All-solid-state sodium battery

Abstract

The invention belongs to the field of solid-state sodium batteries and relates to an all-solid-state sodium battery. The all-solid-state sodium battery sequentially comprises a negative electrode layer, a middle layer, a solid electrolyte layer and a positive electrode layer, the intermediate layer is selected from beta ''-Al2O3; the solid electrolyte layer is selected from amorphous sulfur-doped halide, the chemical general formula of the amorphous sulfur-doped halide is Na < 1 + x > TaCl < n > A < 6-x-n > S < x >, in the formula, A is a mixture of at least one of Br, I and F, and 0 lt; and n is greater than or equal to 5 and less than or equal to 5.5. According to the all-solid-state sodium battery disclosed by the invention, through the arrangement of the beta ''-Al2O3 intermediate layer, the interface reaction between the solid electrolyte layer and the negative electrode can be effectively inhibited, and sodium dendrites are inhibited. The amorphous sulfur-doped halide solid electrolyte Na < 1 + x > TaCl < n > A < 6-x-n > S < x > has high sodium ion conductivity and high voltage resistance, and is beneficial to inhibition of interface reaction with a positive electrode; the Na1 + xTaClnA6-x-nSx and the beta ''-Al2O3 intermediate layer have good interface stability, so that the interface reaction is inhibited, the interface resistance is reduced, and the all-solid-state sodium battery has excellent safety performance and long cycle life.

Description

Technical Field

[0001] The present invention belongs to the field of solid-state sodium batteries, and particularly relates to a all-solid-state sodium battery. Background Art

[0002] In recent years, sodium-ion batteries have received extensive attention due to their advantages such as low price and wide resources, and have broad application prospects in fields such as low-speed electric vehicles, start-stop power supplies, household energy storage, and large-scale energy storage. Due to the relatively low energy density, the safety of sodium-ion batteries has been improved compared with lithium-ion batteries. However, due to the use of organic electrolytes, sodium-ion batteries still have potential safety hazards. In particular, among various positive electrodes, layered positive electrodes still have a risk of thermal runaway under extreme conditions such as extrusion, puncture, and short circuit, which poses challenges even in the relatively suitable field of low-speed vehicles. An effective way to solve the safety problem of sodium-ion batteries is to use solid electrolytes to replace organic electrolytes and assemble all-solid-state sodium batteries. Similar to solid-state lithium-ion batteries, solid-state sodium-ion batteries also face problems such as low conductivity of solid electrolytes and relatively narrow electrochemical windows, which easily trigger interfacial side reactions, resulting in large interfacial resistance, being unfavorable for interfacial charge transfer and battery performance degradation, and ultimately leading to battery failure. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an all-solid-state sodium battery. The all-solid-state sodium battery has both excellent safety performance and long cycle life.

[0004] Another purpose of the present invention is to provide a preparation method of the all-solid-state sodium battery.

[0005] In order to achieve the above purposes, the present invention is implemented by adopting the following technical solutions:

[0006] An all-solid-state sodium battery sequentially includes a negative electrode layer, an intermediate layer, a solid electrolyte layer, and a positive electrode layer;

[0007] The intermediate layer is selected from β”-Al2O3; the solid electrolyte layer is selected from amorphous sulfur-doped halides, and the chemical general formula of the amorphous sulfur-doped halide is Na 1+x TaCl n A 6-x-n S x , where A is a mixture of at least one of Br, I, and F, 0 < x ≤ 0.5, and 5 ≤ n ≤ 5.5.

[0008] In the present invention, using β”-Al2O3 as the intermediate layer can effectively inhibit the interfacial reaction between the solid electrolyte layer and the negative electrode, and inhibit sodium dendrites. At the same time, Na 1+x TaCl n A 6-x-n S xIt also has a low interfacial resistance with β”-Al2O3, which can promote the interfacial transport of sodium ions and more effectively inhibit sodium dendrites. β”-Al2O3 has good interfacial stability with both the negative electrode layer and the solid electrolyte layer, and Na 1+x TaCl n A 6-x-n S x has good interfacial stability with the positive electrode layer.

[0009] Preferably, the ionic conductivity of the β”-Al2O3 is greater than 1×10 -4 S / cm.

[0010] Preferably, the average particle size of the β”-Al2O3 is 50 to 500 nanometers.

[0011] Preferably, the ionic conductivity of the amorphous sulfur-doped halide is greater than 1×10 -3 S / cm.

[0012] In the present invention, the negative electrode layer can be selected from metallic sodium, sodium alloy or carbon material, the sodium alloy is selected from sodium tin alloy, sodium antimony alloy, sodium phosphorus alloy or sodium bismuth alloy, and the carbon material is selected from soft carbon, hard carbon, soft / hard carbon composite material, phosphorus carbon composite material.

[0013] Preferably, adjacent two layers are bonded by a binder.

[0014] Preferably, the binder is selected from polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, polycarbonate, polyethylene oxide or polybutene.

[0015] More preferably, the binder is preferably polytetrafluoroethylene. Polytetrafluoroethylene can be fibrillated by shear dispersion to achieve dry film formation.

[0016] Preferably, the thickness of the intermediate layer is 1 to 10 μm.

[0017] Preferably, the thickness of the solid electrolyte layer is 10 to 100 μm.

[0018] The preparation method of the all-solid-state sodium battery includes the following steps:

[0019] S1. Prepare the negative electrode layer;

[0020] S2. Mix β”-Al2O3 and the binder evenly, roll them into a film, and press it on the surface of the negative electrode layer to form an intermediate layer;

[0021] S3. Mix the amorphous sulfur-doped halide and the binder evenly, roll them into a film, and press it on the surface of the intermediate layer to form a solid electrolyte layer;

[0022] S4. Shear and disperse the positive electrode active material, binder, conductive agent, and the amorphous sulfur-doped halide described in S3, and then roll-press to obtain a positive electrode film; press the positive electrode film on the surface of the solid electrolyte layer to form a positive electrode layer;

[0023] S5. Perform encapsulation treatment to obtain the all-solid-state sodium battery.

[0024] Preferably, the negative electrode layer includes a negative electrode material and a binder. More preferably, the weight ratio of the negative electrode material to the binder is 100: 0.1 - 5.

[0025] Preferably, in the intermediate layer, the weight ratio of β”-Al2O3 to the binder is 100: 0.1 - 5.

[0026] Preferably, in the solid electrolyte layer, the weight ratio of the amorphous sulfur-doped halide to the binder is 100: 0.1 - 5.

[0027] Preferably, the amorphous sulfur-doped halide is prepared by ball milling. More specifically, LiA, Li2S, and TaCl5 can be mixed in a stoichiometric ratio as a precursor, and the amorphous sulfur-doped halide Na 1+x TaCl n A 6-x-n S x .

[0028] More preferably, the ball milling time is 5 - 40 hours.

[0029] More preferably, the ball milling speed is 400 - 600 rpm.

[0030] Preferably, in the positive electrode layer, the positive electrode active material is selected from commercialized layered oxides, polyanion materials, or Prussian blue materials.

[0031] Preferably, in the positive electrode layer, the conductive agent is selected from at least one of graphene, fullerene, acetylene black, Super P, carbon nanotubes, and carbon nanofibers.

[0032] Preferably, in the positive electrode layer, the weight ratio of the positive electrode active material, binder, conductive agent, and the amorphous sulfur-doped halide Na 1+ x TaCl n A 6-x-n S x is 80 - 92: 0.1 - 5: 1 - 10: 1 - 20.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In the all-solid-state sodium battery disclosed by the present invention, through the setting of the β”-Al2O3 intermediate layer, the interfacial reaction between the solid electrolyte layer and the negative electrode can be effectively inhibited, and sodium dendrites can be inhibited. The amorphous sulfur-doped halide solid electrolyte Na 1+x TaCl n A 6-x-n S x has high sodium ion conductivity and high voltage resistance characteristics, which is beneficial to inhibiting the interfacial reaction with the positive electrode, and Na 1+x TaCl n A 6-x-n S x has good interfacial stability with the β”-Al2O3 intermediate layer, thereby inhibiting the interfacial reaction and reducing the interfacial resistance, making the all-solid-state sodium battery of the present invention have excellent safety performance and long cycle life. Description of the Drawings

[0035] Figure 1 The impedance spectrum of the solid electrolyte prepared in Example 1;

[0036] Figure 2 The structural schematic diagram of the all-solid-state sodium battery prepared in Example 1;

[0037] Figure 3 The charge and discharge curve of the all-solid-state sodium battery prepared in Example 1;

[0038] Figure 4 The cycle life diagram of the all-solid-state sodium battery prepared in Example 1;

[0039] Figure 5 The charge and discharge curve of the all-solid-state sodium battery prepared in Comparative Example 1;

[0040] Figure 6 The cycle life diagram of the all-solid-state sodium battery prepared in Comparative Example 1; Detailed Embodiments

[0041] The following further elaborates the present invention in conjunction with specific embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0042] Example 1

[0043] S1. Roll the metallic sodium to obtain a negative electrode layer, and the thickness of the negative electrode layer is 50 microns.

[0044] S2. Mix β”-Al2O3 and polytetrafluoroethylene in a weight ratio of 100:2, subject them to shear dispersion and roll pressing to obtain a β”-Al2O3 film with a thickness of 5 microns, and then press this film onto the surface of the negative electrode layer to obtain an intermediate layer, where the ionic conductivity of β”-Al2O3 is 1.5×10 -4 S / cm, and the average particle size is 200 nanometers.

[0045] S3. Use NaCl, Na2S, NaBr, and TaCl5 as precursors, mix them in a molar ratio of 0.2:0.1:0.7:1, and prepare Na 1.1 TaCl 5.2 Br 0.7 S 0.1 through ball milling, where the ball milling speed is 500 rpm and the ball milling time is 20 hours. After testing, the ionic conductivity of Na 1.1 TaCl 5.2 Br 0.7 S 0.1 is 1.8×10 -3 S / cm, as shown in Figure 1 .

[0046] Mix Na 1.1 TaCl 5.2 Br 0.7 S 0.1 and polytetrafluoroethylene in a weight ratio of 100:2, subject them to shear dispersion and roll pressing to obtain a Na 1.1 TaCl 5.2 Br 0.7 S 0.1 film with a thickness of 60 microns, and then press this film onto the surface of the intermediate layer to obtain a solid electrolyte layer.

[0047] S4. Mix commercial NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 positive electrode, polytetrafluoroethylene, carbon nanotubes, and Na 1.1 TaCl 5.2 Br 0.7 S 0.1 in a weight ratio of 82:2:3:13, subject them to shear dispersion and roll pressing to obtain a positive electrode film with a thickness of 100 microns, and then press the positive electrode film onto the surface of the solid electrolyte layer to obtain a positive electrode layer.

[0048] S5. Place aluminum foil current collectors on the positive and negative sides of the above laminated material, perform isostatic pressing treatment, and then encapsulate and assemble them into an all-solid-state sodium battery. The structure of the battery is shown in Figure 2 . Charge and discharge this battery at 2 - 4V, 0.1C (1C is defined as 150 mA / g) at room temperature. The discharge capacity is 120.7 mAh / g, as shown in Figure 3, the capacity retention rate is 94.4% after 200 cycles at 1C, see Figure 4 . After disassembling and detecting the cycled battery, no sodium dendrites appeared in the solid electrolyte layer.

[0049] Example 2

[0050] S1. Roll Na 15 Sn to obtain a negative electrode layer with a thickness of 70 μm.

[0051] S2. Mix β”-Al2O3 and polytetrafluoroethylene in a weight ratio of 100:2, and obtain a β”-Al2O3 film with a thickness of 8 μm through shear dispersion and rolling. Then press this film on the surface of the negative electrode layer to obtain an intermediate layer, where the ionic conductivity of β”-Al2O3 is 1.5×10 -4 S / cm, and the average particle size is 200 nm.

[0052] S3. Use NaCl, Na2S, and TaCl5 as precursors, mix them in a molar ratio of 0.8:0.2:1, and prepare Na 1.2 TaCl 5.8 S 0.2 through ball milling, where the ball milling speed is 500 rpm and the ball milling time is 20 hours. After detection, the ionic conductivity of Na 1.2 TaCl 5.8 S 0.2 is 1.5×10 -3 S / cm. Mix Na 1.2 TaCl 5.8 S 0.2 and polytetrafluoroethylene in a weight ratio of 100:2.5, and obtain a Na 1.2 TaCl 5.8 S 0.2 film with a thickness of 55 μm through shear dispersion and rolling. Then press this film on the surface of the intermediate layer to obtain a solid electrolyte layer.

[0053] S4. Mix commercial Na3V2(PO4)3 cathode, polytetrafluoroethylene, carbon nanofibers, Na 1.2 TaCl 5.8 S 0.2 in a weight ratio of 83:1.5:2.5:13, and obtain a cathode film with a thickness of 90 μm through shear dispersion and rolling. Then press the cathode film on the surface of the solid electrolyte layer to obtain a cathode layer.

[0054] S5. Place aluminum foil current collectors on the positive and negative sides of the above-mentioned laminated material. After isostatic pressing treatment, it is assembled into a all-solid-state sodium battery through encapsulation. The battery is charged and discharged at 2.5 - 3.7 V, 0.1 C (1 C is defined as 110 mA / g) at room temperature. The discharge capacity is 105.3 mAh / g, and the capacity retention rate is 95.2% after 200 cycles at 1 C. After disassembling and detecting the cycled battery, no sodium dendrites appear in the solid electrolyte layer.

[0055] Example 3

[0056] S1. Mix hard carbon and polytetrafluoroethylene in a weight ratio of 100:2, and obtain a negative electrode layer with a thickness of 60 μm through shear dispersion and rolling.

[0057] S2. Mix β”-Al2O3 and polytetrafluoroethylene in a weight ratio of 100:2, and obtain a β”-Al2O3 film with a thickness of 7 μm through shear dispersion and rolling. Then press this film on the surface of the negative electrode layer to obtain an intermediate layer, where the ionic conductivity of β”-Al2O3 is 1.5×10 -4 S / cm, and the average particle size is 200 nm.

[0058] S3. Use NaCl, NaI, NaBr, Na2S and TaCl5 as precursors, mix them in a molar ratio of 0.5:0.05:0.4:0.05:1, and prepare Na 1.05 TaCl 5.5 Br 0.4 I 0.05 S 0.05 , where the ball milling speed is 500 rpm and the ball milling time is 20 hours. After detection, the ionic conductivity of Na 1.05 TaCl 5.5 Br 0.4 I 0.05 S 0.05 is 2.0×10 -3 S / cm. Mix Na 1.05 TaCl 5.5 Br 0.4 I 0.05 S 0.05 and polytetrafluoroethylene in a weight ratio of 100:1.5, and obtain a Na 1.05 TaCl 5.5 Br 0.4 I 0.05 S 0.05 film with a thickness of 65 μm through shear dispersion and rolling. Then press this film on the surface of the intermediate layer to obtain a solid electrolyte layer.

[0059] S4. Use commercial Na2Fe 0.5 Mn 0.5[Fe(CN)6] positive electrode, polytetrafluoroethylene, graphene, Na 1.05 TaCl 5.5 Br 0.4 I 0.05 S 0.05 Mix them in a weight ratio of 84:2.5:3:10.5, and after shear dispersion and roll pressing, a positive electrode film with a thickness of 80 μm is obtained. Then, the positive electrode film is pressed on the surface of the solid electrolyte layer to obtain a positive electrode layer.

[0060] S5. Place aluminum foil current collectors on both the positive and negative electrode sides of the above laminated material. After isostatic pressing treatment, it is assembled into a all-solid-state sodium battery through encapsulation. The battery is charged and discharged at 1.8 - 3.7 V, 0.1 C (1 C is defined as 150 mA / g) at room temperature. The discharge capacity is 123.3 mAh / g, and the capacity retention rate is 92.1% after 200 cycles at 1 C. After disassembling and detecting the cycled battery, no sodium dendrites appear in the solid electrolyte layer.

[0061] Example 4

[0062] S1. Roll press metallic sodium to obtain a negative electrode layer with a thickness of 65 μm.

[0063] S2. Mix β”-Al2O3 and polytetrafluoroethylene in a weight ratio of 100:2, and after shear dispersion and roll pressing, a β”-Al2O3 film with a thickness of 6 μm is obtained. Then, this film is pressed on the surface of the negative electrode layer to obtain an intermediate layer, where the ionic conductivity of β”-Al2O3 is 1.5×10 -4 S / cm, and the average particle size is 200 nm.

[0064] S3. Use NaBr, Na2S, and TaCl5 as precursors, mix them in a molar ratio of 0.5:0.5:1, and prepare Na 1.5 TaCl5Br 0.5 S 0.5 by ball milling, where the ball milling speed is 500 rpm and the ball milling time is 20 hours. After detection, the ionic conductivity of Na 1.5 TaCl5Br 0.5 S 0.5 is 1.3×10 -3 S / cm. Mix Na 1.5 TaCl5Br 0.5 S 0.5 and polytetrafluoroethylene in a weight ratio of 100:2, and after shear dispersion and roll pressing, a Na 1.5 TaCl5Br 0.5 S 0.5 film with a thickness of 70 μm is obtained. Then, this film is pressed on the surface of the intermediate layer to obtain a solid electrolyte layer.

[0065] S4. Mix commercial positive electrode NaNi 0.4 Fe 0.2 Mn 0.4 O2, polytetrafluoroethylene, Super P, Na 1.5 TaCl5Br 0.5 S 0.5 in a weight ratio of 84.5:2:3.5:10, shear disperse and roll press to obtain a positive electrode film with a thickness of 95 microns, and then press the positive electrode film onto the surface of the solid electrolyte layer to obtain a positive electrode layer.

[0066] S5. Place aluminum foil current collectors on both the positive and negative electrode sides of the above laminated material, perform isostatic pressing treatment, and then encapsulate and assemble into a all-solid-state sodium battery. Charge and discharge this battery at 2 - 4V, 0.1C (1C is defined as 150 mA / g) at room temperature. The discharge capacity is 122.4 mAh / g, and the capacity retention rate after 200 cycles at 1C is 93.2%. Disassemble and test the battery after cycling, and no sodium dendrites appear in the solid electrolyte layer.

[0067] Comparative Example 1

[0068] The manufacturing process of the all-solid-state sodium battery is the same as that in Example 1, except that in S3, adjust the molar ratio of the amorphous sulfur-doped halide raw material so that the prepared amorphous sulfur-doped halide is NaTaCl 5.2 Br 0.8 , that is, no sulfur doping is carried out. After testing, the ionic conductivity of this NaTaCl 5.2 Br 0.8 is 0.4×10 -3 S / cm.

[0069] The discharge capacity of the prepared all-solid-state sodium battery at 2 - 4V, 0.1C is 103.1 mAh / g, as shown in Figure 5 , and the capacity retention rate after 200 cycles at 1C is 78.9%, as shown in Figure 6 . Disassemble and test the battery after cycling, and sodium dendrites appear in the solid electrolyte layer.

[0070] Comparative Example 2

[0071] The manufacturing process of the all-solid-state sodium battery is the same as that in Example 1, except that in S3, adjust the molar ratio of the amorphous sulfur-doped halide raw material so that the prepared amorphous sulfur-doped halide is Na 1.6 TaCl 5.2 Br 0.2 S 0.6 , that is, the amount of sulfur doping is too large. After testing, the ionic conductivity of this Na 1.6 TaCl 5.2 Br 0.2 S 0.6 is 0.2×10 -3S / cm.

[0072] The prepared all-solid-state sodium battery has a discharge capacity of 100.7 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 79.3% after 200 cycles at 1C. After disassembling and testing the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0073] Comparative Example 3

[0074] The manufacturing process of the all-solid-state sodium battery is as in Example 1, with the difference that in S3, the molar ratio of the amorphous sulfur-doped halide raw material is adjusted so that the prepared solid electrolyte is Na 1.1 TaBr 5.9 S 0.1 , that is, TaBr5 is used instead of TaCl5, and NaBr is used instead of NaCl. After testing, the ionic conductivity of this electrolyte is 0.3×10 -4 S / cm.

[0075] The prepared all-solid-state sodium battery has a discharge capacity of 81.2 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 69.4% after 200 cycles at 1C. After disassembling and testing the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0076] Comparative Example 4

[0077] The manufacturing process of the all-solid-state sodium battery is as in Example 1, with the difference that there is no intermediate layer, that is, the solid electrolyte layer is directly pressed on the surface of the negative electrode layer.

[0078] The prepared all-solid-state sodium battery has a discharge capacity of 107.7 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 82.1% after 200 cycles at 1C. After disassembling and testing the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0079] Comparative Example 5

[0080] The manufacturing process of the all-solid-state sodium battery is as in Example 1, with the difference that in the intermediate layer, β-Al2O3 is replaced by β”-Al2O3, and the ionic conductivity of β-Al2O3 is 1.1×10 -5 S / cm, and the average particle size is 200 nanometers.

[0081] The prepared all-solid-state sodium battery has a discharge capacity of 109.5 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 82.8% after 200 cycles at 1C. After disassembling and testing the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0082] Comparative Example 6

[0083] The manufacturing process of the all-solid-state battery is as in Example 1, except that the intermediate layer is commercial Na3Zr2Si2PO 12 replacing β”-Al2O3, where the ionic conductivity of Na3Zr2Si2PO 12 is 5.0×10 -4 S / cm, and the average particle size is 200 nanometers.

[0084] The prepared all-solid-state sodium battery has a discharge capacity of 111.3 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 84.3% after 200 cycles at 1C. After disassembling and detecting the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0085] Comparative Example 7

[0086] The manufacturing process of the all-solid-state battery is as in Example 1, except that the intermediate layer is commercial Na3PS4 replacing β”-Al2O3, where the ionic conductivity of Na3PS4 is 2.2×10 -4 S / cm, and the average particle size is 200 nanometers.

[0087] The prepared all-solid-state sodium battery has a discharge capacity of 112.1 mAh / g at 2 - 4V and 0.1C, and the capacity retention rate is 85.1% after 200 cycles at 1C. After disassembling and detecting the cycled battery, sodium dendrites appear in the solid electrolyte layer.

[0088] Comparative Example 8

[0089] The manufacturing process of the all-solid-state battery is as in Example 1, except that Na 1.1 TaCl 5.2 Br 0.7 S 0.1 is not used to prepare the solid electrolyte, that is, the solid electrolyte layer is not prepared, and the positive electrode film is directly pressed on the surface of the intermediate layer. It is found through experiments that this battery cannot work properly.

[0090] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A all-solid-state sodium battery, characterized in that, It includes a negative electrode layer, an intermediate layer, a solid electrolyte layer and a positive electrode layer in sequence; The intermediate layer is selected from β”-Al2O3; the solid electrolyte layer is selected from amorphous sulfur-doped halides, and the chemical general formula of the amorphous sulfur-doped halides is Na 1+x TaCl n A 6-x-n S x , where A is a mixture of at least one of Br, I, and F, 0 < x ≤ 0.5, and 5 ≤ n ≤ 5.

5.

2. The all-solid-state sodium battery according to claim 1, wherein The ionic conductivity of the β”-Al2O3 is greater than 1×10 -4 S / cm.

3. The all-solid-state sodium battery according to claim 1 or 2, characterized in that, The average particle size of the β"-Al2O3 is 50 to 500 nanometers.

4. The all-solid-state sodium battery according to claim 1, characterized in that, The amorphous sulfur-doped halide is prepared by mixing LiA, Li2S and TaCl5 in a stoichiometric ratio as a precursor and then ball milling.

5. The all-solid-state sodium battery according to claim 1, characterized in that, The ionic conductivity of the amorphous sulfur-doped halide is greater than 1×10 -3 S / cm.

6. The all-solid-state sodium battery according to claim 1, wherein The two adjacent layers are bonded together by an adhesive.

7. The all-solid-state sodium battery according to claim 6, characterized in that, The binder is selected from polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, polycarbonate, polyethylene oxide or polybutylene.

8. The all-solid-state sodium battery according to claim 1, characterized in that, The thickness of the intermediate layer is 1-10 μm.

9. The all-solid-state sodium battery according to claim 1, characterized in that, The thickness of the solid electrolyte layer is 10-100 μm.

10. The preparation method of the all-solid-state sodium battery according to any one of claims 1 to 9, characterized in that, The steps include: S1. Prepare the negative electrode layer; S2. The β"-Al2O3 and the binder are mixed and rolled into a film, and pressed on the surface of the negative electrode layer to form an intermediate layer; S3. The amorphous sulfur-doped halide and the binder are uniformly mixed and rolled into a film, and pressed on the surface of the intermediate layer to form a solid electrolyte layer; S4. The positive electrode active material, the binder, the conductive agent, and the amorphous sulfur-doped halide of S3 are dispersed by shearing, and then rolled to obtain a positive electrode film; the positive electrode film is pressed on the surface of the solid electrolyte layer to form a positive electrode layer; S5. Packaging process to obtain the all-solid-state sodium battery.

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