A lithium fluoride ceramic target, a method of manufacturing the same, and use thereof

Abstract

The application relates to a lithium fluoride ceramic target material and a preparation method and use thereof, the preparation method comprises the following steps: uniformly mixing lithium fluoride and a binder solution to obtain a precursor, performing die pressing or dry pressing forming on the precursor, and then performing cold isostatic pressing forming to obtain a green body; performing pressureless sintering on the green body to obtain a sintered body, and performing HIP post-treatment on the sintered body to obtain the lithium fluoride ceramic target material; in the application, the HIP post-treatment process is added to remove defects such as apparent porosities in the grain boundary region of the sintered body without introducing any sintering aids, and the lithium fluoride ceramic target material with high density is obtained. The lithium fluoride ceramic target material with high density can be obtained by combining the pressureless sintering and the HIP post-treatment, the density of the lithium fluoride ceramic target material prepared by the application is 97%-99%.

Description

Technical Field

[0001] This invention relates to the field of fluoride ceramics technology, and in particular to a lithium fluoride ceramic target, its preparation method, and its applications. Background Technology

[0002] Fluoride and oxide ceramic targets are widely used in high-tech fields. Fluoride targets, such as magnesium fluoride and calcium fluoride, perform exceptionally well in optical lenses and window materials due to their high refractive index and low dispersion properties. Oxide targets, such as alumina and zirconium oxide, are often used to manufacture cutting tools and wear-resistant coatings due to their high hardness and wear resistance. Furthermore, these ceramic targets play an important role in the semiconductor, photovoltaic, and data storage industries, used to prepare thin films and coatings to improve product performance and durability. Regarding the research on ceramic target preparation methods, existing technologies have disclosed methods for preparing oxide ceramics using pressureless sintering, vacuum hot pressing, and cold sintering. Among these, pressureless sintering can significantly reduce production costs, but relying solely on temperature as a sintering aid is insufficient to achieve complete densification of the ceramic, resulting in porosity defects in the grain boundary regions. If hot pressing is used, the use of graphite molds can easily cause carbon contamination of the sample, and because hot pressing involves unidirectional pressure, uneven pressure distribution within the green body during sintering can easily lead to preferred orientation of the microstructure.

[0003] Hot isostatic pressing (HIP) has two types: encased and unencased. Encased HIP involves placing metal powder or a compact within an encasing material and sealing it under vacuum. Isostatic pressure is applied in all directions using an inert gas (N2, Ar, etc.), combined with high temperature, ultimately achieving densification. Unencased HIP involves placing a sintered body with a relative density greater than 93% and no open pores into the high-pressure vessel of a hot isostatic press. Densification is achieved through the combined action of high temperature and high pressure. Unencased HIP is also known as HIP post-processing, which is the method used in this invention.

[0004] Higher density ceramic targets generally mean fewer internal pores and a more uniform microstructure, which significantly impacts target performance. High-density ceramic targets offer advantages such as improved film quality, enhanced mechanical strength, improved electrical properties, improved thermal stability, reduced raw material waste, enhanced chemical stability, improved wear resistance, and improved optical performance. In optical applications, high-density targets can provide more uniform films, thereby improving optical properties such as transmittance and reflectivity.

[0005] Therefore, improving the density of the target material is of great significance for enhancing film performance, extending the lifespan of the target material, and reducing production costs. In practical applications, the density of the target material can be improved by optimizing the sintering process, such as controlling the sintering temperature, time, and atmosphere. Furthermore, using high-purity raw materials, fine grinding and sieving of powders, premixing, and drying are also important factors in improving the quality of the target material.

[0006] With the development of lithium-ion battery technology, the beneficial properties of lithium fluoride materials for batteries have received increasing attention. Among them, introducing lithium fluoride into the interface between the electrode and the solid electrolyte can significantly improve the ion conduction at the interface, thereby improving the performance of lithium-ion batteries. Therefore, there is an urgent need to develop a lithium fluoride ceramic target with high density, which will facilitate the formation of a complete lithium fluoride film with uniform thickness during the process of introducing lithium fluoride into lithium-ion batteries.

[0007] In the preparation of fluoride ceramic targets, common methods include pressureless sintering assisted by sintering aids and vacuum hot pressing sintering. However, the relative density of LiF ceramic targets prepared by these methods is only around 94%, which is relatively low. Therefore, how to provide a lithium fluoride ceramic target with high density and its preparation method has become an urgent problem to be solved. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a lithium fluoride ceramic target material, its preparation method, and its applications. The preparation method of the lithium fluoride ceramic target material of the present invention does not require the introduction of any sintering aids. The green blank is first pre-fired in a pressureless high-temperature environment, and then post-treatment by HIP can effectively reduce or eliminate defects such as residual pores inside the material, adjust the phase composition and microstructure of the material, thereby improving the density of the lithium fluoride ceramic material and enhancing its overall performance.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for preparing a lithium fluoride ceramic target, the method comprising the following steps:

[0011] A precursor is obtained by uniformly mixing lithium fluoride and a binder solution. The precursor is then molded or dry-pressed and cold isostatically pressed to obtain a green body. The green body is then pressurelessly sintered to obtain a sintered body. The sintered body is then subjected to HIP post-treatment to obtain a lithium fluoride ceramic target.

[0012] This invention obtains a high-density lithium fluoride ceramic target by adding a HIP (High-Intensity Intercalation) post-treatment process to remove defects such as visible pores in the grain boundary region of the sintered body without introducing any sintering aids. Existing technologies generally use a hot-pressing sintering step, which results in carburization and reduced material purity; furthermore, this sintering method has high equipment requirements and higher manufacturing costs. This invention, however, uses a sintering method combining pressureless sintering and HIP post-treatment. Pressureless sintering has relatively simple equipment and process requirements and lower production costs; simultaneously, it can produce a sintered body with a certain microstructure; the subsequent HIP heat treatment process can effectively eliminate open pores, thus obtaining a high-density lithium fluoride ceramic target.

[0013] The HIP post-processing method used in this invention is hot isostatic pressing without a casing. Compared with traditional hot isostatic pressing, this method reduces manufacturing costs and process difficulty.

[0014] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0015] Preferably, the temperature of the HIP post-processing is 600℃-750℃, for example, it can be 600℃, 650℃, 700℃ or 750℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] This invention further controls the HIP post-treatment temperature to 600℃-750℃. The HIP post-treatment temperature affects the density of the lithium fluoride ceramic target and needs to be combined with pressureless sintering. The melting point of lithium fluoride is 845℃. If the HIP post-treatment temperature is too high, the ceramic material may undergo over-sintering, resulting in abnormal grain growth. In addition, the high-temperature environment places higher demands on the equipment, which may lead to increased energy consumption and thus increased production costs. If the HIP post-treatment temperature is too low, the binder phase of the pre-sintered ceramic particles may not diffuse sufficiently, resulting in uneven microstructure and a decline in ceramic performance.

[0017] Preferably, the pressure of the HIP post-treatment is 70MPa-100MPa, for example, it can be 70MPa, 75MPa, 80MPa, 85MPa, 90MPa, 95MPa or 100MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] Preferably, the HIP post-processing time is 1h-5h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] Preferably, the lithium fluoride is dried and sieved before mixing.

[0020] Preferably, the drying temperature is 50℃-90℃, for example, it can be 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0021] Preferably, the drying time is 2h-20h, for example, it can be 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h or 20h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the average particle size of the lithium fluoride obtained after the sieving process is 50nm-100nm, for example, it can be 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] This invention further controls the average particle size of the lithium fluoride raw material to be 50nm-100nm, thereby obtaining a uniform and highly dense lithium fluoride ceramic target. If lithium fluoride material with an average particle size lower than 50nm is selected, the excessively fine particles are prone to adsorbing a large amount of gas, which hinders the contact between particles and thus hinders sintering. If lithium fluoride material with an average particle size higher than 100nm is selected, the diffusion path of coarse particles is longer and the atomic diffusion rate is slower, requiring higher sintering temperature and longer sintering time to achieve the same sintering effect.

[0024] Preferably, the concentration of the adhesive solution is 1wt%-5wt%, for example, it can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, or 5wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the adhesive solution comprises a PVA solution or ethanol.

[0026] The purpose of using a binder in this invention is to enable rapid molding of lithium fluoride.

[0027] Preferably, the binder solution accounts for 0.5wt%-5wt% of the precursor by mass, for example, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, or 5wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, the pressure of the cold isostatic pressing is 50MPa-250MPa, for example, it can be 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 110MPa, 120MPa, 130MPa, 140MPa, 150MPa, 160MPa, 170MPa, 180MPa, 190MPa, 200MPa, 210MPa, 220MPa, 230MPa, 240MPa or 250MPa, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0029] In this invention, the pressure during molding or dry pressing is adjusted according to the size of the mold or the size of the sample. The purpose of this step is to shape the powder sample and reduce the gaps between powder particles.

[0030] Preferably, the cold isostatic pressing time is 30-60 minutes, for example, it can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] Preferably, the pressureless sintering temperature is 500℃-700℃, for example, it can be 500℃, 550℃, 600℃, 650℃ or 700℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] This invention further controls the pressureless sintering temperature range to 500℃-700℃. If the pressureless sintering temperature is too high, the grain growth rate will increase significantly, and residual gases in the raw materials (such as moisture, volatile organic compounds, etc.) will be released by thermal decomposition and cannot be discharged in time. As the grain boundaries migrate, these gases become trapped inside the grains, resulting in a decrease in the density of the material and a deterioration in its performance. If the pressureless sintering temperature is too low, the powder particles will not receive enough energy to overcome the interparticle barriers, leading to insufficient sintering driving force. This will affect the diffusion and rearrangement between particles, hindering the sintering densification process and making it difficult to form a compact structure.

[0033] Preferably, the heating rate of the pressureless sintering is 1℃ / min-10℃ / min, for example, it can be 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0034] Preferably, the pressureless sintering time is 1h-5h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:

[0036] Lithium fluoride was dried at 50℃-90℃ for 2h-20h and then sieved to obtain lithium fluoride with an average particle size of 50nm-100nm.

[0037] A precursor is obtained by uniformly mixing lithium fluoride with an average particle size of 50nm-100nm and a PVA solution with a concentration of 1wt%-5wt%, wherein the binder solution accounts for 0.5wt%-5wt% of the precursor by mass fraction; the precursor is then molded or dry-pressed, and then cold isostatically pressed at 50MPa-250MPa for 30min-60min to obtain a green blank.

[0038] The green blank is heated to 500℃-700℃ at a heating rate of 1℃ / min-10℃ / min and sintered without pressure for 1h-5h to obtain a sintered body. The sintered body is then subjected to HIP post-treatment at 600℃-750℃ and 70MPa-100MPa for 1h-5h to obtain a lithium fluoride ceramic target with a density of 97%-99%.

[0039] In a second aspect, the present invention provides a lithium fluoride ceramic target material, which is prepared according to the preparation method of the lithium fluoride ceramic target material described in the first aspect, and the density of the lithium fluoride ceramic target material is 97%-99%.

[0040] The lithium fluoride ceramic target prepared by this invention has a density of over 97.0%, significantly improving the density of the lithium fluoride ceramic target. For example, the density can be 97.0%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8%, 97.9%, 98.0%, 98.1%, 98.2%, 98.3%, 98.4%, 98.5%, 98.6%, 98.7%, 98.8%, 98.9%, or 99%; but it is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0041] Thirdly, the present invention provides an application of a lithium fluoride ceramic target, which is used in the fields of lithium-ion batteries or optical materials; the lithium fluoride ceramic target is prepared according to the lithium fluoride ceramic target described in the second aspect, or according to the preparation method of the lithium fluoride ceramic target described in the first aspect.

[0042] The lithium fluoride ceramic target prepared by this invention has high density, which greatly improves the uniformity and efficiency of the coating during the use of the target, enabling it to play a stable and efficient role in the fields of lithium-ion batteries and optical materials.

[0043] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] (1) Without introducing any sintering aids, the present invention can obtain high-density lithium fluoride ceramic targets by adopting a sintering method that combines pressureless sintering with HIP post-treatment. HIP post-treatment can remove defects such as visible pores in the grain boundary region of the sintered body and obtain lithium fluoride ceramic targets with higher density.

[0046] (2) The density of the lithium fluoride ceramic target prepared by the present invention is above 97.0%, which significantly improves the density of the lithium fluoride ceramic target and greatly improves the uniformity and efficiency of the coating during the use of the target, enabling it to play a stable and efficient role in the fields of lithium-ion batteries and optical materials. Attached Figure Description

[0047] Figure 1 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Embodiment 1 of the present invention;

[0048] Figure 2 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Embodiment 2 of the present invention;

[0049] Figure 3 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Embodiment 3 of the present invention;

[0050] Figure 4 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Embodiment 4 of the present invention;

[0051] Figure 5 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Comparative Example 1 of this invention.

[0052] Figure 6 This is a cross-sectional SEM image of the lithium fluoride ceramic target material in Comparative Example 2 of this invention. Detailed Implementation

[0053] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0054] In the following embodiments, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the art; unless otherwise specified, the experimental preparation methods and techniques used are conventional preparation methods and techniques in the art.

[0055] Example 1

[0056] This embodiment provides a method for preparing a lithium fluoride ceramic target, the method comprising the following steps:

[0057] Lithium fluoride was dried at 80℃ for 8 hours and then sieved to obtain lithium fluoride with an average particle size of 60 nm.

[0058] A precursor is obtained by uniformly mixing lithium fluoride with an average particle size of 60 nm and a PVA solution with a concentration of 2.5 wt%. The binder solution accounts for 3 wt% of the precursor by mass. The precursor is then molded or dry-pressed and cold isostatically pressed at 150 MPa for 35 min to obtain a green preform.

[0059] The green blank was heated to 600℃ and sintered without pressure for 3 hours at a heating rate of 5℃ / min to obtain a sintered body. The sintered body was then subjected to HIP post-treatment at 650℃ and 50MPa for 3 hours to obtain a lithium fluoride ceramic target.

[0060] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 1 As shown.

[0061] Example 2

[0062] This embodiment provides a method for preparing a lithium fluoride ceramic target, the method comprising the following steps:

[0063] Lithium fluoride was dried at 60℃ for 18 hours and then sieved to obtain lithium fluoride with an average particle size of 50 nm.

[0064] A precursor is obtained by uniformly mixing lithium fluoride with an average particle size of 50 nm and a PVA solution with a concentration of 1 wt%. The binder solution accounts for 5 wt% of the precursor by mass. The precursor is then molded or dry-pressed and cold isostatically pressed at 50 MPa for 60 min to obtain a green preform.

[0065] The green blank was heated to 650℃ and sintered without pressure for 3 hours at a heating rate of 1℃ / min to obtain a sintered body. The sintered body was then subjected to HIP post-treatment at 700℃ and 80MPa for 5 hours to obtain a lithium fluoride ceramic target.

[0066] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 2 As shown.

[0067] Example 3

[0068] This embodiment provides a method for preparing a lithium fluoride ceramic target, the method comprising the following steps:

[0069] Lithium fluoride was dried at 90℃ for 5 hours and then sieved to obtain lithium fluoride with an average particle size of 100 nm.

[0070] A precursor is obtained by uniformly mixing lithium fluoride with an average particle size of 100 nm and a PVA solution with a concentration of 5 wt%. The binder solution accounts for 1 wt% of the precursor by mass. The precursor is then molded or dry-pressed and cold isostatically pressed at 250 MPa for 30 min to obtain a green preform.

[0071] The green blank was heated to 700℃ and sintered without pressure for 1 hour at a heating rate of 10℃ / min to obtain a sintered body. The sintered body was then subjected to HIP post-treatment at 750℃ and 60MPa for 1 hour to obtain a lithium fluoride ceramic target.

[0072] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 3 As shown.

[0073] Example 4

[0074] This embodiment provides a method for preparing lithium fluoride ceramic targets, which differs from Example 1 only in that lithium fluoride with an average particle size of 300 nm is obtained after sieving.

[0075] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 4 As shown.

[0076] Example 5

[0077] This embodiment provides a method for preparing lithium fluoride ceramic targets, which differs from Embodiment 1 only in that the HIP sintering temperature is set at 550°C.

[0078] Example 6

[0079] This embodiment provides a method for preparing lithium fluoride ceramic targets, which differs from Embodiment 1 only in that the HIP post-treatment temperature is 800°C.

[0080] Comparative Example 1

[0081] This comparative example provides a method for preparing a lithium fluoride ceramic target, which differs from Example 1 only in that it does not perform HIP post-treatment.

[0082] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 5 As shown in the figure, there are a large number of pores.

[0083] Comparative Example 2

[0084] This comparative example provides a method for preparing a lithium fluoride ceramic target. The only difference from Example 1 is that pressureless sintering is replaced by hot pressing sintering, and the pressure of the hot pressing sintering is 30 MPa.

[0085] The cross-sectional SEM image of the prepared lithium fluoride ceramic target is shown below. Figure 6 As shown.

[0086] Test method: The relative density of the lithium fluoride ceramic targets prepared in Examples 1-6 and Comparative Examples 1-2 was determined by Archimedes' displacement method. The results are shown in Table 1 below.

[0087] Table 1

[0088] Density / % Example 1 97.2 Example 2 97.9 Example 3 98.3 Example 4 92.1 Example 5 90.2 Example 6 95.5 Comparative Example 1 88 Comparative Example 2 96.6

[0089] The test results show that:

[0090] (1) As can be seen from Examples 1-3, the present invention can obtain high-density lithium fluoride ceramic targets by adopting a sintering method that combines pressureless sintering and HIP post-treatment. HIP post-treatment can remove defects such as visible pores in the grain boundary region of the sintered body and obtain lithium fluoride ceramic targets with high density. The density of the prepared lithium fluoride ceramic targets is all above 97.0%.

[0091] (2) By comparing Example 1 and Example 4, it can be seen that the present invention obtains a uniform and dense lithium fluoride ceramic target by further controlling the average particle size of the raw material lithium fluoride to 50nm-100nm. If lithium fluoride material with an average particle size higher than 100nm is selected, the large particles of lithium fluoride material are not easy to form a dense material during pressureless sintering.

[0092] (3) By comparing Example 1 with Examples 5-6, it can be seen that the present invention further controls the temperature of HIP post-treatment to 600℃-750℃. The temperature of HIP post-treatment will affect the density of lithium fluoride ceramic target. The melting point of lithium fluoride is 845℃. If the temperature of HIP post-treatment is too high, it will increase the cost of equipment maintenance and replacement. If the temperature of HIP post-treatment is too low, it will be difficult to effectively eliminate pores and defects under low temperature sintering conditions.

[0093] (4) As can be seen from Example 1 and Comparative Example 1, if HIP post-treatment is not performed, the density of the prepared lithium fluoride ceramic target is only 88%, which cannot achieve the technical effect of improving the density of the lithium fluoride ceramic target.

[0094] (5) As can be seen from Example 1 and Comparative Example 2, when pressureless sintering is replaced by hot pressing sintering, the density of the prepared lithium fluoride ceramic target is not much different from that of the hot pressing sintering method. However, the hot pressing sintering method requires higher equipment and is more complicated. At the same time, the use of graphite molds during sintering causes carburization, which is not as simple and cost-effective as the preparation method of the present invention.

[0095] In summary, this invention can obtain high-density lithium fluoride ceramic targets by using a sintering method that combines pressureless sintering with HIP post-treatment without introducing any sintering aids. HIP post-treatment can remove defects such as visible pores in the grain boundary region of the sintered body, resulting in lithium fluoride ceramic targets with high density. The density of the prepared lithium fluoride ceramic targets is all above 97.0%.

[0096] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a lithium fluoride ceramic target, characterized in that, The preparation method includes the following steps: A precursor is obtained by mixing lithium fluoride with a uniform average particle size of 50nm-100nm and a binder solution. The precursor is then molded or dry-pressed, followed by cold isostatic pressing to obtain a green body. The green body is then pressurelessly sintered at 500℃-700℃ to obtain a sintered body. The sintered body is then subjected to HIP post-treatment at 600℃-750℃ to obtain a lithium fluoride ceramic target. The HIP post-treatment is unencapsulated hot isostatic pressing sintering. The pressure of the HIP post-treatment is 70MPa-100MPa; the time of the HIP post-treatment is 1h-5h; The concentration of the binder solution is 1wt%-5wt%; the binder solution includes PVA solution or ethanol; the mass fraction of the binder solution in the precursor is 0.5wt%-5wt%. The pressure of the cold isostatic pressing is 50MPa-250MPa; the time of the cold isostatic pressing is 30min-60min; The heating rate of the pressureless sintering is 1℃ / min-10℃ / min; the pressureless sintering time is 1h-5h.

2. The preparation method according to claim 1, characterized in that, The lithium fluoride was dried and sieved before mixing.

3. The preparation method according to claim 2, characterized in that, The drying temperature is 50℃-90℃.

4. The preparation method according to claim 2, characterized in that, The drying time is 2h-20h.

5. The preparation method according to claim 1, characterized in that, The preparation method includes the following steps: Lithium fluoride was dried at 50℃-90℃ for 2h-20h and then sieved to obtain lithium fluoride with an average particle size of 50nm-100nm. A precursor is obtained by uniformly mixing lithium fluoride with an average particle size of 50nm-100nm and a PVA solution with a concentration of 1wt%-5wt%, wherein the binder solution accounts for 0.5wt%-5wt% of the precursor by mass fraction; the precursor is then molded or dry-pressed, and then cold isostatically pressed at 50MPa-250MPa for 30min-60min to obtain a green preform. The green blank is heated to 500℃-700℃ at a heating rate of 1℃ / min-10℃ / min and sintered without pressure for 1h-5h to obtain a sintered body. The sintered body is then subjected to HIP post-treatment at 600℃-750℃ and 70MPa-100MPa for 1h-5h to obtain a lithium fluoride ceramic target with a density of 97%-99%.

6. A lithium fluoride ceramic target, characterized in that, The lithium fluoride ceramic target is prepared by the method of preparing lithium fluoride ceramic target according to any one of claims 1-5, and the density of the lithium fluoride ceramic target is 97%-99%.

7. An application of the lithium fluoride ceramic target according to claim 6, characterized in that, The lithium fluoride ceramic target is used in the fields of lithium-ion batteries or optical materials.

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