High-entropy nasicon oxide solid electrolyte and preparation method and application thereof

Abstract

The application belongs to the technical field of solid electrolytes, and particularly relates to a high-entropy NASICON oxide solid electrolyte as well as a preparation method and application thereof. 3±i Zr 2‑x M x Si 2+y P 1‑y O 12 , wherein 0<=i<1, 0 The application introduces multiple metal elements into a NASICON structure solid electrolyte system to form a NASICON oxide solid electrolyte with a specific chemical formula, which is conducive to improving the ionic conductivity, limiting current density and sodium stability of the electrolyte, and the assembled full solid-state battery exhibits excellent cycle stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid electrolytes, and in particular relates to a high-entropy NASICON oxide solid electrolyte and a preparation method and application thereof. Background Art

[0002] Sodium-ion batteries, with their significant advantages of low raw material costs and widespread availability, are considered one of the most competitive alternatives to lithium-ion batteries. However, the flammable organic electrolytes used in traditional sodium-ion batteries pose safety risks such as leakage, combustion, and even explosion, significantly limiting their further development and application. Against this backdrop, NASICON-structured solid electrolyte materials have emerged. Their numerous advantages, including high safety, excellent stability, low cost, and environmental friendliness, have made solid-state sodium batteries possible, making them a research hotspot in the energy storage field.

[0003] Sodium ion solid electrolyte is the core part of solid-state sodium battery, affecting the safety and electrochemical performance of the battery. In order to achieve good application in solid-state sodium battery, sodium ion solid electrolyte needs to have high ionic conductivity and ion migration number, wide electrochemical window, good chemical stability and interface compatibility. According to the material composition, the existing sodium ion solid electrolyte can be mainly divided into polymer solid electrolyte, sulfide solid electrolyte, β-Al2O3 (Na2O-nAl2O3) solid electrolyte and NASICON (Na superionic conductor) structure solid electrolyte. Among them, NASICON structure solid electrolyte has a wide electrochemical window, low thermal expansion, cheap raw materials, easy preparation, and environmental friendliness. It is an ideal sodium ion solid electrolyte material. However, this electrolyte still has problems such as low room temperature conductivity and instability to sodium.

[0004] High-entropy materials have attractive advantages, such as the ease of forming single-phase solid solutions with simple crystal structures and customized functional properties, and have garnered great attention in the fields of thermoelectricity, thermal energy and environmental protection, and electrochemical energy storage. All-solid-state inorganic high-entropy electrolytes are composed of a variety of ions, and their crystal structures do not have an obvious ordered arrangement. The diffusion paths of ions within the material become more diverse. This allows ions to migrate through different channels and positions, reducing mutual hindrance between ions and promoting the rate of ion migration. In crystals with long-range ordered structures, ions tend to form stable arrangements, resulting in stronger ion binding energy. In contrast, the ionic binding energy between ions in high-entropy electrolytes that lack long-range order is much lower, making it easier for ions to dissociate and migrate.

[0005] Solid-state sodium batteries are expected to play a significant role in large-scale energy storage applications from the perspectives of resources, cost, safety, and stability. Therefore, to address the low room-temperature conductivity and sodium instability of NASICON-structured solid electrolytes, a new high-entropy NASICON oxide solid electrolyte with high room-temperature conductivity and critical current density, as well as its preparation method and application, is needed. Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention provides a high-entropy NASICON oxide solid electrolyte and its preparation method and application. The NASICON structured solid electrolyte has excellent sodium stability and high critical current density while ensuring high ionic conductivity, and the assembled all-solid-state battery exhibits excellent cycle stability.

[0007] One aspect of the present invention is to provide a high entropy NASICON oxide solid electrolyte, the general chemical formula of which is Na 3±i Zr 2-x M x Si 2+y P 1-y O 12 , where 0≤i<1, 0<x<1, 0.25≤y≤0.5, and M is four or more of Zn, Mg, Cu, Ca, Sc, In, La, Yb, Y, Hf, Ge, Sb, Ta, and Nb.

[0008] Here, the atomic number x of M refers to the total atomic number of four or more elements.

[0009] Preferably, M is one or more of Cu, Ca, La, and Yb, and one or more of Zn, Mg, Sc, In, Y, Hf, Ge, Sb, Ta, and Nb, and the element types of M are four or more.

[0010] Preferably, the chemical formula is Na 3＋i Zr 2-x M x Si 2+y P 1-y O 12 , where 0.4≤i≤0.9.

[0011] Preferably, in the general chemical formula, x is 0.05 to 0.5, more preferably 0.1 to 0.4.

[0012] Preferably, the room temperature ionic conductivity of the NASICON oxide solid electrolyte is ≥1×10 -3 S cm -1 , more preferably ≥1.5×10 -3 S cm -1, and further preferably ≥1.9×10 -3 S cm -1 , and further preferably 1.9×10 -3 ~8×10 -3 S cm -1 The room temperature here refers to the natural temperature indoors, ranging from 5 to 40°C.

[0013] The second aspect of the present invention is to provide a method for preparing a high-entropy NASICON oxide solid electrolyte, comprising the following steps:

[0014] (1) According to the general formula Na 3±i Zr 2-x M x Si 2+y P 1-y O 12 , respectively weighing a sodium source, a phosphorus source, a zirconium source, a silicon source and an M ion source in a stoichiometric ratio, performing a first wet mixing and drying, and then further performing high-temperature sintering, and a second wet mixing and drying to obtain a precursor powder;

[0015] (2) Precursor powder is mixed with a binder solution, isostatically pressed to form a green body, and then subjected to two-stage sintering to obtain the high-entropy NASICON oxide solid electrolyte.

[0016] Preferably, the sodium source is one or more of Na2CO3, NaNO3, Na2O, NaHCO3, and NaOH; the phosphorus source is one or more of NH4H2PO4, NaH2PO4, Na2HPO4, and P2O5; the zirconium source is ZrO2; the silicon source is SiO2; and the M ion source is an oxide of the M element, specifically four or more of ZnO, MgO, CuO, CaO, Sc2O3, In2O3, La2O3, Yb2O3, Y2O3, HfO2, GeO2, Sb2O5, Ta2O5, and Nb2O5.

[0017] Preferably, the wet mixing method is mechanical ball milling or high-energy ball milling, with a ball-to-material ratio of (2-6):1, a ball milling speed of 200-600 rpm, a ball milling time of 2-12 hours, and a ball milling solvent of one or more of anhydrous ethanol, isopropanol, n-propanol, acetone, and butanol. The first and second wet mixing processes may be the same or different.

[0018] The drying may be carried out by any means capable of evaporating the solvent, such as vacuum drying, forced air drying, etc., and the drying temperature is 40 to 90°C.

[0019] Preferably, the high temperature sintering conditions of step (1) are: 500-1200° C., 2-24 hours in a pure oxygen atmosphere.

[0020] Preferably, in step (2), the mass ratio of the precursor powder to the binder solution is (10-50):1.

[0021] Preferably, the binder solution is formed by dissolving the binder in a solvent, and the concentration of the binder solution is 1-800 mg / ml.

[0022] Preferably, the binder is one or more of polyvinyl alcohol, polyvinyl butyral, polydopamine, and polyacrylic acid.

[0023] Preferably, in step (2), the pressure used for isostatic pressing is 10-700 MPa, and the holding time is 1 min-4 h.

[0024] Preferably, in step (2), the two-stage sintering includes a first-stage sintering and a second-stage sintering. The first-stage sintering temperature is 550-900°C, and the sintering time is 1-4 hours; the second-stage sintering temperature is 1100-1300°C, and the sintering time is 2-24 hours. Both stages of sintering are carried out in a pure oxygen atmosphere.

[0025] The third aspect of the present invention is to provide an all-solid-state sodium secondary battery, comprising a positive electrode, a negative electrode and the high-entropy NASICON oxide solid electrolyte.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention provides a high-entropy NASICON oxide solid electrolyte with a high critical current density. A variety of metal elements are introduced into the NASICON structure solid electrolyte system. The introduced chemical disorder and distortion will disrupt and redistribute the local site energy. When this distribution is wide enough to achieve energy overlap between adjacent sites, it will promote Na+ hopping. The doped high-entropy NASICON oxide solid electrolyte has high ionic conductivity and limiting current density.

[0028] 2. The multiple metal elements introduced in the present invention can lead to local disorder in the high-entropy NASICON oxide solid electrolyte. This disorder effectively promotes site percolation through overlapping site energy distribution, thereby preventing the growth of sodium dendrites and preparing a high-entropy NASICON oxide solid electrolyte with excellent stability to sodium metal.

[0029] 3. The high entropy NASICON oxide solid electrolyte provided by the present invention has high ionic conductivity and sodium stability. Furthermore, the sodium / / sodium symmetric battery assembled by the oxide solid electrolyte is better than Na3Zr2Si2PO12 The sodium / / sodium symmetric battery assembled with oxide solid electrolytes showed better cycling stability for sodium. Furthermore, the high-entropy NASICON oxide solid electrolytes of the present invention, which have a high critical current density, were assembled into an all-solid-state battery, demonstrating excellent cycling stability.

[0030] 4. The doping element of the present invention is further preferably M is one or more of Cu, Ca, La, Yb and one or more of Zn, Mg, Sc, In, Y, Hf, Ge, Sb, Ta, Nb, and the element types of M are four or more. The doping of Cu, Ca, La, and Yb elements is beneficial to improving the ionic conductivity, limiting current density, and sodium stability of the high-entropy NASICON oxide solid electrolyte, and the battery prepared therefrom has better cycle stability.

[0031] 5. The high-entropy NASICON oxide solid electrolyte provided by the present invention not only ensures high ionic conductivity, but also has excellent sodium stability and high critical current density.

[0032] 6. The preparation method of the high-entropy NASICON oxide solid electrolyte provided by the present invention is simple to operate, highly practical, and convenient for large-scale production. It is preferably carried out by two-stage sintering, which is conducive to improving performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Scanning electron microscope image and X-ray energy spectrum scanning element distribution map of oxide solid electrolyte;

[0034] Figure 2 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 X-ray diffraction spectrum of oxide solid electrolyte;

[0035] Figure 3 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 AC impedance spectroscopy of oxide solid electrolytes;

[0036] Figure 4 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Limiting current density curve of sodium||sodium symmetric battery with oxide solid electrolyte;

[0037] Figure 5 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Comparison of electronic conductivity of oxide solid electrolytes;

[0038] Figure 6 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Comparison of activation energies of the oxide solid electrolyte and the Na3Zr2Si2PO12 oxide solid electrolyte of Comparative Example 1;

[0039] Figure 7 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Long cycle curve of sodium||sodium symmetric battery with oxide solid electrolyte;

[0040] Figure 8 is Na in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Long cycle curve of all-solid-state battery with oxide solid electrolyte at 1C rate.

[0041] Figure 9 is Na in Example 14 of the present invention 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Long cycle curve of sodium||sodium symmetric battery with oxide solid electrolyte;

[0042] Figure 10 is Na in Example 14 of the present invention 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 Long cycle curve of all-solid-state battery with oxide solid electrolyte at 1C rate. DETAILED DESCRIPTION

[0043] Below by specific embodiment and accompanying drawing, technical scheme of the present invention is further described explanation, it should be understood that specific embodiment described herein is only for helping to understand the present invention, is not used for specific limitation of the present invention.And accompanying drawing used herein, is only for better illustrating the disclosure of the present invention, does not have limiting effect on protection scope.If no special instructions, the raw materials adopted in the embodiment of the present invention are all raw materials commonly used in this area, and the method adopted in the embodiment is all conventional method in this area. Example 1

[0044] This embodiment Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 (i.e. Na 3.6 Zr 1.8 Zn 0.05 Ca 0.05 Sc 0.05 La 0.05 Si 2.3 P 0.7 O 12 ) The preparation method of the oxide solid electrolyte is as follows:

[0045] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, ZnO, CaO, Sc2O3, and La2O3 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls according to the ball-to-material ratio of 5:1, add anhydrous ethanol, and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixed material in a blast drying oven at 80 ℃ to dry the solvent.

[0046] (2) The dried powder was ground evenly in an agate mortar and placed in a tube furnace for sintering. The sintering atmosphere was pure oxygen, the sintering temperature was 900 degrees, and the sintering time was 12 hours. The sintered powder was placed in an agate ball mill again, and zirconia balls were added according to the ball-to-material ratio of 5:1. Anhydrous ethanol was added, and the ball milling speed was 400 rpm. The ball milling time was 8 hours. After the ball milling was completed, the mixed material was placed in a blast drying oven at 80 ℃ drying the solvent to obtain Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Precursor.

[0047] (3) Weigh a certain mass of Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The precursor was mixed with polyvinyl alcohol aqueous solution (concentration of 10 mg / ml) (Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The precursor and polyvinyl alcohol aqueous solution (at a mass ratio of 40:1) were placed in a custom mold and isostatically pressed to form a green body at a pressure of 200 MPa for 5 minutes. The green body was then sintered in a tubular furnace in a two-stage process using pure oxygen. The first stage was at 700°C for one hour, and the second stage was at 1250°C for six hours. After annealing, the resulting high-entropy NASICON oxide solid electrolyte sheet was obtained.

[0048] Figure 1 The Na prepared in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P0.7 O 12 Scanning electron microscope image and X-ray energy spectrum surface scanning element distribution map of oxide solid electrolyte. From the surface scanning element distribution map, it can be seen that Zn, Mg, Sc, and Hf elements are evenly distributed in Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 oxide solid electrolytes.

[0049] Figure 2 The Na prepared in Example 1 of the present invention 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte and Na3Zr2Si2PO4 of Comparative Example 1 12 The X-ray diffraction spectrum of the oxide solid electrolyte shows that the main phase of the high-entropy NASICON oxide solid electrolyte of this embodiment is a monoclinic phase, and no impurity phase is generated.

[0050] Performance testing and battery assembly

[0051] 1) By ion sputtering in Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 4.24×10 -3 S cm -1 , relative to Na3Zr2Si2PO in Comparative Example 1 12 The ionic conductivity of oxide solid electrolytes has increased by about 11 times. Figure 3 shown.

[0052] 2) Using metallic sodium as the symmetrical electrode, Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 10 mA cm -2The high current density is comparable to that of Na3Zr2Si2PO4 in Comparative Example 1. 12 Compared with oxide solid electrolytes, it has shown excellent resistance to sodium dendrites (see Figure 4 ).

[0053] 3) by ion sputtering in Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 2.47×10 -9 S cm -1 , relative to Na3Zr2Si2PO in Comparative Example 1 12 The electronic conductivity of oxide solid electrolytes is reduced by about 14 times. Figure 5 shown.

[0054] 4) by ion sputtering in Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20 ℃ ~ 80 ℃. Its activation energy was calculated to be 0.244 eV, which is relatively 12 The activation energy of the oxide solid electrolyte is reduced by 0.081eV. Figure 6 shown.

[0055] 5) Using metallic sodium as the symmetrical electrode, Na 3.6 Zr 1.8 (ZnCaScLa) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can be stably cycled for 2600 hours, which is comparable to the Na3Zr2Si2PO 12 Compared with oxide solid electrolytes, it shows excellent stability to sodium (see Figure 7 ).

[0056] 6) Put Na 3.6 Zr 1.8 (ZnCaScLa) 0.05Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 83.4 mAhg. -1 After 500 cycles, the discharge capacity is 70.1 mAh g -1 Compared with Na3Zr2Si2PO in Comparative Example 1 12 Compared with oxide solid electrolytes, it shows excellent electrochemical performance (see Figure 8 ). Example 2

[0057] This embodiment Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0058] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, ZnO, CaO, Yb2O3, and GeO2 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0059] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0060] Performance testing and battery assembly

[0061] 1) By ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.03×10 -3 S cm -1 .

[0062] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.2 mA cm -2 high current density.

[0063] 3) by ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 7.12×10 -9 S cm -1 .

[0064] 4) by ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.267 eV.

[0065] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 1300 hours.

[0066] 6) Put Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 84.7 mAhg. -1 After 500 cycles, the discharge capacity is 64.5 mAh g -1 . Example 3

[0067] This embodiment Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0068] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CuO, La2O3, HfO2, and Nb2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0069] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0070] Performance testing and battery assembly

[0071] 1) By ion sputtering in Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.34×10 -3 S cm -1 .

[0072] 2) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.6 mA cm -2 high current density.

[0073] 3) by ion sputtering in Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 9.12×10 -9 S cm -1 .

[0074] 4) by ion sputtering in Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.273 eV.

[0075] 5) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 1500 hours.

[0076] 6) Put Na 3.4 Zr 1.8 (CuLaHfNb) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 76.5 mAhg. -1After 500 cycles, the discharge capacity is 57.1 mAh g -1 . Example 4

[0077] This embodiment Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0078] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CaO, Y2O3, In2O3, and Sb2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0079] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0080] Performance testing and battery assembly

[0081] 1) By ion sputtering in Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.81×10 -3 S cm -1 .

[0082] 2) Using metallic sodium as the symmetrical electrode, Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 6.4 mA cm -2 high current density.

[0083] 3) by ion sputtering in Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 10.2×10 -9 S cm -1 .

[0084] 4) by ion sputtering in Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.294 eV.

[0085] 5) Using metallic sodium as the symmetrical electrode, Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 900 hours.

[0086] 6) Put Na 3.45 Zr 1.8 (CaYInSb) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 78.1 mAhg. -1 After 500 cycles, the discharge capacity is 57.8 mAh g -1 . Example 5

[0087] This embodiment Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0088] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, ZnO, MgO, Yb2O3, and GeO2 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0089] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0090] Performance testing and battery assembly

[0091] 1) By ion sputtering in Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is tested to be 1.96×10 -3 S cm -1 .

[0092] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 4.4 mA cm -2 high current density.

[0093] 3) by ion sputtering in Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 18.9×10 -9 S cm -1 .

[0094] 4) by ion sputtering in Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.312 eV.

[0095] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can be cycled stably for 500 hours.

[0096] 6) Put Na 3.55 Zr 1.8 (ZnMgYbGe) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 83.2 mAhg. -1 After 500 cycles, the discharge capacity is 54.77 mAh g -1 . Example 6

[0097] This embodiment Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0098] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, MgO, Sc2O3, HfO2, and Nb2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0099] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0100] Performance testing and battery assembly

[0101] 1) By ion sputtering in Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.11×10 -3 S cm -1 .

[0102] 2) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 4.2 mA cm -2 high current density.

[0103] 3) by ion sputtering in Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 20.6×10 -9 S cm -1 .

[0104] 4) by ion sputtering in Na3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.311 eV.

[0105] 5) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can circulate stably for 550 hours.

[0106] 6) Put Na 3.4 Zr 1.8 (MgScHfNb) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 75.8 mAhg. -1 After 500 cycles, the discharge capacity is 53.2 mAh g -1 . Example 7

[0107] This embodiment Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0108] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, ZnO, Ta2O5, Yb2O3, and GeO2 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1 and add anhydrous ethanol. The ball mill is rotated at 400 rpm for 8 hours. After the ball milling is completed, the mixture is placed in a forced air drying oven at 80°C to dry the solvent.

[0109] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 Oxide solid electrolyte.

[0110] Performance testing and battery assembly

[0111] 1) By ion sputtering in Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.02×10 -3 S cm -1 .

[0112] 2) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 4.4 mA cm -2 high current density.

[0113] 3) by ion sputtering in Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 19.5×10 -9 S cm -1 .

[0114] 4) by ion sputtering in Na3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.309 eV.

[0115] 5) Using metallic sodium as the symmetrical electrode, Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can circulate stably for 600 hours.

[0116] 6) Put Na 3.4 Zr 1.8 (ZnTaYbGe) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 78.2 mAhg. -1 After 500 cycles, the discharge capacity is 54.5 mAh g -1 . Example 8

[0117] This embodiment Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0118] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CuO, CaO, Yb2O3, and GeO with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0119] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0120] Performance testing and battery assembly

[0121] 1) By ion sputtering in Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.34×10 -3 S cm -1 .

[0122] 2) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 8.2 mA cm -2 high current density.

[0123] 3) by ion sputtering in Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 6.91×10 -9 S cm -1 .

[0124] 4) by ion sputtering in Na3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.293 eV.

[0125] 5) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 1700 hours.

[0126] 6) Put Na 3.65 Zr 1.8 (CuCaYbGe) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 75.8 mAhg. -1 After 500 cycles, the discharge capacity is 56.8 mAh g -1 . Example 9

[0127] This embodiment Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0128] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, MgO, ZnO, Yb2O3, and GeO with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0129] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0130] Performance testing and battery assembly

[0131] 1) By ion sputtering in Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.26×10 -3 S cm -1 .

[0132] 2) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 5.6 mA cm -2 high current density.

[0133] 3) by ion sputtering in Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 17.9×10 -9 S cm -1 .

[0134] 4) by ion sputtering in Na3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.302 eV.

[0135] 5) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can circulate stably for 600 hours.

[0136] 6) Put Na 3.65 Zr 1.8 (MgZnYbGe) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 75.3 mAhg. -1 After 500 cycles, the discharge capacity is 53.9 mAh g -1 . Example 10

[0137] This embodiment Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0138] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CaO, MgO, HfO2, and Ta2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0139] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0140] Performance testing and battery assembly

[0141] 1) By ion sputtering in Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.17×10 -3 S cm -1 .

[0142] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.8 mA cm -2 high current density.

[0143] 3) by ion sputtering in Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 8.24×10 -9 S cm -1 .

[0144] 4) by ion sputtering in Na3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.292 eV.

[0145] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can circulate stably for 1100 hours.

[0146] 6) Put Na 3.55 Zr 1.8 (CaMgHfTa) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 84.8 mAhg. -1 After 500 cycles, the discharge capacity is 60.2 mAh g -1 . Example 11

[0147] This embodiment Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0148] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CaO, Y2O3, HfO2, and Nb2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1 and add anhydrous ethanol. The ball mill is rotated at 400 rpm for 8 hours. After the ball milling is completed, the mixture is placed in a forced air drying oven at 80°C to dry the solvent.

[0149] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0150] Performance testing and battery assembly

[0151] 1) By ion sputtering in Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is tested to be 2.48×10 -3 S cm -1 .

[0152] 2) Using metallic sodium as the symmetrical electrode, Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 6.2 mA cm -2 high current density.

[0153] 3) by ion sputtering in Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 15.4×10 -9 S cm -1 .

[0154] 4) by ion sputtering in Na3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.296 eV.

[0155] 5) Using metallic sodium as the symmetrical electrode, Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 900 hours.

[0156] 6) Put Na 3.5 Zr 1.8 (CaYHfNb) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 77.2 mAhg. -1 After 500 cycles, the discharge capacity is 55.5 mAh g -1 . Example 12

[0157] This embodiment Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0158] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CuO, Sc2O3, In2O3, and Nb2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0159] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0160] Performance testing and battery assembly

[0161] 1) By ion sputtering in Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.81×10 -3 S cm -1 .

[0162] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 6.6 mA cm -2 high current density.

[0163] 3) by ion sputtering in Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 12.4×10 -9 S cm -1 .

[0164] 4) by ion sputtering in Na3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.287 eV.

[0165] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can be cycled stably for 1000 hours.

[0166] 6) Put Na 3.55 Zr 1.8 (CuScInSb) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 79.6 mAhg. -1 After 500 cycles, the discharge capacity is 58.2 mAh g -1 . Example 13

[0167] This embodiment Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0168] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CaO, ZnO, GeO2, and Ta2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0169] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0170] Performance testing and battery assembly

[0171] 1) By ion sputtering in Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.97×10 -3 S cm -1 .

[0172] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.0 mA cm -2 high current density.

[0173] 3) by ion sputtering in Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 11.4×10 -9 S cm -1 .

[0174] 4) by ion sputtering in Na3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.289 eV.

[0175] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 900 hours.

[0176] 6) Put Na 3.55 Zr 1.8 (CaZnGeTa) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 76.8 mAhg. -1 After 500 cycles, the discharge capacity is 56.7 mAh g -1 . Example 14

[0177] This embodiment Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0178] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CuO, MgO, La2O3, and HfO2 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0179] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 Oxide solid electrolyte.

[0180] Performance testing and battery assembly

[0181] 1) By ion sputtering in Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.41×10 -3 S cm -1 .

[0182] 2) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.4 mA cm -2 high current density.

[0183] 3) by ion sputtering in Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 3.21×10 -9 S cm -1 .

[0184] 4) by ion sputtering in Na3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.271 eV.

[0185] 5) Using metallic sodium as the symmetrical electrode, Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 2000 hours.

[0186] 6) Put Na 3.65 Zr 1.8 (CuMgLaHf) 0.05 Si 2.4 P 0.6 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 76.8 mAhg. -1 After 500 cycles, the discharge capacity is 62.9 mAh g -1 . Example 15

[0187] This embodiment Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The preparation method of the oxide solid electrolyte is as follows:

[0188] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, CaO, ZnO, GeO2, and Ta2O5 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 500 rpm for 10 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0189] (2) The dried powder was ground evenly in an agate mortar and placed in a tube furnace for sintering. The sintering atmosphere was pure oxygen, the sintering temperature was 1000 degrees, and the sintering time was 10 hours. The sintered powder was placed in an agate ball mill again, and zirconia balls were added according to the ball-to-material ratio of 5:1. Anhydrous ethanol was added, and the ball milling speed was 500 rpm. The ball milling time was 10 hours. After the ball milling was completed, the mixed material was placed in a blast drying oven at 80 ℃ drying the solvent to obtain Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 Precursor.

[0190] (3) Weigh a certain mass of Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The precursor was mixed with polyacrylic acid aqueous solution (concentration of 10 mg / ml) (Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The precursor and polyacrylic acid aqueous solution (at a mass ratio of 50:1) were placed into a custom mold and isostatically pressed to form a green body at a pressure of 300 MPa for 4 minutes. The green body was then sintered in a tubular furnace in a two-stage process using pure oxygen. The first stage was sintered at 800°C for 1.5 hours, and the second stage was sintered at 1300°C for 7 hours. After annealing, the resulting high-entropy NASICON oxide solid electrolyte sheet was obtained.

[0191] Performance testing and battery assembly

[0192] 1) By ion sputtering in Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 3.25×10 -3 S cm -1 .

[0193] 2) Using metallic sodium as the symmetrical electrode, Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 7.3mA cm -2 high current density.

[0194] 3) by ion sputtering in Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 9.3×10 -9 S cm -1 .

[0195] 4) by ion sputtering in Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.282 eV.

[0196] 5) Using metallic sodium as the symmetrical electrode, Na 3.71 Zr 1.72 (CaZnGeTa) 0.07 Si 2.5 P 0.5 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 1300 hours.

[0197] 6) Put Na 3.71 Zr 1.72 (CaZnGeTa)0.07 Si 2.5 P 0.5 O 12 An all-solid-state battery was assembled using an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 82.2 mAh g -1 After 500 cycles, the discharge capacity is 61.3 mAh g -1 . Example 16

[0198] The difference between Example 16 and Example 2 is that the first stage sintering temperature in step (3) of Example 16 is 400 degrees and the sintering time is one hour. The rest is the same as Example 2. 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 .

[0199] Performance testing and battery assembly

[0200] 1) By ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 2.44×10 -3 S cm -1 .

[0201] 2) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 6.5 mA cm -2 high current density.

[0202] 3) by ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3P 0.7 O 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 15.47×10 -9 S cm -1 .

[0203] 4) by ion sputtering in Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.303 eV.

[0204] 5) Using metallic sodium as the symmetrical electrode, Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can be cycled stably for 1000 hours.

[0205] 6) Put Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 The all-solid-state battery is assembled with an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 83.6 mAhg. -1 After 500 cycles, the discharge capacity is 60.6 mAh g -1 .

[0206] Comparative Example 1

[0207] Comparative Example Na3Zr2Si2PO 12 The preparation method of the oxide solid electrolyte is as follows:

[0208] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, and NH4H2PO4 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0209] Steps (2) and (3) are the same as in Example 1 to prepare Na3Zr2Si2PO 12 Oxide solid electrolyte.

[0210] Performance testing and battery assembly

[0211] 1) by ion sputtering on Na3Zr2Si2PO 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is 0.36×10 -3 S cm -1 .

[0212] 2) Using metallic sodium as the symmetrical electrode, Na3Zr2Si2PO 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 0.6 mA cm -2 high current density.

[0213] 3) by ion sputtering on Na3Zr2Si2PO 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is 35.1×10 -9 S cm -1 .

[0214] 4) by ion sputtering on Na3Zr2Si2PO 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.325 eV.

[0215] 5) Using metallic sodium as the symmetrical electrode, Na3Zr2Si2PO 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can circulate stably for 4 hours.

[0216] 6) Na3Zr2Si2PO 12An all-solid-state battery was assembled using an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 8.4 mAh g -1 After 500 cycles, the discharge capacity is 5.7 mAh g -1 .

[0217] Comparative Example 2

[0218] Na in Comparative Example 2 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The preparation method of the oxide solid electrolyte is as follows:

[0219] (1) According to the stoichiometric ratio, weigh Na2CO3, ZrO2, SiO2, NH4H2PO4, ZnO, CaO, Yb2O3, and GeO2 with a purity of more than 99% and place them in an agate ball mill. Add zirconia balls at a ball-to-material ratio of 5:1. Add anhydrous ethanol and mill at a speed of 400 rpm for 8 hours. After the ball milling is completed, place the mixture in a forced air drying oven at 80°C to dry the solvent.

[0220] Steps (2) and (3) are the same as in Example 1 to prepare Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 Oxide solid electrolyte.

[0221] Performance testing and battery assembly

[0222] 1) By ion sputtering in Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature ionic conductivity is tested to be 1.73×10 -3 S cm -1 .

[0223] 2) Using metallic sodium as the symmetrical electrode, Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The limiting current density was tested under ℃ conditions and can reach 5.2 mA cm -2 high current density.

[0224] 3) by ion sputtering in Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The oxide solid electrolyte sheet is gold-plated on both sides, and its room temperature electronic conductivity is tested to be 17.12×10 -9 S cm -1 .

[0225] 4) by ion sputtering in Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The oxide solid electrolyte sheet was gold-plated on both sides, and its ionic conductivity was tested at -20°C to 80°C, and its activation energy was calculated to be 0.297 eV.

[0226] 5) Using metallic sodium as the symmetrical electrode, Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 The oxide solid electrolyte is used as the electrolyte layer, and the battery is assembled into a symmetrical battery. The cycle test is carried out using the Blue Power CT2001A battery test system. The battery was tested at a current density of 5 mA cm -2 It can cycle stably for 900 hours.

[0227] 6) Put Na 3.25 Zr 1.8 (ZnCaYbGe) 0.05 Si2PO 12 An all-solid-state battery was assembled using an oxide solid electrolyte, a Na3V2(PO4)3 positive electrode, and a metallic sodium negative electrode. The battery was electrochemically tested using a Blue Power CT2001A battery test system. The charge and discharge voltage range was 2.5-3.8 V, and the rate was 1C. The initial discharge capacity reached 76.7 mAh g -1 After 500 cycles, the discharge capacity is 56.8 mAh g -1 .

[0228] By comparing Examples 1-16 with Comparative Example 1, it can be seen that the doping of multiple elements such as Zn, Mg, Cu, Ca, Sc, In, La, Yb, Y, Hf, Ge, Sb, Ta, and Nb is beneficial to improving the ionic conductivity and limiting current density of the solid electrolyte, and has excellent sodium stability, and further utilizing the oxide solid electrolyte to obtain an all-solid-state sodium secondary battery with better long-cycle stability. Examples 5, 6, 7, and 9 do not include Cu, Ca, La, and Yb elements, and the performance of the solid electrolytes prepared therefrom is lower than that of other embodiments including one or more of Cu, Ca, La, and Yb elements. The atomic number of Si in Comparative Example 2 is 2, and its performance relative to that of Example 2 is reduced. Although Example 16 adopts two-stage sintering, the sintering temperature in the first stage is low, resulting in a decrease in the performance of Example 16 relative to that of Example 2.

[0229] The various aspects, embodiments, and features of the present invention should be considered in all respects as illustrative and not limiting, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0230] In the preparation method of the present invention, the order of the steps is not limited to the order listed. Persons skilled in the art will appreciate that variations in the order of the steps are within the scope of the present invention without inventive effort. Furthermore, two or more steps or actions may be performed simultaneously.

[0231] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit its implementation. Persons skilled in the art may make various modifications, additions, or substitute similar methods for the described specific embodiments. It is not necessary and impossible to provide comprehensive examples of all implementations here. However, obvious variations or modifications arising from the essential spirit of the present invention remain within the scope of protection of the present invention, and interpreting them as any additional limitations would be contrary to the spirit of the present invention.

Claims

1. A high entropy NASICON oxide solid electrolyte, characterized in that: Its chemical formula is Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 .

2. A high entropy NASICON oxide solid electrolyte according to claim 1, characterized in that: The room temperature ionic conductivity of the NASICON oxide solid electrolyte is 3.03×10 -3 S cm -1 .

3. The method for preparing a high-entropy NASICON oxide solid electrolyte according to claim 1, wherein: The following steps are involved: (1) According to the chemical formula Na 3.55 Zr 1.8 (ZnCaYbGe) 0.05 Si 2.3 P 0.7 O 12 , respectively weighing a sodium source, a phosphorus source, a zirconium source, a silicon source, a Zn ion source, a Ca ion source, a Yb ion source, and a Ge ion source in a stoichiometric ratio, performing a first wet mixing and drying, and then further performing high-temperature sintering, and a second wet mixing and drying to obtain a precursor powder; (2) Precursor powder is mixed with a binder solution, isostatically pressed to form a green body, and then subjected to two-stage sintering to obtain the high-entropy NASICON oxide solid electrolyte.

4. The preparation method according to claim 3, characterized in that The wet mixing method is mechanical ball milling or high-energy ball milling, the ball-to-material ratio is (2-6):1, the ball milling speed is 200-600 rpm, the ball milling time is 2-12 hours, and the ball milling solvent is one or more of anhydrous ethanol, isopropanol, n-propanol, acetone, and butanol.

5. The preparation method according to claim 3, wherein The high temperature sintering conditions of step (1) are: 500-1200°C in a pure oxygen atmosphere for 2-24 hours.

6. The preparation method according to claim 3, characterized in that In step (2), the mass ratio of the precursor powder to the binder solution is (10-50):1, and the binder is one or more of polyvinyl alcohol, polyvinyl butyral, polydopamine, and polyacrylic acid.

7. The preparation method according to claim 3, wherein The pressure used in isostatic pressing is 10~700 MPa, and the holding time is 1 min~4 h.

8. The preparation method according to claim 3, characterized in that In step (2), the two-stage sintering includes a first-stage sintering and a second-stage sintering; The first stage sintering temperature is 550~900℃ and the sintering time is 1~4 hours; The second stage sintering temperature is 1100~1300℃ and the sintering time is 2~24 hours; The two-stage sintering is both carried out in a pure oxygen atmosphere.

9. An all-solid-state sodium secondary battery, characterized in that: The invention comprises a positive electrode, a negative electrode and the high-entropy NASICON oxide solid electrolyte according to claim 1 or the high-entropy NASICON oxide solid electrolyte prepared by the preparation method according to claim 3.

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