Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires, methods of making the same, and applications in sodium-ion batteries

Abstract

This invention relates to the field of sodium-ion battery technology, specifically to Na... 0.86 Cu 0.43 Ti 3.57 O8 nanowires, their preparation method, and their application in sodium-ion batteries. This invention aims to solve the problems disclosed in the prior art regarding Na... 0.86 Cu 0.43 Ti 3.57 To address the technical shortcomings of high preparation temperatures and poor safety in existing O8 material preparation methods, a method for preparing Na using electrospinning is provided. 0.86 Cu 0.43 Ti 3.57 A new method for producing O8, and the resulting Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires are used as anode materials for Na-ion batteries.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sodium ion batteries, in particular to Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires, a preparation method thereof and application thereof in sodium ion batteries. BACKGROUND

[0002] Compared with the currently commercialized lithium ion batteries, sodium ion batteries have similar reaction working principles. Since the abundance of sodium resources in the earth's crust is much higher than that of lithium elements, and aluminum foil is used as the current collector of the positive and negative electrodes at a lower cost, sodium ion batteries have a significant cost advantage, are a strong backup force for lithium ion batteries, have unlimited sustainable development potential, and are expected to play an important role in large-scale energy storage systems in the future.

[0003] In 2001, Avdeev, M. et al. uploaded the structure parameters of new crystal Na 0.86 Cu 0.43 Ti 3.57 O8 to the International Centre for Diffraction Data (ICDD), and the lattice constant thereof is: α = 90°, β = 107.245°, γ = 90°, V = 289.1, and the space group is C2 / m (12). The substance appears in the form of a heterogeneous phase in Nathaniel Coleman Jr's work on metal-doped TiO2.

[0004] Currently, the synthesis method of Na 0.86 Cu 0.43 Ti 3.57 O8 material uses Na2O2 as raw material, and Na2O2 is a hazardous chemical, which can rapidly absorb moisture and carbon dioxide in the air, and will cause combustion or explosion after contacting with organic matter, so the experimental conditions are harsh and not easy to prepare; in addition, Na 0.86 Cu 0.43 Ti 3.57 O8 material is currently synthesized by a solid-state double decomposition method, and the preparation temperature is as high as 1000℃; these reasons all limit the large-scale preparation and application of Na 0.86 Cu 0.43 Ti 3.57 O8 material; and the Na 0.86 Cu 0.43 Ti 3.57 O8 material prepared by the traditional high-temperature synthesis has a large micro size and a small specific surface area, so the exploration of the material as a negative electrode material of a sodium ion battery is relatively scarce. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire and its preparation method and application in sodium ion battery, aiming at solving the technical defects of high preparation temperature and poor safety in the preparation method of the prior art Na 0.86 Cu 0.43 Ti 3.57 O8 material, a new method for preparing Na 0.86 Cu 0.43 Ti 3.57 O8 is provided, and the prepared Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire is applied as a negative electrode material of a sodium ion battery.

[0006] To achieve the above-mentioned purposes, the technical scheme of the present application is as follows:

[0007] A preparation method of a Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire, comprising the following steps:

[0008] (1) Preparation of nanofiber membrane: uniformly mix a sodium source, a copper source, a titanium source, polyvinylpyrrolidone, a dissolving promoter, acetic acid and ethanol, and configure into a mixed solution, and electrospinning the mixed solution to obtain a nanofiber membrane, polyvinylpyrrolidone is a surfactant, and the dissolving promoter, acetic acid and ethanol together are solvents to fully dissolve the raw materials;

[0009] (2) Preparation of Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire: after heat treatment of the nanofiber membrane of step (1) at 600-700℃ for 2-6h, the residual impurities and organic matter in the product are washed away to obtain Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire.

[0010] Preferably, the sodium source in step (1) is selected from sodium acetate trihydrate, sodium carbonate or sodium sulfate, the copper source is selected from copper nitrate trihydrate, copper oxide or copper sulfate, and the titanium source is selected from tetrabutyl titanate, titanium dioxide or titanium sulfate.

[0011] Preferably, in the sodium source, copper source and titanium source of step (1), the molar ratio of sodium element, copper element and titanium element is (2.5-4.5):(1-2):(6-9), and the mass ratio of polyvinylpyrrolidone to titanium source is (1-2):(0.5-1).

[0012] The volume ratio of the solubility promoter, acetic acid and ethanol is (1-3):(1-2):(6-8).

[0013] Preferably, in the sodium source, copper source and titanium source of step (1), the molar ratio of sodium element, copper element and titanium element is 4.5:1:6.8.

[0014] Preferably, the electrostatic spinning condition in step (1) is that the nanofiber membrane is prepared under the condition that the spinning voltage is negative pressure-1kV and positive pressure 27kV, the spinning temperature is 40-60℃, and the pushing rate is 1.5-2mL / h.

[0015] Preferably, in step (2), the nanofiber membrane of step (1) is heat treated at 600-700℃ for 2-4h.

[0016] Preferably, the residual impurities and organic matter cleaning method in the product of step (2) is that first, a 5% nitric acid solution is used for cleaning, and then deionized water is used for washing until neutral.

[0017] The application also protects the Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire prepared by the preparation method.

[0018] The application also protects the Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire prepared by the preparation method.

[0019] The Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire, a conductive agent and a binder are mixed, and then dissolved in a solvent to obtain a slurry, an aluminum foil is used as a current collector, the slurry is uniformly coated on the surface of the current collector, and a sodium ion battery negative electrode sheet is obtained after drying.

[0020] Preferably, the binder is selected from one or more of polyvinylidene fluoride, polyacrylic acid, sodium carboxymethyl cellulose, sodium alginate and gelatin, the conductive agent is selected from acetylene black, carbon black, Super-P or ketjen black, and the solvent is N-methyl pyrrolidone; the mass ratio of the Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire, the conductive agent and the binder is 8:1:1.

[0021] The application also protects the application of the sodium-ion battery negative electrode sheet in the preparation of a sodium-ion battery, and the sodium-ion battery is prepared according to the following steps:

[0022] Preparation of the positive electrode sheet: tabletting and cutting of the metal sodium;

[0023] Preparation of the electrolyte: dissolving sodium perchlorate in an organic solvent to prepare a sodium perchlorate electrolyte with a concentration of 1 mol / L;

[0024] Preparation of the sodium-ion battery: sequentially assembling the positive electrode sheet, the glass fiber diaphragm, the electrolyte and the negative electrode sheet, and preparing the sodium-ion battery through formation and standing processes.

[0025] Compared with the prior art, the application has the beneficial effects that:

[0026] The application discloses a novel preparation method of semiconductor Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires, and the preparation method is simple, the reaction time is short, the reaction condition is mild, the raw material is safe, and the Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires with higher purity can be obtained, and the technical defects of high reaction temperature and poor safety in the prior art solid-state metathesis method are overcome. 0.86 Cu 0.43 Ti 3.57 O8 nanowires are direct band gap semiconductors with a band gap energy Eg between 2.3-2.6 eV, and the nanowires are uniform in size, high in purity and good in crystallinity. 0.86 Cu 0.43 Ti 3.57 O8 nanowires are small in micro-size and good in conductivity, and can be used as a negative electrode material of a Na-ion battery and have a high specific capacity of the Na-ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The XRD pattern of the Na-ion battery negative electrode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1;

[0028] Figure 2 The SEM pattern of the Na-ion battery negative electrode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1;

[0029] Figure 3 The thermogravimetric curve of the nanofiber membrane of Example 1;

[0030] Figure 4 XRD patterns of the nanofiber membrane samples of Example 5, Comparative Example 1, Comparative Example 2 after heat treatment at different temperatures;

[0031] Figure 5 XRD patterns of the samples prepared at different Cu:Ti molar ratios;

[0032] Figure 6 SEM images of the Na-ion battery anode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1;

[0033] Figure 7 SEM images of the Na-ion battery anode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 4;

[0034] Figure 8 UV-Vis diffuse reflectance spectra of the Na-ion battery anode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1, Example 4, Example 6, Example 7;

[0035] Figure 9 Charge-discharge curves of the Na-ion battery anode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1 as the Na-ion battery anode material;

[0036] Figure 10 Stability and coulombic efficiency of the Na-ion battery anode material Na 0.86 Cu 0.43 Ti 3.57 O8 prepared in Example 1 after 100 cycles of charge-discharge. DETAILED DESCRIPTION

[0037] The specific embodiments of the present application are described in detail below, but it should be understood that the scope of the present application is not limited to the specific embodiments. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts, fall within the scope of the present application. The experimental methods described in the embodiments of the present application are conventional methods, unless otherwise specified.

[0038] Example 1

[0039] Na 0.86 Cu 0.43Ti 3.57 A method for preparing Na

[0040] (1) Preparation of nanofiber membrane: sodium acetate trihydrate (CH3COONa·3H2O), copper sulfate (CuSO4·5H2O), titanium dioxide (TiO2), N,N'-dimethylformamide (DMF), acetic acid, and ethanol were mixed and configured into a solution. After being fully stirred for 8 h, the obtained solution was transferred into a syringe for spinning and electrospinning was performed to obtain a nanofiber membrane; 16 H 36 O4Ti), polyvinylpyrrolidone (PVP), N,N'-dimethylformamide (DMF), acetic acid, and ethanol were mixed and configured into a solution. After being fully stirred for 8 h, the obtained solution was transferred into a syringe for spinning and electrospinning was performed to obtain a nanofiber membrane;

[0041] The molar ratio of sodium, copper, and titanium in sodium acetate trihydrate, copper sulfate trihydrate, and tetrabutyl titanate was 4.5:1:6.8, the amount of PVP was 2 g, the volume ratio of DMF, acetic acid, and ethanol was 3:1:6, the total volume of the spinning solution was 15 mL, and the nanofiber was prepared under the conditions of a spinning voltage of -1 kV, a positive voltage of 27 kV, a spinning temperature of 50℃, and a pushing rate of 2 mL / h;

[0042] (2) Preparation of Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires: after the nanofiber membrane of step (1) was removed, it was heat treated at 600℃ for 2 h, and then the obtained product was washed once with a 5% nitric acid solution, washed with deionized water until neutral, and dried to obtain the battery negative electrode material Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires.

[0043] Example 2

[0044] Na 0.86 Cu 0.43 Ti 3.57 A method for preparing Na

[0045] (1) Preparation of nanofiber membrane: sodium acetate trihydrate (CH3COONa·3H2O), copper sulfate (CuSO4·5H2O), titanium dioxide (TiO2), N,N'-dimethylformamide (DMF), acetic acid, and ethanol were mixed and configured into a solution. After being fully stirred for 8 h, the obtained solution was transferred into a syringe for spinning and electrospinning was performed to obtain a nanofiber membrane;

[0046] The molar ratio of sodium element, copper element and titanium element in sodium carbonate, copper sulfate and titanium dioxide is 3:1.5:6, the amount of PVP is 2g, the volume ratio of DMF, acetic acid and ethanol is 2:1.5:7, the total volume of the prepared spinning solution is 15mL, the nanofiber is prepared under the conditions of a negative voltage of-1kV, a positive voltage of 27kV, a spinning temperature of 40℃ and a pushing rate of 2mL / h;

[0047] (2)Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires are prepared: after the nanofiber film of step (1) is taken out, heat treatment is carried out at 650℃ for 6h, then the obtained product is washed once with a 5% nitric acid solution, washed with deionized water to neutral, and dried to obtain the battery negative material Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires.

[0048] Example 3

[0049] Na 0.86 Cu 0.43 Ti 3.57 The preparation method of Na

[0050] (1) Preparation of nanofiber film: sodium sulfate, copper oxide, titanium sulfate, polyvinylpyrrolidone (PVP), N,N'-dimethylformamide (DMF), acetic acid and ethanol are mixed and configured into a solution, after being stirred for 8h, the obtained solution is transferred to a spinning syringe and electrospun to obtain a nanofiber film;

[0051] The molar ratio of sodium element, copper element and titanium element in sodium acetate trihydrate, copper nitrate trihydrate and tetrabutyl titanate is 2.5:1:9, the amount of PVP is 2g, the volume ratio of DMF, acetic acid and ethanol is 1:2:8, the total volume of the prepared spinning solution is 15mL, the nanofiber is prepared under the conditions of a negative voltage of-1kV, a positive voltage of 27kV, a spinning temperature of 60℃ and a pushing rate of 1.5mL / h;

[0052] (2)Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires are prepared: after the nanofiber film of step (1) is taken out, heat treatment is carried out at 700℃ for 4h, then the obtained product is washed once with a 5% nitric acid solution, washed with deionized water to neutral, and dried to obtain the battery negative material Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires.

[0053] Example 4

[0054] The preparation steps are the same as in Example 1, except that the heat treatment time in step (2) is changed from 2 hours to 4 hours.

[0055] Example 5

[0056] The preparation steps are the same as in Example 4, except that the heat treatment temperature in step (2) is replaced with 650°C instead of 600°C.

[0057] Example 6

[0058] The preparation steps are the same as in Example 1, except that the heat treatment temperature in step (2) is replaced with 700°C instead of 600°C.

[0059] Example 7

[0060] The preparation steps are the same as in Example 4, except that the heat treatment temperature in step (2) is replaced with 700°C instead of 600°C.

[0061] Comparative Example 1

[0062] The preparation steps are the same as in Example 4, except that the heat treatment temperature in step (2) is replaced with 450°C instead of 600°C.

[0063] Comparative Example 2

[0064] The preparation steps are the same as in Example 4, except that the heat treatment temperature in step (2) is replaced with 550°C instead of 600°C.

[0065] I. Sample Testing

[0066] Na was obtained in Examples 1-7 of this invention. 0.86 Cu 0.43 Ti 3.57 O8 nanowires, the following examples show the Na prepared in Examples 1 and 4-7. 0.86 Cu 0.43 Ti 3.57 Taking O8 nanowires as an example, a comparative study was conducted with samples from Comparative Examples 1-2, and the results are as follows: Figure 1 and Figure 2 As shown, Figure 1 The XRD characterization results of the samples prepared in this study are similar to those of Na. 0.86 Cu 0.43 Ti 3.57 The O8 standard card PDF#53-0081 is a perfect match, indicating that a pure phase sample can be successfully prepared under the stated example conditions. Figure 2 The results showed that the prepared Na 0.86 Cu 0.43 Ti3.57 The micro-morphology of O8 is nanowire.

[0067] II. In order to determine the process conditions and specific parameters of the present application, the inventors have carried out a large number of experimental explorations, and the specific test results and analysis are as follows:

[0068] 1. Determination of reaction temperature:

[0069] Thermogravimetric analysis was performed on the prepared nanofiber membrane to determine the appropriate reaction temperature. Figure 3 The thermogravimetric analysis results show that the mass of the nanofiber membrane obtained by spinning does not decrease after reaching 400℃, therefore, the precursor fiber membrane was heat treated at 450℃, 550℃ and 650℃ for 4h, respectively.

[0070] Figure 4 XRD of the obtained powder shows that at 450℃, the target product Na 0.86 Cu 0.43 Ti 3.57 O8 does not appear, at 550℃, the target product Na 0.86 Cu 0.43 Ti 3.57 O8 appears, but TiO2 exists, and at 650℃, the content of Na 0.86 Cu 0.43 Ti 3.57 O8 increases, indicating that the suitable phase formation temperature range is 550-650℃, therefore, 600℃ is selected to continue to debug other parameters.

[0071] 2. Determination of element ratio:

[0072] The spinning solution was prepared according to the Cu element: Ti element molar ratio of 1:4.5, 1:6, 1:6.6, 1:6.8, 1:7, and 1:9, the total volume of the spinning solution was 15mL, the spinning voltage was-1kV, the positive pressure was 27kV, the temperature was 50℃, and the pushing rate was 2mL / h, under the conditions of preparing nanofiber membrane, the obtained fiber membrane was sintered at 600℃ for 2h;

[0073] Figure 5 XRD of the obtained powder was tested, when the Cu:Ti ratio was 1:4.5, the sample was CuO, with the increase of Ti concentration, the peak of the impurity phase CuO gradually decreased, when the Ti concentration was too high, the Cu:Ti ratio was 1:9, the characteristic peak of TiO2 appeared, the results showed that when the Cu:Ti ratio was 1:6.8, the obtained phase was the pure target product Na 0.86 Cu 0.43 Ti 3.57 O8.

[0074] 3. Morphology characterization:

[0075] Figure 6 SEM image of sodium copper titanate obtained by treating at 600℃ for 2h, Figure 7 SEM image of sodium copper titanate obtained by treating at 600℃ for 4h, the results show that the holding time has a certain influence on the morphology, compared with the holding time of 2h, the holding time of 4h will make the size of the nanoparticles constituting the nanowire larger.

[0076] 4. UV-Vis diffuse reflectance spectrum:

[0077] From the UV-Vis diffuse reflectance spectrum of the sodium copper titanate sample, it can be seen that the absorption edge is between 484.78-521.62nm, and the estimated band gap is between 2.37-2.56eV. Figure 8 5. Performance test of sodium copper titanate as negative electrode material of Na-ion battery:

[0078] Installation of sodium-ion battery: the sodium copper titanate prepared in Example 1 was mixed with conductive agent acetylene black and adhesive polyvinylidene fluoride, then dissolved in N-methyl pyrrolidone, coated on an aluminum foil as a substrate to form a uniform electrode sheet, and then cut into a circular sheet with a diameter of 16mm to prepare a sodium-ion battery negative electrode sheet;

[0079] The metal sodium was pressed and cut into a circular sheet with a diameter of 16mm to obtain a battery positive electrode sheet;

[0080] Sodium perchlorate was dissolved in an organic solvent of EC:PC:FEC=47.5:47.5:5(v / v) to prepare a sodium perchlorate electrolyte with a concentration of 1mol / L; the positive electrode sheet, glass fiber separator, electrolyte and negative electrode sheet were sequentially assembled, and a sodium-ion button cell was prepared after formation and standing process; the sodium-ion button cell was subjected to cycle test on a new battery performance test system, as shown in

[0081] Figure 9 Figure 10 Table 1 shows the results of the cycle test of the sodium copper titanate as the negative electrode material of the Na-ion battery for 100 cycles.

[0082] Table 1: Parameters of sodium copper titanate as negative electrode material of Na-ion battery for 100 cycles

[0083]

[0084]

[0085] The results show that when the current density is 50mA / g, the first cycle discharge capacity of the sodium-ion button cell using sodium copper titanate as the negative electrode material is 324.2mAh / g, the second cycle discharge capacity is 121.6mAh / g, and the capacity retention rate is 57.2% for 2-100 cycles. Compared with the theoretical capacity of 66.632mAh / g, it has a high specific capacity. ​​

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A Na 0.86 Cu 0.43 Ti 3.57 O8 nanowire, characterized by, It comprises the following steps: (1) Preparation of nanofiber membrane: uniformly mix sodium source, copper source, titanium source, polyvinylpyrrolidone, solubilizing agent, acetic acid and ethanol, and configure into a mixed solution, and electrospinning the mixed solution to obtain a nanofiber membrane; In the sodium source, copper source and titanium source of step (1), the molar ratio of sodium element, copper element and titanium element is (2.5-4.5):(1-2):(6-9); (2) Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires: after the nanofiber film of step (1) is heat treated at 600-700 °C for 2-6 h, residual impurities and organic matter in the product are washed away to obtain Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires.

2. The Na of claim 1 0.86 Cu 0.43 Ti 3.57 A method for preparing O8 nanowires, characterized in that, The sodium source in step (1) is selected from sodium acetate trihydrate, sodium carbonate or sodium sulfate, the copper source is selected from copper nitrate trihydrate, copper oxide or copper sulfate, and the titanium source is selected from tetrabutyl titanate, titanium dioxide or titanium sulfate.

3. The Na of claim 1 0.86 Cu 0.43 Ti 3.57 A method for preparing O8 nanowires, characterized in that, The mass ratio of polyvinylpyrrolidone to titanium source is (1-2):(0.5-1); The solubilizing agent is selected from N,N'-dimethylformamide or N,N'-diethylformamide, and the volume ratio of solubilizing agent, acetic acid and ethanol is (1-3):(1-2):(6-8).

4. The Na according to claim 3 0.86 Cu 0.43 Ti 3.57 The method for preparing O8 nanowires is characterized by... In the sodium source, copper source and titanium source of step (1), the molar ratio of sodium element, copper element and titanium element is 4.5:1:6.

8.

5. The Na of claim 1 0.86 Cu 0.43 Ti 3.57 A method for preparing O8 nanowires, characterized in that, The electrospinning conditions in step (1) are as follows: the spinning voltage is negative pressure-1 kV and positive pressure 27 kV, the spinning temperature is 40-60℃, and the pushing rate is 1.5-2 mL / h.

6. The Na of claim 1 0.86 Cu 0.43 Ti 3.57 A method for preparing O8 nanowires, characterized by, In step (2), the nanofiber membrane of step (1) is heat treated at 600-700℃ for 2-4h.

7. The Na of claim 1 0.86 Cu 0.43 Ti 3.57 A method for preparing O8 nanowires, characterized by, The cleaning method of residual impurities and organic matter in the product of step (2) is as follows: first clean with 5% nitric acid solution, and then wash with deionized water until neutral.

8. Na8 nanowires produced by the method of any one of claims 1-7. 0.86 Cu 0.43 Ti 3.57 O8 nanowires.

9. A sodium-ion battery negative electrode sheet prepared using the Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires, characterized in that, The sodium ion battery negative electrode sheet is prepared according to the following steps: Na 0.86 Cu 0.43 Ti 3.57 O8 nanowires, a conductive agent and a binder are mixed, and then dissolved in a solvent to obtain a slurry, an aluminum foil is used as a current collector, the slurry is uniformly coated on the surface of the current collector, and after drying, a sodium ion battery negative electrode sheet is obtained. The binder is selected from one or more of polyvinylidene fluoride, polyacrylic acid, sodium carboxymethyl cellulose, sodium alginate, and gelatin, the conductive agent is selected from acetylene black, carbon black, Super-P, or Ketjen black, and the solvent is N-methyl pyrrolidone; the Na 0.86 Cu 0.43 Ti 3.57 The mass ratio of the O8 nanowire, the conductive agent, and the binder is 8:1:

1.

10. Use of the sodium-ion battery negative electrode sheet according to claim 9 for the preparation of a sodium-ion battery, characterized in that, The sodium ion battery is prepared according to the following steps: Preparation of positive electrode sheet: tabletting and cutting of metallic sodium; Preparation of electrolyte: dissolving sodium perchlorate in an organic solvent to prepare a sodium perchlorate electrolyte with a concentration of 1 mol / L; Preparation of sodium ion battery: sequentially assembling the positive electrode sheet, glass fiber separator, electrolyte and negative electrode sheet, and preparing the sodium ion battery through formation and standing processes.

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