Prussian white-based halide-based high-performance sodium ion battery and preparation method thereof

Abstract

The invention discloses a Prussian white-based halide-based high-performance sodium ion battery and a preparation method thereof, and the preparation method comprises the following steps: S1, pressing sodium-tin alloy powder to complete the preparation of a negative electrode layer; s2, sulfide solid electrolyte powder and heterostructure halide solid electrolyte powder are sequentially spread on the surface of one side of the negative electrode layer and then pressed, and preparation of a solid electrolyte layer is completed; and S3, spreading the Prussian white positive electrode powder on one side, opposite to the negative electrode layer, of the solid electrolyte layer, and pressing to complete preparation of the positive electrode layer, so as to obtain the Prussian white based halide-based high-performance sodium ion battery. The room-temperature ionic conductivity of the heterostructure halide solid electrolyte reaches 2.6 mS / cm, the electrochemical window is 3.9-4.2 V, the capacity of an all-solid-state sodium ion battery assembled by combining the Prussian white positive electrode, the Na3PS4 sulfide solid electrolyte and the sodium-tin alloy negative electrode can reach 139 mAh g <-1 >, and the heterostructure halide solid electrolyte shows excellent cycle performance and rate capability and has commercial application potential.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and particularly relates to a high-performance sodium-ion battery based on Prussian white halide and a preparation method thereof. Background Art

[0002] In recent years, due to the limitations of fossil fuels, the development of renewable energy has become a technological frontier and attracted much attention. Traditional lithium-ion batteries have been widely used in the field of electric vehicles due to their high energy density, long cycle life, lightweight and miniaturization. However, due to the shortage of lithium resources, uneven geographical distribution and excessive price fluctuations, it is difficult to meet the long-term requirements of the large-scale energy storage market. Metal sodium has the advantages of low cost and wide distribution, and the charge-discharge principle of sodium-ion batteries is similar to that of lithium-ion batteries, so sodium-ion batteries are regarded as the most promising alternatives. However, traditional sodium-ion batteries using liquid organic electrolytes still face the same safety hazards as traditional lithium-ion batteries: the flammability of the electrolyte leads to the risk of thermal runaway, and sodium dendrites are prone to pierce the diaphragm and cause short circuits during repeated charge and discharge. In this context, all-solid-state sodium-ion batteries completely replace the liquid electrolyte with a solid electrolyte. In theory, all-solid-state sodium-ion batteries can meet the requirements of both high energy density and high safety. Therefore, it is still necessary to develop all-solid-state sodium-ion batteries. Halide solid electrolytes, with their high ionic conductivity, wide voltage window and interface compatibility, have become a very promising candidate material in the field of all-solid-state sodium-ion batteries.

[0003] Currently, the cathode materials of sodium-ion batteries usually use layered transition metal oxides, polyanion compounds, organic cathode materials and Prussian white analogues. Layered transition metal oxides have high capacity and mature processes, but poor cycling ability and are sensitive to air; polyanion compounds have long life and high safety, but low capacity. Organic materials are renewable and have high theoretical capacity, but low voltage and are easily soluble; Prussian white is considered to be one of the most promising cathode materials for sodium-ion batteries due to its large ion diffusion channels, low lattice strain, simple preparation, non-toxicity and low cost. Among them, Prussian white as a cathode material for sodium-ion batteries has the advantages of high theoretical capacity (up to 170 mAh / g), low raw material price and scalable preparation, and has good prospects in industrial production and large-scale energy storage technologies. Prussian white materials have an open three-dimensional ion channel, which enables extremely fast sodium ion insertion / extraction kinetics, achieving low lattice tension and fast ion diffusion kinetics. However, crystallization water is inevitably introduced into the lattice of Prussian white materials. If an organic electrolyte is used in sodium-ion batteries, the presence of crystallization water will cause battery capacity loss, and the interface formed by Prussian white and the electrolyte is unstable, which will prevent sodium-ion batteries from achieving stable long-term cycling and hinder their practical applications. Summary of the Invention

[0004] The object of the present invention is to provide a Prussian white-based high-performance halide-based sodium ion battery and a preparation method thereof. The specific technical solution is as follows: A preparation method of a Prussian white-based high-performance halide-based sodium ion battery includes: S1, pressing sodium-tin alloy powder to complete the preparation of the negative electrode layer; S2, spreading sulfide solid electrolyte powder and heterostructure-type halide solid electrolyte powder on one side surface of the negative electrode layer in sequence and then pressing to complete the preparation of the solid electrolyte layer; S3, spreading Prussian white positive electrode powder on the side of the solid electrolyte layer facing away from the negative electrode layer and then pressing to complete the preparation of the positive electrode layer, obtaining a Prussian white-based high-performance halide-based sodium ion battery.

[0005] The preparation method of the Prussian white positive electrode powder includes: synthesizing Prussian white by the organic solvothermal method; mixing and grinding Prussian white, a conductive agent, and a high ion conductivity solid electrolyte to obtain the Prussian white positive electrode powder.

[0006] Synthesizing Prussian white by the organic solvothermal method specifically includes: dissolving sodium ferrocyanide in an organic solvent to obtain solution A; dissolving a soluble divalent transition metal salt in an organic solvent, and then adding a chelating agent to obtain solution B; mixing solution A and solution B for a solvothermal reaction to obtain a reaction solution; performing solid-liquid separation on the reaction solution, and washing and drying the obtained solid matter to obtain Prussian white with the general formula Na x Fe[Fe(CN)6], where 1.8 ≤ x < 2.2.

[0007] The mass ratio of Prussian white, the conductive agent, and the high ion conductivity solid electrolyte is: (30 - 40):(5 - 10):(60 - 70).

[0008] The conductive agent is at least one of carbon black, acetylene black, carbon nanotubes, and Ketjen black, and the high ion conductivity solid electrolyte is 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] or 0.57[Na 0.75 La 1.75 Cl6]-0.43[NaTaCl6].

[0009] The preparation method of the heterostructure-type halide solid electrolyte powder includes: ball-milling sodium chloride, tantalum chloride, samarium chloride, and lanthanum chloride to obtain a precursor powder; ball-milling the precursor powder again according to a preset ratio to obtain the heterostructure-type halide solid electrolyte.

[0010] When ball-milling sodium chloride, tantalum chloride, samarium chloride, and lanthanum chloride: After mixing sodium chloride, tantalum chloride, samarium chloride, and lanthanum chloride respectively, they are sealed in a zirconia jar under vacuum for dry ball-milling, and ball-milled at a speed of 500 - 550 rpm for 18 - 24 hours to obtain precursor powder; among them, the atomic ratio of sodium chloride to tantalum chloride is 1:1, the atomic ratio of sodium chloride to samarium chloride is 0.75:1.75, and the atomic ratio of sodium chloride to lanthanum chloride is 0.75:1.75.

[0011] When ball-milling the precursor powder again according to a preset ratio: The precursor powder is sealed in a zirconia jar under vacuum for dry ball-milling, and ball-milled at a speed of 500 - 550 rpm for 9 - 18 hours to obtain a heterostructured halide solid electrolyte powder composed of high-coordination framework Na 3x M 2-x Cl6 (M = La, Sm) and low-coordination framework NaTaCl6; among them, the atomic ratio of NaTaCl6 to Na 0.75 Sm 1.75 Cl6 is (0.38 - 0.40):(0.60 - 0.62), and the atomic ratio of NaTaCl6 to Na 0.75 La 1.75 Cl6 is (0.40 - 0.43):(0.57 - 0.60).

[0012] The preparation method of sulfide solid electrolyte powder includes: Ball-milling sodium sulfide and phosphorus pentasulfide to obtain sulfide solid electrolyte precursor powder; After calcining the sulfide solid electrolyte precursor powder, sulfide solid electrolyte is obtained.

[0013] When ball-milling sodium sulfide and phosphorus pentasulfide: Sodium sulfide and phosphorus pentasulfide are sealed in a zirconia jar under vacuum for dry ball-milling, and ball-milled at a speed of 500 - 600 rpm for 6 - 12 hours to obtain sulfide solid electrolyte precursor powder; among them, the atomic ratio of sodium sulfide to phosphorus pentasulfide is (1.3 - 1.5):(0.3 - 0.5).

[0014] When calcining the sulfide solid electrolyte precursor powder: The sulfide solid electrolyte precursor powder is calcined at 200 - 260 °C under vacuum conditions for 6 - 8 hours to obtain sulfide solid electrolyte powder with the composition of Na3PS4.

[0015] The preparation method of sodium-tin alloy powder includes: Heating metallic sodium to the molten state at 100 °C under vacuum conditions, adding tin metal powder, and after sufficient grinding, obtaining sodium-tin alloy powder with the composition of Na 15 Sn4, Na9Sn4, or Na3Sn1.

[0016] A high-performance sodium-ion battery based on Prussian white, prepared by using the preparation method of any one of the high-performance sodium-ion batteries based on Prussian white in claims 1-12, includes a Prussian white positive electrode, a heterostructured halide solid electrolyte, a sulfide solid electrolyte, and a sodium-tin alloy negative electrode.

[0017] The above technical solution of the present invention has the following beneficial technical effects: In the present invention, the sodium-ion battery is assembled by a Prussian white positive electrode, a sodium-tin alloy sodium negative electrode, a heterostructured halide solid electrolyte, and a sulfide solid electrolyte. Among them, the composition of the heterostructured halide solid electrolyte is a high-coordination framework Na 3x M 2-x Cl6 (M = La, Sm) and a low-coordination framework NaTaCl6. By utilizing the synergistic effect between the high-coordination and low-coordination halide frameworks, the incorporation of the amorphous component NaTaCl6 significantly increases the ionic conductivity of the target component and helps to achieve fast long-range sodium conduction macroscopically; the main component of the sulfide solid electrolyte is Na3PS4, which is mainly used to protect the sodium-tin alloy negative electrode; the Prussian white material has an open three-dimensional ion channel, enabling extremely fast sodium ion insertion and extraction kinetics, achieving low lattice tension and fast ion diffusion kinetics. In combination with the heterostructured halide solid electrolyte with high room-temperature ionic conductivity and the sodium-tin alloy negative electrode, the electrochemical performance of the all-solid-state sodium-ion battery at room temperature is effectively improved. The room-temperature ionic conductivity of the heterostructured halide solid electrolyte of the present invention reaches 2.6 mS / cm, and the electrochemical window is 3.9-4.2 V. The all-solid-state sodium-ion battery assembled with the Prussian white positive electrode, Na3PS4 sulfide solid electrolyte, and sodium-tin alloy negative electrode can reach a capacity of 139 mAh g-1 and exhibits excellent cycle performance and rate performance, having the potential for commercial application. This sodium-ion battery is assembled by a Prussian white positive electrode, a sodium-tin alloy sodium negative electrode, a heterostructured halide solid electrolyte, and a sulfide solid electrolyte. The Prussian white positive electrode is synthesized by the organic solvent thermal method, with few defect vacancies and low crystal water content in itself. And the heterostructured halide solid electrolyte inhibits the lattice distortion of Prussian white. Prussian white is prone to structural collapse during the sodium ion insertion and extraction process, while the solid electrolyte has high mechanical strength, can buffer volume changes, reduce the rupture of positive electrode particles, and extend the cycle life. Solving the crystal water problem, the residual crystal water in the synthesis of Prussian white is easy to react with the traditional liquid electrolyte to generate gas, while the halide solid electrolyte has no liquid components, which can avoid side reactions caused by water molecules and improve safety. Description of the Drawings

[0018] Figure 1 Schematic diagram of the structural composition of the all-solid-state battery prepared in Example 1; Figure 2 For 0.62[Na0.75 Sm 1.75 Impedance spectrum of 0.62[Na Figure 3 Sm 0.75 Sm 1.75 Linear sweep voltammogram of 0.62[Na Figure 4 Charge-discharge curve of the all-solid-state battery in Example 1 at 25 °C room temperature; Figure 5 Cycling performance (upper) of the all-solid-state battery prepared in Example 1 at a current density of 0.5 C and cycling performance (lower) at a current density of 0.1 C; Figure 6 Rate performance (upper) of the all-solid-state battery prepared in Example 1 at 50 °C high temperature and corresponding charge-discharge curve (lower); Figure 7 Rate performance (upper) of the all-solid-state battery prepared in Example 1 at 25 °C room temperature and corresponding charge-discharge curve (lower); Figure 8 Charge-discharge curve (upper) of the all-solid-state battery prepared in Example 2 at 25 °C room temperature and charge-discharge curve (lower) of the all-solid-state battery prepared in Example 3 at 25 °C room temperature; Figure 9 Charge-discharge curve (upper) of the all-solid-state battery prepared in Example 4 at 25 °C room temperature and charge-discharge curve (lower) of the all-solid-state battery prepared in Example 5 at 25 °C room temperature. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the detailed implementation manners and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0020] Such as Figure 1As shown, a preparation method of a Prussian white-based high-performance halide-based sodium ion battery includes: S1. Pressing sodium-tin alloy powder to complete the preparation of the negative electrode layer; S2. Spreading sulfide solid electrolyte powder and heterostructured halide solid electrolyte powder on one side surface of the negative electrode layer in sequence and then pressing to complete the preparation of the solid electrolyte layer; S3. Spreading Prussian white positive electrode powder on the side of the solid electrolyte layer facing away from the negative electrode layer and then pressing to complete the preparation of the positive electrode layer, obtaining a Prussian white-based high-performance halide-based sodium ion battery. The sodium ion battery is assembled by a Prussian white positive electrode, a sodium-tin alloy sodium negative electrode, a heterostructured halide solid electrolyte, and a sulfide solid electrolyte, wherein the composition of the heterostructured halide solid electrolyte is a high-coordination framework Na 3x M 2-x Cl6 (M = La, Sm) and a low-coordination framework NaTaCl6. By utilizing the synergistic effect between the high-coordination and low-coordination halide frameworks, the incorporation of the amorphous component NaTaCl6 significantly increases the ionic conductivity of the target component and contributes to achieving fast long-range sodium conduction macroscopically; the main component of the sulfide solid electrolyte is Na3PS4, which is mainly used to protect the sodium-tin alloy negative electrode; the Prussian white material has an open three-dimensional ion channel, enabling extremely fast sodium ion deintercalation kinetics, achieving low lattice tension and fast ion diffusion kinetics. Cooperating with the heterostructured halide solid electrolyte with high room-temperature ionic conductivity and the sodium-tin alloy negative electrode, it effectively improves the electrochemical performance of the all-solid-state sodium ion battery at room temperature. The room-temperature ionic conductivity of the heterostructured halide solid electrolyte of the present invention reaches 2.6 mS / cm, and the electrochemical window is 3.9 - 4.2 V. The all-solid-state sodium ion battery assembled by combining the Prussian white positive electrode, the Na3PS4 sulfide solid electrolyte, and the sodium-tin alloy negative electrode can reach a capacity of 139 mAh g-1 and exhibits excellent cycling performance and rate performance, having the potential for commercial application. The sodium ion battery is assembled by a Prussian white positive electrode, a sodium-tin alloy sodium negative electrode, a heterostructured halide solid electrolyte, and a sulfide solid electrolyte. The Prussian white positive electrode is synthesized by the organic solvothermal method, with few self-defect vacancies and low crystal water content. And the heterostructured halide solid electrolyte inhibits the lattice distortion of Prussian white. Prussian white is prone to structural collapse during the sodium ion deintercalation process, while the solid electrolyte has high mechanical strength, can buffer volume changes, reduce the rupture of positive electrode particles, and extend the cycle life. Solving the crystal water problem, the residual crystal water in the synthesis of Prussian white is easy to react with the traditional liquid electrolyte to generate gas, while the halide solid electrolyte has no liquid components, which can avoid side reactions caused by water molecules and improve safety.

[0021] The preparation method of the Prussian white positive electrode powder includes: synthesizing Prussian white by the organic solvothermal method; mixing and grinding Prussian white, a conductive agent, and a high-ion-conductivity solid electrolyte to obtain the Prussian white positive electrode powder.

[0022] The synthesis of Prussian white by the organic solvothermal method specifically includes: dissolving sodium ferrocyanide in an organic solvent to obtain solution A; dissolving a soluble divalent transition metal salt in an organic solvent, and then adding a chelating agent to obtain solution B; mixing solution A and solution B for solvothermal reaction to obtain a reaction solution; performing solid-liquid separation on the reaction solution, and washing and drying the obtained solid matter to obtain Prussian white with the general formula Na x Fe[Fe(CN)6], where 1.8 ≤ x < 2.2.

[0023] The mass ratio of Prussian white, conductive agent and high ionic conductivity solid electrolyte is: (30 - 40):(5 - 10):(60 - 70).

[0024] The conductive agent is at least one of carbon black, acetylene black, carbon nanotubes and Ketjen black, and the high ionic conductivity solid electrolyte is 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] or 0.57[Na 0.75 La 1.75 Cl6]-0.43[NaTaCl6].

[0025] The preparation method of the heterostructure-type halide solid electrolyte powder includes: ball-milling sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride to obtain a precursor powder; ball-milling the precursor powder again according to a preset ratio to obtain a heterostructure-type halide solid electrolyte.

[0026] When ball-milling sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride: after mixing sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride respectively, they are sealed in a zirconia jar under vacuum for dry ball-milling, and ball-milled at a speed of 500 - 550 rpm for 18 - 24 hours to obtain a precursor powder; wherein, the atomic ratio of sodium chloride to tantalum chloride is 1:1, the atomic ratio of sodium chloride to samarium chloride is 0.75:1.75, and the atomic ratio of sodium chloride to lanthanum chloride is 0.75:1.75.

[0027] When ball-milling the precursor powder again according to a preset ratio: the precursor powder is sealed in a zirconia jar under vacuum for dry ball-milling, and ball-milled at a speed of 500 - 550 rpm for 9 - 18 hours to obtain a heterostructure-type halide solid electrolyte powder with a composition of high coordination framework Na 3x M 2-x Cl6 (M = La, Sm) and low coordination framework NaTaCl6; wherein, the ratio of NaTaCl6 to Na 0.75 Sm 1.75The atomic ratio of Cl6 is (0.38 - 0.40):(0.60 - 0.62), and the atomic ratio of NaTaCl6 to Na 0.75 La 1.75 The atomic ratio of Cl6 is (0.40 - 0.43):(0.57 - 0.60).

[0028] The method for preparing the sulfide solid electrolyte powder includes: ball - milling sodium sulfide and phosphorus pentasulfide to obtain the sulfide solid electrolyte precursor powder; after calcining the sulfide solid electrolyte precursor powder, obtaining the sulfide solid electrolyte.

[0029] When ball - milling sodium sulfide and phosphorus pentasulfide: sodium sulfide and phosphorus pentasulfide are sealed in a zirconia pot under vacuum for dry ball - milling, and ball - milled at a speed of 500 - 600 rpm for 6 - 12 hours to obtain the sulfide solid electrolyte precursor powder; wherein, the atomic ratio of sodium sulfide to phosphorus pentasulfide is (1.3 - 1.5):(0.3 - 0.5).

[0030] When calcining the sulfide solid electrolyte precursor powder: the sulfide solid electrolyte precursor powder is calcined at 200 - 260 °C under vacuum conditions for 6 - 8 hours to obtain the sulfide solid electrolyte powder with the composition of Na3PS4.

[0031] The method for preparing the sodium - tin alloy powder includes: heating metallic sodium to the molten state at 100 °C under vacuum conditions, adding tin metal powder, and after sufficient grinding, obtaining the sodium - tin alloy powder with the composition of Na 15 Sn4, Na9Sn4 or Na3Sn1.

[0032] A Prussian - white - based high - performance sodium - ion battery, prepared by using the preparation method of any Prussian - white - based high - performance sodium - ion battery according to claims 1 - 12, includes a Prussian - white positive electrode, a heterostructure - type halide solid electrolyte, a sulfide solid electrolyte, and a sodium - tin alloy negative electrode.

[0033] To address the structural defects and crystallization water problems existing in the existing Prussian white cathode materials, namely, the easy formation of vacancy defects and adsorbed crystallization water during the synthesis process, resulting in poor structural stability and short cycle life (usually only a few hundred cycles), and the side reactions that may be caused by the crystallization water, the present invention proposes a heterostructured halide solid electrolyte with high ionic conductivity at room temperature. By utilizing the synergistic effect between the high-coordination and low-coordination halide frameworks, the incorporation of the amorphous component NaTaCl6 significantly improves the ionic conductivity of the target component and helps to achieve fast long-range sodium conduction macroscopically, thereby greatly increasing the ionic conductivity of the solid electrolyte. In addition, the present invention also proposes an effective application method of the Prussian white cathode material in sodium-ion batteries, by reducing the nucleation and growth processes of Prussian white, to obtain a Prussian white cathode material with fewer defect vacancies and low crystallization water content. In synergistic action with the heterostructured halide solid electrolyte, sulfide solid electrolyte, and sodium-tin alloy with high room-temperature ionic conductivity, it significantly improves the electrochemical performance of all-solid-state sodium-ion batteries at room temperature, and has high application value. Among them, the prepared 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] halide solid electrolyte has an ionic conductivity of 2.6 mS / cm at room temperature and an electrochemical window of 3.9 - 4.2 V. An all-solid-state sodium-ion battery assembled with Prussian white as the cathode material, Na3PS4 sulfide solid electrolyte as the anode protective layer, and sodium-tin alloy as the anode material can reach a capacity of 139 mAh / g, and exhibits excellent cycle performance and rate performance, having the potential for commercial application.

[0034] To make this application easier to understand, it is further described below in conjunction with embodiments.

[0035] Example 1 This example provides a preparation method of a halide-based high-performance sodium-ion battery based on Prussian white, and the specific steps are as follows: S1. Cathode preparation: Prussian white material is synthesized by organic solvothermal method: 0.01 mol of Na4Fe(CN)6·10H2O is dissolved in 40 mL of ethylene glycol to form solution A, and 0.02 mol of FeCl2·4H2O and 0.5 g of sodium citrate are dissolved in 40 mL of ethylene glycol to form solution B. Then solution A and solution B are mixed and stirred evenly, and the mixed solution is transferred to a high-pressure reaction kettle with a polytetrafluoroethylene liner, sealed and placed in an oven, heated to 160 °C, and reacted for 8 hours. After the reaction is completed, it is naturally cooled to room temperature, washed 3 times with ethanol, and vacuum dried at 60 °C for 12 hours to obtain the Prussian white cathode material.

[0036] Using the above Prussian white, conductive agent carbon black, and high-ion-conductivity solid electrolyte 0.62[Na0.75 Sm 1.75 Mix 0.62[Na

[0037] S2, the heterostructured halide solid electrolyte 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] Preparation: Weigh sodium chloride and tantalum chloride according to the atomic ratio of 1:1 and 0.75:1.75 respectively; sodium chloride and samarium chloride. Seal them in a zirconia jar (100 mL) under vacuum for dry ball milling, and ball mill at a speed of 500 rpm for 18 hours to obtain the precursor powders NaTaCl6 and Na 0.75 Sm 1.75 Cl6; Weigh the precursor powders NaTaCl6 and Na 0.75 Sm 1.75 Cl6 according to the atomic ratio of 0.38:0.62, and then carry out dry ball milling, ball mill at a speed of 500 rpm for 9 hours to obtain the heterostructured halide solid electrolyte powder 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6].

[0038] S3. Preparation of sulfide solid electrolyte: Weigh sodium sulfide and phosphorus pentasulfide according to the atomic ratio of 1:1, then seal them in a zirconia jar (100 mL) under vacuum for dry ball milling, and ball mill at a speed of 600 rpm for 6 hours to obtain the precursor powder of sulfide solid electrolyte; calcine the precursor powder of sulfide solid electrolyte at 200 °C for 6 hours under vacuum to obtain the sulfide solid electrolyte powder Na3PS4.

[0039] S4. Preparation of sodium-tin alloy negative electrode: Weigh metallic sodium and metallic tin according to the atomic ratio of 15:4, then heat metallic sodium to the molten state at 100 °C under vacuum, add tin metal powder, and grind thoroughly to obtain a uniform dark gray alloy powder Na 15 Sn4.

[0040] S5. Assembly of all-solid-state battery: Weigh 60 mg of the sodium-tin alloy negative electrode and place it in a solid-state battery pressure test mold, press it with 200 MPa for 4 minutes, then weigh 20 mg of the sulfide solid electrolyte powder and spread it on one side surface of the sodium-tin alloy negative electrode, and then spread the heterostructured halide solid electrolyte powder 0.62[Na 0.75 Sm 1.75120 mg of [NaCl6]-0.38[NaTaCl6] was weighed and spread on the surface of one side of the sulfide solid electrolyte, and pressed at 400 MPa for 5 minutes. Finally, the Prussian white positive electrode was evenly spread on the surface of one side of the heterogeneous structure halide solid electrolyte and pressed at 200 MPa for 2 minutes. The whole assembly process was carried out in the glove box. At this point, the assembly of the all-solid-state battery was completed.

[0041] Example 2 This embodiment provides Prussian white || NaTaCl6 || Na 15 The preparation method of Sn4 all-solid-state sodium ion battery, the specific steps are as follows: S1. Preparation of positive electrode: Prussian white material was synthesized by organic solvent thermal synthesis: 0.01 mol Na4Fe(CN)6·10H2O was dissolved in 40 mL ethylene glycol to form solution A, and 0.02 mol FeCl2·4H2O and 0.5 g sodium citrate were dissolved in 40 mL ethylene glycol to form solution B. Then solution A and solution B were mixed and stirred evenly, and the mixture was transferred to a polytetrafluoroethylene-lined autoclave, sealed and placed in an oven, heated to 160 °C, and reacted for 8 hours. After the reaction was completed, it was naturally cooled to room temperature, washed with ethanol 3 times, and vacuum dried at 60 °C for 12 hours to obtain the Prussian white positive electrode material.

[0042] The above-mentioned Prussian white was mixed with the conductive agent carbon black and the solid electrolyte NaTaCl6 in a mass ratio of 30:5:65, and ground into a positive electrode powder in a mortar to obtain a composite Prussian white positive electrode.

[0043] S2. Preparation of halide solid electrolyte NaTaCl6: Sodium chloride and tantalum chloride were weighed in an atomic ratio of 1:1. The mixture was sealed in a zirconia jar (100 mL) under vacuum and dry-milled at 500 rpm for 18 hours to obtain halide solid electrolyte NaTaCl6.

[0044] S3. Preparation of sulfide solid electrolyte: Sodium sulfide and phosphorus pentasulfide were weighed in an atomic ratio of 1:1, sealed in a zirconia can (100 mL) under vacuum, and dry ball milled at 600 rpm for 6 hours to obtain a sulfide solid electrolyte precursor powder; the sulfide solid electrolyte precursor powder was calcined at 200 °C under vacuum conditions for 6 hours to obtain a sulfide solid electrolyte powder Na3PS4.

[0045] S4. Preparation of sodium-tin alloy negative electrode: After weighing metallic sodium and metallic tin according to the atomic ratio of 15:4, the metallic sodium was heated to molten state at 100 °C under vacuum conditions, and tin metal powder was added and fully ground to obtain a uniform dark gray alloy powder Na 15Sn4.

[0046] S5. All-solid-state battery assembly: 60 mg of the sodium-tin alloy negative electrode is weighed and placed in a solid-state battery pressure test mold, and pressed at 200 MPa for 4 minutes. Then 20 mg of the sulfide solid electrolyte powder is weighed and spread on the surface of one side of the sodium-tin alloy negative electrode. Then 120 mg of the halide solid electrolyte powder NaTaCl6 is weighed and spread on the surface of one side of the sulfide solid electrolyte, and pressed at 400 MPa for 5 minutes. Finally, the Prussian white positive electrode is evenly spread on the surface of one side of the halide solid electrolyte, and pressed at 200 MPa for 2 minutes. The entire assembly process is carried out in a glove box. At this point, the all-solid-state battery assembly is completed.

[0047] Example 3 This example provides Prussian white || Na 0.75 Sm 1.75 Cl6||Na 15 The preparation method of Sn4 all-solid-state sodium ion battery, the specific steps are as follows: S1. Preparation of positive electrode: Prussian white material was synthesized by organic solvent thermal synthesis: 0.01 mol Na4Fe(CN)6·10H2O was dissolved in 40 mL ethylene glycol to form solution A, and 0.02 mol FeCl2·4H2O and 0.5 g sodium citrate were dissolved in 40 mL ethylene glycol to form solution B. Then solution A and solution B were mixed and stirred evenly, and the mixture was transferred to a polytetrafluoroethylene-lined autoclave, sealed and placed in an oven, heated to 160 °C, and reacted for 8 hours. After the reaction was completed, it was naturally cooled to room temperature, washed with ethanol 3 times, and vacuum dried at 60 °C for 12 hours to obtain the Prussian white positive electrode material.

[0048] The above-mentioned Prussian white and conductive agent carbon black and solid electrolyte Na 0.75 Sm 1.75 Cl6 were mixed in a mass ratio of 30:5:65, placed in a mortar and ground into positive electrode powder to obtain a composite Prussian white positive electrode.

[0049] S2, halide solid electrolyte Na 0.75 Sm 1.75 Preparation of Cl6: Sodium chloride and samarium chloride were weighed according to the atomic ratio of 0.75:1.75. The mixture was sealed in a zirconia jar (100 mL) under vacuum and dry milled at 500 rpm for 18 hours to obtain the halide solid electrolyte Na 0.75 Sm 1.75 Cl6.

[0050] S3. Preparation of sulfide solid electrolyte: Sodium sulfide and phosphorus pentasulfide were weighed in an atomic ratio of 1:1, sealed in a zirconia can (100 mL) under vacuum, and dry ball milled at 600 rpm for 6 hours to obtain a sulfide solid electrolyte precursor powder; the sulfide solid electrolyte precursor powder was calcined at 200 °C under vacuum conditions for 6 hours to obtain a sulfide solid electrolyte powder Na3PS4.

[0051] S4. Preparation of sodium-tin alloy negative electrode: After weighing metallic sodium and metallic tin according to the atomic ratio of 15:4, the metallic sodium was heated to molten state at 100 °C under vacuum conditions, and tin metal powder was added and fully ground to obtain a uniform dark gray alloy powder Na 15 Sn4.

[0052] S5. All-solid-state battery assembly: 60 mg of the sodium-tin alloy negative electrode was weighed and placed in a solid-state battery pressure test mold and pressed at 200 MPa for 4 minutes. Then 20 mg of the sulfide solid electrolyte powder was weighed and spread on the surface of one side of the sodium-tin alloy negative electrode. Then, 20 mg of the halide solid electrolyte powder was spread on the surface of the sodium-tin alloy negative electrode. 0.75 Sm 1.75 120 mg of Cl6 was weighed and spread on the surface of one side of the sulfide solid electrolyte, and pressed at 400 MPa for 5 minutes. Finally, the Prussian white positive electrode was evenly spread on the surface of one side of the halide solid electrolyte and pressed at 200 MPa for 2 minutes. The whole assembly process was carried out in the glove box. At this point, the assembly of the all-solid-state battery was completed.

[0053] Example 4 This example provides Prussian white (coprecipitation method) || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]||Na 15 The preparation method of Sn4 all-solid-state sodium ion battery, wherein the positive electrode is Prussian white (containing more crystal water) synthesized by hydrothermal method, compared with Prussian white synthesized by organic solvent thermal method, the specific steps are as follows: S1. Preparation of positive electrode: Prussian white material was synthesized by coprecipitation method: 0.02 mol Na4Fe(CN)6·10H2O was dissolved in 100 mL deionized water to form solution A, and 0.03 mol FeSO4·7H2O and 7.5 g sodium citrate were dissolved in 100 mL deionized water to form solution B. Then the mixture was mixed and stirred evenly, placed at room temperature for 12 h and then aged for 18 h. The precipitate was centrifuged and washed with deionized water and anhydrous ethanol for several times to remove excess impurities, and finally placed in a vacuum drying oven at 100 °C for 18 h to obtain Prussian white positive electrode material.

[0054] The above Prussian white, conductive agent carbon black, and high ionic conductivity solid electrolyte 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] are mixed in a mass ratio of 30:5:65, placed in a mortar and ground into a positive electrode powder to obtain a composite Prussian white positive electrode.

[0055] S2. Preparation of heterostructured halide solid electrolyte 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]: Weigh sodium chloride and tantalum chloride according to an atomic ratio of 1:1 and 0.75:1.75 respectively; weigh sodium chloride and samarium chloride. Seal them in a zirconia jar (100 mL) under vacuum for dry ball milling, and ball mill at a speed of 500 rpm for 18 hours to obtain precursor powders NaTaCl6 and Na 0.75 Sm 1.75 Cl6; Weigh the precursor powders NaTaCl6 and Na 0.75 Sm 1.75 Cl6 in an atomic ratio of 0.38:0.62, and then perform dry ball milling, ball milling at a speed of 500 rpm for 9 hours to obtain heterostructured halide solid electrolyte powder 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6].

[0056] S3. Preparation of sulfide solid electrolyte: Weigh sodium sulfide and phosphorus pentasulfide according to an atomic ratio of 1:1, seal them in a zirconia jar (100 mL) under vacuum, perform dry ball milling, and ball mill at a speed of 600 rpm for 6 hours to obtain a sulfide solid electrolyte precursor powder; calcine the sulfide solid electrolyte precursor powder under vacuum at 200 °C for 6 hours to obtain sulfide solid electrolyte powder Na3PS4.

[0057] S4. Preparation of sodium-tin alloy negative electrode: Weigh metallic sodium and metallic tin according to an atomic ratio of 15:4, heat metallic sodium to the molten state at 100 °C under vacuum, add tin metal powder, and after sufficient grinding, obtain a uniform dark gray alloy powder Na 15 Sn4.

[0058] S5. Assembly of all-solid-state battery: After weighing 60 mg of the sodium-tin alloy negative electrode, place it in a solid-state battery pressure test mold, press it with 200 MPa for 4 minutes, then weigh 20 mg of the sulfide solid electrolyte powder and spread it on one side surface of the sodium-tin alloy negative electrode, and then spread the heterostructured halide solid electrolyte powder 0.62[Na0.75 Sm 1.75 120 mg of [NaCl6]-0.38[NaTaCl6] was weighed and spread on the surface of one side of the sulfide solid electrolyte, and pressed at 400 MPa for 5 minutes. Finally, the Prussian white positive electrode was evenly spread on the surface of one side of the heterogeneous structure halide solid electrolyte and pressed at 200 MPa for 2 minutes. The whole assembly process was carried out in the glove box. At this point, the assembly of the all-solid-state battery was completed.

[0059] Example 5 This embodiment provides a method for preparing an all-solid-state battery, wherein the sulfide solid electrolyte is not used, and the rest is the same as that of embodiment 1, and the specific steps are as follows: S1. Preparation of positive electrode: Prussian white material was synthesized by organic solvent thermal synthesis: 0.01 mol Na4Fe(CN)6·10H2O was dissolved in 40 mL ethylene glycol to form solution A, and 0.02 mol FeCl2·4H2O and 0.5 g sodium citrate were dissolved in 40 mL ethylene glycol to form solution B. Then solution A and solution B were mixed and stirred evenly, and the mixture was transferred to a polytetrafluoroethylene-lined autoclave, sealed and placed in an oven, heated to 160 °C, and reacted for 8 hours. After the reaction was completed, it was naturally cooled to room temperature, washed with ethanol 3 times, and vacuum dried at 60 °C for 12 hours to obtain the Prussian white positive electrode material.

[0060] The above-mentioned Prussian white is combined with conductive carbon black and high ion conductivity solid electrolyte 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] were mixed in a mass ratio of 30:5:65, placed in a mortar and ground into positive electrode powder to obtain a composite Prussian white positive electrode.

[0061] S2, Heterostructured Halide Solid Electrolyte 0.62[Na 0.75 Sm 1.75 Preparation of NaCl6]-0.38[NaTaCl6]: Sodium chloride and tantalum chloride; sodium chloride and samarium chloride were weighed according to the atomic ratio of 1:1 and 0.75:1.75 respectively. The mixture was sealed in a zirconia jar (100 mL) under vacuum and dry milled at 500 rpm for 18 hours to obtain the precursor powders NaTaCl6 and Na 0.75 Sm 1.75 Cl6; the precursor powder NaTaCl6 and Na 0.75 Sm 1.75 After weighing Cl6 with an atomic ratio of 0.38:0.62, dry ball milling was performed at a speed of 500 rpm for 9 hours to obtain a heterogeneous structure halide solid electrolyte powder 0.62[Na 0.75Sm 1.75 Cl6]-0.38[NaTaCl6].

[0062] S4. Preparation of sodium-tin alloy negative electrode: After weighing metallic sodium and metallic tin according to the atomic ratio of 15:4, the metallic sodium was heated to molten state at 100 °C under vacuum conditions, and tin metal powder was added and fully ground to obtain a uniform dark gray alloy powder Na 15 Sn4.

[0063] S5. S5. All-solid-state battery assembly: 60 mg of the sodium-tin alloy negative electrode is weighed and placed in a solid-state battery pressure test mold and pressed at 200 MPa for 4 minutes to form a heterogeneous structure halide solid electrolyte powder 0.62 [Na 0.75 Sm 1.75 120 mg of [NaCl6]-0.38[NaTaCl6] was weighed and spread on the surface of one side of the sulfide solid electrolyte, and pressed at 400 MPa for 5 minutes. Finally, the Prussian white positive electrode was evenly spread on the surface of one side of the heterogeneous structure halide solid electrolyte and pressed at 200 MPa for 2 minutes. The whole assembly process was carried out in the glove box. At this point, the assembly of the all-solid-state battery was completed.

[0064] The following performance tests were performed on the materials prepared in the above embodiments: 1. Ionic conductivity test The 0.62[Na 0.75 Sm 1.75 After weighing 200 mg of [NaTaCl6]-0.38[NaTaCl6] solid electrolyte, it was placed in a solid-state battery pressure test mold, aluminum-coated carbon was spread on both sides of the solid electrolyte, and it was pressed at 200 MPa. The ionic conductivity of the solid electrolyte was then tested using the AC impedance method. Figure 2 is 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] solid electrolyte impedance spectrum.

[0065] from Figure 2 It can be seen that: 0.62[Na 0.75 Sm 1.75 The total impedance of the solid electrolyte of 0.62[NaCl6]-0.38[NaTaCl6] is 21.46 Ω. 0.75 Sm 1.75 The ionic conductivity of the solid electrolyte is 2.6 mS / cm.

[0066] 2. Electrochemical window test The 0.62[Na0.75 Sm 1.75 After weighing 150 mg of the solid electrolyte of 0.62[NaSmCl6]-0.38[NaTaCl6], it was pressed into a tablet at 250 MPa using a 10 mm tablet press die. After taking it out, metallic sodium was attached to the negative electrode side, and the linear sweep voltammetry was used to test the electrochemical window of the solid electrolyte. Figure 3 For 0.62[Na 0.75 Sm 1.75 Linear sweep voltammogram of the solid electrolyte of 0.62[NaSmCl6]-0.38[NaTaCl6].

[0067] From Figure 3 It can be seen that the electrochemical window of the solid electrolyte of 0.62[NaSmCl6]-0.38[NaTaCl6] is 3.9 - 4.2 V. 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] solid electrolyte is 3.9 - 4.2 V.

[0068] 3. Full cell performance test The Prussian white || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] || Na 15 Sn4 all-solid-state sodium ion battery was subjected to charge-discharge tests at a current density of 0.1 C at room temperature. Figure 4 For Prussian white || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] || Na 15 Sn4 all-solid-state sodium ion battery charge-discharge curve graph. The results show that the Prussian white || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] || Na 15 Sn4 all-solid-state sodium ion battery has an initial discharge specific capacity of 139 mAh / g at room temperature. Figure 5 For Prussian white || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] || Na 15 Sn4 all-solid-state sodium ion battery cycle performance graph. The results show that the Prussian white || 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] || Na 15After 500 cycles at a current density of 0.5 C at room temperature, the Sn4 all-solid-state sodium-ion battery has a capacity retention rate of up to 90% and a Coulombic efficiency close to 100%. After 50 cycles at a current density of 0.1 C at room temperature, the capacity retention rate is close to 100% and the Coulombic efficiency also remains at a high level. Figure 6 For Prussian white||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]||Na 15 The rate performance (top) and corresponding charge-discharge curves (bottom) of the Sn4 all-solid-state sodium-ion battery at 50 °C. The results show that Prussian white||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]|| Na 15 The Sn4 all-solid-state sodium-ion battery exhibits excellent rate performance at 50 °C, and the corresponding charge-discharge curves also have excellent symmetry. Figure 7 For Prussian white||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]|| Na 15 The rate performance (top) and corresponding charge-discharge curves (bottom) of the Sn4 all-solid-state sodium-ion battery at 25 °C. The results show that Prussian white||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]||Na 15 The Sn4 all-solid-state sodium-ion battery exhibits excellent rate performance at 25 °C, and the corresponding charge-discharge curves also have excellent symmetry. Figure 8 For Prussian white||NaTaCl6||Na 15 The charge-discharge curves (top) of the Sn4 all-solid-state sodium-ion battery at 25 °C and Prussian white||Na 0.75 Sm 1.75 Cl6||Na 15 The charge-discharge curves (bottom) of the Sn4 all-solid-state sodium-ion battery at 25 °C. The results show that Prussian white||NaTaCl6|| Na prepared in Example 2 15 The Sn4 all-solid-state sodium-ion battery shows poor performance at 25 °C. At 25 °C, its capacity is only about 83 mAh / g. Prussian white||Na prepared in Example 3 0.75 Sm 1.75 Cl6||Na 15The Sn4 all-solid-state sodium-ion battery exhibits very poor discharge capacity and Coulombic efficiency at room temperature of 25 °C. Figure 9 All-solid-state sodium-ion battery with Prussian white prepared by co-precipitation method as the positive electrode Prussian white (co-precipitation method)||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6||Na 15 Charge-discharge curves of Sn4 at room temperature of 25 °C (upper) and all-solid-state sodium-ion battery without using sulfide solid electrolyte to protect the negative electrode (lower), Prussian white (co-precipitation method) prepared in Example 4||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6||Na 15 The discharge capacity of the Sn4 all-solid-state sodium-ion battery is only about 110 mAh / g, and its performance is poor; for the all-solid-state sodium-ion battery without sulfide solid electrolyte prepared in Example 5, its discharge capacity is about 115 mAh / g, and at the same time, its Coulombic efficiency is relatively low, about 80%. In summary, the Prussian white||0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6]||Na 15 The Sn4 all-solid-state sodium-ion battery system exhibits more excellent electrochemical performance compared to other systems.

[0069] The numerical ranges of the present invention not only include the point values listed in the above embodiments, but also include any point values between the above numerical ranges not listed. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the said ranges.

[0070] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0071] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0072] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a halide-based high-performance sodium-ion battery based on Prussian white, characterized in that: include: S1, pressing the sodium-tin alloy powder to complete the preparation of the negative electrode layer; S2, spreading sulfide solid electrolyte powder and heterostructure halide solid electrolyte powder in sequence on the surface of one side of the negative electrode layer and then pressing them to complete the preparation of the solid electrolyte layer; S3. Spread the Prussian white positive electrode powder on the side of the solid electrolyte layer facing away from the negative electrode layer and then press it to complete the preparation of the positive electrode layer, thereby obtaining a halide-based high-performance sodium ion battery based on Prussian white.

2. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white according to claim 1, characterized in that: The method for preparing the Prussian white cathode powder comprises: Dissolving sodium ferrocyanide in an organic solvent to obtain solution A; A soluble divalent transition metal salt is dissolved in an organic solvent, and then a chelating agent is added to obtain a solution B; The solution A and the solution B are mixed to perform a solvothermal reaction to obtain a reaction solution; The reaction solution is subjected to solid-liquid separation, and the obtained solid is washed and dried to obtain a general formula of Na x Fe[Fe(CN)6], Prussian white with 1.8≤x<2.2; The Prussian white, the conductive agent and the high ion conductivity solid electrolyte are mixed and ground to obtain the Prussian white positive electrode powder.

3. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 2, characterized in that: The mass ratio of the Prussian white, the conductive agent and the high ion conductivity solid electrolyte is: (30-40): (5-10): (60-70).

4. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 2, characterized in that: The conductive agent is at least one of carbon black, acetylene black, carbon nanotubes and Ketjen black, and the high ionic conductivity solid electrolyte is 0.62[Na 0.75 Sm 1.75 Cl6]-0.38[NaTaCl6] or 0.57[Na 0.75 La 1.75 Cl6]-0.43[NaTaCl6].

5. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 1, characterized in that: The method for preparing the heterostructured halide solid electrolyte powder comprises: ball-milling sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride to obtain a precursor powder; The precursor powder is ball-milled again according to a preset ratio to obtain a heterogeneous structure halide solid electrolyte.

6. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 5, characterized in that: When the sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride are ball-milled: Sodium chloride, tantalum chloride, samarium chloride and lanthanum chloride are mixed separately, sealed in a zirconia tank under vacuum for dry ball milling, and ball milled at a speed of 500-550 rpm for 18-24 hours to obtain a precursor powder; Among them, the atomic ratio of sodium chloride to tantalum chloride is 1:1, the atomic ratio of sodium chloride to samarium chloride is 0.75:1.75, and the atomic ratio of sodium chloride to lanthanum chloride is 0.75:1.75; When the precursor powder is ball-milled again according to a preset ratio: The precursor powder is sealed in a zirconia jar under vacuum, dry-milled, and ball-milled at a speed of 500 to 550 rpm for 9 to 18 hours to obtain a high-coordination framework Na 3x M 2-x Heterostructured halide solid electrolyte powders of Cl6 (M = La, Sm) and low-coordination framework NaTaCl6; Among them, NaTaCl6 and Na 0.75 Sm 1.75 The atomic ratio of Cl6 is (0.38-0.40):(0.60-0.62), NaTaCl6 and Na 0.75 La 1.75 The atomic ratio of Cl6 is (0.40~0.43):(0.57~0.60).

7. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 1, characterized in that: The method for preparing the sulfide solid electrolyte powder comprises: Ball milling sodium sulfide and phosphorus pentasulfide to obtain sulfide solid electrolyte precursor powder; The sulfide solid electrolyte is obtained by calcining the sulfide solid electrolyte precursor powder.

8. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 7, characterized in that: When the sodium sulfide and phosphorus pentasulfide are ball-milled: The sodium sulfide and phosphorus pentasulfide are sealed in a zirconia can under vacuum, and dry ball milled at a speed of 500 to 600 rpm for 6 to 12 hours to obtain a sulfide solid electrolyte precursor powder; Wherein, the atomic ratio of sodium sulfide to phosphorus pentasulfide is (1.3-1.5):(0.3-0.5); When the sulfide solid electrolyte precursor powder is calcined: The sulfide solid electrolyte precursor powder is calcined at 200-260° C. under vacuum conditions for 6-8 hours to obtain a sulfide solid electrolyte powder having a composition of Na3PS4.

9. The method for preparing a halide-based high-performance sodium-ion battery based on Prussian white as claimed in claim 1, characterized in that: The method for preparing sodium-tin alloy powder comprises: Sodium metal was heated to molten state at 100 °C under vacuum conditions, tin metal powder was added, and after sufficient grinding, a composition of Na 15 Sodium-tin alloy powder of Sn4, Na9Sn4 or Na3Sn1.

10. A halide-based high-performance sodium-ion battery based on Prussian white, prepared by the preparation method of a halide-based high-performance sodium-ion battery based on Prussian white according to any one of claims 1 to 9, characterized in that: Including Prussian white positive electrode, heterostructure halide solid electrolyte, sulfide solid electrolyte and sodium-tin alloy negative electrode.

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