CN114804051A

CN114804051A - NASICON type solid electrolyte, preparation method and application thereof, and secondary battery

Info

Publication number: CN114804051A
Application number: CN202110130052.0A
Authority: CN
Inventors: 马朝晖; 付文浩; 王英杰; 张莹莹; 卜瑶; 李子坤; 任建国; 贺雪琴
Original assignee: BTR New Material Group Co Ltd
Current assignee: BTR New Material Group Co Ltd
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2022-07-29

Abstract

The application provides a NASICON type solid electrolyte, a preparation method, application and a secondary battery thereof, and relates to the technical field of solid electrolytes. The raw materials for preparing the NASICON type solid electrolyte comprise a first type raw material and a second type raw material, wherein the sintering activity of the first type raw material is higher than or equal to that of the second type raw material; the particle size D50 of the NASICON type solid electrolyte is 2-500 μm. The method and the device can reduce the introduction of metal impurities, the particle size of the prepared solid electrolyte is controllable, the processing speed is high, the mechanical action of high energy is not needed, the production cost can be reduced, and the production efficiency is improved.

Description

NASICON type solid electrolyte, preparation method and application thereof, and secondary battery

Technical Field

The application relates to the technical field of solid electrolytes, in particular to a NASICON type solid electrolyte, a preparation method, application and a secondary battery thereof.

Background

The NASICON type solid electrolyte has ultrahigh ionic conductivity, has the advantages of stable structure, wide electrochemical window, environmental friendliness and the like, has a wide working temperature range, and is widely concerned by people in related fields. The development of the solid electrolyte can solve the potential safety hazard of the battery and is beneficial to prolonging the service life of the battery.

The main methods for preparing the solid electrolyte at present comprise a high-temperature solid phase method, a sol-gel method and the like, wherein the high-temperature solid phase method has the problems of poor precursor mixing effect, high required phase forming temperature, serious energy consumption and the like although the process is simple. In addition, in the preparation process of the solid electrolyte, the prior art generally uses a mechanical crushing or breaking method to process large particles with larger size into small particle materials. However, the existing operation mode may cause product pollution in the operation process, such as metal impurities introduced in the mechanical crushing process, and the solid electrolyte with a specific size is difficult to obtain by the mechanical crushing mode. In order to improve the performance of the battery, it is desired to reduce impurities in the solid electrolyte material and to highly crystallize and micronize the solid electrolyte material.

For example, a method for producing crystal grains of LTP or LATP, which comprises crystallizing LATP in zinc phosphate and removing zinc phosphate particles with an acid. The acid used is hydrochloric acid or nitric acid of high concentration. When the scheme is used for preparing the LATP, the preparation cost of the material is greatly increased by adding a large amount of zinc phosphate, increasing and reducing the temperature for many times and treating strong acid. And the use of strong acid treatment can damage the LATP material, reducing its performance as a solid electrolyte. Further, for example, a method for producing a solid electrolyte of NASICON type, which synthesizes a NASICON structural material using a large amount of alkali metal hydroxide as molten salt, and then washes off the hydroxide with water. The excess hydroxide in this solution is simply washed out later as molten salt, which increases the production costs. In addition, when sodium hydroxide or potassium hydroxide is used as a molten salt, Na-NASICON material and K-NASICON material are contained in the product, which affects the lithium ion conductivity. There is thus a need for further improvements in the process for the preparation of NASICON-type solid electrolytes.

In view of this, it is desirable to find a simple, efficient and fast method capable of reducing the introduction of impurities and controlling the particle size to produce a NASICON-type solid electrolyte excellent in performance.

Disclosure of Invention

The invention aims to provide a NASICON type solid electrolyte, a preparation method, application and a secondary battery thereof, which can reduce the introduction of metal impurities, can control the particle size, can obtain the solid electrolyte with the particle size in a specific range, has higher processing speed, does not need high-energy mechanical action, can reduce the production cost and improve the production efficiency.

In order to achieve the purpose, the technical scheme adopted by the application is as follows:

according to a first aspect of the present application, there is provided a NASICON-type solid electrolyte whose raw material for production includes a first type raw material and a second type raw material, the sintering activity of the first type raw material being higher than or equal to the sintering activity of the second type raw material;

the particle size D50 of the NASICON type solid electrolyte is 2-500 μm.

In this aspect, by preparing a NASICON-type solid electrolyte using the first type raw material and the second type raw material, it is easier to control the crystal grain size of the synthesized material, and a solid electrolyte product with a controllable particle size or within a desired particle size range can be obtained. The solid electrolyte has the particle size D50 of 2-500 μm, has good processing and coating performances, and is more suitable for application on batteries.

In one possible implementation, the particle size D50 of the NASICON-type solid electrolyte is between 2.9 μm and 478 μm.

In one possible implementation, the NASICON-type solid electrolyte satisfies at least one of the following a to d:

a. the melting point of the first type of raw material is lower than or equal to the melting point of the second type of raw material;

b. the molar ratio of the first type of raw material to the second type of raw material is (1.05-3): 1;

c. the first raw material includes LiOH and Li ₂ HPO ₄ 、LiH ₂ PO ₄ 、LiNH ₃ HPO ₄ 、Al(OH) ₃ 、Al(H ₂ PO ₄ ) ₃ ·nH ₂ O、Ti(H ₂ PO ₄ ) ₄ 、(NH ₄ ) ₃ PO ₄ 、(NH ₄ ) ₂ HPO ₄ And NH ₄ H ₂ PO ₄ At least one of; the second type of raw material comprises Li ₂ CO ₃ 、Li ₃ PO ₄ 、Al ₂ O ₃ 、AlPO ₄ 、Al ₂ (P ₂ O ₇ ) ₃ 、TiO ₂ 、Ti ₃ (PO ₄ ) ₄ And Ti (P) ₂ O ₇ ) ₂ At least one of;

alternatively, the first raw material comprises NaOH and Na ₂ HPO ₄ 、NaH ₂ PO ₄ 、NaNH ₃ HPO ₄ 、Zr(H ₂ PO ₄ ) ₄ ·nH ₂ O、Zr(HPO ₄ ) ₂ ·nH ₂ O、Na ₂ Si ₃ (HO ₄ ) ₂ 、NaSi ₂ (HO ₂ ) ₃ 、NaSi ₈ H ₇ O ₂₀ And H ₂ SiO ₃ At least one of; the second type of raw material comprises Na ₂ CO ₃ 、Na ₃ PO ₄ 、ZrO ₂ 、ZrP ₂ O ₇ 、Zr ₂ P ₂ O ₉ And SiO ₂ At least one of;

d. the NASICON type solid electrolyte has a chemical formula as follows: li _1+x M _x N _2-x (PO ₄ ) ₃ Wherein x is more than or equal to 0.05 and less than or equal to 0.07, M comprises at least one of Al, Ga, Sc, Y, Ca, Sr, Zn and Si, and N comprises at least one of Ti, Ge and Zr;

alternatively, the NASICON-type solid electrolyte has the chemical formula: na (Na) _1+2w+x-y+z A _w B _x C _y D _2-w-x-y (SiO ₄ ) _z (PO ₄ ) _3-z Wherein w, x, y, z satisfy the following constraint conditions: 0 is more than or equal to 2w + x-y + z is less than or equal to 3, and 0 is more than or equal to w + x + y<2、0≤z<3; a comprises Cd ² ⁺ 、Mn ²⁺ 、Co ²⁺ 、Ni ²⁺ And Zn ²⁺ B comprises Al ³⁺ 、Ga ³⁺ 、In ³⁺ 、Sc ³⁺ 、Ti ³⁺ 、V ³⁺ 、Cr ³⁺ 、Fe ³⁺ 、Y ³⁺ 、La ³⁺ And Lu ³⁺ C comprises Si ⁴⁺ 、Ge ⁴⁺ 、Sn ⁴⁺ 、Ti ⁴⁺ 、Zr ⁴⁺ 、Hf ⁴⁺ 、V ⁴⁺ 、Nb ⁴⁺ And Mo ⁴⁺ D comprises V ⁵⁺ 、Nb ⁵⁺ 、Ta ⁵⁺ 、Sb ⁵⁺ And As ⁵⁺ At least one of (1).

According to a second aspect of the present application, there is provided a method for producing a NASICON-type solid electrolyte, comprising the steps of:

mixing a first type of raw material and a second type of raw material, and calcining to obtain an intermediate, wherein the sintering activity of the first type of raw material is higher than or equal to that of the second type of raw material;

carrying out liquid phase crushing on the intermediate to obtain a mixture;

and carrying out solid-liquid separation on the mixture to obtain the NASICON type solid electrolyte.

In the scheme, the first raw material and the second raw material are mixed and then calcined to obtain an intermediate with expected grain size, and the intermediate is subjected to liquid phase crushing, so that the introduction of metal impurities can be reduced, the treatment speed is high, a high-energy mechanical action is not required, the production cost can be reduced, and the production efficiency can be improved; and the particle size is controllable, and a solid electrolyte with a particle size in a specific range can be obtained.

In the method for producing a NASICON-type solid electrolyte, the sintering activity of the first type raw material and the second type raw material are different in some cases, and the sintering activity of the first type raw material is higher than that of the second type raw material. In other cases, the same type of sintering-active raw materials may be used, i.e., the first type of raw materials and the second type of raw materials have the same sintering activity, and in this case, the raw materials used are all raw materials having relatively low sintering activity (higher melting point).

Preferably, a first type of raw material and a second type of raw material having different sintering activities are mixed.

In one possible implementation, the preparation method satisfies at least one of the following conditions e to i:

e. the calcining temperature is 500-900 ℃;

f. the calcining time is 1-24 h;

g. the liquid phase crushing is to place the intermediate in a solution for treatment, and the treatment process comprises at least one of standing, stirring, shaking and ultrasound;

h. the liquid phase crushing time is 1 second to 1 month;

i. the solid-liquid separation comprises at least one of filtration, suction filtration, filter pressing, sedimentation, centrifugation, cleaning, drying, freeze drying and spray drying.

In one possible implementation, the solution comprises at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbons, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, or 1-methyl-2-pyrrolidone;

and/or, the solution comprises a solvent and a solute, wherein the solvent comprises at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbons, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, or 1-methyl-2-pyrrolidone;

and/or the solute comprises at least one of sodium hydroxide, lithium bicarbonate, sodium bicarbonate, nitric acid, hydrochloric acid, phosphoric acid, lithium carbonate, sodium carbonate, formic acid, acetic acid, ammonia, urea, or ethylenediamine;

and/or the concentration of the solute is 0.001-0.05 mol/L;

and/or the pH range of the solution is 4-10.

In one possible implementation, the agitation includes at least one of mechanical agitation, liquid convection agitation, and electromagnetic induction agitation;

and/or the mass ratio of the intermediate to the solution is 1: 1000-1000: 1.

it is to be noted that the above numerical ranges are inclusive of the endpoints.

According to a third aspect of the present application, there is provided a use of an NASICON-type solid electrolyte, which is the NASICON-type solid electrolyte as described above, or the NASICON-type solid electrolyte prepared according to the preparation method as described above, in the preparation of a secondary battery.

According to a fourth aspect of the present application, there is provided a secondary battery comprising the NASICON-type solid electrolyte as described above, or the NASICON-type solid electrolyte prepared according to the production method as described above.

Compared with the prior art, the technical scheme provided by the application can achieve the following beneficial effects:

according to the NASICON type solid electrolyte and the preparation method thereof, a first raw material and a second raw material which are different in sintering activity are mixed and then calcined to obtain an intermediate with an expected grain size, and then the intermediate is subjected to liquid phase crushing and solid-liquid separation in sequence to obtain the NASICON type solid electrolyte. The method replaces the existing mechanical crushing and smashing with a liquid phase smashing method, so that the introduction of metal impurities can be reduced, the production cost is reduced, and the production efficiency is improved; and the grain size of the product (intermediate) obtained by calcination can be controlled by using two types of raw materials with different sintering activities, and micron-sized particles with controllable particle sizes can be further obtained. Therefore, the method is simple to operate and easy to control, can reduce the introduction of metal impurities, improves the production efficiency and reduces the production cost.

The particle size D50 of the NASICON type solid electrolyte is in the range of 2-500 μm, has good processing and coating performances, and is more suitable for application on batteries.

A secondary battery comprising the NASICON-type solid electrolyte provided herein has at least all of the features and advantages of the NASICON-type solid electrolyte, and will not be described herein again.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

Fig. 1 is a comparative graph of XRD tests of NASICON-type solid electrolytes provided in example 1 and example 21 of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below with reference to the embodiments and examples of the team group. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. Those who do not specify the conditions are performed according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone.

In the present invention, unless otherwise stated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, including a and b, and both a and b are real numbers. For example, a range of values of "1 to 24" means that all real numbers between "1 to 24" have been listed herein, and "1 to 24" is only a shorthand representation of the combination of these values. The "ranges" disclosed herein may have one or more lower limits and one or more upper limits, respectively, in the form of lower limits and upper limits.

All the technical features mentioned herein, as well as preferred features, may be combined with each other to form new solutions, if not mentioned specifically. Unless defined or indicated otherwise, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art. In addition, any methods or materials similar or equivalent to those described herein can also be used in the present invention.

As will be appreciated by those skilled in the art, as the background art shows, the prior art has certain defects in the preparation of NASICON-type solid electrolytes, and the prior art generally uses mechanical crushing or pulverization methods to convert large particles into small particles, which causes problems such as easy pollution to products and difficulty in controlling the size of the particles.

Therefore, in order to overcome the defects of the prior art, the technical scheme of the embodiment of the invention provides an NASICON type solid electrolyte, a preparation method thereof, application of the solid electrolyte and a secondary battery comprising the solid electrolyte, so that the introduction of metal impurities is reduced, the particle size of the obtained product is controllable, the service performance of the NASICON type solid electrolyte is ensured, the method is simple and easy to operate, the production efficiency can be improved, and the production cost can be reduced.

Some embodiments of the present application provide a NASICON-type solid electrolyte whose preparation raw materials include a first type raw material and a second type raw material, the sintering activity of the first type raw material being higher than or equal to the sintering activity of the second type raw material. By using the first type of raw material and the second type of raw material to prepare a NASICON-type solid electrolyte, it is easier to control the grain size of the composite material, and a solid electrolyte product with a controllable particle size or within a desired particle size range can be obtained.

In some embodiments, the NASICON-type solid electrolyte has a particle size D50 of 2 μm to 500 μm. Further, the particle size D50 of the NASICON type solid electrolyte is 2.9 to 478 μm. Further, the particle size D50 of the NASICON type solid electrolyte is 4 to 120 μm. Typically, but not by way of limitation, the particle size D50 of the NASICON type solid electrolyte is, for example, 2 μm, 2.5 μm, 2.9 μm, 3 μm, 4.1 μm, 4.5 μm, 5 μm, 6.3 μm, 7.5 μm, 7.8 μm, 8.4 μm, 10 μm, 15 μm, 19.3 μm, 20 μm, 40 μm, 50 μm, 113.4 μm, 120 μm, 200 μm, 300 μm, 476.9 μm, 478 μm, 500 μm, etc., but is not limited to the values listed, and other non-listed values within this range of values are equally applicable.

The solid electrolyte has the particle size D50 of 2-500 μm, has good processing and coating performances, and is more suitable for application on batteries.

The NASICON type solid electrolyte provided by the embodiment of the application can be applied to a solid secondary battery, and is beneficial to design and assembly of the solid secondary battery.

In some embodiments, a secondary battery is provided that includes a NASICON-type solid electrolyte provided herein. Specific examples of the secondary battery include various kinds of solid-state secondary batteries such as a solid-state lithium ion secondary battery, a solid-state sodium ion secondary battery, and the like. It will be understood by those skilled in the art that the above-described secondary battery, such as a solid lithium ion secondary battery, is merely an example, and that the secondary battery may be other types of batteries without departing from the disclosure of the present application.

In order to obtain a NASICON-type solid electrolyte in the above-specified particle size range, which facilitates the design assembly of the solid secondary battery, the following method provided in the present application may be employed for preparation. Hereinafter, the NASICON-type solid electrolyte and the method for preparing the same will be further described in detail in conjunction with the method for preparing the NASICON-type solid electrolyte provided in the present application.

Specifically, an embodiment of the present application provides a method for preparing a NASICON-type solid electrolyte, including the steps of:

mixing a first type of raw materials and a second type of raw materials, and then calcining to obtain an intermediate with a desired grain size, wherein the sintering activity of the first type of raw materials is higher than or equal to that of the second type of raw materials;

carrying out liquid phase crushing on the intermediate to obtain a mixture;

It is noted that in the method for producing a NASICON-type solid electrolyte, in some cases, the sintering activities of the first type raw material and the second type raw material are different, and the sintering activity of the first type raw material is higher than that of the second type raw material, i.e., the first type raw material may be a high sintering activity raw material and the second type raw material may be a low sintering activity raw material. In other cases, the same type of sintering-active raw materials may be used, i.e., the first type of raw materials and the second type of raw materials have the same sintering activity, and in this case, the raw materials used are both raw materials with relatively low sintering activity (higher melting point), i.e., the first type of raw materials and the second type of raw materials are both low sintering-active raw materials.

The method is a preparation method of phosphate solid electrolyte powder with NASICON structure, and the method can control the grain size of a product (obtained intermediate) by controlling the selection of raw materials (preferably adopting raw materials with different sintering activities) and the calcination process; then, the NASICON type solid electrolyte with particles of a specific size can be obtained by the technology of liquid phase pulverization and solid-liquid separation.

The method avoids the problems of product pollution, low efficiency, high cost and the like in the traditional scheme of firstly calcining, then mechanically crushing and crushing. In addition, in the conventional preparation method, the particle size of the calcined product is not taken into consideration, but the particle size of the material can be reduced to some extent by using mechanical methods such as crushing, pulverizing, or ball milling, sand milling, etc. The preparation method of the embodiment of the invention aims to control the grain size of the calcined material, and then obtains a product with the same size as the grain size of the calcined material by reducing the mechanical strength of the grain boundary.

Specifically, the preparation method can be a method for preparing the phosphate fast ion conductor powder with the NASCION structure with specific size distribution, and comprises 5 steps of raw material design, precursor preparation, high-temperature calcination, liquid phase crushing and solid-liquid separation. The grain size of the calcined material can be changed through proper raw material proportioning design, and the bulk material is crushed to a specific grain diameter by a liquid phase crushing method, so that the grain size is controllable, the introduction of impurities is reduced, and the quality of the prepared product is improved.

[ design of raw materials ]

The raw material design mainly refers to that when the raw materials are selected, the raw materials are divided into two types or two types according to the physical and chemical properties of the raw materials, one type is a high sintering activity raw material, and the other type is a low sintering activity raw material. Exemplary, high sintering activity raw materials include, but are not limited to, ammonium dihydrogen phosphate, lithium hydroxide, aluminum dihydrogen phosphate, titanium dihydrogen phosphate, and the like; low sintering activity raw materials include, but are not limited to, lithium carbonate, titanium dioxide, alumina, titanium phosphate, aluminum phosphate, and the like. It should be understood that the above-mentioned high sintering activity raw material and low sintering activity raw material are relative terms, and the specific sintering activity of the present invention is not limited to the embodiment, and can be selectively adjusted and controlled by a person skilled in the art according to the actual situation.

The sintering activity is defined as whether or not the target product is easily obtained by the same sintering process, and generally, the sintering activity is high when the target product is easily obtained (for example, at a lower temperature and a shorter reaction time), whereas the sintering activity is low when the target product is not easily obtained.

In contrast, materials with lower melting points generally have the internal elements which are easier to diffuse at high temperature, and can be sintered at lower temperature in shorter time, namely, the sintering activity is higher; conversely, materials with higher melting points have lower sintering activity.

The method selects two types of raw materials with different sintering activities, adjusts the proportion of the raw materials with high sintering activity and the raw materials with low sintering activity, and can control the grain size of the synthetic material. And then the synthesized material is subjected to liquid phase crushing, such as water washing crushing, so that a product with controllable particle size can be obtained. The particle size D50 value of the product can be matched with the raw material ratio.

In detail, the reason for selecting two types of raw materials with different sintering activities is mainly that the grains inside the inorganic material grow continuously during the calcination process. The longer the calcination time and the higher the calcination temperature, the larger the final product grain size. Likewise, the sintering activity of the raw materials also affects the grain size. If the raw materials contain components with lower melting points, the sintering activity of the whole raw materials can be greatly improved, and grains with larger sizes can be obtained at lower calcining temperature and shorter calcining time. If the melting point of the material in the raw material is high, the elements are difficult to diffuse into each other during calcination, and a high calcination temperature and a long calcination time are required to obtain particles with a large size. Therefore, the invention can control the grain size of the composite material by selecting two types of raw materials with different sintering activities and adjusting the proportion of the raw materials with high sintering activity and the raw materials with low sintering activity, for example, the grain size can be in a micron order.

In an embodiment of the invention, the sintering activity of the first type of raw material is higher than the sintering activity of the second type of raw material, which may be characterized, for example, by the melting point of the material. In particular, the melting point of the first type of raw material is lower than the melting point of the second type of raw material.

Illustratively, some low melting point high sintering activity raw materials have melting points below 1000 ℃, and even some raw materials have melting points below the target product synthesis temperature. While some high melting point low sintering activity raw materials typically have melting points above 1000 c, or even some raw materials have melting points higher than the synthesis temperature of the target product.

The NASICON-type solid electrolyte described above includes a fast ion conductor material that may be Li-containing, or may be a Na-containing fast ion conductor material. Different fast ion conductor materials need to be selected from different first type raw materials and second type raw materials.

Specifically, in some embodiments, the NASICON-type solid-state electrolyte may be a Li-containing fast ion conductor material having the formula: li _1+x M _x N _2-x (PO ₄ ) ₃ Wherein x is more than or equal to 0.05 and less than or equal to 0.07, M comprises at least one of Al, Ga, Sc, Y, Ca, Sr, Zn and Si, and N comprises at least one of Ti, Ge and Zr.

The fast ion conductor material of Li comprises Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.05 < x < 0.9) (LATP) material, Li ₁₊ _x Ge _x Ti _2-x (PO ₄ ) ₃ (0.05 < x < 0.9) (LAGP), and the like.

Exemplarily, with Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.05 < x < 0.9) (LATP) material is described as an example. The raw materials are divided into two types, namely 'high sintering activity', namely a first type raw material and 'low sintering activity', namely a second type raw material. Wherein the second type of raw material comprises a high melting point Li salt such as Li ₂ CO ₃ 、Li ₃ PO ₄ Oxides of Al such asAl ₂ O ₃ 、AlPO ₄ 、Al ₂ (P ₂ O ₇ ) ₃ Oxides of Ti such as TiO ₂ 、Ti ₃ (PO ₄ ) ₄ 、Ti(P ₂ O ₇ ) ₂ Etc.; the first type of raw material comprises low melting point Li salts such as LiOH, Li ₂ HPO ₄ 、LiH ₂ PO ₄ 、LiNH ₃ HPO ₄ Phosphates of Al such as Al (OH) ₃ 、Al(H ₂ PO ₄ ) ₃ ·nH ₂ O, Ti phosphates such as Ti (H) ₂ PO ₄ ) ₄ Etc., also P-containing materials such as (NH) ₄ ) ₃ PO ₄ 、(NH ₄ ) ₂ HPO ₄ Or NH ₄ H ₂ PO ₄ And the like.

Precursor raw materials are prepared according to the target proportion of three elements of Al, Ti and P, and the Li content is X times of the target value (X is more than or equal to 1 and less than or equal to 1.2) when the Li-containing raw materials are selected. The molar ratio of the raw materials with high sintering activity and low sintering activity selected from the corresponding raw materials of Li, Al, Ti and P elements is not less than 1.

In the process of preparing the Li-containing fast ion conductor material, the addition amount of a first type raw material needs to be higher than that of a second type raw material, and specifically, in some embodiments, the molar ratio of the first type raw material to the second type raw material is (1.05-3): 1; for example, it may be 1.05: 1. 1.08: 1. 1.12: 1. 1.15: 1. 1.18: 1. 1.2: 1. 1.23: 1. 1.28: 1. 1.3: 1. 1.5: 1.2: 1. 3: 1, and any value in the range of any two of these point values.

It should be understood that, in the preparation of the Li-containing fast ion conductor material, the first and second raw materials listed above as exemplary are not to be considered as limitations on the first and second raw materials, and other raw materials may be selected in other embodiments, and are not described in detail herein.

In other embodiments, the NASICON-type solid electrolyte may be a Na-containing fast ion conductor material having the formula: na (Na) _1+2w+x-y+z A _w B _x C _y D _2-w-x-y (SiO ₄ ) _z (PO ₄ ) _3-z Wherein w, x, y, z satisfy the following constraint conditions: 0 is more than or equal to 2w + x-y + z is less than or equal to 3, and 0 is more than or equal to w + x + y<2、0≤z<3；

A comprises Cd ²⁺ 、Mn ²⁺ 、Co ²⁺ 、Ni ²⁺ And Zn ²⁺ B comprises Al ³⁺ 、Ga ³⁺ 、In ³⁺ 、Sc ³⁺ 、Ti ³⁺ 、V ³ ⁺ 、Cr ³⁺ 、Fe ³⁺ 、Y ³⁺ 、La ³⁺ And Lu ³⁺ C comprises Si ⁴⁺ 、Ge ⁴⁺ 、Sn ⁴⁺ 、Ti ⁴⁺ 、Zr ⁴⁺ 、Hf ⁴⁺ 、V ⁴⁺ 、Nb ⁴⁺ And Mo ⁴⁺ D is V ⁵⁺ 、Nb ⁵⁺ 、Ta ⁵⁺ 、Sb ⁵⁺ And As ⁵⁺ At least one of (1).

The fast ion conductor material of Na comprises Na _1+z Zr(SiO ₄ ) _z (PO ₄ ) _3-z Material, Na _1+z Hf(SiO ₄ ) _z (PO ₄ ) _3-z And the like.

Exemplarily, with Na _1+z Zr(SiO ₄ ) _z (PO ₄ ) _3-z Materials are described as examples. The raw materials are divided into two types, namely 'high sintering activity', namely a first type raw material and 'low sintering activity', namely a second type raw material. Wherein the second type of material comprises a high melting point Na salt such as Na ₂ CO ₃ 、Na ₃ PO ₄ ZrO of oxides of Zr ₂ Oxides containing P, e.g. ZrP ₂ O ₇ 、Zr ₂ P ₂ O ₉ Si-containing oxides such as SiO ₂ Etc.; the first raw material comprises low-melting Na salt such as NaOH and Na ₂ HPO ₄ 、NaH ₂ PO ₄ 、NaNH ₃ HPO ₄ Zr-containing raw materials such as Zr (H) ₂ PO ₄ ) ₄ ·nH ₂ O、Zr(HPO ₄ ) ₂ ·nH ₂ O, Si-containing material such as Na ₂ Si ₃ (HO ₄ ) ₂ 、NaSi ₂ (HO ₂ ) ₃ 、NaSi ₈ H ₇ O ₂₀ 、H ₂ SiO ₃ And the like.

Precursor raw materials are configured according to the target proportion of four elements of Na, Zr, P and Si, and the Na content of the selected Na-containing raw materials is X times of the target value (X is more than or equal to 1.1 and less than or equal to 1.5). The raw materials with high sintering activity and low sintering activity are selected from corresponding raw materials of Na, Zr, P and Si elements, and the ratio of the raw materials is X (X is more than 0 and less than or equal to 1).

It should be understood that, in the preparation of the Na-containing fast ion conductor material, the above exemplary listed first and second types of raw materials should not be considered as limitations to the first and second types of raw materials, and other raw materials may be selected in other embodiments, which are not described in detail herein.

In the embodiment of the present invention, the raw material used contains an alkali metal element in excess of the target proportion, preferably, the excess percentage is 0.1 to 50%, more preferably, 1 to 30%, and still more preferably, 2 to 8%.

[ preparation of precursor ]

The preparation of the precursor refers to preparing the first raw material and the second raw material according to the raw material proportioning scheme, and uniformly mixing the raw materials to obtain the precursor.

[ high temperature calcination ]

In the embodiment of the invention, the obtained precursor is calcined at high temperature to obtain the phosphate with the NASCION structure, namely the intermediate with expected grain size. The intermediate may be a bulk structure.

Specifically, in some embodiments, the calcination temperature is 500 to 900 ℃, further 550 to 850 ℃, further 600 to 800 ℃; typically, but not by way of limitation, the temperature of calcination may be, for example, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃ and any value in the range of any two of these values.

The calcining time is 1-24 h, further 1-12 h, further 2-6 h; typically, but not by way of limitation, the calcination time may be, for example, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h, 6h, 8h, 10h, 12h, 16h, 18h, 20h, 24h, and any value within a range defined by any two of these values.

[ liquid-phase pulverization ]

In the embodiment of the invention, the obtained intermediate is subjected to liquid phase crushing, the intermediate is placed in a solution for treatment, and the treatment process comprises any one or combination of at least two of standing, stirring, shaking and ultrasound.

The embodiment of the invention adopts liquid phase crushing, namely a method for crushing inorganic materials by liquid. The liquid phase crushing method needs to prepare a solution with specific components, and the aim of crushing the block material can be fulfilled by stirring the block material, namely the intermediate, in the solution according to a certain proportion.

For example, liquid phase crushing can be realized by stirring with deionized water for 0.5-3 h.

Specifically, in some embodiments, in the liquid phase pulverization, the solution may be a pure solution, or may be a solution containing a solvent and a solute. For example, in some cases, the solution is a pure solution including, but not limited to, at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbons, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, and 1-methyl-2-pyrrolidone. As yet another example, in other instances, the solution includes a solvent and a solute, wherein the solvent includes, but is not limited to, at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbons, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, and 1-methyl-2-pyrrolidone.

The solute includes, but is not limited to, at least one of sodium hydroxide, lithium bicarbonate, sodium bicarbonate, nitric acid, hydrochloric acid, phosphoric acid, lithium carbonate, sodium carbonate, formic acid, acetic acid, ammonia, urea, and ethylenediamine.

In some embodiments, in the liquid phase pulverization, the solution comprises a solvent and a solute, and the concentration of the solute is 0.001-0.05 mol/L, further can be 0.002-0.04 mol/L, further can be 0.005-0.03 mol/L; typically, but not by way of limitation, the solute concentration may be, for example, 0.001mol/L, 0.002mol/L, 0.003mol/L, 0.005mol/L, 0.006mol/L, 0.008mol/L, 0.01mol/L, 0.02mol/L, 0.03mol/L, 0.04mol/L, 0.05mol/L, or any value in the range of any two of these points.

In some embodiments, the solution pH range required for liquid phase comminution is between 4 and 10, preferably between 5 and 9.

In some embodiments, the liquid phase pulverization time is 1 second to 1 month, further may be 1min to 20 days, further may be 30min to 24 hours; typically, but not by way of limitation, the time for the liquid phase pulverization may be, for example, any value in the range of 1s, 30s, 1min, 10min, 30min, 60min, 1.5h, 2h, 3h, 5h, 10h, 20h, 1 day, 10 days, 20 days, 30 days, and any two of these values.

In some embodiments, the mass ratio of the intermediate to the solution is 1: 1000-1000: 1.

in some embodiments, the stirring manner is any one or a combination of at least two of mechanical stirring, liquid convection stirring and electromagnetic induction stirring.

Preferably, the standing time is 1 second to 1 month.

Preferably, the frequency range of the oscillation operation is 0.1-100 Hz, and the operation time is 1 second-1 month.

Preferably, the frequency of the ultrasonic operation is 0.02M-1 MHz, and the ultrasonic power is 0.1-10 kW per kilogram of sample.

It should be noted that the specific operation modes and operation parameter ranges of the ultrasonic wave, the oscillation and the like in the liquid phase pulverization can be adjusted and controlled by those skilled in the art according to actual situations, and the embodiments of the present invention are not limited thereto and will not be described in detail herein.

[ solid-liquid separation ]

In the embodiment of the invention, the mixture obtained by crushing the liquid phase is subjected to solid-liquid separation, and the target product NASICON type solid electrolyte can be obtained.

Specifically, in some embodiments, the solid-liquid separation comprises any one or a combination of at least two of filtration, suction filtration, pressure filtration, sedimentation, centrifugation, washing, drying, freeze drying and spray drying.

It should be noted that the specific operation modes and operation parameter ranges of the filtration, suction filtration, pressure filtration and the like in the solid-liquid separation are controllable by those skilled in the art according to actual situations, and the embodiments of the present invention are not limited thereto and will not be described in detail herein.

As can be seen from the above description, in view of the potential contamination of the product during current operations, such as mechanical crushing, metal impurities can be introduced. The embodiment of the invention uses a liquid phase stirring and crushing method to replace mechanical crushing and crushing, can reduce the introduction of metal impurities, has higher processing speed, does not need high-energy mechanical action, reduces the production cost and improves the production efficiency. And different types of precursors, namely raw materials with different sintering activities are mixed and then sintered, and then the material with the specific particle size can be prepared by a liquid phase crushing method. Compared with the traditional ball milling, sand milling, air flow crushing and other methods, the method is simpler, and can greatly save the processing cost.

The following examples are intended to illustrate the invention in more detail. The embodiments of the present invention are not limited to the following specific examples. The present invention can be modified and implemented as appropriate within the scope of the main claim.

In the following examples and comparative examples, the method for testing the properties of the materials comprises:

the particle size distribution of the sample was characterized using a laser particle sizer manufactured by Malvern.

The crystal structure of the sample was characterized using an X-ray diffractometer from PANalytical.

And testing the content of the elements in the sample by adopting an ICP-AES method.

Example 1

The chemical formula of the NASICON type solid electrolyte is as follows: li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ 。

Mixing a first raw material with high sintering activity and a second raw material with low sintering activity according to a certain proportion, and then calcining for 2 hours at 850 ℃ to obtain an intermediate;

carrying out liquid phase crushing on the intermediate, wherein the solution used in the liquid phase crushing is 0.001mol/L LiOH aqueous solution, and the crushing process is to stir the LATP material in the solution for 1h to obtain a mixture;

and centrifuging and drying the obtained mixture to obtain LATP powder. The operating conditions of example 1 are shown in table 1.

In example 1, the molar ratio of the raw materials required per mole of the NASICON-type solid electrolyte is as follows:

starting material NH of the first kind ₄ H ₂ PO ₄ Is 3.0, the amount of total material of the first type of raw material is 3.0; second type raw material Li ₂ CO ₃ In a molar ratio of 0.6858, Al ₂ O ₃ In a molar ratio of 0.15, TiO ₂ Is 1.7 and the total amount of the second type of starting material is 2.53. The molar ratio of the first type of raw material to the second type of raw material was 1.18.

The particle size D50 of the material obtained in example 1 was 4.5. mu.m.

Examples 2 to 3

Examples 2 to 3 are each a NASICON type solid electrolyte, which is different from example 1 in that the calcination time is 10 hours and 20 hours, respectively, and the rest is the same as example 1, and the specific operating conditions are shown in Table 1.

The specific raw material selection of examples 2-3 was the same as in example 1.

The particle size D50 of the material obtained in example 2 was 8.4. mu.m.

The particle size D50 of the material obtained in example 3 was 19.3 μm.

Examples 4 to 5

Examples 4 to 5 are each a NASICON type solid electrolyte, which is different from example 1 in that the calcination temperatures are 750 ℃ and 950 ℃ respectively, and the operation conditions are the same as those in example 1, and are shown in Table 1.

The specific raw material selection of examples 4-5 was the same as in example 1.

The particle size D50 of the material obtained in example 4 was 6 μm.

The particle size D50 of the material obtained in example 5 was 45 μm.

Examples 6 to 8

Examples 6 to 8 are each a NASICON type solid electrolyte, which is different from example 1 in the solution used for liquid phase pulverization, and practical examples 6 to 8 are each 0.01mol/L aqueous LiOH solution, 0.05mol/L aqueous LiOH solution and 0.002mol/L HNO solution ₃ The aqueous solution and the rest were the same as in example 1, and the specific operating conditions are shown in Table 1.

The specific raw material selection for examples 6-8 was the same as in example 1.

The particle size D50 of the material obtained in example 6 was 8.1. mu.m.

The particle size D50 of the material obtained in example 7 was 7.8. mu.m.

The particle size D50 of the material obtained in example 8 was 7.5. mu.m.

Examples 9 to 12

Examples 9 to 12 are each a NASICON type solid electrolyte, and they are different from example 1 in that the liquid phase pulverization process is different, the liquid phase pulverization time in practical example 9 is 0.1 hour, stirring, shaking and ultrasonication are used in the liquid phase pulverization process in practical example 10, only LATP is left in solution in the liquid phase pulverization process in practical example 11 without using shaking, stirring or ultrasonication, the liquid phase pulverization time in practical example 12 is 5 hours, and the rest are the same as example 1, and the specific operating conditions are shown in table 1.

The specific raw material selection for examples 9-12 was the same as in example 1.

The particle size D50 of the material obtained in example 9 was 113.4. mu.m.

The particle size D50 of the material obtained in example 10 was 7.6. mu.m.

The particle size D50 of the material obtained in example 11 was 476.9 μm.

The particle size D50 of the material obtained in example 12 was 6.2. mu.m.

Examples 13 to 15

Examples 13 to 15 are each a NASICON type solid electrolyte differing from example 1 in the composition, and examples 13 to 15 are each a NASICON type solid electrolyte of Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ 、Li _1.5 Al _0.5 Ti _1.5 (PO ₄ ) ₃ And Li _1.6 Al _0.6 Ti _1.4 (PO ₄ ) ₃ The specific operating conditions are shown in Table 1.

The specific raw material selection of example 13 was: low sintering activity material Li ₂ CO ₃ 0.735 (molar ratio), Al ₂ O ₃ 0.2、TiO ₂ 1.6, low sintering activity material total mass 2.54; high sintering activity material NH ₄ H ₂ PO ₄ 3.0, total mass of high sintering activity material 3.0; the molar ratio of high sintering activity/low sintering activity raw material is 1.18.

The specific raw material selection of example 14 is: low sintering activity material Li ₂ CO ₃ 0.7875 (molar ratio), Al ₂ O ₃ 0.15、TiO ₂ 1.5, low sintering activity material total mass 2.44; high sintering activity material NH ₄ H ₂ PO ₄ 3.0, total mass of high sintering activity material 3.0; the molar ratio of high sintering activity/low sintering activity raw material is 1.23.

The specific raw material selection of example 15 is: low sintering activity material Li ₂ CO ₃ 0.84 (molar ratio), Al ₂ O ₃ 0.1、TiO ₂ 1.4, lowThe total mass of sintered active material 2.34; high sintering activity material NH ₄ H ₂ PO ₄ 3.0, total mass of high sintering activity material 3.0; the molar ratio of high sintering activity/low sintering activity raw material is 1.28.

The particle size D50 of the material obtained in example 13 was 8.2. mu.m.

The particle size D50 of the material obtained in example 14 was 7.4. mu.m.

The particle size D50 of the material obtained in example 15 was 8.5. mu.m.

Examples 16 to 20

Examples 16 to 20 are each a NASICON type solid electrolyte, which is different from example 1 in the selection of raw materials and is the same as example 1 except that the specific raw material types and operation conditions of examples 16 to 20 are shown in Table 1.

In example 16, the molar ratio of raw materials required per mole of NASICON-type solid electrolyte was: second type raw material Li ₂ CO ₃ In a molar ratio of 0.0325, Li ₃ PO ₄ In a molar ratio of 0.4333, AlPO ₄ Is 0.3, Ti ₃ (PO ₄₎₄ Is 0.5667 and the total amount of the second type of starting material is 1.33.

In example 17, the molar ratio of raw materials required per mole of NASICON-type solid electrolyte was: second type raw material Li ₂ CO ₃ In a molar ratio of 0.14, Li ₃ PO ₄ In a molar ratio of 0.3833, Al ₂ O ₃ In a molar ratio of 0.05, AlPO ₄ Is 0.05, Al ₂ (P ₂ O ₇ ) ₃ In a molar ratio of 0.05, TiO ₂ Is 0.4, Ti ₃ (PO ₄ ) ₄ In a molar ratio of 0.1667, Ti (P) ₂ O ₇ ) ₂ Is 0.4 and the total amount of the second type of raw material is 1.64.

In example 18, the molar ratio of the raw materials required per unit mole of the NASICON type solid electrolyteComprises the following steps: TiO as a second raw material ₂ Is 1.2, the total amount of the second type of raw material is 1.2; the molar ratio of LiOH as a first raw material is 0.97, and Li ₂ HPO ₄ In a molar ratio of 0.2, LiH ₂ PO ₄ Is 0.1, LiNH ₃ HPO ₄ In a molar ratio of 0.1, Al (OH) ₃ Is 0.2, Al (H) ₂ PO ₄ ) ₃ ·nH ₂ O is 0.1, Ti (H) ₂ PO ₄ ) ₄ Is 0.5, (NH) ₄ ) ₃ PO ₄ Is 0.1, (NH) ₄ ) ₂ HPO ₄ Is 0.1, NH ₄ H ₂ PO ₄ Is 0.1, the total amount of the first type of raw material is 2.47; the molar ratio of the first type of raw material to the second type of raw material was 2.05.

In example 19, the molar ratio of raw materials required per mole of NASICON-type solid electrolyte was: TiO as a second raw material ₂ Is 1.4, the amount of total material of the second type of raw material is 1.4; the molar ratio of LiOH as a first raw material is 0.17, and Li ₂ HPO ₄ In a molar ratio of 1, LiH ₂ PO ₄ Is 0.1, LiNH ₃ HPO ₄ In a molar ratio of 0.1, Al (OH) ₃ Is 0.2, Al (H) ₂ PO ₄ ) ₃ ·nH ₂ O is 0.1, Ti (H) ₂ PO ₄ ) ₄ Is 0.3, (NH) ₄ ) ₃ PO ₄ Is 0.1, (NH) ₄ ) ₂ HPO ₄ Is 0.1, NH ₄ H ₂ PO ₄ Is 0.1, the amount of total mass of the first type of starting material is 2.27; the molar ratio of the first type of raw material to the second type of raw material was 1.62.

In example 20, the molar ratio of raw materials required per mole of NASICON-type solid electrolyte was: TiO as a second raw material ₂ Is 1.7, the amount of total material of the second type of raw material is 1.7; the first raw material LiOH has the molar ratio of 0.17 and Li ₂ HPO ₄ Has a molar ratio of 1 to LiH ₂ PO ₄ In a molar ratio of 0.1, LiNH ₃ HPO ₄ In a molar ratio of 0.1 to Al (OH) ₃ Has a molar ratio of 0.2 to Al (H) ₂ PO ₄ ) ₃ ·nH ₂ The molar ratio of O is 0.1 and (NH) ₄ ) ₃ PO ₄ Is 0.5, (NH) ₄ ) ₂ HPO ₄ Is 0.5, NH ₄ H ₂ PO ₄ Is 0.5, the amount of total mass of the first type of starting material is 3.17; the molar ratio of the first type of raw material to the second type of raw material was 1.86.

The particle size D50 of the material obtained in example 16 was 4.1. mu.m.

The particle size D50 of the material obtained in example 17 was 2.9. mu.m.

The particle size D50 of the material obtained in example 18 was 37.6. mu.m.

The particle size D50 of the material obtained in example 19 was 24.6. mu.m.

The particle size D50 of the material obtained in example 20 was 16.9. mu.m.

Example 21

Specific operating conditions for example 21 are shown in table 1. The specific raw material selection of example 21 was the same as in example 1.

Example 21 is different from example 1 in that 1mol/L nitric acid aqueous solution was used for liquid phase pulverization. The final LATP particle size D50 was 2.8 μm.

However, as can be seen from the XRD results in FIG. 1, decomposition of LATP occurred in the product obtained in example 21. Example 21 does not yield the expected LATP product compared to example 1. Thus, it was demonstrated that suitable liquid phase pulverization conditions contribute to obtaining a desired solid electrolyte product.

Comparative example 1

In comparative example 1, the conventional method for producing a NASICON-type solid electrolyte was used, the raw material ratio and the calcination process were the same as in example 1, but in contrast to example 1, the calcined sample was not subjected to liquid-phase pulverization, and instead, LATP was pulverized by a roll crusher and then by a mechanical pulverizer, and the finally obtained LATP particle size D50 was 15.6 μm.

Comparative example 2

In this comparative example 2, the preparation of the solid electrolyte was carried out in the manner of the molten salt mentioned in the background art. The method uses excessive sodium hydroxide as molten salt, the usage amount is the ratio of the chemical valence of the total metal ions to 1.2:1, and the raw material is Li ₂ CO ₃ 、TiO ₂ 、Al ₂ O ₃ 、NH ₄ H ₂ PO ₄ As a starting material. The raw materials are uniformly mixed, calcined at 850 ℃ for 5h and then cooled. Then washing with deionized water for 5 times, and drying to obtain the product.

The ICP test showed that the product obtained in comparative example 2 had a Na content of 5.41% and a high impurity content.

The calcined product of example 1 and the final product of example 1 were tested for the content of transition metals in the final product of comparative example 1, and the test results are shown in table 2.

As can be seen from table 2, compared to example 1, the use of the scheme of comparative example 1 increases the content of impurity elements such as Fe, and the resulting product has a larger particle size. As can be seen from the results of table 2, the total impurity content in comparative example 1 is about 3.8 times that of example 1. Thus, the method of the present invention can reduce the introduction of metal impurities, reduce the content of metal impurities, and ensure the performance of the obtained solid electrolyte material.

TABLE 1 specific operating conditions for the examples and comparative examples

Table 2 results of element content test in samples of example 1 and comparative example 1

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

It is noted that a portion of this patent application contains material which is subject to copyright protection. The copyright owner reserves copyright rights except for copies of patent documents or patent document contents of records at the patent office.

Claims

1. A NASICON-type solid electrolyte characterized in that a preparation raw material of the NASICON-type solid electrolyte includes a first type raw material and a second type raw material, the sintering activity of the first type raw material being higher than or equal to the sintering activity of the second type raw material;

the particle size D50 of the NASICON type solid electrolyte is 2-500 μm.

2. The NASICON-type solid electrolyte according to claim 1, wherein the particle size D50 of the NASICON-type solid electrolyte is 2.9 μm to 478 μm.

3. The NASICON-type solid electrolyte according to claim 1 or 2, characterized in that the NASICON-type solid electrolyte satisfies at least one of the following a to d:

alternatively, the first raw material comprises NaOH and Na ₂ HPO ₄ 、NaH ₂ PO ₄ 、NaNH ₃ HPO ₄ 、Zr(H ₂ PO ₄ ) ₄ ·nH ₂ O、Zr(HPO ₄ ) ₂ ·nH ₂ O、Na ₂ Si ₃ (HO ₄ ) ₂ 、NaSi ₂ (HO ₂ ) ₃ 、NaSi ₈ H ₇ O ₂₀ And H ₂ SiO ₃ At least one of (a); the second type of raw material comprises Na ₂ CO ₃ 、Na ₃ PO ₄ 、ZrO ₂ 、ZrP ₂ O ₇ 、Zr ₂ P ₂ O ₉ And SiO ₂ At least one of;

alternatively, the NASICON-type solid electrolyte has the chemical formula: na (Na) _1+2w+x-y+z A _w B _x C _y D _2-w-x-y (SiO ₄ ) _z (PO ₄ ) _3-z Wherein w, x, y, z satisfy the following constraint conditions: 0 is more than or equal to 2w + x-y + z is less than or equal to 3, and 0 is more than or equal to w + x + y<2、0≤z<3; a comprises Cd ²⁺ 、Mn ²⁺ 、Co ²⁺ 、Ni ²⁺ And Zn ²⁺ B comprises Al ³⁺ 、Ga ³⁺ 、In ³⁺ 、Sc ³⁺ 、Ti ³⁺ 、V ³⁺ 、Cr ³⁺ 、Fe ³⁺ 、Y ³⁺ 、La ³⁺ And Lu ³⁺ C comprises Si ⁴⁺ 、Ge ⁴⁺ 、Sn ⁴⁺ 、Ti ⁴⁺ 、Zr ⁴⁺ 、Hf ⁴⁺ 、V ⁴⁺ 、Nb ⁴⁺ And Mo ⁴⁺ D comprises V ⁵⁺ 、Nb ⁵⁺ 、Ta ⁵⁺ 、Sb ⁵⁺ And As ⁵⁺ At least one of (1).

4. A preparation method of the NASICON type solid electrolyte is characterized by comprising the following steps:

carrying out liquid phase crushing on the intermediate to obtain a mixture;

5. The method for producing the NASICON-type solid electrolyte according to claim 4, wherein the NASICON-type solid electrolyte satisfies at least one of the following a to d:

6. The method for producing the NASICON-type solid electrolyte according to claim 4 or 5, wherein the method satisfies at least one of the following e to i:

e. the calcining temperature is 500-900 ℃;

f. the calcining time is 1-24 h;

h. the liquid phase crushing time is 1 second to 1 month;

7. The method for preparing a NASICON-type solid electrolyte according to claim 6, wherein the solution includes at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbon, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, and 1-methyl-2-pyrrolidone;

and/or the pH range of the solution is 4-10;

and/or, the solution comprises a solvent and a solute, wherein the solvent comprises at least one of water, ethanol, isopropanol, acetone, ethyl acetate, cyclohexane, halogenated hydrocarbons, diethyl ether, ethylenediamine, trimethyl phosphate, dimethyl sulfoxide, dimethylformamide, and 1-methyl-2-pyrrolidone; the solute comprises at least one of sodium hydroxide, lithium bicarbonate, sodium bicarbonate, nitric acid, hydrochloric acid, phosphoric acid, lithium carbonate, sodium carbonate, formic acid, acetic acid, ammonia, urea and ethylenediamine;

and/or the concentration of the solute is 0.001 mol/L-0.05 mol/L.

8. The method for producing a NASICON-type solid electrolyte according to claim 6, wherein the agitation includes at least one of mechanical agitation, liquid convection agitation, and electromagnetic induction agitation;

and/or the mass ratio of the intermediate to the solution is 1: 1000-1000: 1.

9. use of an NASICON-type solid electrolyte in the manufacture of a secondary battery, wherein the NASICON-type solid electrolyte is the NASICON-type solid electrolyte according to any one of claims 1 to 3, or the NASICON-type solid electrolyte manufactured by the manufacturing method according to any one of claims 4 to 8.

10. A secondary battery comprising the NASICON-type solid electrolyte according to any one of claims 1 to 3 or the NASICON-type solid electrolyte obtained by the production method according to any one of claims 4 to 8.