 h and sonicate for 2 h. Then transfer the mixture to a solvothermal reactor and react at 120℃ for 20 h. After cooling, add 168 ml of 0.25 mol / L lithium nitrate solution and stir for 2 h to obtain a uniform slurry.
[0088] S4: The slurry was heated to dryness in a water bath at 40°C while stirring, and then dried at 100°C for 28 hours before grinding to obtain LLZO precursor material. The precursor material was then treated in a muffle furnace at 300°C for 8 hours and at 1300°C for 10 hours to obtain nickel-manganese-doped LLZO nanopowder material, named Sample 10.
[0089] Example 10
[0090] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0091] S1: Weigh 5 mmol of zirconium acetate and 7.5 mmol of lanthanum acetate, add them to 40 ml of isopropanol solution, then add 2 mL of 0.5 mol / L tantalum nitrate solution, and stir to form a clear solution 1;
[0092] S2: Weigh 10.625 mmol of 3,3',4,4'-benzophenone tetracarboxylic acid (BTA) and dissolve it in 42.5 ml of 1 mol / L ammonium bicarbonate solution to obtain solution 2;
[0093] S3: Slowly add solution 2 dropwise to solution 1, and add 40 ml of deionized water. Stir continuously for 24 h and sonicate for 0.1 h. Then transfer the mixture to a solvothermal reactor and react at 160 °C for 20 h. After cooling, take out the MOFs slurry and add it to 210 ml of 0.1 mol / L lithium acetate solution. Stir for 6 h to obtain a uniform slurry.
[0094] S4: The slurry was heated to dryness in a water bath at 80°C while stirring, and then dried at 180°C for 5 hours. The LLZO precursor material was then ground to obtain the precursor material. The precursor material was then treated in an oxygen atmosphere tube furnace at 600°C for 3 hours and at 1100°C for 10 hours to obtain LLZO nanopowder material, which was named Sample Eleven.
[0095] Table. Selection of substances in different embodiments
[0096]
[0097] Comparative Example 1
[0098] This embodiment provides a method for preparing solid electrolyte lithium lanthanum zirconium oxide, including the following steps: (without the addition of 3,3',4,4'-benzophenone tetracarboxylic acid (BTA))
[0099] Weigh 5 mmol of zirconium acetate and 7.5 mmol of lanthanum acetate, add them to 40 ml of isopropanol solution, then add 2 mL of 0.5 mol / L tantalum nitrate solution, and stir to form a clear solution 1. Measure 42.5 ml of deionized water as solution 2. Slowly add solution 2 dropwise to solution 1, and add 40 ml of deionized water, stirring continuously for 24 h, and then sonicating for 0.1 h. Then transfer the mixture to a solvothermal reactor and react at 100℃ for 10 h. After cooling, take out the slurry and add it to 210 ml of 0.1 mol / L lithium acetate solution. Stir for 6 h to obtain a homogeneous slurry. While stirring, heat the slurry in a water bath at 80℃ to evaporate it, and then dry it at 180℃ for 5 h. Grind to obtain LLZO precursor material. Treat the precursor material in an oxygen atmosphere tube furnace at 600℃ for 3 h and at 1000℃ for 5 h to obtain LLZO nanopowder material, named Sample Twelve.
[0100] Comparative Example 2
[0101] This embodiment provides a method for preparing a solid electrolyte, lithium lanthanum zirconium oxide, comprising the following steps:
[0102] 10 mmol of zirconium acetate and 15 mmol of lanthanum sulfate were weighed and added to 80 mL of water and ethylene glycol solution, and stirred to form a clear solution 1. 85 mL of deionized water was measured as solution 2. Solution 2 was slowly added to solution 1, along with 40 mL of a mixture of deionized water and ethanol. The mixture was stirred continuously at 2000 r / min for 6 h and sonicated for 4 h. The mixture was then transferred to a solvothermal reactor and reacted at 100 °C for 10 h. After cooling, 100 mL of 0.5 mol / L lithium acetate solution was added, and the mixture was stirred for 6 h to obtain a homogeneous slurry. The slurry was evaporated by heating in a water bath at 60 °C while stirring, and then dried at 100 °C for 20 h and ground to obtain the LLZO precursor material. The precursor material was treated in a muffle furnace at 600 °C for 2 h and then at 1200 °C for 5 h to obtain LLZO nanopowder material, named Sample Thirteen.
[0103] pass Figure 6 Samples 2 to 11 (corresponding to Examples 1 to 10, respectively) all yielded high-purity cubic LLZO. The optimal implementation method was a pre-calcination temperature of 550°C for 2 hours, followed by a calcination temperature of 900-1100°C for 5 hours. Comparative Example 1 (Sample 12), under similar conditions but without the addition of an organic ligand solution, did not yield high-purity cubic LLZO, even with a final calcination temperature increased to 1200°C (Sample 13 / Comparative Example 2), only a small amount of cubic LLZO was generated.
[0104] Based on the above-described preferred embodiments according to this application, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A method for preparing a solid electrolyte lithium lanthanum zirconium oxide, characterized in that, Includes the following steps: S1: Prepare a mixed solution by mixing soluble zirconium salt, lanthanum salt, doped element salt and solvent; S2: Prepare an organic ligand solution from aromatic polycarboxylic acids or aromatic polybases; S3: After uniformly mixing the mixed solution with the organic ligand solution, heat the reaction to obtain MOF slurry; S4: Evaporate the solvent from the MOF material slurry, dry and grind to obtain lithium lanthanum zirconium oxide precursor material; In step S1, a lithium source material is added to prepare a mixed solution, or in step S3, the lithium source material is mixed together with the mixed solution and the organic ligand solution.
2. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, The soluble zirconium and lanthanum salts in step S1 are organic acid salts or organic salts, and the molar ratio of zirconium to lanthanum in the zirconium and lanthanum salts is 1:1-2.
3. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 2, characterized in that, The doped element salts are soluble salts of Na, Ca, Al, Ga, Ge, Y, Ti, Ce, Ta, Mo, Mn, Ni, Mo, Ru, Nb, Rh and their group-related elements.
4. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, The solvents used in step S1 are: deionized water, anhydrous ethanol, polyethylene glycol, N,N-dimethylformamide, and N,N-dimethylacetamide.
5. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, In step S2, the aromatic polycarboxylic acid is terephthalic acid, pyromellitic acid, pyromellitic tetracarboxylic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 1,3,6,7-naphthalitetraic acid, 4,4-biphenyl dicarboxylic acid, 3,3,4,4-biphenyltetracarboxylic acid, perylene-3,4,9,10-tetracarboxylic anhydride, or 3,3'4,4'-benzophenone tetracarboxylic acid.
6. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, In step S2, the aromatic polyalkali is imidazole, pyrazole, pyrimidine, 2,2'-dipyrrole, 2,2'-bipyridine, 2,2'-biimidazole, or 2,2'-bipyrimidine.
7. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 5 or 6, characterized in that, The organic ligand solution also includes a pH buffer, which is ethanol, water, sodium carbonate solution, acetic acid solution, formic acid solution, methylamine solution, or ammonium bicarbonate solution.
8. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, The lithium source is lithium oxide, lithium chloride, lithium hydroxide, lithium carbonate, lithium formate, lithium acetate, and lithium nitrate. The molar ratio of lithium to lanthanum added in step S1 is 2-3.
5.
9. The method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to claim 1, characterized in that, The heating reaction in step S3 is carried out in a solvothermal reactor at a heating temperature of 100-200℃. The drying temperature during drying and grinding in step S4 is 80-200℃. Step S4 also includes the step of calcining the lithium lanthanum zirconium oxide precursor material. The calcination atmosphere is oxygen or air; The pre-firing temperature is 400-700℃, the pre-firing time is 1-12h, the calcination temperature is 700-1400℃, and the calcination time is 2-60h.
10. A solid electrolyte lithium lanthanum zirconium oxide, prepared by the method for preparing the solid electrolyte lithium lanthanum zirconium oxide according to any one of claims 1-9.