LATP solid electrolyte and preparation method and application thereof

Abstract

The invention belongs to the technical field of battery materials, and provides an LATP solid electrolyte and a preparation method and application thereof.The preparation method comprises the steps that an LATP solid raw material, inorganic weak acid powder and organic alcohol powder are subjected to dry mixing, the organic alcohol powder comprises at least one of polyvinyl alcohol, polyethylene glycol or polypropylene glycol, and a mixed material is obtained; and sintering the mixed material to obtain the LATP solid electrolyte. Organic alcohol powder and inorganic weak acid powder are adopted to neutralize the acid-base properties of a phosphorus source and a lithium source, so that efficient, mild and uniform reaction is effectively ensured; long-time wet ball milling using a dispersion medium is replaced by dry mixing, so that the phenomena of non-uniform dispersion and segregation of various raw materials caused by an organic dispersion medium are avoided, the situation that the granularity difference value of the raw materials is enlarged due to long-time ball milling is avoided, and the consistency of the raw materials is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery materials, and relates to a LATP solid electrolyte, a preparation method thereof and a use thereof. Background Art

[0002] Lithium-ion batteries have been widely used in the fields of vehicle power, energy storage power grids and 3C consumer power due to their advantages such as high working voltage, high energy density and high cycle life. In order to further meet the market demand for lithium-ion batteries, it has become an inevitable way to develop lithium-ion batteries with higher energy density, higher safety and higher cycle life. Among them, semi-solid / quasi-solid / full-solid-state batteries that use solid electrolytes to completely replace or partially replace liquid electrolytes have become the research focus due to their advantages such as an energy density of up to 500 wh / kg, higher safety and longer cycle life.

[0003] Among solid electrolytes, LATP solid electrolyte (lithium aluminum titanium phosphate) has advantages such as low cost, good environmental adaptability and high ionic conductivity, and significant industrialization progress has been made at present. The theoretical ionic conductivity of LATP solid electrolyte can be as high as 1×10 -3 S / cm, which basically meets the requirements of all-solid-state batteries for electrolyte performance. However, the ionic conductivity of the currently prepared LATP solid electrolyte is only 1×10 -4 S / cm, far lower than the theoretical value. The relatively low actual conductivity will seriously affect the lithium-ion migration rate inside the solid electrolyte and hinder the development of solid-state battery technology.

[0004] Regarding this problem, traditional improvement processes use ethanol ball milling - calcination for high-entropy doping to prepare high-performance LATP solid electrolytes. However, this scheme has the problems that the calcination and ball milling processes take too long, and the raw material state differences are likely to increase and the particle size ratio is unbalanced during the ball milling process of each substance, resulting in uneven distribution. In addition, high-entropy element doping also amplifies the harm of uneven element distribution, resulting in poor consistency and stability of product performance. In addition, due to the different acid-base properties of lithium salts, phosphates and other oxide raw materials in the raw materials, local reactions are extremely likely to occur during the mixing process, which will also lead to deterioration of product performance.

[0005] Therefore, it is of great practical significance to explore new methods for synthesizing high-performance LATP solid electrolytes. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a LATP solid electrolyte, a preparation method and a use thereof. The preparation method includes dry-mixing a LATP solid raw material, an inorganic weak acid powder and an organic alcohol powder to obtain a mixed material; and sintering the mixed material to obtain a LATP solid electrolyte. By using the organic alcohol powder and the inorganic weak acid powder to neutralize the acidity and alkalinity of the phosphorus source and the lithium source, the reaction can be effectively ensured to be efficient, mild and uniform; by replacing the long-time wet ball milling using a dispersion medium with dry mixing, the problems of uneven dispersion and segregation of various raw materials caused by the organic dispersion medium are avoided, and the amplification of the particle size difference value of the raw materials caused by long-time ball milling is avoided, effectively improving the consistency of the raw materials.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a preparation method of a solid electrolyte, and the preparation method includes:

[0009] Dry-mixing a LATP solid raw material, an inorganic weak acid powder and an organic alcohol powder to obtain a mixed material; and sintering the mixed material to obtain a LATP solid electrolyte.

[0010] The preparation method of the present invention is a method for synthesizing a LATP solid electrolyte assisted by acid-base balance. By using the acid-base balance auxiliary materials, namely, an inorganic weak acid powder and an organic alcohol powder, the inorganic weak acid is used to reduce the alkalinity of the lithium source (such as lithium carbonate) in the LATP solid raw material, and the organic alcohol powder is used to lock the phosphorus source (such as phosphate) in the LATP solid raw material, reducing the local reaction and alleviating the intensity of the acid-base reaction, so as to ensure uniform mixing, mild, efficient and uniform reaction. At the same time, by replacing the long-time liquid-phase ball milling in the dispersion medium in the prior art with a specific dry-mixing method, the problems of segregation, insufficient reaction or side reactions caused by uneven distribution of multiple substances can be effectively avoided. And it can effectively shorten the mixing time, realize rapid mixing in a short time, avoid damage to the materials caused by long-time ball milling, and cause an increase in material differences. The preparation method is simple to operate, has a fast production speed, is easy to scale up, and can obtain a high-performance LATP solid electrolyte product with high ionic conductivity, having broad prospects.

[0011] The following are the preferred technical solutions of the present invention, but not the limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical purposes and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, based on the mass of the LATP solid raw material being 100%, the mass of the inorganic weak acid powder accounts for 0.1% - 1.5%, such as 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.23%, 0.25%, 0.28%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, etc., preferably 0.2% - 1.4%, and further preferably 0.4% - 1.2%.

[0013] As a preferred technical solution of the present invention, the inorganic weak acid powder includes at least one of boric acid, silicic acid, metasilicic acid or oxalic acid.

[0014] Preferably, the particle size D of the inorganic weak acid powder 50 is 10 nm - 50 μm, such as 10 nm, 25 nm, 50 nm, 75 nm, 100 nm, 300 nm, 500 nm, 800 nm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 28 μm, 30 μm, 33 μm, 35 μm, 38 μm, 40 μm, 45 μm, 48 μm or 50 μm, etc.

[0015] As a preferred technical solution of the present invention, based on the mass of the LATP solid raw material being 100%, the mass of the organic alcohol powder accounts for 0.1% - 1.5%, such as 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.23%, 0.25%, 0.28%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, etc., preferably 0.2% - 1.4%, and further preferably 0.4% - 1.2%.

[0016] Preferably, the organic alcohol powder includes at least one of polyvinyl alcohol, polyethylene glycol or polypropylene alcohol.

[0017] Preferably, the particle size D of the organic alcohol powder 50 is 10 nm - 50 μm, such as 10 nm, 25 nm, 50 nm, 75 nm, 100 nm, 300 nm, 500 nm, 800 nm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 28 μm, 30 μm, 33 μm, 35 μm, 38 μm, 40 μm, 45 μm, 48 μm or 50 μm, etc.

[0018] In the present invention, the reaction activity of the organic alcohol powder increases during the sintering process, but its molecular weight has little effect on the acid-base reaction. The relatively common and frequently used molecular weights of each substance can be applied to the present invention, but ultra-high molecular weights far exceeding the common market level should not be used. For example, the common molecular weight of polyvinyl alcohol is 16,000 - 200,000, and polyvinyl alcohol with an ultra-high degree of polymerization greater than 200,000 should not be used.

[0019] As a preferred technical solution of the present invention, the LATP solid raw material includes a lithium source, an aluminum source, a titanium source, and a phosphorus source.

[0020] Preferably, the lithium source includes at least one of lithium carbonate, lithium hydroxide, or lithium oxide.

[0021] Preferably, the aluminum source includes aluminum oxide and / or aluminum hydroxide.

[0022] Preferably, the titanium source includes titanium dioxide and / or titanate.

[0023] Preferably, the phosphorus source includes at least one of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, or ammonium phosphate.

[0024] Preferably, the mass dosage of the lithium source is in excess by 1% - 50%, such as 1%, 3%, 5%, 8%, 10%, 13%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 33%, 35%, 38%, 40%, 42%, 45%, 48%, or 50%, etc.

[0025] Preferably, the particle size D of the LATP solid raw material 50 is 10 nm - 100 μm, such as 10 nm, 25 nm, 50 nm, 75 nm, 100 nm, 300 nm, 500 nm, 800 nm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, or 100 μm, etc.

[0026] As a preferred technical solution of the present invention, the process of dry mixing includes first performing a first pre-dry mixing of the inorganic weak acid powder and the lithium source to obtain a mixture A, and simultaneously performing a second pre-dry mixing of the organic alcohol powder and the phosphorus source to obtain a mixture B, and then performing a dry mixing of the mixture A, the mixture B, the aluminum source, and the titanium source to obtain the mixed material;

[0027] Preferably, the time for the first pre-dry mixing and the second pre-dry mixing is ≤ 2 h, such as 2 h, 1.8 h, 1.5 h, 1.3 h, 1 h, 0.8 h, 0.5 h, 0.3 h, 0.2 h, 0.1 h, 5 min, 3 min or 1 min, etc., preferably 1 min to 1 h, and more preferably 1 min to 5 min.

[0028] As a preferred technical solution of the present invention, the time for dry mixing is ≤ 4 h, such as 4 h, 3.8 h, 3.5 h, 3.3 h, 3 h, 2.8 h, 2.5 h, 2.3 h, 2 h, 1.8 h, 1.5 h, 1.3 h, 1 h, 0.8 h, 0.5 h, 0.3 h, 0.2 h or 0.1 h, 5 min, 3 min or 1 min, etc., preferably 1 min to 3 h, and more preferably 2 min to 10 min.

[0029] Preferably, the equipment for dry mixing includes at least one of an agate mortar, a small juicer, a traditional Chinese medicine mixer, a ball mill, a V-shaped mixer or a high-speed mixer.

[0030] As a preferred technical solution of the present invention, the sintering temperature is 800 - 1000 °C, such as 800 °C, 830 °C, 850 °C, 880 °C, 900 °C, 920 °C, 940 °C, 960 °C, 980 °C or 1000 °C, etc., and the time is 2 - 6 h, such as 2 h, 2.3 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h, 4.2 h, 4.5 h, 4.8 h, 5 h, 5.3 h, 5.5 h, 5.8 h or 6 h, etc.

[0031] Preferably, the equipment for sintering includes at least one of a box furnace, a muffle furnace, a tube furnace, a pusher kiln or a roller hearth kiln.

[0032] In a second aspect, the present invention provides an LATP solid electrolyte obtained according to the preparation method described in the first aspect.

[0033] Preferably, the particle size D of the LATP solid electrolyte 50 is 50 nm to 10 μm, such as 50 nm, 65 nm, 75 nm, 85 nm, 95 nm, 100 nm, 150 nm, 230 nm, 300 nm, 360 nm, 420 nm, 500 nm, 660 nm, 740 nm, 800 nm, 850 nm, 900 nm, 960 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm, etc.

[0034] In a third aspect, the present invention provides a battery, and the battery contains the LATP solid electrolyte described in the second aspect.

[0035] It should be noted that due to space limitations and to avoid redundancy, the present invention does not exhaustively list all the point values within the above numerical range, nor is it limited only to the listed numerical values. Other unlisted numerical values within the above numerical range are equally applicable.

[0036] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0037] In the preparation method of the present invention, by using inorganic weak acid powder and organic alcohol powder as acid-base balance auxiliary materials, it is beneficial to reduce local reactions, moderate the intensity of acid-base reactions, ensure uniform mixing, and enable mild, efficient, and uniform reactions. At the same time, by replacing the long-time liquid-phase ball milling in the dispersion medium in the prior art with a specific dry-mixing method, problems such as segregation, insufficient reaction, or side reactions caused by uneven distribution of multiple substances can be effectively avoided. Moreover, it can effectively shorten the mixing time, achieve rapid mixing in a short time, and avoid damage to the materials caused by long-time ball milling, resulting in an increase in material differences. The preparation method is simple to operate, has a fast production speed, is easy to scale up, and can obtain high-performance LATP solid electrolytes with high ionic conductivity, having broad prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the EIS test chart of the LATP solid electrolyte obtained in Example 1.

[0039] Figure 2 It is the EIS test chart of the LATP solid electrolyte obtained in Example 4.

[0040] Figure 3 It is the EIS test chart of the LATP solid electrolyte obtained in Example 12.

[0041] Figure 4 It is the EIS test chart of the LATP solid electrolyte obtained in Comparative Example 1.

[0042] Figure 5 It is the EIS test chart of the LATP solid electrolyte obtained in Comparative Example 2.

[0043] Figure 6 It is the EIS test chart of the LATP solid electrolyte obtained in Comparative Example 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The technical solutions of the present invention will be further described below through specific embodiments.

[0045] Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0046] Example 1

[0047] This embodiment provides a preparation method of LATP solid electrolyte, and the preparation method includes:

[0048] Weigh 2640 g of lithium carbonate, 770 g of alumina, 6790 g of titanium dioxide, 17250 g of ammonium dihydrogen phosphate, 210 g of boric acid, and 210 g of polyvinyl alcohol in solid powder form. The particle sizes D of lithium carbonate, alumina, titanium dioxide, and ammonium dihydrogen phosphate 50 are all in the range of 10 nm to 100 μm, the particle size D of boric acid 50 is in the range of 10 nm to 50 μm, and the particle size D of polyvinyl alcohol 50 is in the range of 10 nm to 50 μm. That is, based on the total mass of lithium carbonate, alumina, titanium dioxide, and ammonium dihydrogen phosphate being 100%, the mass of boric acid accounts for 0.77%, and the mass of polyvinyl alcohol accounts for 0.77%. First, pre-mix lithium carbonate and boric acid for 3 minutes to form mixture A. At the same time, pre-mix only ammonium dihydrogen phosphate and polyvinyl alcohol for 3 minutes to form mixture B. Put mixture A, mixture B, and the remaining raw materials into a high-speed mixer for dry mixing for 5 minutes, end the mixing, and obtain the mixed material. Put the obtained mixed material into a sagger and sinter it in a sintering furnace. The sintering temperature is set at 900 °C, and the sintering time is 4 hours to obtain the LATP solid electrolyte.

[0049] Example 2

[0050] This embodiment provides a preparation method of LATP solid electrolyte. In this preparation method, the mass of boric acid is adjusted from 210 g to 15 g, so that the mass proportion of boric acid is adjusted from 0.77% to 0.055%. Except for the above, other conditions are exactly the same as those in Example 1.

[0051] Example 3

[0052] This embodiment provides a preparation method of LATP solid electrolyte. In this preparation method, the mass of boric acid is adjusted from 210 g to 60 g, so that the mass proportion of boric acid is adjusted to 0.22%. Except for the above, other conditions are exactly the same as those in Example 1.

[0053] Example 4

[0054] This embodiment provides a preparation method of LATP solid electrolyte. In this preparation method, the mass of boric acid is adjusted from 210 g to 120 g, so that the mass proportion of boric acid is adjusted to 0.44%. Except for the above, other conditions are exactly the same as those in Example 1.

[0055] Example 5

[0056] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of boric acid is adjusted from 210 g to 240 g, so that the mass ratio of boric acid is adjusted to 0.87%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0057] Embodiment 6

[0058] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of boric acid is adjusted from 210 g to 480 g, so that the mass ratio of boric acid is adjusted to 1.74%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0059] Embodiment 7

[0060] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of polyvinyl alcohol is adjusted from 210 g to 10 g, so that the mass ratio of polyvinyl alcohol is adjusted from 0.77% to 0.04%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0061] Embodiment 8

[0062] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of polyvinyl alcohol is adjusted from 210 g to 60 g, so that the mass ratio of polyvinyl alcohol is adjusted from 0.77% to 0.22%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0063] Embodiment 9

[0064] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of polyvinyl alcohol is adjusted from 210 g to 120 g, so that the mass ratio of polyvinyl alcohol is adjusted to 0.44%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0065] Embodiment 10

[0066] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of polyvinyl alcohol is adjusted from 210 g to 240 g, so that the mass ratio of polyvinyl alcohol is adjusted from 0.77% to 0.87%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0067] Embodiment 11

[0068] This embodiment provides a method for preparing an LATP solid electrolyte. In this preparation method, the mass of polyvinyl alcohol is adjusted from 210 g to 480 g, so that the mass ratio of polyvinyl alcohol is adjusted to 1.74%. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0069] Example 12

[0070] This example provides a preparation method of LATP solid electrolyte. In this preparation method, boric acid is replaced by oxalic acid, and polyvinyl alcohol is replaced by polyethylene glycol. Except for the above, other conditions are exactly the same as those in Example 1.

[0071] Example 13

[0072] This example provides a preparation method of LATP solid electrolyte. In this preparation method, boric acid is replaced by metasilicic acid, and polyvinyl alcohol is replaced by polypropylene alcohol. Except for the above, other conditions are exactly the same as those in Example 1.

[0073] Example 14

[0074] This example provides a preparation method of LATP solid electrolyte. In this preparation method, boric acid is replaced by silicic acid, and polyvinyl alcohol is replaced by polyethylene glycol. Except for the above, other conditions are exactly the same as those in Example 1.

[0075] Example 15

[0076] This example provides a preparation method of LATP solid electrolyte. In this preparation method, lithium carbonate, aluminum oxide, titanium dioxide, ammonium dihydrogen phosphate, boric acid and ammonium dihydrogen phosphate are simultaneously put into a high-speed mixer and dry-mixed for 8 minutes to obtain the mixed material. Except for the above, other conditions are exactly the same as those in Example 1.

[0077] Comparative Example 1

[0078] This comparative example provides a preparation method of LATP solid electrolyte. In this preparation method, boric acid and ammonium dihydrogen phosphate are not used. Except for the above, other conditions are exactly the same as those in Example 1.

[0079] Comparative Example 2

[0080] This comparative example provides a preparation method of LATP solid electrolyte. In this preparation method, ammonium dihydrogen phosphate is not used. Except for the above, other conditions are exactly the same as those in Example 1.

[0081] Comparative Example 3

[0082] This comparative example provides a preparation method of LATP solid electrolyte. In this preparation method, boric acid is not used. Except for the above, other conditions are exactly the same as those in Example 1.

[0083] Comparative Example 4

[0084] This comparative example provides a method for preparing LATP solid electrolyte. In this preparation method, lithium carbonate, aluminum oxide, titanium dioxide, ammonium dihydrogen phosphate, boric acid and ammonium dihydrogen phosphate are wet-milled using ethanol as a dispersion medium for 6 hours. After drying and pulverization, a mixed material is obtained. Except for the above, other conditions are exactly the same as those in Example 1.

[0085] The particle size D of the LATP solid electrolyte obtained in the examples and comparative examples was 50 tested.

[0086] The ionic conductivity of the LATP solid electrolyte obtained in the examples and comparative examples was tested. The LATP solid electrolyte powder was pressed into an electrolyte sheet under a certain pressure, and then the electrolyte sheet was sintered into a dense ceramic sheet. After spraying gold or brushing conductive silver paste on both sides, EIS testing was carried out using an electrochemical workstation to obtain its resistance value R. Then, according to the formula σ = L / (R×S) for calculation, the ionic conductivity can be obtained. Among them, L is the thickness (cm) of the electrolyte sheet during testing, and S is the area (cm 2 ) of the electrolyte sheet during testing.

[0087] Figures 1 to 6 Figures 1 to 6 are the EIS test diagrams of the LATP solid electrolytes obtained in Example 1, Example 4, Example 12, Comparative Example 1, Comparative Example 2 and Comparative Example 3 respectively. After obtaining the resistance value from them, the ionic conductivity was calculated according to the formula, and the obtained results and the results of other examples were recorded in Table 1.

[0088] Table 1

[0089]

[0090] It can be seen from Table 1 that: on the premise of using acid-base balance auxiliary materials, LATP electrolyte materials with high conductivity and low particle size can be obtained, which is helpful for the application of LATP electrolyte materials. However, adding too much or too little acid-base auxiliary materials will cause varying degrees of decrease in conductivity and increase in particle size.

[0091] In summary, the preparation method of the present invention uses an inorganic weak acid powder and an organic alcohol powder as acid-base balance auxiliary materials, which is beneficial to reducing local reactions, alleviating the intensity of acid-base reactions, ensuring uniform mixing, and enabling mild, efficient, and uniform reactions. At the same time, by replacing the long-term liquid-phase ball milling in a dispersion medium in the prior art with a specific dry-mixing method, problems such as segregation, insufficient reaction, or side reactions caused by uneven distribution of multiple substances can be effectively avoided. Moreover, it can effectively shorten the mixing time, achieve rapid mixing in a short time, and avoid damage to the materials caused by long-term ball milling, resulting in an increase in material differences. The preparation method is simple to operate, has a fast production speed, is easy to scale up, and can obtain a high-performance LATP solid electrolyte product with high ionic conductivity, having broad prospects. The preparation method of the present invention is of great significance for the synthesis of LATP through synchronous acid-base assistance, and the prepared nano-LATP is of great significance in the fields of cathode material coating and organic-inorganic composite electrolytes.

[0092] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0093] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable way. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0094] Furthermore, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a LATP solid electrolyte, characterized in that: The preparation method comprises: The LATP solid raw material, inorganic weak acid powder and organic alcohol powder are dry-mixed to obtain a mixed material; the mixed material is sintered to obtain a LATP solid electrolyte.

2. The method for preparing the LATP solid electrolyte according to claim 1, characterized in that: Taking the mass of the LATP solid raw material as 100%, the mass of the inorganic weak acid powder accounts for 0.1% to 1.5%; The inorganic weak acid powder includes at least one of boric acid, silicic acid, metasilicic acid or oxalic acid; The particle size D of the inorganic weak acid powder 50 10nm~50μm.

3. The method for preparing the LATP solid electrolyte according to claim 1, characterized in that: Taking the mass of the LATP solid raw material as 100%, the mass of the organic alcohol powder accounts for 0.1% to 1.5%; The organic alcohol powder includes at least one of polyvinyl alcohol, polyethylene glycol or polypropylene alcohol; The particle size D of the organic alcohol powder 50 10nm~50μm.

4. The method for preparing the LATP solid electrolyte according to claim 1, characterized in that: The LATP solid raw materials include lithium source, aluminum source, titanium source and phosphorus source; The lithium source includes at least one of lithium carbonate, lithium hydroxide or lithium oxide; the aluminum source includes aluminum oxide and / or aluminum hydroxide; the titanium source includes titanium dioxide and / or titanate; the phosphorus source includes at least one of ammonium dihydrogen phosphate, diammonium hydrogen phosphate or ammonium phosphate; The mass amount of the lithium source is in excess of 1% to 50%; The particle size D of the LATP solid raw material 50 10nm~100μm.

5. The method for preparing the LATP solid electrolyte according to claim 4, characterized in that: The dry mixing process includes first pre-dry mixing the inorganic weak acid powder with the lithium source to obtain a mixture A, and simultaneously pre-dry mixing the organic alcohol powder with the phosphorus source to obtain a mixture B, and then dry mixing the mixture A, the mixture B, the aluminum source and the titanium source to obtain the mixed material; The time for the first pre-dry mixing and the second pre-dry mixing is ≤ 2 hours.

6. The method for preparing the LATP solid electrolyte according to claim 1 or 5, characterized in that: The dry mixing time is ≤ 4h; The equipment used for the dry mixing includes at least one of an agate mortar, a small juicer, a Chinese medicine mixer, a ball mill, a V-shaped mixer or a high-speed mixer.

7. The method for preparing the LATP solid electrolyte according to claim 1, characterized in that: The sintering temperature is 800-1000°C and the sintering time is 2-6 hours; The equipment used for the sintering includes at least one of a box furnace, a muffle furnace, a tube furnace, a push plate kiln or a roller kiln.

8. A LATP solid electrolyte, characterized in that: Obtained according to the preparation method according to any one of claims 1 to 7.

9. The LATP solid electrolyte according to claim 8, characterized in that The particle size D of the LATP solid electrolyte 50 50nm~10μm.

10. A battery, characterized in that: Containing the LATP solid electrolyte according to claim 8 or 9.

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