Method for efficiently preparing garnet-type solid electrolyte, solid electrolyte, and lithium battery

Abstract

The embodiment of the application relates to a method for efficiently preparing a garnet type solid electrolyte, the solid electrolyte and a lithium battery. The solid electrolyte is specifically Li 7‑3x+y‑z A x La 3‑y B y Zr 2‑z C z O 12 , wherein 0<=x<=0.3, 0<=y<=2; 0<=z<=0.6; the preparation method comprises the following steps: taking each raw material and a sintering aid of the target solid electrolyte according to a required stoichiometric ratio, wherein the excess amount of Li is 0-15%, and the average particle size D and the apparent density p of each raw material and the sintering aid satisfy the condition that all the raw materials and the sintering aid are put into a boiling bed reactor, and the raw materials and the sintering aid are boiled and mixed for 0.5-6 hours; after being uniformly mixed, hot air is introduced into the bed layer of the boiling bed and the bed layer is kept in a boiling state for 6-25 hours, so that the powder material of the garnet type solid electrolyte can be prepared.

Description

Technical Field

[0001] This invention relates to the field of battery material preparation technology, and in particular to a method for efficiently preparing Garnet-type solid electrolytes, solid electrolytes, and lithium batteries. Background Technology

[0002] Liquid lithium-ion batteries are now widely used commercially in fields such as electric vehicles, ships, and aerospace; however, they still face various problems and defects, the most serious being safety issues. In contrast, solid-state lithium-ion batteries exhibit superior performance in many aspects, gradually attracting the attention of the electric vehicle industry and prompting extensive research.

[0003] Solid-state batteries require solid electrolytes to replace liquid electrolytes, making them a key material. Currently, the most researched solid electrolyte types include LISICON, Garnet, and perovskite. Garnet-type solid electrolytes offer advantages such as high ionic conductivity, high energy density, a wide electrochemical window, and suppression of Li dendrite growth. However, the preparation conditions for Garnet-type solid electrolytes are quite demanding. Traditional solid-phase preparation methods require temperatures above 1200℃ to produce dense solid electrolyte powders. Excessive temperatures can lead to rapid Li volatilization and the generation of other inert impurities, affecting the overall material performance. Furthermore, the higher sintering temperature increases the preparation cost of Garnet-type solid electrolytes. Meanwhile, the market demand for Garnet-type solid electrolytes is growing, therefore, the current preparation process for Garnet-type solid electrolytes needs improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a method for efficiently preparing Garnet-type solid electrolytes, the solid electrolyte itself, and a lithium battery. This method prepares Garnet-type solid electrolytes by using airflow to ensure continuous and intense collision and mixing between particles, resulting in uniform temperature within the equipment, high reaction efficiency, and good product consistency. Furthermore, it eliminates the need for raw material mixing and product pulverization, greatly simplifying the preparation process and improving material yield and efficiency.

[0005] Therefore, in a first aspect, embodiments of the present invention provide a method for efficiently preparing Garnet-type solid electrolytes, wherein the solid electrolyte is specifically Li 7-3x+y-z A x La 3-y B y Zr 2-z C z O 12 Where 0≤x≤0.3, 0≤y≤2; 0≤z≤0.6;

[0006] The preparation method includes the following steps:

[0007] Weigh out the raw materials and sintering aids of the target solid electrolyte according to the required stoichiometric ratio, wherein Li is in excess by 0-15%, and the average particle size D and apparent density ρ of each raw material and sintering aid satisfy the following conditions: The raw materials include: lithium carbonate or lithium hydroxide, oxides or hydroxides of La, Zr, and A, B, and C; A is one or more of Al, Zn, Fe, and Ga; B is one or more of Ca, Sr, Ba, and Ce; and C is one or more of Ta, Nb, Ge, Sc, W, Hf, and Sn.

[0008] All the raw materials and sintering aids are added to the fluidized bed reactor and mixed in a fluidized bed for 0.5-6 hours.

[0009] After mixing evenly, hot air is introduced into the fluidized bed and the bed is kept in a boiling state for 6-25 hours to obtain the powder material of Garnet-type solid electrolyte.

[0010] Preferably, the sintering aid includes one or more of alumina, aluminum nitrate, and tantalum oxide.

[0011] Preferably, the fluidized bed reactor is filled with an air atmosphere, and the temperature of the hot air is 700℃-1100℃.

[0012] Preferably, the particle size of the powder material of the Garnet-type solid electrolyte is 0.5μm-100μm.

[0013] Preferably, the powder material of the Garnet-type solid electrolyte has a particle shape of one or more of the following: spherical, elliptical, square, or irregular.

[0014] Secondly, embodiments of the present invention provide a Garnet-type solid electrolyte prepared by the method described in the first aspect above.

[0015] Thirdly, embodiments of the present invention provide a lithium battery, the lithium battery comprising the Garnet-type solid electrolyte described in the first aspect above.

[0016] The method for efficiently preparing Garnet-type solid electrolytes provided in this invention simplifies the preparation process by controlling and optimizing the particle size of each raw material and combining the advantages of a fluidized bed reactor. Because the particles are constantly in a state of intense collision within the bed during electrolyte material preparation, and the temperature within the equipment is uniform, the reaction efficiency is high, and the product consistency is better. Furthermore, it eliminates the need for mixing raw materials and pulverizing the product after sintering, greatly simplifying the preparation process, reducing production costs, and improving material yield and efficiency. Attached Figure Description

[0017] Figure 1 A flowchart of the Garnet-type solid electrolyte preparation method provided by the present invention;

[0018] Figure 2 This is the X-ray diffraction (XRD) pattern of the solid electrolyte in Example 1 of the present invention;

[0019] Figure 3 This is a scanning electron microscope (SEM) image of the solid electrolyte in Example 1 of the present invention;

[0020] Figure 4 This is a particle size distribution diagram of the solid electrolyte in Example 1 of the present invention;

[0021] Figure 5 The image shows the XRD pattern of the solid electrolyte in Example 2 of this invention.

[0022] Figure 6 This is a SEM image of the solid electrolyte in Example 2 of the present invention.

[0023] Figure 7 The image shows the XRD pattern of the solid electrolyte in Example 3 of this invention.

[0024] Figure 8 This is the XRD pattern of the solid electrolyte in Example 4 of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] This invention provides a method for efficiently preparing Garnet-type solid electrolytes, as well as the solid electrolyte and lithium battery.

[0027] The solid electrolyte prepared in this invention is specifically Li 7-3x+y-z A x La 3-y B y Zr 2-z C z O 12 , where 0≤x≤0.3, 0≤y≤2; 0≤z≤0.6; where A is one or more of Al, Zn, Fe, Ga; B is one or more of Ca, Sr, Ba, Ce; C is one or more of Ta, Nb, Ge, Sc, W, Hf, Sn.

[0028] Preparation methods include, for example Figure 1 As shown, the main steps include the following:

[0029] Step 110: Weigh the raw materials and sintering aids of the target solid electrolyte according to the required stoichiometric ratio, wherein Li is in excess by 0-15%.

[0030] Among them, the average particle size D and apparent density ρ of each raw material and sintering aid satisfy the following conditions: D1, D2, ... D n These are the average particle sizes of each raw material and sintering aid, ρ1, ρ2, ..., ρ n The apparent densities of each raw material and sintering aid are ρ, respectively. 气 This refers to the gas density during the reaction process inside the fluidized bed reactor.

[0031] The above formulas are derived through scientific calculations based on the reactor operating conditions required for each raw material. The values ​​in subsequent embodiments all satisfy the average particle size, apparent density, and gas density of this formula.

[0032] The approximation of each expression in the formula is specifically defined as a deviation not exceeding 10%, which satisfies the condition of approximation.

[0033] Step 120: Add all raw materials and sintering aids into the fluidized bed reactor and fluidize and mix for 0.5-6 hours.

[0034] The raw materials include: lithium carbonate or lithium hydroxide, oxides or hydroxides of La, Zr, and A, B, and C; the sintering aids include one or more of alumina, aluminum nitrate, and tantalum oxide.

[0035] Step 130: After mixing evenly, hot air is introduced into the fluidized bed and the bed is kept in a boiling state for 6-25 hours to obtain the powder material of Garnet-type solid electrolyte.

[0036] The fluidized bed reactor is filled with air. In this invention, the air carries heat and the temperature of the hot air transferred to the reactor is 700℃-1100℃.

[0037] The powder material of Garnet-type solid electrolyte obtained by the above method has a particle size of 0.5μm-100μm. The particle shape of the Garnet-type solid electrolyte powder material is one or more of the following: spherical, elliptical, square, or irregular.

[0038] The powder material of the Garnet-type solid electrolyte prepared above can be used in lithium batteries.

[0039] To better understand the technical solution provided by this invention, the technical solution of this invention will be further described in detail below through specific examples.

[0040] Example 1

[0041] This embodiment provides a method for preparing Li7La3Zr2O 12 The specific steps of the solid electrolyte method are as follows:

[0042] Lithium carbonate, lanthanum oxide, and zirconium oxide were selected as raw materials for the preparation of solid electrolyte, and alumina was selected as a sintering aid. Particles with an average particle size of 9.1 μm and an apparent density of 2.06 g / cm³ were weighed at 102% of the stoichiometric ratio. 3 1328.9 g of lithium carbonate was weighed, with an average particle size of 5.2 μm and an apparent density of 6.28 g / cm³. 3 2459.8 g of lanthanum oxide was weighed, with an average particle size of 5.5 μm and an apparent density of 5.68 g / cm³. 3 1237.4 g of zirconium oxide, and weighed out particles with an average particle size of 7.2 μm and an apparent density of 3.27 g / cm³. 3 46.8g of alumina, a sintering aid, was added. All four materials were then added to the fluidized bed reactor, the air valve was opened, and the flow rate was adjusted to 2m³ / h. 3 The mixture is stirred at a rate of 1.205 kg / m³ for 2 hours until all raw materials in the bed are in a boiling state. 3 After mixing evenly, turn on the air heating switch to set the inlet hot air temperature to 850℃ and maintain the bed in a boiling state for 20 hours. Then turn off the heating switch and cool the bed to room temperature with cold air to obtain solid electrolyte powder. Figure 2 Li7La3Zr2O prepared for this example 12 XRD pattern of solid electrolyte. Figure 3 Here is a SEM image of the solid electrolyte. Figure 4 The particle size distribution curve of the prepared solid electrolyte is shown.

[0043] from Figure 2 As can be seen from the XRD pattern of the material, the solid electrolyte prepared by the method in this embodiment matches the standard spectrum, indicating that the material prepared by this method has high purity; from Figure 3 The SEM image of the material shows that the particle morphology is irregular, and the particle size is approximately 5 μm. Figure 4 The particle size D50 of the material shown in the particle size curve is basically consistent with 4.8 μm.

[0044] Example 2

[0045] This embodiment provides a method for preparing Li 6.4 La3Zr 1.4 Ta 0.6 O 12 The specific steps of the solid electrolyte method are as follows:

[0046] Lithium carbonate, lanthanum oxide, zirconium oxide, and tantalum pentoxide were selected as raw materials for the preparation of the solid electrolyte, and alumina was selected as a sintering aid. Particles with an average particle size of 9.1 μm and an apparent density of 2.06 g / cm³ were weighed at 104% of the stoichiometric ratio. 3 1194.8 g of lithium carbonate was weighed, with an average particle size of 5.2 μm and an apparent density of 6.28 g / cm³. 3 2372.4 g of lanthanum oxide was weighed, with an average particle size of 5.5 μm and an apparent density of 5.68 g / cm³. 3 835.4 g of zirconium oxide was weighed, with an average particle size of 4.7 μm and an apparent density of 8.02 g / cm³. 3 643.3 g of tantalum pentoxide, and weighed out particles with an average particle size of 7.2 μm and an apparent density of 3.27 g / cm³. 3 32g of alumina, a sintering aid, was added. All five materials were then added to the fluidized bed reactor, the air valve was opened, and the flow rate was adjusted to 2.5m³ / h. 3 The mixture is stirred at a rate of 1.185 kg / m³ for 2.5 hours until all raw materials in the bed are in a boiling state. 3 After mixing evenly, turn on the air heating switch to set the inlet hot air temperature to 950℃ and maintain the bed in a boiling state for 16 hours. Then turn off the heating switch and cool the bed to room temperature with cold air to obtain solid electrolyte powder. Figure 5 Li prepared for this embodiment 6.4 La3Zr 1.4 Ta 0.6 O 12 XRD pattern of solid electrolyte. Figure 6 This is a SEM image of the solid electrolyte.

[0047] from Figure 5 As can be seen from the XRD pattern of the material, the solid electrolyte prepared by the method in this embodiment matches the standard spectrum, indicating that the material prepared by this method has high purity; from Figure 6 The SEM image of the material shows that the particle morphology is irregular and the particle size is approximately 3 μm.

[0048] Example 3

[0049] This embodiment provides a method for preparing Li 6.75 La3Zr 1.75 Ta 0.25 O 12 The specific steps of the solid electrolyte method are as follows:

[0050] Lithium carbonate, lanthanum oxide, zirconium oxide, and tantalum pentoxide were selected as raw materials for the preparation of the solid electrolyte, and alumina was selected as a sintering aid. Particles with an average particle size of 9.1 μm and an apparent density of 2.06 g / cm³ were weighed at 104% of the stoichiometric ratio.3 1286.8 g of lithium carbonate was weighed, with an average particle size of 5.2 μm and an apparent density of 6.28 g / cm³. 3 2422.6 g of lanthanum oxide was weighed, with an average particle size of 5.5 μm and an apparent density of 5.68 g / cm³. 3 1066.4 g of zirconium oxide was weighed, with an average particle size of 4.7 μm and an apparent density of 8.02 g / cm³. 3 273.7 g of tantalum pentoxide, and weighed out particles with an average particle size of 7.2 μm and an apparent density of 3.27 g / cm³. 3 54g of alumina, a sintering aid, was added. All five materials were then added to the fluidized bed reactor, the air valve was opened, and the flow rate was adjusted to 2.5m³ / h. 3 The mixture is stirred at a rate of 1.220 kg / m³ for 3 hours until all raw materials in the bed are in a boiling state. 3 After mixing evenly, turn on the air heating switch to set the inlet hot air temperature to 1050℃ and maintain the bed in a boiling state for 12 hours. Then turn off the heating switch and allow the cold air to cool to room temperature to obtain solid electrolyte powder. Figure 7 Li prepared for this embodiment 6.75 La3Zr 1.75 Ta 0.25 O 12 XRD pattern of solid electrolyte. Figure 7 As can be seen from the XRD pattern of the material, the solid electrolyte prepared by the method of this embodiment is in good agreement with the standard spectrum, indicating that the material prepared by this method has high purity.

[0051] Example 4

[0052] This embodiment provides a method for preparing Li 6.75 La3Zr 1.75 Nb 0.25 O 12 The specific steps of the solid electrolyte method are as follows:

[0053] Lithium carbonate, lanthanum oxide, zirconium oxide, and niobium pentachloride were selected as raw materials for the preparation of the solid electrolyte, and alumina was selected as a sintering aid. Particles with an average particle size of 9.1 μm and an apparent density of 2.06 g / cm³ were weighed at 102% of the stoichiometric ratio. 3 1289.5g of lithium carbonate was weighed, with an average particle size of 5.2µm and an apparent density of 6.28g / cm³. 3 2475.3 g of lanthanum oxide was weighed, with an average particle size of 5.5 μm and an apparent density of 5.68 g / cm³. 3 1089.6 g of zirconium oxide was weighed, with an average particle size of 6.4 μm and an apparent density of 4.25 g / cm³. 3170.8 g of niobium pentachloride, and weighed samples with an average particle size of 7.2 μm and an apparent density of 3.27 g / cm³. 3 Add 40g of alumina as a sintering aid. Add all five materials to the fluidized bed reactor, open the air valve, and adjust the flow rate to 2m³ / h. 3 The mixture is stirred at a rate of 1.193 kg / m³ for 3.5 hours until all raw materials in the bed are in a boiling state. 3 After mixing evenly, turn on the air heating switch to set the inlet hot air temperature to 1000℃ and maintain the bed in a boiling state for 16 hours. Then turn off the heating switch and cool the bed to room temperature with cold air to obtain solid electrolyte powder. Figure 8 Li prepared for this embodiment 6.75 La3Zr 1.75 Nb 0.25 O 12 XRD pattern of solid electrolyte. Figure 8 As can be seen from the XRD pattern of the material, the solid electrolyte prepared by the method of this embodiment is in good agreement with the standard spectrum, indicating that the material prepared by this method has high purity.

[0054] The method for efficiently preparing Garnet-type solid electrolytes provided in this invention simplifies the preparation process by controlling and optimizing the particle size of each raw material and combining the advantages of a fluidized bed reactor. Because the particles are constantly in a state of intense collision within the bed during electrolyte material preparation, and the temperature within the equipment is uniform, the reaction efficiency is high, and the product consistency is better. Furthermore, it eliminates the need for mixing raw materials and pulverizing the product after sintering, greatly simplifying the preparation process, reducing production costs, and improving material yield and efficiency.

[0055] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for efficiently preparing Garnet-type solid electrolytes, characterized in that, The solid electrolyte is specifically Li 7-3x+y-z A x La 3-y B y Zr 2-z C z O 12 Where 0≤x≤0.3, 0≤y≤2; 0≤z≤0.6; The method includes the following steps: Weigh out the raw materials and sintering aids of the target solid electrolyte according to the required stoichiometric ratio, wherein Li is in excess by 0-15%, and the average particle size D and apparent density ρ of each raw material and sintering aid satisfy the formula The raw materials include: lithium carbonate or lithium hydroxide, oxides or hydroxides of La, Zr, and A, B, and C; A is one or more of Al, Zn, Fe, and Ga; B is one or more of Ca, Sr, Ba, and Ce; C is one or more of Ta, Nb, Ge, Sc, W, Hf, and Sn; and the approximate or equal to terms in the formulas indicate a deviation not exceeding 10%. All the raw materials and sintering aids are added to the fluidized bed reactor and mixed in a fluidized bed for 0.5-6 hours. After mixing evenly, hot air is introduced into the fluidized bed and the bed is kept in a boiling state for 6-25 hours to obtain the powder material of Garnet-type solid electrolyte.

2. The method for efficiently preparing Garnet-type solid electrolytes according to claim 1, characterized in that, The sintering aid includes one or more of alumina, aluminum nitrate, and tantalum oxide.

3. The method for efficiently preparing Garnet-type solid electrolytes according to claim 1, characterized in that, The fluidized bed reactor is filled with air, and the temperature of the hot air is 700℃-1100℃.

4. The method for efficiently preparing Garnet-type solid electrolytes according to claim 1, characterized in that, The particle size of the powder material of the Garnet-type solid electrolyte is 0.5μm-100μm.

5. The method for efficiently preparing Garnet-type solid electrolytes according to claim 1, characterized in that, The powder material of the Garnet-type solid electrolyte has a particle shape that is one or more of the following: spherical, elliptical, and square.

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