Sodium-ion solid-state electrolyte and preparation method therefor, and all-solid-state sodium-ion battery

Abstract

A sodium-ion solid-state electrolyte and a preparation method therefor, and an all-solid-state sodium-ion battery. The electrolyte comprises a substrate and an interface protection layer, wherein the interface protection layer covers a surface of the substrate; the substrate is a polymer electrolyte; the interface protection layer is a metal; and the metal comprises at least one of Sn, Zn, In, Sb, Bi and Ge. By covering the surface of the substrate with the metal source serving as the interface protection layer, a stable metal thin layer interface is formed by means of the alloying of sodium and the metal source, which metal thin layer interface can effectively prevent the growth of sodium dendrites, reduce damage to the sodium-ion solid-state electrolyte in the cycling process of a battery, improve the interfacial wettability and reduce the interfacial charge transfer resistance, thereby improving the interface stability of a sodium metal negative electrode and the solid-state electrolyte, and therefore a stable long-cycle all-solid-state sodium-ion battery is obtained.

Description

A sodium ion solid-state electrolyte, a preparation method thereof and a full solid-state sodium ion battery TECHNICAL FIELD

[0001] The present application relates to the technical field of sodium ion batteries, in particular to a sodium ion solid-state electrolyte, a preparation method thereof and a full solid-state sodium ion battery. BACKGROUND

[0002] Sodium metal has a high theoretical specific capacity (1166 mAh g -1 ) and a low electrochemical potential (-2.714 V), making it an ideal negative electrode candidate material for rechargeable sodium ion batteries. However, traditional sodium metal batteries are composed of organic liquid electrolytes, which have a potential risk of fire or even explosion. Solid-state sodium ion batteries based on solid-state electrolytes are compatible with sodium metal anodes, have high voltage, high capacity and high energy density, and excellent safety and mechanical properties. However, the poor stability and interface compatibility of sodium ion solid-state electrolytes greatly hinder their practical application. On the one hand, some solid-state electrolytes may undergo irreversible chemical reactions with sodium metal, and the by-products generated greatly affect the normal operation of the battery; on the other hand, the solid-state electrolyte itself may be penetrated by sodium dendrites, causing damage and short circuit; for example, PEO-NaTFSI, PEO-NaFSI, PVDF-NaTFSI, PVDF-NaFSI, etc.

[0003] In order to improve the stability and interface compatibility of the solid-state electrolyte and the sodium metal anode interface, the main methods at present include adding fillers to form a composite electrolyte in the solid-state electrolyte or modifying the surface of the solid-state electrolyte. Among them, the composite electrolyte is mainly applied in polymer electrolytes, and the fillers added include inorganic materials such as SiO2 and Al2O3, or functional materials with ordered microporous structure such as MOF and COF. Surface modification of solid-state electrolyte usually forms an in-situ or non-in-situ protective layer on the interface between electrolyte and sodium metal.

[0004] In a solid-state sodium ion battery, the surface of the sodium anode is usually prone to generate sharp dendrites during the cycling process, which can pierce the electrolyte layer, causing damage to the electrolyte interface, and in severe cases, leading to short circuit failure of the battery. Traditional methods, whether adding fillers to form a composite electrolyte or surface modification, mainly block the growth of dendrites, thereby inhibiting the damage of the electrolyte interface. Such strategies do not fundamentally change the dendrite growth kinetics, only delay the failure of the battery, and cannot fundamentally improve the stability of the sodium metal and electrolyte interface. In addition, some methods require expensive materials or precise equipment, which is high in cost and complex in operation. Some interface modification methods reported may also change the intrinsic electrochemical properties of the electrolyte material, leading to a decrease in the energy density of the battery.

[0005] Therefore, it is necessary to provide a sodium ion solid-state electrolyte, a preparation method thereof and a full solid-state sodium ion battery, so as to improve the interface stability between the solid-state electrolyte and sodium metal in the solid-state sodium ion battery, thereby improving the safety and stability of the solid-state battery.

[0006] SUMMARY

[0007] The present application aims to at least solve one of the technical problems existing in the prior art, and therefore proposes a sodium ion solid-state electrolyte, a preparation method thereof and a full solid-state sodium ion battery, so as to improve the interface stability between the solid-state electrolyte and sodium metal in the solid-state sodium ion battery, thereby improving the safety and stability of the solid-state battery.

[0008] A first aspect of the present application provides a sodium ion solid-state electrolyte.

[0009] Specifically, the sodium ion solid-state electrolyte comprises a substrate and an interface protection layer.

[0010] The interface protection layer covers the surface of the substrate.

[0011] The substrate is a polymer electrolyte.

[0012] The interface protection layer is a metal.

[0013] The metal comprises at least one of Sn, Zn, In, Sb, Bi and Ge.

[0014] Preferably, the polymer electrolyte comprises a polymer and a sodium salt.

[0015] The polymer comprises at least one of polyethylene oxide, polyvinylidene fluoride, polyvinyl alcohol, polyacrylonitrile, polyethyl acrylate and polyethylene glycol.

[0016] The sodium salt comprises at least one of sodium bis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide, sodium hexafluorophosphate, sodium fluoroborate and sodium nitrate.

[0017] Further preferably, the polymer is polyethylene oxide.

[0018] Further preferably, the sodium salt is sodium bis(trifluoromethanesulfonyl)imide.

[0019] Preferably, the metal comprises at least one of Sn, Zn and In.

[0020] The application covers a suitable metal as an interface protective layer (including Sn, Zn, In, Sb, Bi, Ge) on the surface of a sodium ion solid-state electrolyte substrate, forming a thin layer of metal on the surface of the electrolyte, which can enhance the surface wettability of sodium metal and the stability of the electrolyte interface after alloying with the negative electrode sodium metal, facilitating uniform deposition of sodium, thereby reducing the interface impedance and inhibiting the generation of sodium dendrites. Metals with better alloying performance with metallic sodium exhibit better performance in this process. This interface protective layer strategy can effectively reduce the damage to the solid-state electrolyte interface and reduce the risk of electrolyte penetration by dendrites, thereby significantly improving the cycle stability and safety performance of the battery.

[0021] Preferably, the thickness of the interface protective layer is 50 nm to 2000 nm.

[0022] Further preferably, the thickness of the interface protective layer is 50 nm to 1000 nm.

[0023] Preferably, the polymer electrolyte includes at least one of a polyethylene oxide-bis-trifluoromethane sulfonimide sodium electrolyte sheet, a polyethylene oxide-bis-fluorosulfonimide sodium electrolyte sheet, a polyethylene glycol-bis-trifluoromethane sulfonimide sodium electrolyte sheet, and a polyethylene glycol-sodium hexafluorophosphate electrolyte sheet.

[0024] Preferably, the thickness of the polyethylene oxide-bis-trifluoromethane sulfonimide sodium electrolyte sheet is 50 μm to 500 μm.

[0025] Further preferably, the thickness of the polyethylene oxide-bis-trifluoromethane sulfonimide sodium electrolyte sheet is 80 μm to 200 μm.

[0026] Preferably, the method for preparing the polyethylene oxide-bis-trifluoromethane sulfonimide sodium electrolyte sheet includes the following steps:

[0027] Disperse polyethylene oxide and bis-trifluoromethane sulfonimide sodium in a solvent, stir to obtain a mixed solution; coat the mixed solution on a carrier and dry to obtain a polyethylene oxide-bis-trifluoromethane sulfonimide sodium electrolyte sheet.

[0028] Preferably, the molar ratio of EO units in the polyethylene oxide to sodium ions in the bis-trifluoromethane sulfonimide sodium is 5-30:1.

[0029] Further preferably, the molar ratio of EO units in the polyethylene oxide to sodium ions in the bis-trifluoromethane sulfonimide sodium is 15-25:1. This ratio can achieve good dissolution and transport of sodium ions in the electrolyte, thereby improving the ionic conductivity of the electrolyte.

[0030] Preferably, the solvent includes acetonitrile.

[0031] Preferably, the coating method comprises at least one of doctor blade coating, pouring.

[0032] Preferably, the carrier comprises any one of silicone oil paper, silica gel sheet, polytetrafluoroethylene plate.

[0033] Preferably, the stirring temperature is 30-120°C, and the stirring time is 4-48h.

[0034] Further preferably, the stirring temperature is 60-90°C, and the stirring time is 24-36h. Under this stirring condition, polyethylene oxide and sodium bis-trifluoromethanesulfonimide can be fully mixed to form a uniform mixed solution, and the polymer and the sodium salt are uniformly distributed, thereby improving the uniformity and consistency of the electrolyte; the ionic conductivity of the electrolyte can also be improved, and the internal resistance is reduced, thereby improving the battery performance while taking into account the production efficiency.

[0035] Preferably, the drying temperature is 30-120°C, and the drying time is 8-48h.

[0036] Further preferably, the drying temperature is 80-100°C, and the drying time is 24-36h. This drying condition can reduce the formation of bubbles and pores in the electrolyte, improve the density and stability of the electrolyte, and at the same time take into account the production efficiency.

[0037] The second aspect of the present application provides a preparation method of a sodium ion solid-state electrolyte.

[0038] Specifically, the method comprises the following steps:

[0039] The metal is sputtered on the surface of the substrate by a magnetron sputtering technique to form an interface protection layer, and the sodium ion solid-state electrolyte is prepared.

[0040] Preferably, the sputtering power is 3-20W, the sputtering time is 10-1200s, and the pressure is 0.2-20Pa.

[0041] Further preferably, the sputtering power is 5-15W, the sputtering time is 50-600s, and the pressure is 0.2-8Pa.

[0042] Preferably, the sputtering gas comprises argon.

[0043] The preparation method uniformly sputters metal atoms to the surface of the solid-state polymer electrolyte by a magnetron sputtering technology, and the properties and thickness of the sputtered metal thin layer are accurately controlled by controlling the composition, power, time and pressure of the sputtering gas during the preparation process, so as to realize the accurate regulation of the solid-state electrolyte. Moreover, the preparation method is suitable for different types of polymer electrolytes and inorganic electrolytes, has strong universality, and in actual production, the most suitable electrolyte material can be selected according to the specific application requirement, and the corresponding solid-state electrolyte can be prepared. In summary, the preparation method realizes flexible preparation of different types of electrolytes, and has the advantages of high purity, high control accuracy, good thin film uniformity, high preparation efficiency and the like.

[0044] The third aspect of the present application provides a full solid-state sodium ion battery.

[0045] Specifically, the full solid-state sodium ion battery comprises the sodium ion solid-state electrolyte provided in the first aspect.

[0046] Compared with the prior art, the beneficial effects of the present application are as follows:

[0047] The present application can effectively prevent the growth of sodium dendrites, reduce the damage of the sodium ion solid-state electrolyte during the battery cycle process, improve the interface wettability, reduce the interface charge conduction impedance, thereby improving the interface stability of the sodium metal anode and the solid-state electrolyte, and further obtaining a stable long-cycle full solid-state sodium ion battery, by covering a suitable metal source (such as Sn, Zn, In, Sb, Bi and Ge, etc.) on the surface of the substrate as an interface protection layer, and forming a stable metal thin layer interface by alloying sodium and the metal source. BRIEF DESCRIPTION OF DRAWINGS

[0048] FIG. 1 is a photograph of a PEO substrate without sputtered metal and a sodium ion solid-state electrolyte after sputtering different metals;

[0049] FIG. 2 is a surface morphology SEM graph of PEO-Sn deposited sodium provided in Example 1;

[0050] FIG. 3 is a surface morphology SEM graph of PEO-NaTFSI deposited sodium provided in Comparative Example 1;

[0051] FIG. 4 is an XRD characterization test result graph of the sodium ion solid-state electrolyte provided in Example 1, Example 2, Example 3, Example 4, Comparative Example 1;

[0052] FIG. 5 is a FIB-SEM characterization test result graph of the sodium ion solid-state electrolyte provided in Example 1;

[0053] FIG. 6 is an AC impedance spectrum graph of a sodium-sodium symmetric battery made of the sodium ion solid-state electrolyte corresponding to Example 1, Example 5, Example 6, Comparative Example 1, Comparative Example 2 and Comparative Example 3;

[0054] Figure 7 is an AC impedance spectrum of a sodium-sodium symmetric battery made of the sodium ion solid-state electrolyte of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1;

[0055] Figure 8 is a comparison chart of the cycle charge-discharge performance results of the sodium-sodium symmetric batteries made of the sodium ion solid-state electrolyte of Example 1 and Comparative Example 1;

[0056] Figure 9 is a comparison chart of the long cycle voltage distribution test results of the sodium-sodium symmetric batteries made of the sodium ion solid-state electrolyte of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0057] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0058] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0059] Example 1

[0060] Sodium ion solid-state electrolyte and preparation method thereof.

[0061] The preparation method is as follows:

[0062] (1) Polyethylene oxide (PEO) and sodium bis-trifluoromethanesulfonimide (NaTFSI) (Macklin, >98%) were added to ultra-dry acetonitrile, the molar ratio of EO units to sodium ions was set to 20:1, and the concentration of PEO in acetonitrile was 0.1 g / mL; stirred at 80°C for 24h until a uniform mixed solution was formed, then the mixed solution was poured on a silicone oil paper, coated with a doctor blade, and dried at 80°C for 24h; finally, after cooling, it was cut into a round piece of appropriate size, and the thickness was measured to be 140μm, i.e. PEO-NaTFSI electrolyte sheet was obtained.

[0063] (2) The PEO-NaTFSI electrolyte sheet was subjected to magnetron sputtering, and Sn was sputtered onto the surface of the PEO-NaTFSI electrolyte sheet using magnetron sputtering technology under argon environment with Sn metal source as the target material, to obtain sodium ion solid-state electrolyte PEO-Sn; the sputtering power was 15W; the sputtering time was 600s; and the sputtering vacuum degree pressure was 5Pa.

[0064] Example 2

[0065] Sodium ion solid-state electrolyte and preparation method thereof.

[0066] The difference from Example 1 is that the sputtering time is 50 s.

[0067] Example 3

[0068] Sodium-ion solid-state electrolyte and method for producing the same.

[0069] The difference from Example 1 is that the sputtering time is 150 s.

[0070] Example 4

[0071] Sodium-ion solid-state electrolyte and method for producing the same.

[0072] The difference from Example 1 is that the sputtering time is 300 s.

[0073] Example 5

[0074] Sodium-ion solid-state electrolyte and method for producing the same.

[0075] The difference from Example 3 is that the metal is Zn.

[0076] Example 6

[0077] Sodium-ion solid-state electrolyte and method for producing the same.

[0078] The difference from Example 3 is that the metal is In.

[0079] Comparative Example 1

[0080] Sodium-ion solid-state electrolyte and method for producing the same.

[0081] The difference from Example 1 is that no metal is sputtered.

[0082] Comparative Example 2

[0083] Sodium-ion solid-state electrolyte and method for producing the same.

[0084] The difference from Example 1 is that the metal is Au.

[0085] Comparative Example 3

[0086] Sodium-ion solid-state electrolyte and method for producing the same.

[0087] The difference from Example 1 is that the metal is Cu.

[0088] Performance test:

[0089] 1. The sodium-sodium symmetric batteries assembled with the sodium ion solid electrolytes provided by Example 1 and Comparative Example 1 were subjected to metal sodium deposition, and then the batteries were disassembled, and each sodium ion solid electrolyte was subjected to SEM characterization, and the detection results are shown in FIG. 2 and FIG. 3, FIG. 2 is the surface morphology of the PEO-Sn after deposition of metal sodium, and FIG. 3 is the surface morphology of the PEO-NaTFSI after deposition of sodium.

[0090] As can be seen from FIG. 2, the surface of the modified PEO-Sn in Example 1 appears to be spherical and moss-like metal sodium deposition; as can be seen from FIG. 3, the surface of the PEO-NaTFSI without surface metal modification in Comparative Example 1 appears to be dendritic metal sodium dendrites; these morphological characteristics show that, under the modification of the Sn layer, Na nucleates and grows in a spherical or moss-like form, thereby preventing the formation of Na dendrites.

[0091] 2. The sodium ion solid electrolytes provided by Example 1, Example 2, Example 3, Example 4, Comparative Example 1 were subjected to XRD characterization test, and Example 1 was subjected to FIB-SEM characterization test, and the detection results are shown in FIG. 4 and FIG. 5, respectively.

[0092] As can be seen from FIG. 4, as the sputtering time increases, the Sn corresponding diffraction peak signal is enhanced, indicating that the Sn metal content on the surface of the PEO-NaTFSI is continuously increasing. As can be seen from FIG. 5, after focused ion beam cutting, the thickness of the Sn layer can be observed to be about 0 nm to about 800 nm, wherein the thickness after magnetron sputtering for 600 s is about 600 nm to about 800 nm. At the same time, it is found that the thickness after magnetron sputtering for 300 s is about 300 nm to about 400 nm, the thickness after magnetron sputtering for 150 s is about 150 nm to about 200 nm, and the thickness after magnetron sputtering for 50 s is about 50 nm to about 100 nm. It can be seen that by adjusting the sputtering time, the thickness of the interface protection layer on the surface of the solid electrolyte substrate can be accurately controlled.

[0093] 3. The sodium ion solid electrolytes provided by Example 1, Example 5, Example 6, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were prepared into corresponding sodium-sodium symmetric batteries. A bias voltage of 10 mV was applied in a frequency range of 1 Hz to 7 MHz, and electrochemical impedance test was performed, and the impedance data graph is shown in FIG. 6.

[0094] In FIG. 6, Example 1 (PEO-Sn), Example 5 (PEO-Zn), Example 6 (PEO-In), Comparative Example 2 (PEO-Au), Comparative Example 3 (PEO-Cu) are sodium-sodium symmetric batteries assembled by sodium ion solid-state electrolytes obtained after sputtering the same time 150s with PEO-NaTFSI as the base and different metal sources; PEO is a sodium-sodium symmetric battery directly assembled by PEO-NaTFSI solid-state electrolyte without sputtering metal, corresponding to Comparative Example 1. As can be seen from FIG. 6, among these metal layers, the metal Sn, Zn, In has a certain optimization effect on the sodium metal interface resistance, among which the Sn layer has the best optimization effect on the resistance of the sodium-sodium symmetric battery, and Au and Cu as comparative examples not only fail to reduce the interface impedance, but also affect the original performance of the battery. Among them, the impedance of sputtered Cu is much larger than that of unsputtered PEO, and the sputtered Au PEO is directly penetrated by the spray, resulting in short circuit. In particular, the difference in resistance of these sodium-sodium symmetric batteries is equivalent to the difference in interface resistance between the solid-state electrolyte and the sodium metal negative electrode, because the resistance of the bulk PEO is constant.

[0095] 4. The sodium ion solid-state electrolytes provided by Example 1, Example 2, Example 3, Example 4, Comparative Example 1 were prepared into corresponding sodium-sodium symmetric batteries for electrochemical impedance testing. For the sodium-sodium symmetric batteries prepared from the above sodium ion solid-state electrolytes, a bias voltage of 10 mV was applied in the frequency range of 1 Hz to 7 MHz for EIS testing, and the AC impedance spectrum of the sodium-sodium symmetric battery corresponding to the solid-state electrolyte of Example 1, Example 2, Example 3, Example 4, Comparative Example 1 was obtained as shown in FIG. 7.

[0096] In FIG. 7, Example 2 (PEO-50s), Example 3 (PEO-150s), Example 4 (PEO-300s), Example 1 (PEO-600s) are sodium-sodium symmetric batteries assembled by sodium ion solid-state electrolytes obtained after sputtering different times with PEO-NaTFSI as the base and Sn as the metal source; PEO is a sodium-sodium symmetric battery directly assembled by PEO-NaTFSI solid-state electrolyte without sputtering metal, corresponding to Comparative Example 1. As can be seen from FIG. 7, as the sputtering time increases, the impedance of the sodium-sodium symmetric battery gradually decreases, which indicates that the degree of alloying between Na metal and the electrolyte is continuously improving, the interface impedance is gradually decreasing, and the interface compatibility is gradually improving. Among them, the sodium ion solid-state electrolyte corresponding to Example 1 obtained by sputtering 600s has the best interface impedance performance. It can be understood that the sputtering time of the metal plays a key role in the performance of the obtained sodium ion solid-state electrolyte, and appropriately prolonging the sputtering time can effectively improve the interface contact performance of the solid-state electrolyte.

[0097] 5. Sodium-ion solid-state electrolytes provided by Example 1 and Comparative Example 1 were prepared into corresponding sodium-sodium symmetric batteries and sodium-ion batteries, and the above batteries were subjected to the following electrochemical performance tests:

[0098] (1) Cyclic charge-discharge test. For the sodium-ion batteries prepared from the above sodium-ion solid-state electrolytes, the first 2 cycles were subjected to charge-discharge at 0.2C, and the following cycles were subjected to charge-discharge at 0.5C, and the cyclic charge-discharge performance diagram shown in Figure 8 was obtained.

[0099] In Figure 8, PEO is a sodium-ion battery composed of PEO-NaTFSI electrolyte corresponding to Comparative Example 1 without sputtered metal, and PEO-Sn is a sodium-ion battery assembled from the solid-state electrolyte PEO-Sn provided by Example 1. As can be seen from Figure 8, PEO without a sputtered metal layer exhibits extremely poor stability of coulombic efficiency, and the coulombic efficiency jumps during the initial cycle process, and the capacity begins to rapidly decay after 180 cycles; PEO-Sn exhibits extremely stable cycle performance, with a coulombic efficiency of nearly 99% for each cycle, and can be stably cycled for more than 400 cycles without significant capacity decay.

[0100] (2) Long cycle voltage distribution test. For the sodium-sodium symmetric batteries prepared from the above sodium-ion solid-state electrolytes, a single cycle was subjected to 0.1 mA / cm 2 discharge for 30 min each, and the voltage distribution in the long cycle test was recorded, and the test results are shown in Figure 9.

[0101] In Figure 9, the long cycle test of the sodium-sodium symmetric batteries assembled with the electrolytes of Example 1 and Comparative Example 1 was carried out at 60°C, in order to ensure that the batteries can be charged and discharged within the normal voltage range while observing the Na deposition morphology on the surface of the multiple electrolytes. As can be seen from Figure 9, the sodium symmetric battery prepared from the PEO-NaTFSI electrolyte corresponding to Comparative Example 1 without sputtered metal has extremely unstable voltage during the cycle process, and micro-short circuits and large voltage fluctuations occur multiple times, and finally the battery is pierced by dendritic crystals after 116 h of cycling, the voltage drops to 0V, and the battery is short-circuited; while the sodium-sodium symmetric battery assembled from the electrolyte corresponding to Example 1 with sputtered Sn can still be stably cycled after 1200 h of continuous cycle charging, and the charge-discharge voltage remains basically stable.

[0102] The preferred embodiments of the present application are described in detail above. It should be understood that those of ordinary skill in the art can make modifications and changes to the embodiments of the present application without creative effort, based on the concept of the present application. Therefore, any modifications, equivalent replacements, improvements, etc. obtained by logical analysis, reasoning or limited experiments based on the prior art according to the concept of the present application shall be within the scope of protection defined by the claims.

Claims

1. A sodium-ion solid-state electrolyte, characterized by, The interface protection layer covers the surface of the substrate; The interface protection layer covers the surface of the substrate; The substrate is a polymer electrolyte; The interface protection layer is a metal; The metal includes at least one of Sn, Zn, In, Sb, Bi and Ge.

2. The sodium-ion solid-state electrolyte of claim 1, wherein, The polymer electrolyte includes a polymer and a sodium salt; The polymer includes at least one of polyethylene oxide, polyvinylidene fluoride, polyvinyl alcohol, polyacrylonitrile, polyethyl acrylate and polyethylene glycol; The sodium salt includes at least one of sodium bis-trifluoromethanesulfonimide, sodium bisfluorosulfonimide, sodium hexafluorophosphate, sodium fluoroborate and sodium nitrate.

3. The sodium-ion solid-state electrolyte of claim 1, wherein, The thickness of the interface protection layer is 50 nm to 2000 nm.

4. The sodium-ion solid-state electrolyte of claim 1, wherein, The polymer electrolyte includes at least one of polyethylene oxide-sodium bis-trifluoromethanesulfonimide electrolyte sheet, polyethylene oxide-sodium bisfluorosulfonimide electrolyte sheet, polyethylene glycol-sodium bis-trifluoromethanesulfonimide electrolyte sheet and polyethylene glycol-sodium hexafluorophosphate electrolyte sheet.

5. The sodium-ion solid-state electrolyte of claim 4, wherein, The thickness of the polyethylene oxide-sodium bis-trifluoromethanesulfonimide electrolyte sheet is 50 μm to 500 μm.

6. The sodium-ion solid-state electrolyte of claim 4, wherein, The preparation method of the polyethylene oxide-sodium bis-trifluoromethanesulfonimide electrolyte sheet includes the following steps: The polyethylene oxide and the sodium bis-trifluoromethanesulfonimide are dispersed in a solvent, stirred to obtain a mixed solution; the mixed solution is coated on a carrier and dried to obtain the polyethylene oxide-sodium bis-trifluoromethanesulfonimide electrolyte sheet.

7. The sodium-ion solid-state electrolyte of claim 4, wherein, The molar ratio of the EO unit in the polyethylene oxide to the sodium ion in the sodium bis-trifluoromethanesulfonimide is 5-30:

1.

8. The method of producing a sodium-ion solid-state electrolyte according to any one of claims 1 to 7, characterized by, The method includes the following steps: The metal is sputtered on the surface of the substrate by a magnetron sputtering technology to form an interface protection layer, and a sodium ion solid-state electrolyte is prepared.

9. The production method according to claim 8, characterized by, The sputtering power is 3 W to 20 W, the time is 10 s to 1200 s, and the pressure is 0.2 Pa to 20 Pa.

10. An all-solid-state sodium-ion battery, characterized by, The all-solid-state sodium ion battery includes the sodium ion solid-state electrolyte according to any one of claims 1 to 7.

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