Lithium ion solid electrolyte li-ta-v-o ceramic material and preparation method thereof

Abstract

The application belongs to the technical field of lithium ion battery solid electrolyte, discloses a lithium ion solid electrolyte Li-Ta-V-O ceramic material and a preparation method thereof. The main crystal phase of the lithium ion solid electrolyte Li-Ta-V-O ceramic material is composed of Ta9VO 25 and LiTa3O8; the ion conductivity of the lithium ion solid electrolyte Li-Ta-V-O ceramic material reaches 10 ‑4 S / cm order of magnitude in a room temperature environment. The application overcomes the technical problem that the preparation of general oxide type solid electrolyte needs to be sintered at high temperature for a long time, provides a method with simple preparation process, low required maximum production temperature, short sintering time and low production cost, and proposes a brand new lithium ion solid electrolyte Li-Ta-V-O ceramic material, which is expected to be applied in the preparation of lithium ion batteries.

Description

Technical Field

[0001] This invention belongs to the field of solid electrolyte technology for lithium-ion batteries, and specifically discloses the lithium-ion solid electrolyte Li-Ta-VO ceramic material and its preparation method. Background Technology

[0002] Electrochemical energy storage is more efficient and safer than traditional energy storage methods (such as electromagnetic and physical energy storage). Secondary batteries, in particular, are widely used in people's production and daily lives as portable electrochemical power sources. Common secondary batteries include lead-acid, sodium-sulfur, nickel-cadmium, and lithium-ion batteries. Among them, lithium-ion batteries, due to their high energy density and operating voltage, long cycle life, safety, and environmental friendliness, have been industrialized on a large scale since the 1990s due to their excellent intercalation-deintercalation properties.

[0003] With the development of the lithium battery industry, the market demand for rechargeable lithium batteries is increasing, and the annual production of lithium batteries is gradually increasing. Traditional lithium-ion batteries mainly consist of a positive electrode casing, positive electrode current collector, positive electrode sheet, separator, liquid organic electrolyte, negative electrode sheet, negative electrode current collector, and negative electrode casing. However, the internal liquid organic electrolyte poses many safety hazards, such as flammability, leakage, and volatility. During charging and discharging, lithium dendrites formed due to uneven lithium deposition can easily pierce the separator, leading to direct contact between the positive and negative electrodes, and potentially causing a short circuit and fire. In recent years, the number of lithium battery explosions and fires has been gradually increasing, highlighting the significant safety risks of traditional lithium-ion batteries. Replacing the separator and liquid electrolyte in traditional lithium batteries with solid-state electrolytes reduces the risk of short circuits and fires caused by lithium dendrite piercing, improving the safety of lithium batteries. Furthermore, solid-state lithium batteries can directly use lithium sheets as the negative electrode, greatly increasing the energy density of lithium batteries.

[0004] Solid electrolytes mainly include oxide solid electrolytes, sulfide solid electrolytes, and polymer solid electrolytes. Each of these materials has its own advantages and disadvantages. For example, although sulfide solid electrolytes have high ionic conductivity (around 10⁻⁶), they also have their own advantages and disadvantages. -3 -10 - 2 While its conductivity is between S / cm, it is overly sensitive to moisture and air, easily generating toxic gases, and its preparation cost is high, making industrialization difficult. Polymer solid electrolytes mainly include PEO-based, PAN-based, PVDF-based, PVP-based, and PMMA-based electrolytes. They possess excellent salt solubility and electrode interface compatibility, but they cannot suppress lithium dendrites and have low ionic conductivity, approximately 10. -9 -10 -6 S / cm.

[0005] The ionic conductivity of oxide-type solid electrolytes is approximately 10. -4 -10 -3S / cm, but oxide-type solid electrolytes generally require long-term sintering at high temperatures, resulting in higher costs and more complex production processes; such as Li7La3Zr2O 12 (LLZO) is a relatively popular oxide-type solid electrolyte in recent years. It has two phases: one is a stable tetragonal phase structure with the I41 / acd space group at low temperatures (with low ionic conductivity, approximately 2.3 × 10⁻⁶). -5 One is a stable cubic phase structure with the Ia3d space group at high temperatures (high ionic conductivity, approximately 3 × 10⁻⁶ S / cm), while the other is a stable cubic phase structure with the Ia3d space group at high temperatures (high ionic conductivity, approximately 3 × 10⁻⁶ S / cm). -4 The preparation process of cubic phase LLZO with high ionic conductivity (S / cm) includes: ball milling in a planetary ball mill for 12 hours, followed by preheating at 900℃ and 1125℃ and then repeating the ball milling process, and finally sintering at 1230℃ for 36 hours. The preparation process is complicated, requires high-end equipment, and has a high sintering temperature, making it difficult to produce on a large scale. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, this invention provides a lithium-ion solid electrolyte Li-Ta-VO ceramic material, its preparation method, and its applications. This invention provides a lithium-ion solid electrolyte material with high conductivity, wherein the main crystalline phase of this lithium-ion solid electrolyte material is Ta9VO. 25 Composed of LiTa3O8, it achieves an ionic conductivity of 10 at room temperature. -4 Li-Ta-VO ceramic materials, with a strength on the order of S / cm, are expected to be used in the preparation of lithium-ion batteries. Furthermore, this invention overcomes the technical problem that the preparation of general oxide-type solid electrolytes requires long-term sintering at high temperatures, and provides a method with a simple preparation process, low maximum production temperature, short sintering time, and low production cost.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A lithium-ion solid electrolyte Li-Ta-VO ceramic material, wherein the main crystalline phase of the lithium-ion solid electrolyte Li-Ta-VO ceramic material is Ta9VO 25 Composed of LiTa3O8; the lithium-ion solid electrolyte Li-Ta-VO ceramic material exhibits an ionic conductivity of 10 at room temperature. -4 With a conductivity on the order of S / cm, this invention provides a novel lithium-ion solid electrolyte Li-Ta-VO ceramic material, and its high ionic conductivity is expected to be applied in the preparation of lithium-ion batteries.

[0009] Preferably, the chemical formula is Ta9VO 25 The principal crystal phase belongs to the tetragonal crystal system, space group I-4(82), and the unit cell parameters are:

[0010] The main crystalline phase with the chemical formula LiTa3O8 belongs to the monoclinic crystal system, space group C12 / c1(15), and its unit cell parameters are: β=91.108(5)°.

[0011] This invention also protects the preparation method of the above-mentioned lithium-ion solid electrolyte Li-Ta-VO ceramic material, which can be prepared by solid-state method or aqueous solution method, thus using two methods to prepare the ceramic material.

[0012] Preferably, the solid-state method is prepared according to the following steps:

[0013] After mixing lithium-containing compounds, tantalum-containing compounds, and vanadium-containing compounds, they are subjected to a single-stage grinding process. The purpose of this single-stage grinding is to increase the contact area of ​​the particles and avoid incomplete reaction. After grinding, the mixture is preheated and sintered at 400-450℃ for 2-3 hours to fully ensure the solid-phase reaction of the raw materials and obtain a single-stage sintered product.

[0014] The first-stage sintered material is cooled to room temperature, and then a second-stage grinding is carried out. The purpose of the second-stage grinding is to increase the contact area of ​​the particles and ensure that the reaction is complete. After grinding, high-temperature sintering is carried out to provide the conditions for the reaction to occur and the energy required to form the target sample. The material is sintered at 830-850℃ for 6-8 hours to obtain the second-stage sintered material.

[0015] The sintered material from the second stage is cooled to room temperature, and then subjected to a third stage of grinding. The third stage of grinding increases the contact area of ​​the particles, ensuring a complete electrochemical reaction and yielding a lithium-ion solid electrolyte Li-Ta-VO ceramic material. In terms of reaction time, the longer the sintering time at the target temperature, the better, as it ensures a complete reaction. Shorter times will lead to incomplete reactions, resulting in more impurities in the material and making it impossible to obtain a relatively pure target sample. In terms of temperature, if the temperature is too low, there will not be enough energy to synthesize the target sample, while if the temperature is too high, the sample will shrink, sinter into lumps, and cannot be dispersed.

[0016] Preferably, the lithium-containing compound includes lithium carbonate, lithium nitrate, lithium hydroxide, lithium hydride, and lithium nitride; the tantalum-containing compound includes tantalum pentoxide, tantalum powder, tantalum carbide, tantalum nitride, and lithium tantalate; and the vanadium-containing compound includes vanadium pentoxide, ammonium metavanadate, and lithium vanadium oxide.

[0017] Preferably, the aqueous solution method is prepared according to the following steps:

[0018] Deionized water, tantalum ethanol, lithium nitrate, and ammonium metavanadate are mixed evenly and then dried to obtain the sample to be treated. Tantalum ethanol, lithium nitrate, and ammonium metavanadate are water-soluble lithium-containing compounds, tantalum-containing compounds, and vanadium-containing compounds, respectively. The three can be mixed evenly in water, which effectively increases the contact area between sample particles. Then, the grinding and sintering steps are repeated.

[0019] The sample to be treated was preheated and sintered at 360-410℃ for 2-3 hours to obtain a sintered material.

[0020] The first sintered material is cooled to room temperature, then the second sintering is continued, followed by high-temperature sintering at 790-810℃ for 6-8 hours to obtain the second sintered material.

[0021] The two-stage sintered material was cooled to room temperature and then subjected to three-stage grinding to obtain lithium-ion solid electrolyte Li-Ta-VO ceramic material. Compared with the solid-state method, the aqueous solution method can effectively increase the contact area of ​​sample particles, so the product preparation temperature can be reduced by 20-40°C from the maximum preheating and sintering temperature of the solid-state method.

[0022] Preferably, the stoichiometric ratio of the lithium-containing compound, tantalum-containing compound, and vanadium-containing compound is Li:Ta:V:O = 0.5–3:0.5–3:1–4:8–12; the stoichiometric ratio of the tantalum ethoxide, lithium nitrate, and ammonium metavanadate is Li:Ta:V:O = 0.5–3:0.5–3:1–4:8–12; further, the stoichiometric ratio of the lithium-containing compound, tantalum-containing compound, and vanadium-containing compound is Li:Ta:V:O = 1:2:1:8.

[0023] Preferably, the particle size of the first stage of grinding is 2-3 μm, the particle size of the second stage of grinding is 2-3 μm, and the particle size of the third stage of grinding is 5-7 μm.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The lithium-ion solid electrolyte Li-Ta-VO ceramic material prepared by this invention has high ionic conductivity, up to 10. -4 It has an efficiency on the order of S / cm and is suitable for solid-state lithium battery systems. Moreover, the raw materials are readily available, inexpensive, and pollution-free. The preparation process does not generate harmful gases or waste, making it environmentally friendly and green.

[0026] 2. The preparation method disclosed in this invention is carried out in an air atmosphere, and the preparation process is simple, thus requiring less sophisticated production equipment. The maximum temperature required for production is also lower, and the sintering time is shorter, resulting in simpler equipment requirements. This invention uses a high-temperature solid-state method to prepare a mixed-phase Li-Ta-VO ceramic material with high ionic conductivity, abbreviated as LTVO, in an air atmosphere. The maximum sintering temperature is much lower than that of LLZO, and the sintering time is significantly shortened, effectively reducing the requirements for production equipment and consuming less energy, making it suitable for large-scale production.

[0027] 3. This invention discloses a lithium-ion solid electrolyte Li-Ta-VO ceramic material and its preparation method. The main crystalline phase of this material is Ta9VO. 25 Composed of LiTa3O8 materials, LTVO exhibits high ionic conductivity at room temperature, reaching 10. -4 With a strength on the order of S / cm, this material has the potential to be used as a solid electrolyte material for lithium-ion batteries. Attached Figure Description

[0028] Figure 1 The impedance diagram is shown for the lithium-ion solid electrolyte Li-Ta-VO ceramic material of Example 1 of the present invention.

[0029] Figure 2 The image shows the XRD pattern of the lithium-ion solid electrolyte Li-Ta-VO ceramic material of Example 1 of the present invention. Detailed Implementation

[0030] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0031] A novel oxide-based solid electrolyte material with high ionic conductivity has been reported in the literature. Inspired by this material's structure, we observed that the small size of the PO4 groups in its framework structure leads to small voids, significantly hindering lithium-ion transport and limiting its conductivity. Therefore, we decided to replace the P atoms with larger V atoms and the PO4 groups with VO4 groups to synthesize a similar LiTa2VO8 compound. Logically, synthesizing a similar compound would enhance its ionic conductivity. Based on this consideration, we attempted to synthesize LiTa2VO8, but after considerable effort, we were unable to synthesize the target compound. However, we creatively synthesized a novel mixed-phase material, with its main phase consisting of Ta9VO4. 25 The composition of this oxide-based solid electrolyte material is LiTa3O8 and Li3TaO4. The results show that it exhibits good ionic conductivity, reaching 10 Ω·cm at room temperature. -4 With a conductivity on the order of S / cm, it meets the requirements for ionic conductivity of oxide-type solid electrolytes and has the potential to be used as a solid electrolyte material for lithium-ion batteries.

[0032] Looking at the preparation methods of the lithium-ion solid electrolyte Li-Ta-VO ceramic material in this application, whether it is the solid-state method or the aqueous solution method, the highest sintering temperature is only 850℃, which is lower than the preparation temperature of existing solid electrolytes. This solves the technical defects of high production cost and complex production process.

[0033] The technical solution of this application is illustrated below with specific embodiments:

[0034] Example 1

[0035] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0036] (1) Weigh Li2CO3, Ta2O5 and V2O5 according to the element stoichiometric ratio of Li:Ta:V:O=1:2:1:8, then put them into an agate mortar and grind them evenly with a grinding rod. Then put the sample into a ceramic crucible and put the crucible into a muffle furnace at 450℃ for preheating and sintering for 2 hours to obtain a sintered material.

[0037] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 850°C for 8 hours to obtain two sections of sintered material.

[0038] After the second-stage sintering material has been sintered for 4 hours, it is taken out and ground again. Then it is put into the muffle furnace for sintering again. After sintering, the sample is taken out and ground evenly to obtain the target sample lithium-ion solid electrolyte Li-Ta-VO ceramic material, abbreviated as LTVO.

[0039] Example 2

[0040] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0041] (1) Weigh LiOH, tantalum powder and LiVO3 according to the element stoichiometric ratio of Li:Ta:V:O=0.5:0.5:1:8, then put them into an agate mortar and grind them evenly with a grinding rod. Then put the sample into a ceramic crucible and sinter it in a muffle furnace at 400℃ for 3 hours to obtain a sintered material.

[0042] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 830℃ for 7 hours to obtain two sections of sintered material.

[0043] When the two-stage sintered material has been sintered for 4 hours, it is taken out and ground again, and then put into the muffle furnace for sintering. The sintered sample is taken out and ground evenly to obtain the target sample LTVO.

[0044] Example 3

[0045] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0046] (1) Weigh Li2CO3, LiTaO3 and NH4VO3 according to the element stoichiometric ratio of Li:Ta:V:O=3:3:4:10, then put them into an agate mortar and grind them evenly with a grinding rod. Then put the sample into a ceramic crucible and sinter it in a muffle furnace at 450℃ for 2.5h to obtain a sintered material.

[0047] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 840℃ for 8 hours to obtain two sections of sintered material.

[0048] When the two-stage sintered material has been sintered for 4 hours, it is taken out and ground again, and then put into the muffle furnace for sintering. The sintered sample is taken out and ground evenly to obtain the target sample LTVO.

[0049] Example 4

[0050] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0051] (1) Weigh tantalum ethanol, lithium nitrate and ammonium metavanadate according to the elemental stoichiometry of Li:Ta:V:O=1:2:1:8, then disperse them in deionized water, dry the water in the sample to obtain the sample to be treated, put the sample to be treated into a ceramic crucible, put the crucible into a muffle furnace at 400℃ for preheating and sintering for 2.5h to obtain a sintered material;

[0052] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 800℃ for 7 hours to obtain two sections of sintered material.

[0053] After the second-stage sintering material has been sintered for 4 hours, it is taken out and ground again. Then it is put into the muffle furnace for sintering again. After sintering, the sample is taken out and ground evenly to obtain the target sample lithium-ion solid electrolyte Li-Ta-VO ceramic material, abbreviated as LTVO.

[0054] Example 5

[0055] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0056] (1) Weigh tantalum ethanol, lithium nitrate and ammonium metavanadate according to the elemental stoichiometric ratio of Li:Ta:V:O=0.5:0.5:1:8, then disperse them in deionized water, dry the water in the sample to obtain the sample to be treated, put the sample to be treated into a ceramic crucible, put the crucible into a muffle furnace at 360℃ for preheating and sintering for 3h to obtain a sintered material;

[0057] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 810℃ for 6 hours to obtain two sections of sintered material.

[0058] When the second-stage sintered material has been sintered for 3 hours, it is taken out and ground again, and then put into the muffle furnace for sintering. After sintering, the sample is taken out and ground evenly to obtain the target sample lithium-ion solid electrolyte Li-Ta-VO ceramic material, abbreviated as LTVO.

[0059] Example 6

[0060] The preparation method of lithium-ion solid electrolyte Li-Ta-VO ceramic material includes the following steps:

[0061] (1) Weigh tantalum ethanol, lithium nitrate and ammonium metavanadate according to the elemental stoichiometric ratio of Li:Ta:V:O=3:3:4:12, then disperse them in deionized water, and then dry the water in the sample to obtain the sample to be treated. Put the sample to be treated into a ceramic crucible, and put the crucible into a muffle furnace at 410℃ for preheating and sintering for 2 hours to obtain a sintered material.

[0062] (2) Take out one section of sintered material, let it cool to a temperature suitable for grinding, continue grinding until uniform, then put it into a crucible and sinter it in a muffle furnace at 790℃ for 8 hours to obtain two sections of sintered material.

[0063] After the second-stage sintering material has been sintered for 4 hours, it is taken out and ground again. Then it is put into the muffle furnace for sintering again. After sintering, the sample is taken out and ground evenly to obtain the target sample lithium-ion solid electrolyte Li-Ta-VO ceramic material, abbreviated as LTVO.

[0064] In Examples 1-6 of this invention, lithium-ion solid electrolyte Li-Ta-VO ceramic materials were prepared with similar ionic conductivity. The LTVO prepared in Example 1 is used as an example for further study. The specific research methods and results are shown below:

[0065] Test method:

[0066] 1. Ionic conductivity test:

[0067] The ionic conductivity of solid electrolytes is generally calculated from an AC impedance diagram, using the following formula:

[0068]

[0069] In the formula: σtotal is the total conductivity, in S / cm; L is the thickness of the material, in cm; S is the area of ​​the material circle, in cm². 2 R is the impedance of the material, in Ω.

[0070] Weigh 1.5g of the LTVO sample from Example 1 and place it into a tableting mold with an inner diameter of 16mm. Place the mold on a tablet press (model 769YP-24B) and press at 20MPa for 10 minutes. Remove the pressed sample and place it in a muffle furnace for sintering at 850℃ for 1 hour. Remove the sintered tablet and smooth both sides with sandpaper. After polishing both sides flat, measure and record its thickness L (1.06mm) and radius r (15.8mm) using calipers. The LTVO sample will shrink during high-temperature sintering. Then, use the formula S = πr 2 Calculate the area of ​​the circular piece;

[0071] First, apply conductive silver paste to one side of the tablet, being careful not to let it flow to the sides. Then, place it in a muffle furnace and sinter at 350℃ for 5 minutes to dry and solidify the conductive silver paste. The drying and solidification temperature can be 300-400℃, maintained for 3-5 minutes. After the silver paste has solidified at high temperature, remove the tablet and repeat the same process on the other side. This yields the sample to be tested. Then, use an impedance meter to measure the impedance data of the tablet. Import the data into ZView software, fit a graph in ZView, export the fitted data, and generate a plot. Figure 1 The fitted image was used to generate an AC impedance diagram of the LTVO. From the diagram, the impedance value R of the LTVO was found to be approximately 300Ω. This value was used for calculation. The impedance value R was then substituted into the formula σ_total = L / RS. Before substituting, the thickness and area of ​​the material were measured. This allowed for the calculation of the ionic conductivity of the LTVO at room temperature, which was found to be approximately 1.8 × 10⁻⁶. -4 S / cm.

[0072] Figure 2 Ta9VO 25 XRD patterns of LiTa3O8, Li3TaO4, and Li-Ta-VO ceramic materials, using Ta9VO 25 A comparison was made between samples of Li3TaO4 and LiTa3O8 and lithium-ion solid electrolyte Li-Ta-VO ceramic materials. The main peak of the lithium-ion solid electrolyte Li-Ta-VO ceramic material is similar to that of Ta9VO. 25 The high peak overlap between Li3TaO4 and LiTa3O8 indicates that the main crystalline phase of the lithium-ion solid electrolyte Li-Ta-VO ceramic material includes Ta9VO. 25 It contains Li3TaO4, LiTa3O8, and some unknown glass phases.

[0073] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations. The above-described embodiments are merely preferred embodiments for fully illustrating the invention, and their scope of protection is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this invention are all within the scope of protection of this invention, which is defined by the claims.

Claims

1. A lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material, characterized in that, The main crystal phase of the lithium ion solid electrolyte Li-Ta-V-O ceramic material consists of Ta9VO 25 and LiTa3O8; the ion conductivity of the lithium ion solid electrolyte Li-Ta-V-O ceramic material reaches 10 -4 S / cm order of magnitude at room temperature. The lithium ion solid electrolyte Li-Ta-V-O ceramic material is prepared by a solid phase method or an aqueous solution method: The solid phase method is prepared according to the following steps: After the lithium-containing compound, the tantalum-containing compound and the vanadium-containing compound are mixed, a first-stage grinding is performed, and then a pre-sintering is performed to obtain a first-stage sintering product; The first-stage sintering product is cooled to room temperature, and then a second-stage grinding is performed, and a high-temperature sintering is performed to obtain a second-stage sintering product; The second-stage sintering product is cooled to room temperature, and then a third-stage grinding is performed to obtain the lithium ion solid electrolyte Li-Ta-V-O ceramic material; The aqueous solution method is prepared according to the following steps: The deionized water, the tantalum ethoxide, the lithium nitrate and the ammonium metavanadate are uniformly mixed, and then are dried to obtain a to-be-processed sample; The to-be-processed sample is pre-sintered to obtain a first-stage sintering product; The first-stage sintering product is cooled to room temperature, and then a second-stage grinding is performed, and a high-temperature sintering is performed to obtain a second-stage sintering product; The second-stage sintering product is cooled to room temperature, and then a third-stage grinding is performed to obtain the lithium ion solid electrolyte Li-Ta-V-O ceramic material.

2. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 1, wherein, The main crystal phase of the chemical formula Ta9VO 25 belongs to tetragonal system, space group I -4 (82), with cell parameters of a = 15.665(6) Å c = 3.821(3) Å; The main crystal phase with the chemical formula LiTa3O8 belongs to a monoclinic system, a space group C 12 / c 1 (15), and a unit cell parameter of a=9.410(1) Å, b=11.521(1) Å, c=5.0506(5) Å and β=91.108(5) °.

3. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 1, wherein, The lithium-containing compound includes lithium carbonate, lithium nitrate, lithium hydroxide, lithium hydride and lithium nitride; the tantalum-containing compound includes tantalum pentoxide, tantalum powder, tantalum carbide, tantalum nitride and lithium tantalate; and the vanadium-containing compound includes vanadium pentoxide, ammonium metavanadate and lithium vanadium oxide.

4. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 1, wherein, The pre-sintering condition of the solid phase method is sintering at 400-450 °C for 2-3 h; The high-temperature sintering condition is sintering at 830-850 °C for 6-8 h.

5. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 4, wherein, The pre-sintering condition of the aqueous solution method is sintering at 360-410 °C for 2-3 h; and the high-temperature sintering condition is sintering at 790-810 °C for 6-8 h.

6. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 1, wherein, The stoichiometric ratio of the lithium-containing compound, the tantalum-containing compound and the vanadium-containing compound is Li:Ta:V:O=0.5-3:0.5-3:1-4:8-12; The stoichiometric ratio of the tantalum ethoxide, the lithium nitrate and the ammonium metavanadate is Li:Ta:V:O=0.5-3:0.5-3:1-4:8-12.

7. The lithium ion solid-state electrolyte Li-Ta-V-0 ceramic material of claim 1, wherein, The particle size of the first-stage grinding is 2-3 μm, the particle size of the second-stage grinding is 2-3 μm, and the particle size of the third-stage grinding is 5-7 μm.

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