Zirconium magnesium phosphate solid electrolyte target material annealing method, target material, and battery

Abstract

The application relates to an annealing method of a thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target material, a solid electrolyte target material and a battery, and belongs to the technical field of magnesium batteries. After four-stage heat preservation, the annealing method is adopted to cool the furnace to 110-125 DEG C for continuous heat preservation, then the furnace is naturally cooled to room temperature, and the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target material is obtained; the first-stage heat preservation temperature is less than the second-stage heat preservation temperature, the second-stage heat preservation temperature is less than the third-stage heat preservation temperature, the third-stage heat preservation temperature is less than the fourth-stage heat preservation temperature, and the fourth-stage heat preservation temperature is 660-680 DEG C. The thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target material treated by the annealing method is uniform in composition, free of segregation, good in grain size consistency, free of cracks, free of stratification, free of bulges, convenient to machine in subsequent machining, and convenient to thin-film deposition in the preparation of the all-solid-state thin-film magnesium battery.

Description

Technical Field

[0001] This invention relates to the field of magnesium battery technology, and more particularly to an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, the solid electrolyte target, and the battery. Background Technology

[0002] Currently, theoretical research on all-solid-state thin-film magnesium batteries has begun. All-solid-state thin-film magnesium batteries utilize solid-state materials for all cells, including the positive and negative electrodes and the electrolyte. Their structure is simpler than traditional magnesium-ion batteries. The solid electrolyte not only conducts magnesium ions but also acts as a separator, possessing advantages such as high mechanical strength, absence of liquid components, lack of flammable and volatile components, and good temperature resistance. However, research on all-solid-state thin-film magnesium batteries remains theoretical; no technology has yet been developed to provide the actual fabrication techniques and finished products that demonstrate the composition and functional structure of all-solid-state thin-film magnesium batteries. Summary of the Invention

[0003] In view of the above, the present invention aims to provide an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, a solid electrolyte target, and a battery. The present invention can provide a magnesium zirconium phosphate solid electrolyte target for all-solid-state thin-film magnesium batteries.

[0004] The objective of this invention is mainly achieved through the following technical solutions:

[0005] On one hand, the present invention provides an annealing method for a thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target. The annealing method adopts a four-stage heat preservation, followed by furnace cooling to 110-125°C and continued heat preservation, and then natural cooling to room temperature in the furnace to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target. The first stage heat preservation temperature is < the second stage heat preservation temperature < the third stage heat preservation temperature < the fourth stage heat preservation temperature, and the fourth stage heat preservation temperature is 660-680°C.

[0006] Furthermore, annealing methods include:

[0007] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate it to a vacuum level of 1–2.8 × 10⁻⁶. -4 Maintain this vacuum level for 3-4 hours.

[0008] S3. H2+Ar mixed gas is continuously introduced, and the temperature is raised from room temperature to 170-190℃ and held for 4-6 hours.

[0009] S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 310-330℃, and held for 3-5 hours;

[0010] S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 450-470℃, and held for 4-6 hours;

[0011] S6. H2+Ar mixed gas is continuously introduced, and the furnace temperature is raised to 660-680℃ and held for 5-7 hours.

[0012] S7. H2+Ar mixed gas is continuously introduced, and the furnace is slowly cooled to 110-125℃ and held for 3-5 hours.

[0013] S8, then evacuate to a vacuum of 1-2.8 × 10⁻⁶. -4 Maintain this vacuum level for 2.5–3.5 hours.

[0014] S9. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0015] Furthermore, in S3 to S7, the volume ratio of H2 to Ar is 5–15:85–95.

[0016] Furthermore, in S3 to S7, the pressure inside the vacuum annealing furnace is always kept greater than the atmospheric pressure outside the furnace.

[0017] Furthermore, the magnesium zirconium phosphate solid electrolyte target for the thin-film magnesium battery in S1 is prepared using the following method, including:

[0018] Step 1: Mix magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder;

[0019] Step 2: Place the above mixed powder into a sealed ball mill jar and mix it with zirconia balls, then add a dispersant and continue mixing and ball milling;

[0020] Step 3: Then add binder into the ball mill jar and continue ball milling;

[0021] Step 4: After ball milling, the synthetic powder is passed through a 500-mesh sieve. The sieved synthetic powder is weighed and then poured into a vibrating mold. Pressure is applied to form a molded blank.

[0022] Step 5: Place the billet into a cold isostatic press, apply pressure and hold pressure to obtain the cold isostatically pressed magnesium zirconium phosphate solid electrolyte target billet.

[0023] Step 6: Place the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace or a vacuum sintering furnace, and after multi-stage heat preservation, slowly cool it to 490-510℃ and hold it for 3-5 hours. Then, allow it to cool naturally to room temperature to obtain the zirconium magnesium phosphate solid electrolyte target for thin-film magnesium batteries.

[0024] Furthermore, in step 1, the magnesium salt includes one or more of magnesium oxide, magnesium carbonate, magnesium nitrate, and magnesium hydroxide.

[0025] Furthermore, in step 1, the mass ratio of magnesium salt, phosphorus pentoxide and zirconium oxide is controlled to be 1.1-1.3:0.9-1.1:0.1-0.2.

[0026] Furthermore, in step 2, the particle size of the zirconia spheres is controlled to be 0.5 mm to 1.3 mm.

[0027] The present invention also provides a zinc phosphate magnesium solid electrolyte target for thin-film magnesium batteries, which is prepared by the above method.

[0028] The present invention also provides an all-solid-state thin-film magnesium battery, wherein the solid electrolyte of the all-solid-state thin-film magnesium battery is prepared using the above-mentioned magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1) The annealing method of the thin-film magnesium battery zirconium phosphate solid electrolyte target of the present invention is controlled by four-stage heat preservation, followed by furnace cooling to 110-125°C and continued heat preservation, and then natural cooling to room temperature to obtain the annealed thin-film magnesium battery zirconium phosphate solid electrolyte target; and it is necessary to precisely control the first stage heat preservation temperature < the second stage heat preservation temperature < the third stage heat preservation temperature < the fourth stage heat preservation temperature, with the fourth stage heat preservation temperature being 660-680°C. The thin-film magnesium battery zirconium phosphate solid electrolyte target obtained by the above annealing method has uniform composition, no segregation, good grain size consistency, controllable grain deviation, no single phase or defect components, no cracks, no delamination, no bulging, and no cracking in the target material, which facilitates subsequent machining, reduces internal stress, has a high yield, and also facilitates thin film deposition in the preparation of all-solid-state thin-film magnesium batteries.

[0031] 2) The preparation of the thin-film magnesium battery zirconium phosphate magnesium solid electrolyte target of the present invention involves first mixing magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder, then mixing the above mixed powder with zirconium oxide balls, adding a dispersant and continuing mixing and ball milling; then adding a binder and continuing ball milling; the ball-milled synthetic powder is sieved (e.g., 500 mesh), poured into a vibrating mold, and pressed to form a molded blank; the blank is placed in a cold isostatic press and pressed and held to obtain a cold isostatically pressed zirconium phosphate magnesium solid electrolyte target blank; finally, the zirconium phosphate magnesium solid electrolyte target blank is placed in an atmosphere sintering furnace or a vacuum sintering furnace, subjected to multi-stage heat preservation, and then naturally cooled to room temperature with the furnace to obtain the thin-film magnesium battery zirconium phosphate magnesium solid electrolyte target. The preparation method of the present invention ensures the successful preparation of the thin-film magnesium battery zirconium phosphate magnesium solid electrolyte target by precisely controlling the proportion of raw materials, the order of addition of each raw material, the ball milling process parameters, the sintering steps, and the process parameters of each step.

[0032] 3) The solid electrolyte layer of the all-solid-state thin-film magnesium battery of the present invention is prepared using the magnesium zirconium phosphate solid electrolyte target of the present invention. The all-solid-state thin-film magnesium battery of the present invention has high safety and extremely high capacity and capacity retention. In addition, the all-solid-state thin-film magnesium battery of the present invention also has excellent interfacial bonding and coordination, with very low interfacial internal resistance. It can easily realize the direct series connection of multiple single cells, the direct parallel connection of multiple single cells, and the series and parallel combination of multiple single cells, which conveniently achieves the goal of increasing the output voltage of the battery, increasing the single cell capacity of the battery pack, or achieving a perfect combination of voltage boosting and capacity expansion.

[0033] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description. Attached Figure Description

[0034] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0035] Figure 1 This is a schematic diagram of the magnesium zirconium phosphate solid electrolyte target for a thin-film magnesium battery according to Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the magnesium zirconium phosphate solid electrolyte target for a thin-film magnesium battery according to Embodiment 2 of the present invention.

[0037] Figure 3 This is a schematic diagram of the magnesium zirconium phosphate solid electrolyte target for a thin-film magnesium battery according to Comparative Example 1 of the present invention.

[0038] Figure 4 This is a schematic diagram of the zinc phosphate magnesium solid electrolyte target for a thin-film magnesium battery according to Comparative Example 2 of the present invention. Detailed Implementation

[0039] The preferred embodiments of the present invention are described in detail below, which are mainly used to explain the principles of the present invention and are not intended to limit the scope of the present invention.

[0040] This invention provides an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries. The annealing method involves four stages of heat preservation, followed by furnace cooling to 110-125°C and continued heat preservation, and then natural cooling to room temperature in the furnace to obtain the annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries. The first stage heat preservation temperature is less than the second stage heat preservation temperature, the third stage heat preservation temperature is less than the fourth stage heat preservation temperature, and the fourth stage heat preservation temperature is 660-680°C.

[0041] Specifically, the above annealing methods include:

[0042] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate it to a vacuum level of 1–2.8 × 10⁻⁶. -4 Maintain this vacuum level for 2–4 hours.

[0043] S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 40–60 minutes, and then evacuate to a vacuum of 1–2.8 × 10⁻⁶. -4 Maintain this vacuum level for 3-4 hours.

[0044] S3. H2+Ar mixed gas is continuously introduced and heated from room temperature to 170-190℃, and held at this temperature for 4-6 hours; wherein the volume ratio of H2 to Ar is 5-15:85-95.

[0045] S4. H2+Ar mixed gas is continuously introduced, and the furnace temperature is raised to 310-330℃ and held for 3-5 hours; wherein the volume ratio of H2 to Ar is 5-15:85-95.

[0046] S5. H2+Ar mixed gas is continuously introduced, and the furnace temperature is raised to 450-470℃ and held for 4-6 hours; wherein the volume ratio of H2 to Ar is 5-15:85-95.

[0047] S6. H2+Ar mixed gas is continuously introduced, and the furnace temperature is raised to 660-680℃ and held for 5-7 hours; wherein the volume ratio of H2 to Ar is 5-15:85-95.

[0048] S7. H2+Ar mixed gas is continuously introduced and slowly cooled to 110-125℃ in the furnace, and held for 3-5 hours; wherein the volume ratio of H2 to Ar is 5-15:85-95.

[0049] S8, then evacuate to a vacuum of 1-2.8 × 10⁻⁶. -4 Maintain this vacuum level for 2.5–3.5 hours.

[0050] S9. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0051] Specifically, in steps S3 to S7 above, the pressure inside the vacuum annealing furnace is always kept greater than the atmospheric pressure outside the furnace.

[0052] Specifically, considering that if the holding temperature of the aforementioned thin-film magnesium battery zirconium phosphate solid electrolyte target is too low, delamination defects will occur; if the holding temperature is too high, bulging or cracking will occur. Therefore, after in-depth research, the above annealing method is precisely controlled to involve four stages of holding, followed by furnace cooling to 110-125℃ for further holding, and then natural cooling to room temperature in the furnace to obtain the annealed thin-film magnesium battery zirconium phosphate solid electrolyte target. Furthermore, it is necessary to precisely control the holding temperature of the first stage < the second stage < the third stage < the fourth stage, with the fourth stage holding temperature being 660-680℃.

[0053] Specifically, the annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries exhibits uniform composition, no segregation, good grain size consistency, controllable grain deviation, and no single-phase or defective components. The target is free of cracks, delamination, bulges, and fissures, facilitating subsequent machining, reducing internal stress, increasing yield, and aiding in subsequent thin-film deposition. Without treatment within these parameters, the material is prone to cracking during machining, contains numerous micro-cracks, and produces large powder particles during sputtering deposition.

[0054] Specifically, the thin-film magnesium battery zirconium phosphate solid electrolyte target in S1 above is prepared using the following method, including:

[0055] Step 1: Mix magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder;

[0056] Step 2: Place the above mixed powder into a sealed ball mill jar and mix it with zirconia balls, then add a dispersant and continue mixing and ball milling;

[0057] Step 3: Then add binder into the ball mill jar and continue ball milling;

[0058] Step 4: After ball milling, the synthetic powder is passed through a 500-mesh sieve. The sieved synthetic powder is weighed and then poured into a vibrating mold. Pressure is applied to form a molded blank.

[0059] Step 5: Place the billet into a cold isostatic press, apply pressure and hold pressure to obtain the cold isostatically pressed magnesium zirconium phosphate solid electrolyte target billet.

[0060] Step 6: Place the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace or a vacuum sintering furnace, and after multi-stage heat preservation, slowly cool it to 490-510℃ and hold it for 3-5 hours. Then, allow it to cool naturally to room temperature to obtain the zirconium magnesium phosphate solid electrolyte target for thin-film magnesium batteries.

[0061] Specifically, in step 1 above, the magnesium salt may include one or more of magnesium oxide, magnesium carbonate, magnesium nitrate, and magnesium hydroxide.

[0062] Specifically, in step 1 above, the mass ratio of magnesium salt, phosphorus pentoxide and zirconium oxide is controlled to be 1.1-1.3:0.9-1.1:0.1-0.2.

[0063] Specifically, step 2 above also includes drying the mixed powder.

[0064] Specifically, in step 2 above, to ensure uniform mixing of the powders and to control the particle size of the powder by adjusting the size of the zirconia balls, thus ensuring uniformity in grain size and crystal structure of the sintered magnesium zirconium phosphate product, and to guarantee that the powders are broken down and in close contact, reducing the chemical kinetic barrier during synthesis, the particle size of the zirconia balls is controlled to be 0.5–1.3 mm. When the zirconia ball particle size is outside this range, the mixed powder has a large particle size deviation, resulting in uneven mixing, the presence of many elemental substances, and the inability to sputter the sintered target material.

[0065] Specifically, in step 2 above, the grinding jar is a hard ceramic jar or a stainless steel jar lined with hard ceramic.

[0066] Specifically, in step 2 above, the total volume of the zirconia balls is controlled to be no more than 1 / 3 of the volume of the ball mill jar, and the total volume of the mixed powder is 1 / 5 to 2 / 5 of the volume of the ball mill jar.

[0067] Specifically, in step 2 above, considering that too much dispersant would be wasteful, while too little dispersant would cause the powder to agglomerate and fail to mix and contact sufficiently, which would be detrimental to synthesis and sintering, the mass ratio of dispersant to mixed powder is controlled at 1.8–2.0:100.

[0068] Specifically, in step 2 above, the dispersant may include isopropanol and isotetracycline. Preferably, the mass ratio of isopropanol to isotetracycline is 1-3:4-6.

[0069] Specifically, in step 2 above, the ball milling process includes:

[0070] S201. Ball milling in the mill jar at an initial speed of 150-240 rpm for 3-5 hours;

[0071] S202. Grind the balls in a milling jar at a speed of 370-390 rpm for more than 12 hours.

[0072] Specifically, in step 2 above, the ball milling process first uses a lower rotation speed and then a higher rotation speed. This ensures that the powder is mixed evenly, facilitating subsequent synthesis reactions. Without using the appropriate ball milling parameters, the mixture will be uneven, containing many elemental substances, and the sintered target material will not be able to be sputtered.

[0073] Specifically, in step 3 above, polyvinyl butyral can be used as the binder. Too much binder will be wasteful, while too little binder will prevent the uniformly mixed raw material powder from fully contacting and rapidly participating in the chemical reaction during sintering. Therefore, the mass ratio of binder to mixed powder should be controlled at (1.0–1.2):100.

[0074] Specifically, in step 3 above, in order to ensure that the powder is mixed evenly, the ball mill speed is controlled at 440-450 rpm and the ball milling time is 5-7 hours.

[0075] Specifically, in step 4 above, to ensure the uniformity of grain size and crystal phase structure of the sintered magnesium zirconium phosphate product, the synthesized powder is controlled to pass through a 500-mesh sieve. If this parameter is not within the range, the powder particle size will be dispersed, resulting in large voids in the target compact, preventing complete ceramization after sintering and hindering sputtering deposition.

[0076] Specifically, in step 4 above, considering that excessive pressure would place high demands on the equipment, while insufficient pressure would be ineffective, the pressure is controlled at 1450–1550 tons to form the molded blank.

[0077] Specifically, in step 5 above, considering that excessive pressure during the cold isostatic pressing process places high demands on the equipment, while insufficient pressure renders it ineffective, the pressure is controlled to be 270–290 MPa and held for 40–60 minutes.

[0078] Specifically, step 6 above, which involves using an atmosphere sintering furnace, includes:

[0079] S601. Place the solid electrolyte target blank of zirconium magnesium phosphate into an atmosphere sintering furnace, continuously introduce N2+Ar mixed gas, raise the temperature from room temperature to 210-230℃, and hold for 4-6 hours; wherein, the volume ratio of N2 to Ar is 7.5-8.5:2.

[0080] S602, heat again to 450-470℃, continuously purging with a N2+Ar mixed gas, and hold for 9-11 hours; wherein the volume ratio of N2 to Ar is 7.5-8.5:2;

[0081] S603, heat again to 670-690℃, and continuously purge N2+Ar mixed gas, and keep at this temperature for 12-14 hours; wherein, the volume ratio of N2 to Ar is 5.5-6.5:4.

[0082] S604, heat again to 970-990℃, continuously purging with a N2+Ar mixed gas, and hold for 14-16 hours; wherein the volume ratio of N2 to Ar is 5.5-6.5:4.

[0083] S605, slowly cool to 490-510℃ in the furnace, and hold for 3-5 hours;

[0084] S606, and then naturally cooled to room temperature in the furnace to obtain the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0085] Specifically, in S605 and S606 above, in order to ensure the uniformity of the microstructure of the obtained zirconium magnesium phosphate solid electrolyte target, it is necessary to first slowly cool it to 490-510℃ in the furnace and hold it for 3-5 hours; then cool it naturally to room temperature in the furnace.

[0086] Specifically, step 6 above, which involves using a vacuum sintering furnace, includes:

[0087] S601. Place the zirconium magnesium phosphate solid electrolyte target blank into a vacuum sintering furnace, maintaining a vacuum level of 10. -3 Below Pa, the temperature is raised from room temperature to 210–230℃ and held for 4–6 hours;

[0088] S602, heat up again to 450-470℃, and keep warm for 9-11 hours;

[0089] S603, heat again to 670-690℃, and keep warm for 12-14 hours;

[0090] S604, heat again to 970-990℃, and keep warm for 14-16 hours;

[0091] S605, slowly cool to 490-510℃ in the furnace, and hold for 3-5 hours;

[0092] S606, and then naturally cooled to room temperature in the furnace to obtain the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0093] Specifically, in S602 to S604 above, the vacuum level is always maintained at 10. -3 Below pa.

[0094] Specifically, in S605 and S606 above, in order to ensure the uniformity of the microstructure of the obtained zirconium magnesium phosphate solid electrolyte target, it is necessary to first slowly cool it to 490-510℃ in the furnace and hold it for 3-5 hours; then cool it naturally to room temperature in the furnace.

[0095] Specifically, in step 6 above, the parameters such as temperature, atmosphere, and holding time for each of the multiple heating stages are all taken into account the chemical reaction kinetics requirements of sintering. These parameters are controlled to ensure the uniformity of composition and the required grain structure of the synthesized magnesium zirconium phosphate during the sintering process. Sintering outside this temperature range will result in incomplete ceramization of the target material, leading to over-sintering, under-sintering, porosity, and deformation, rendering the target material unusable.

[0096] Specifically, in step 6 above, the resulting thin-film magnesium battery zirconium phosphate solid electrolyte target has a uniform composition, no segregation, good grain size consistency, controllable grain deviation, no single phase or defect components, and no cracks in the target, which facilitates thin film deposition.

[0097] Specifically, the annealed zinc-magnesium phosphate solid electrolyte target for thin-film magnesium batteries exhibits uniform composition, no segregation, good grain size consistency, controllable grain deviation, no single-phase or defective components, and no internal cracks, facilitating thin-film deposition. During machining, the target remains crack-free. The grain size of the annealed zinc-magnesium phosphate solid electrolyte target for thin-film magnesium batteries is between 320nm and 420nm, the flatness after sintering is approximately 0.11–0.16mm, and the relative density after sintering is approximately 94%–96.5%.

[0098] The present invention also provides a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, which is prepared by the above-mentioned annealing method.

[0099] The present invention also provides an all-solid-state thin-film magnesium battery, wherein the solid electrolyte of the all-solid-state thin-film magnesium battery is prepared using the above-mentioned magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0100] Specifically, the aforementioned all-solid-state thin-film magnesium battery includes a positive electrode layer, an electrolyte layer, and a negative electrode layer. The solid electrolyte layer is prepared using the aforementioned thin-film magnesium battery zirconium phosphate solid electrolyte target.

[0101] Specifically, the preparation method of the above-mentioned all-solid-state thin-film magnesium battery includes:

[0102] Step 1: Deposit a thin film of magnesium anode on the surface of copper foil;

[0103] Step 2: Next, a solid electrolyte film is deposited on the negative electrode magnesium film using the aforementioned thin-film magnesium battery zirconium phosphate solid electrolyte target.

[0104] Step 3: Deposit a positive electrode film on the solid electrolyte film;

[0105] Step 4: After formation, an all-solid-state thin-film magnesium battery is obtained.

[0106] Specifically, the all-solid-state thin-film magnesium battery of the present invention, in addition to high safety, also has high capacity and capacity retention. For example, with a capacity of 15840 mAh or higher (e.g., 15840–46464 mAh), the capacity remains essentially unchanged after more than 10,000 cycles. Furthermore, the all-solid-state thin-film magnesium battery of the present invention also has excellent interfacial bonding and compatibility, with very low interfacial resistance, for example, less than 0.01 ohms / cm. 2It can very easily realize the direct series connection of multiple single cells, the direct parallel connection of multiple single cells, and the series and parallel combination of multiple single cells, which can conveniently increase the output voltage of the battery, increase the single cell capacity of the battery pack, or achieve a perfect combination of voltage boosting and capacity expansion.

[0107] The preparation method and application of the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries of the present invention will be further described below with reference to specific embodiments. Unless otherwise specified, all raw materials used are commercially available.

[0108] Example 1

[0109] This embodiment provides an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, including:

[0110] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate to a vacuum level of 1.5 × 10⁻⁶. -4 Maintain this vacuum level for 3 hours.

[0111] S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 50 minutes, and then evacuate to a vacuum of 1.5 × 10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0112] S3. H2+Ar mixed gas is continuously introduced and heated from room temperature to 180℃, and held at that temperature for 5 hours; wherein the volume ratio of H2 to Ar is 10:90.

[0113] S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 320℃ and held for 4 hours; wherein the volume ratio of H2 to Ar is 10:90.

[0114] S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 460℃ and held for 5 hours; wherein the volume ratio of H2 to Ar is 10:90.

[0115] S6. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 670℃ and held for 6 hours; wherein the volume ratio of H2 to Ar is 10:90.

[0116] S7. H2+Ar mixed gas is continuously introduced and slowly cooled to 120℃ in the furnace, and held at that temperature for 4 hours; wherein the volume ratio of H2 to Ar is 10:90.

[0117] S8, then evacuate to 1.5×10 -4 Maintain this vacuum level for 3 hours.

[0118] S9. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0119] Specifically, the thin-film magnesium battery zirconium phosphate solid electrolyte target in S1 above is prepared using the following method, including:

[0120] Step 1: Mix magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder; the magnesium salt used is magnesium oxide, and the mass ratio of magnesium oxide, phosphorus pentoxide and zirconium oxide is 1.3:1.1:0.1;

[0121] Step 2: After drying the above mixed powder, place it in a sealed ball mill jar and mix it with zirconia balls with a particle size of 0.5-1.3 mm. Then add a dispersant and continue mixing and ball milling. The ball mill jar is a hard ceramic jar. The total volume of the zirconia balls occupies 1 / 3 of the volume of the ball mill jar, and the total volume of the mixed powder occupies 2 / 5 of the volume of the ball mill jar. The mass ratio of dispersant to mixed powder is 1.9:100.

[0122] Specifically, in step 2, the ball milling process includes:

[0123] S201. The ball mill jar is used to ball mill at an initial speed of 180 rpm for 4 hours.

[0124] S202, ball milling in a milling jar at a speed of 380 rpm for 13 hours;

[0125] Step 3: Then add binder into the ball mill jar and ball mill at 445 rpm for 6 hours; the mass ratio of binder to mixed powder is 1.1:100.

[0126] Step 4: After ball milling, the synthetic powder is passed through a 500-mesh sieve. The sieved synthetic powder is weighed and then poured into a vibrating mold. It is then pressed with 1500 tons to form a molded blank.

[0127] Step 5: Place the billet into a cold isostatic press, pressurize it to 280 MPa, and hold the pressure for 50 minutes to obtain the cold isostatically pressed magnesium zirconium phosphate solid electrolyte target billet.

[0128] Step 6: After placing the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace for multi-stage heat preservation, it is naturally cooled to room temperature with the furnace to obtain the zirconium magnesium phosphate solid electrolyte target for thin film magnesium battery.

[0129] Step 6 includes:

[0130] S601. Place the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace and continuously introduce a N2+Ar (ratio 8:2) mixed gas. Raise the temperature from room temperature to 220℃ and hold for 5 hours.

[0131] S602, raise the temperature again to 460℃, and keep it at that temperature for 10 hours while continuously purging the N2+Ar (ratio 8:2) mixed gas.

[0132] S603, heat up to 680℃ again, and continuously purge N2+Ar (ratio 6:4) mixed gas for 13 hours;

[0133] S604, raise the temperature again to 980℃, and continuously introduce a N2+Ar (ratio 6:4) mixed gas, and keep it at this temperature for 15 hours;

[0134] S605, slowly cool to 500℃ in the furnace and hold for 4 hours;

[0135] S606, and then naturally cooled to room temperature in the furnace to obtain the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0136] The annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in this embodiment has a uniform composition, no segregation, good grain size consistency, controllable grain deviation, no single phase or defect components, no cracks in the target, which facilitates thin film deposition, and no cracking during machining.

[0137] Specifically, the annealed thin-film magnesium battery zirconium phosphate magnesium solid electrolyte target of this embodiment is as follows: Figure 1 As shown, the grain size of the solid electrolyte target is between 345nm and 400nm, the flatness of the target after sintering is about 0.14mm, and the relative density of the sintered target is about 94.5%.

[0138] Example 2

[0139] This embodiment provides an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, including:

[0140] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate it to a vacuum level of 1×10⁻⁶. -4 Maintain this vacuum level for 3 hours.

[0141] S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 45 minutes, and then evacuate to a vacuum of 1.5 × 10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0142] S3. A mixture of H2 and Ar gas is continuously introduced, and the temperature is raised from room temperature to 175°C and held for 5.5 hours; wherein the volume ratio of H2 to Ar is 8:92.

[0143] S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 330℃ and held for 3 hours; wherein, the volume ratio of H2 to Ar is 8:92.

[0144] S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 455℃, and held for 5.5h; wherein the volume ratio of H2 to Ar is 8:92.

[0145] S6. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 665℃ and held for 6.5h; wherein the volume ratio of H2 to Ar is 8:92.

[0146] S7. H2+Ar mixed gas is continuously introduced and slowly cooled to 110℃ in the furnace, and held at that temperature for 4.5h; wherein the volume ratio of H2 to Ar is 8:92.

[0147] S8, then evacuate to 1.5×10 -4 Maintain this vacuum level for 3 hours.

[0148] S0. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace. Then, the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0149] Specifically, the thin-film magnesium battery zirconium phosphate solid electrolyte target in S1 above is prepared using the following method, including:

[0150] Step 1: Mix magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder; the magnesium salt used is magnesium oxide, and the mass ratio of magnesium oxide, phosphorus pentoxide and zirconium oxide is 1.2:1.0:0.1;

[0151] Step 2: After drying the above mixed powder, place it in a sealed ball mill jar and mix it with zirconia balls with a particle size of 0.5 mm to 1.3 mm. Then add a dispersant and continue mixing and ball milling. The ball mill jar is a hard ceramic jar. The total volume of the zirconia balls occupies 1 / 3 of the volume of the ball mill jar, and the total volume of the mixed powder occupies 2 / 5 of the volume of the ball mill jar. The mass ratio of dispersant to mixed powder is 2.0:100.

[0152] Specifically, in step 2, the ball milling process includes:

[0153] S201. The ball mill jar is used to ball mill at an initial speed of 160 rpm for 5 hours.

[0154] S202, ball milling in a milling jar at a speed of 390 rpm for 12 hours;

[0155] Step 3: Then add the binder into the ball mill jar and ball mill at 450 rpm for 6 hours; the mass ratio of binder to mixed powder is 1.15:100.

[0156] Step 4: After ball milling, the synthetic powder is passed through a 500-mesh sieve. The sieved synthetic powder is weighed and then poured into a vibrating mold. It is then pressed with 1530 tons to form a molded blank.

[0157] Step 5: Place the billet into a cold isostatic press, pressurize it to 280 MPa, and hold the pressure for 50 minutes to obtain the cold isostatically pressed magnesium zirconium phosphate solid electrolyte target billet.

[0158] Step 6: After placing the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace for multi-stage heat preservation, it is naturally cooled to room temperature with the furnace to obtain the zirconium magnesium phosphate solid electrolyte target for thin film magnesium battery.

[0159] Step 6 includes:

[0160] S601. Place the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace and continuously introduce a N2+Ar (ratio 8.3:2) mixed gas. Raise the temperature from room temperature to 230℃ and hold for 4 hours.

[0161] S602, raise the temperature again to 450℃, and continuously purge the mixture of N2 + Ar (ratio 8.3:2) gas for 10.5 hours;

[0162] S603, heat up to 690℃ again, and continuously purify with a N2+Ar (ratio 5.8:4) mixed gas for 13 hours;

[0163] S604, raise the temperature again to 990℃, and continuously introduce a N2+Ar (ratio 5.8:4) mixed gas, and keep it at this temperature for 14 hours;

[0164] S605, slowly cooled to 495℃ in the furnace, and held for 5 hours;

[0165] S606, and then naturally cooled to room temperature in the furnace to obtain the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries.

[0166] In this embodiment, the annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries has a uniform composition, no segregation, good grain size consistency, controllable grain deviation, no single phase or defect components, no cracks in the target, which facilitates thin film deposition, and no cracking during machining.

[0167] Specifically, the annealed thin-film magnesium battery zirconium phosphate magnesium solid electrolyte target of this embodiment is as follows: Figure 2 As shown, the grain size of the solid electrolyte target is between 355nm and 410nm, the flatness of the target after sintering is about 0.15mm, and the relative density of the sintered target is about 95.5%.

[0168] Example 3

[0169] This embodiment provides an all-solid-state thin-film magnesium battery. The fabrication method of this embodiment for depositing a single-cell all-solid-state thin-film magnesium battery includes:

[0170] Step 1: Deposit a negative electrode magnesium film on a 1 square meter copper foil surface. The thickness of the negative electrode magnesium film is 4.5 μm.

[0171] Step 2: Next, a solid electrolyte film is deposited on the negative electrode magnesium film using the magnesium zirconium phosphate solid electrolyte target of the thin-film magnesium battery described in Example 1 above. The thickness of the solid electrolyte film is 1.5 μm.

[0172] Step 3: Deposit a positive electrode film on the solid electrolyte film; the thickness of the positive electrode film is 15 μm;

[0173] Step 4: After formation, an all-solid-state thin-film magnesium battery is obtained.

[0174] The interfacial resistance of the all-solid-state thin-film magnesium battery in this embodiment is less than 0.01 ohms / cm. 2 With a capacity of 15840 mAh, the capacity remains essentially unchanged after more than 10,000 cycles.

[0175] Example 4

[0176] This embodiment provides an all-solid-state thin-film magnesium battery. The fabrication method for this embodiment involves depositing two series-connected all-solid-state thin-film magnesium batteries.

[0177] The magnesium anode film thickness of each thin-film magnesium battery was 5.5 μm, deposited on a 1 square meter copper foil surface. Then, a solid electrolyte film was deposited using the magnesium zirconium phosphate solid electrolyte target from Example 1. The solid electrolyte film thickness of each battery was 2.0 μm. The positive electrode film thickness was then further deposited to 18.5 μm. The resulting battery, after formation, had a capacity of 19536 mA h; the capacity remained essentially unchanged after more than 10000 cycles; and the interfacial resistance was less than 0.01 ohms / cm. 2 .

[0178] Example 5

[0179] This embodiment provides an all-solid-state thin-film magnesium battery. The method for depositing two parallel all-solid-state thin-film magnesium batteries includes:

[0180] The thickness of the negative electrode magnesium film deposited on the surface of a 1 square meter copper foil was 6.5 μm. Then, a solid electrolyte film was deposited using the zirconium phosphate magnesium solid electrolyte target of Example 2. The thickness of the solid electrolyte film deposited in each cell was 2.5 μm. The thickness of the positive electrode film deposited was 22 μm. The resulting battery, after formation, had a capacity of 46464 mA h; the capacity remained essentially unchanged after more than 10000 cycles; and the interfacial resistance was less than 0.01 ohms / cm. 2 .

[0181] Comparative Example 1

[0182] This comparative example provides an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, as detailed below:

[0183] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate to a vacuum level of 3×10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0184] S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 35 minutes, and then evacuate to a vacuum of 1.5 × 10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0185] S3. H2+Ar mixed gas is continuously introduced and heated from room temperature to 150℃ and held for 5 hours; wherein the volume ratio of H2 to Ar is 7:93.

[0186] S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 250℃ and held for 4 hours; wherein the volume ratio of H2 to Ar is 7:93.

[0187] S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 520℃ and held for 7 hours; wherein the volume ratio of H2 to Ar is 7:93.

[0188] S6. H2+Ar mixed gas is continuously introduced and slowly cooled to 180℃ in the furnace, and held at that temperature for 4.5h; wherein the volume ratio of H2 to Ar is 7:93.

[0189] S7, then evacuate to 1.5×10 -4 Maintain this vacuum level for 3 hours.

[0190] S8. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0191] Specifically, the preparation method of the thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target in S1 is the same as that in Example 1, and will not be repeated here.

[0192] The annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in this comparative example is as follows: Figure 3 As shown, the target material for the magnesium zirconium phosphate solid electrolyte in thin-film magnesium batteries has delamination, and the target material is prone to cracking during machining.

[0193] Comparative Example 2

[0194] This comparative example provides an annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, as detailed below:

[0195] S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate to a vacuum level of 3×10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0196] S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 35 minutes, and then evacuate to a vacuum of 1.5 × 10⁻⁶. -4 Maintain this vacuum level for 3.5 hours.

[0197] S3. H2+Ar mixed gas is continuously introduced and heated from room temperature to 190℃, and held at that temperature for 5 hours; wherein the volume ratio of H2 to Ar is 7:93.

[0198] S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 370℃ and held for 4 hours; wherein the volume ratio of H2 to Ar is 7:93.

[0199] S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 690℃ and held for 10h; wherein, the volume ratio of H2 to Ar is 7:93.

[0200] S6. H2+Ar mixed gas is continuously introduced and slowly cooled to 180℃ in the furnace, and held at that temperature for 4.5h; wherein the volume ratio of H2 to Ar is 7:93.

[0201] S7, then evacuate to 1.5×10 -4 Maintain this vacuum level for 3 hours.

[0202] S8. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target.

[0203] Specifically, the preparation method of the thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target in S1 is the same as that in Example 1, and will not be repeated here.

[0204] The annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in this comparative example is as follows: Figure 4 As shown, the target material for the magnesium zirconium phosphate solid electrolyte in thin-film magnesium batteries has bulges and cracks, and the target material is prone to cracking during machining.

[0205] Comparative Example 3

[0206] This comparative example provides a method for preparing the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in S1, as detailed below:

[0207] In step 2 of this comparative example, the particle size of the zirconia balls is 1.8–2.5 mm; in step 3, the balls are ball-milled at 250 rpm for 6 hours; the remaining steps are the same as those in Example 1.

[0208] The comparative example of the thin-film magnesium battery zirconium phosphate solid electrolyte target material has a large grain deviation, uneven mixing, and contains many elemental substances, making it impossible to sputter the sintered target material.

[0209] Comparative Example 4

[0210] This comparative example provides a method for preparing the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in S1, as detailed below:

[0211] In step 4 of this comparative example, the synthetic powder is controlled to pass through a 300-mesh sieve; the remaining steps are the same as those in Example 1.

[0212] The zinc phosphate magnesium solid electrolyte target blank for thin-film magnesium batteries in this comparative example has large voids, and cannot be completely ceramicized after sintering, thus making sputtering deposition impossible.

[0213] Comparative Example 5

[0214] This comparative example provides a method for preparing the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries in S1, as detailed below:

[0215] In step 6 of this comparative example, steps S603-S606 are performed directly; the remaining steps are the same as those in Example 1.

[0216] The target material in this comparative example cannot be fully ceramicized and is therefore unusable.

[0217] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An annealing method for a magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, characterized in that, The annealing method involves four stages of heat preservation followed by furnace cooling to 110-125°C, then further heat preservation, and finally natural cooling to room temperature to obtain the annealed magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries. The first stage heat preservation temperature is lower than the second stage heat preservation temperature, which is lower than the third stage heat preservation temperature, which is lower than the fourth stage heat preservation temperature. The fourth stage heat preservation temperature is 660-680°C. The annealing method includes: S1. Place the magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries into a vacuum annealing furnace and evacuate it to a vacuum level of 1–2.8 × 10⁻⁶. -4 Pa, maintain this vacuum level for 3~4 h; S2. Introduce high-purity nitrogen gas to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, maintain this pressure for 40-60 minutes, and then evacuate to a vacuum of 1-2.8 × 10⁻⁶. -4 Pa, maintain this vacuum level for 3~4 h; S3. H2+Ar mixed gas is continuously introduced, and the temperature is raised from room temperature to 170~190℃ and held for 4~6 hours; S4. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 310~330℃, and held for 3~5 hours; S5. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 450~470℃, and held for 4~6 hours; S6. H2+Ar mixed gas is continuously introduced, the furnace temperature is raised to 660~680℃, and held for 5~7 hours; S7. H2+Ar mixed gas is continuously introduced, and the furnace is slowly cooled to 110~125℃ and held for 3~5 hours. S8, then evacuate to 1-2.8×10 -4 Pa, maintain this vacuum level for 2.5~3.5h; S9. High-purity nitrogen gas is introduced to make the pressure inside the furnace greater than the atmospheric pressure outside the furnace, and then the furnace is naturally cooled to room temperature to obtain the annealed thin-film magnesium battery zirconium magnesium phosphate solid electrolyte target. The composition of the thin-film magnesium battery zirconium phosphate solid electrolyte target obtained by the annealing method is uniform.

2. The annealing method according to claim 1, characterized in that, In the annealing method, S1, the magnesium zirconium phosphate solid electrolyte target for the thin-film magnesium battery is placed in a vacuum annealing furnace and evacuated to a vacuum level of 1–1.5 × 10⁻⁶. -4 Pa, maintain this vacuum level for 3~4 hours.

3. The annealing method according to claim 2, characterized in that, In S3 to S7, the volume ratio of H2 to Ar is 5~15:85~95.

4. The annealing method according to claim 2, characterized in that, From S3 to S7, the pressure inside the vacuum annealing furnace is always kept greater than the atmospheric pressure outside the furnace.

5. The annealing method according to claim 2, characterized in that, The thin-film magnesium battery zirconium phosphate solid electrolyte target in S1 is prepared by the following method, including: Step 1: Mix magnesium salt powder with phosphorus pentoxide and zirconium oxide powder to obtain a mixed powder; Step 2: Place the above mixed powder into a sealed ball mill jar and mix it with zirconia balls, then add a dispersant and continue mixing and ball milling; Step 3: Then add binder into the ball mill jar and continue ball milling; Step 4: After ball milling, the synthetic powder is passed through a 500-mesh sieve. The sieved synthetic powder is weighed and then poured into a vibrating mold. Pressure is applied to form a molded blank. Step 5: Place the billet into a cold isostatic press, apply pressure and hold pressure to obtain the cold isostatically pressed magnesium zirconium phosphate solid electrolyte target billet. Step 6: Place the zirconium magnesium phosphate solid electrolyte target blank into an atmosphere sintering furnace or a vacuum sintering furnace, and after multi-stage heat preservation, slowly cool it to 490~510℃ and hold it for 3~5 hours. Then, allow it to cool naturally to room temperature to obtain the zirconium magnesium phosphate solid electrolyte target for thin-film magnesium batteries.

6. The annealing method according to claim 5, characterized in that, In step 1, the magnesium salt includes one or more of magnesium oxide, magnesium carbonate, magnesium nitrate, and magnesium hydroxide.

7. The annealing method according to claim 5, characterized in that, In step 1, the mass ratio of magnesium salt, phosphorus pentoxide and zirconium oxide is controlled to be 1.1~1.3:0.9~1.1:0.1~0.

2.

8. The annealing method according to claim 5, characterized in that, In step 2, the particle size of the zirconia spheres is controlled to be 0.5 mm to 1.3 mm.

9. A magnesium zirconium phosphate solid electrolyte target for thin-film magnesium batteries, characterized in that, The thin-film magnesium battery zirconium phosphate solid electrolyte target is prepared by the method described in any one of claims 1-8.

10. A fully solid-state thin-film magnesium battery, characterized in that, The solid electrolyte of the all-solid-state thin-film magnesium battery is prepared using the magnesium zirconium phosphate solid electrolyte target of the thin-film magnesium battery as described in claim 9.

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