Preparation method of fast-charging electrolyte for sodium-ion battery

Abstract

The invention discloses a preparation method of a fast-charging electrolyte for a sodium-ion battery, and relates to the technical field of sodium-ion batteries. The specific preparation method comprises the following steps: mixing the main film-forming agent, the additive, the solvent and the sodium salt, and then performing ultrasonic dissolution to obtain the electrolyte. Fluoroethylene carbonate is used as a main film-forming agent and preferentially participates in the formation of a negative electrode solid electrolyte interface film, so that the interface impedance is reduced and the continuous decomposition of the electrolyte is inhibited; additives including triphenyl phosphate, isodecyl diphenyl phosphate, trineopentyl phosphate and 4-aminophenylboronic acid pinacol ester are introduced, so that a desolvation energy barrier of Na < + > at an interface is reduced, and a more stable and effective interface film is formed; propylene carbonate and methyl ethyl carbonate are used as solvents, so that the sodium ion transmission efficiency is ensured; high-concentration sodium salt is used for promoting formation of a solvation structure for anion aggregation; and finally, the button cell prepared from the prepared electrolyte can effectively support fast charging and has good electrochemical performance.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium ion batteries, and in particular to a method for preparing a fast-charging electrolyte for sodium ion batteries. Background Art

[0002] When conventional sodium-ion battery electrolytes are charged and discharged at high rates, the electrode interface film is easily broken, resulting in an increase in side reactions and a decrease in cycle life. In high-temperature environments, electrolyte decomposition is exacerbated, leading to more side reactions, further affecting performance stability. These problems jointly restrict the practical application of sodium-ion battery fast-charging technology. Although ester additives can improve film formation, existing ester additives have obvious defects. For example, they have poor high-temperature adaptability and are easily oxidized and decomposed at high potentials, destroying the formed solid electrolyte membrane and resulting in poor battery rate performance. Traditional solvent systems (such as carbonate / ether combinations) do not effectively balance viscosity and ionic conductivity, limiting the sodium ion diffusion efficiency and ultimately limiting the battery's charging and discharging at high currents. Therefore, there is still a need for a method for preparing an electrolyte that can be used for sodium-ion battery fast charging. Summary of the Invention

[0003] The object of the present invention is to provide a method for preparing a fast-charging electrolyte for sodium ion batteries, so as to solve the problems of low cycle life and limited high-current charging and discharging in existing sodium ion batteries.

[0004] In order to solve the above technical problems, the present invention specifically provides the following technical solutions: The invention discloses a sodium ion battery fast-charge electrolyte, comprising: a main film-forming agent, an additive, a solvent and a sodium salt; the mass ratio of the main film-forming agent to the solvent is 1:47-65.

[0005] Preferably, the main film-forming agent is fluoroethylene carbonate, the additives include at least one of triphenyl phosphate, isodecyl diphenyl phosphate, tripentyl phosphite and 4-aminophenylboronic acid pinacol ester, the solvent includes propylene carbonate and ethyl methyl carbonate, and the sodium salt includes at least one of sodium hexafluorophosphate and sodium bis(trifluoromethanesulfonyl)imide.

[0006] More preferably, the mass ratio of fluoroethylene carbonate to triphenyl phosphate is 1:0.4-0.65.

[0007] More preferably, the mass ratio of fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.25-0.8.

[0008] More preferably, the mass ratio of fluoroethylene carbonate to trineopentyl phosphite is 1:0.2-0.45. Using isodecyl diphenyl phosphate and trineopentyl phosphite can improve electrolyte stability and regulate the electrode-electrolyte interface film, promoting the formation of a denser, more stable, and more effective interface film on the electrode surface, improving charge transfer, thereby achieving a relatively high discharge capacity and enhancing cycling stability.

[0009] More preferably, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester is 1:0.5-2.5.

[0010] More preferably, the mass ratio of fluoroethylene carbonate to propylene carbonate is 1:12-20.

[0011] More preferably, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate is 1:35-45.

[0012] More preferably, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate is 1:7-14, and the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide is 1:1-1.5.

[0013] The present invention also discloses the use of any of the above-mentioned sodium ion battery fast-charging electrolytes in preparing batteries.

[0014] The present invention discloses a method for preparing a sodium ion battery fast-charge electrolyte, comprising: In a glove box, the main film-forming agent, additives, solvent and sodium salt are mixed, then ultrasonically dissolved to obtain an electrolyte, which is then stored in the glove box.

[0015] Preferably, the main film-forming agent is fluoroethylene carbonate.

[0016] Preferably, the additive is triphenyl phosphate, isodecyl diphenyl phosphate, tripentyl phosphite and 4-aminophenylboronic acid pinacol ester.

[0017] More preferably, the mass ratio of fluoroethylene carbonate to triphenyl phosphate is 1:0.4-0.65.

[0018] More preferably, the mass ratio of fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.25-0.8.

[0019] More preferably, the mass ratio of fluoroethylene carbonate to trineopentyl phosphite is 1:0.2-0.45. More preferably, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester is 1:0.5-2.5.

[0020] Preferably, the solvents are propylene carbonate and ethyl methyl carbonate.

[0021] More preferably, the mass ratio of fluoroethylene carbonate to propylene carbonate is 1:12-20.

[0022] More preferably, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate is 1:35-45.

[0023] Preferably, the sodium salts are sodium hexafluorophosphate and sodium bis(trifluoromethanesulfonyl)imide.

[0024] More preferably, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate is 1:7-14.

[0025] More preferably, the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide is 1:1-1.5.

[0026] Preferably, the ultrasonication time is 3-10 min.

[0027] Preferably, the water / oxygen values ​​in the glove box are both <0.01 ppm.

[0028] More preferably, in the present invention, diethylene glycol dimethanesulfonate may be used in addition to isodecyl diphenyl phosphate and trineopentyl phosphite during the preparation of the electrolyte. The synergistic use of diethylene glycol dimethanesulfonate further alters the composition and structure of the positive and negative electrode interfaces, promotes the stable formation of the interfacial film, and prevents the reaction between the electrolyte and the electrodes, thereby improving the discharge capacity and long-term cycling performance.

[0029] Preferably, the mass ratio of fluoroethylene carbonate to diethylene glycol dimethanesulfonate is 1:0.2-0.55.

[0030] Compared with the prior art, the present invention has the following beneficial effects: The present invention proposes a method for preparing a fast-charging electrolyte for sodium ion batteries, comprising mixing a main film-forming agent, an additive, a solvent, and a sodium salt, and then ultrasonically dissolving the mixture to obtain an electrolyte. Fluorinated ethylene carbonate is used as the main film-forming agent, and the high reducing activity of the fluorine element preferentially participates in the formation of the negative electrode solid electrolyte interface film, thereby reducing the interface impedance and inhibiting the continuous decomposition of the electrolyte. The electron-withdrawing effect of the fluorine atom can also reduce the binding energy between the solvent and the sodium ion. The additives triphenyl phosphate, isodecyl diphenyl phosphate, trineopentyl phosphite, and 4-aminophenylboronic acid pinacol ester are introduced to reduce the Na + The desolvation energy barrier at the interface forms a more stable and effective interfacial film, weakens the coupling between anions and cations, and accelerates the Na +The researchers used propylene carbonate and ethyl methyl carbonate as solvents to ensure the sodium ion transmission efficiency. They also utilized high-concentration sodium salts to promote the formation of anion-aggregated solvation structures, reducing side reactions between free solvent molecules and electrodes. Ultimately, the button batteries made from the prepared electrolytes can effectively support fast charging and exhibit good electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0032] Figure 1 This is the charge capacity result diagram of the button battery at different rates; Figure 2 This is the discharge capacity result diagram of button battery at different rates; Figure 3 This is the cycle performance diagram of the button battery. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The following first describes the concepts involved in this application with reference to the accompanying drawings. It should be noted that the following description of each concept is intended only to make the content of this application easier to understand and does not limit the scope of protection of this application. At the same time, the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The following detailed description of this application will be made with reference to the accompanying drawings and in conjunction with the embodiments.

[0035] The abbreviations used in the specification and claims have the following meanings: Example 1: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, 4-aminophenylboronic acid pinacol ester, propylene carbonate, ethyl methyl carbonate, and sodium hexafluorophosphate were mixed and dissolved by ultrasonication for 5 minutes to obtain the electrolyte. The electrolyte was then stored in the glove box. The mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester was 1:2, the mass ratio of fluoroethylene carbonate to propylene carbonate was 1:40, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate was 1:44, and the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate was 1:13. The water / oxygen values ​​in the glove box were all <0.01 ppm.

[0036] Example 2: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, triphenyl phosphate, 4-aminophenylboronic acid pinacol, propylene carbonate, ethyl methyl carbonate, sodium hexafluorophosphate, and sodium bis(trifluoromethanesulfonyl)imide were mixed and dissolved by ultrasonication for 5 minutes to obtain the electrolyte, which was then stored in the glove box. The mass ratio of fluoroethylene carbonate to triphenyl phosphate was 1:0.8, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol was 1:0.67, the mass ratio of fluoroethylene carbonate to propylene carbonate was 1:19.2, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate was 1:35.67, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate was 1:8.33, and the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide was 1:1. The water / oxygen values ​​in the glove box were all <0.01 ppm.

[0037] Example 3: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, 4-aminophenylboronic acid pinacol ester, propylene carbonate, ethyl methyl carbonate, and sodium hexafluorophosphate were mixed and dissolved by ultrasonication for 5 minutes to obtain the electrolyte. The electrolyte was then stored in the glove box. The mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester was 1:1, the mass ratio of fluoroethylene carbonate to propylene carbonate was 1:16.67, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate was 1:38.67, and the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate was 1:9.33. The water / oxygen values ​​in the glove box were all <0.01 ppm.

[0038] Example 4: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, triphenyl phosphate, 4-aminophenylboronic acid pinacol ester, propylene carbonate, ethyl methyl carbonate, sodium hexafluorophosphate, and sodium bis(trifluoromethanesulfonyl)imide were mixed and dissolved by ultrasonication for 5 minutes to obtain the electrolyte, which was then stored in the glove box. The mass ratio of fluoroethylene carbonate to triphenyl phosphate was 1:0.53, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester was 1:1, the mass ratio of fluoroethylene carbonate to propylene carbonate was 1:16.67, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate was 1:38.67, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate was 1:8, and the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide was 1:1.27. The water / oxygen values ​​in the glove box were all <0.01 ppm.

[0039] Example 5: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, triphenyl phosphate, propylene carbonate, ethyl methyl carbonate, and sodium hexafluorophosphate were mixed and dissolved by ultrasonication for 5 minutes to obtain the electrolyte. The electrolyte was then stored in the glove box. The mass ratio of fluoroethylene carbonate to triphenyl phosphate was 1:1, the mass ratio of fluoroethylene carbonate to propylene carbonate was 1:16.67, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate was 1:38.67, and the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate was 1:9.33. The water / oxygen values ​​in the glove box were all <0.01 ppm.

[0040] Example 6: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, triphenyl phosphate, isodecyl diphenyl phosphate, trineopentyl phosphite, 4-aminophenylboronic acid pinacol ester, propylene carbonate, ethyl methyl carbonate, sodium hexafluorophosphate, and sodium bis(trifluoromethanesulfonyl)imide were mixed and then sonicated for 5 minutes to dissolve the electrolyte, which was then stored in the glove box. The mass ratio of fluoroethylene carbonate to triphenyl phosphate is 1:0.53, the mass ratio of fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.35, the mass ratio of fluoroethylene carbonate to trineopentyl phosphite is 1:0.25, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester is 1:1, the mass ratio of fluoroethylene carbonate to propylene carbonate is 1:16.67, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate is 1:38.67, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate is 1:8, the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide is 1:1.27, and the water / oxygen values ​​in the glove box are all <0.01ppm.

[0041] Example 7: Preparation of electrolyte: The preparation of the electrolyte in this embodiment is different from that in Example 6, except that the mass ratio of fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.65, and other conditions and parameters are the same as in Example 6.

[0042] Example 8: Preparation of the electrolyte: In a glove box, fluoroethylene carbonate, triphenyl phosphate, isodecyl diphenyl phosphate, trineopentyl phosphite, diethylene glycol dimethanesulfonate, 4-aminophenylboronic acid pinacol ester, propylene carbonate, ethyl methyl carbonate, sodium hexafluorophosphate, and sodium bis(trifluoromethanesulfonyl)imide were mixed and then sonicated for 5 minutes to dissolve the electrolyte, which was then stored in the glove box. The mass ratio of fluoroethylene carbonate to triphenyl phosphate is 1:0.53, the mass ratio of fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.35, the mass ratio of fluoroethylene carbonate to trineopentyl phosphite is 1:0.25, the mass ratio of fluoroethylene carbonate to diethylene glycol dimethanesulfonate is 1:0.25, the mass ratio of fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester is 1:1, the mass ratio of fluoroethylene carbonate to propylene carbonate is 1:16.67, the mass ratio of fluoroethylene carbonate to ethyl methyl carbonate is 1:38.67, the mass ratio of fluoroethylene carbonate to sodium hexafluorophosphate is 1:8, and the mass ratio of fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide is 1:1.27. The water / oxygen values ​​in the glove box are all <0.01ppm.

[0043] Example 9: Preparation of electrolyte: The preparation of the electrolyte in this embodiment is compared with that in Example 8, except that the mass ratio of fluoroethylene carbonate to diethylene glycol dimethanesulfonate is 1:0.45, and other conditions and parameters are the same as in Example 8.

[0044] Comparative Example 1: Preparation of electrolyte: The preparation of the electrolyte in this comparative example is compared with that in Example 6, except that isodecyl diphenyl phosphate is not used. Other conditions and parameters are the same as in Example 6.

[0045] Comparative Example 2: Preparation of electrolyte: The preparation of the electrolyte in this comparative example is compared with that in Example 6, except that trineopentyl phosphite is not used. Other conditions and parameters are the same as those in Example 6.

[0046] Experimental Example 1: Preparation of positive electrode: Polycrystalline layered oxide, carbon black and polytetrafluoroethylene were mixed, and then N-methylpyrrolidone was added and stirred for 12 hours to obtain a slurry. The slurry was then coated on aluminum foil using a 200μm scraper. The coated electrode was vacuum dried at 100℃ for 12 hours. After drying, it was punched into discs with a diameter of 12mm. The active material loading was 4mg / cm -2 The mass ratio of carbon black to polycrystalline layered oxide is 1:8, the mass ratio of polytetrafluoroethylene to polycrystalline layered oxide is 1:8, and the mass ratio of polytetrafluoroethylene to N-methylpyrrolidone is 1:1.5.

[0047] Assembly of button cells: In a glove box, the positive electrode sheet was used as the positive electrode, PP was used as the separator, and the metal sodium sheet was used as the negative electrode. The electrolyte prepared in Example 1-5 was added in an amount of 50 μL.

[0048] Determination of rate performance: The cycle performance of button batteries is tested using a battery tester.

[0049] The results are as follows Figure 1 and Figure 2 As shown, Figure 1 The charge capacity measurement results of button batteries made from the electrolytes prepared in Examples 1-5 at different rates are shown; Figure 2 The discharge capacity of button batteries made from the electrolytes prepared in Examples 1-5 at different rates is measured. Figure 1 and Figure 2 It can be seen that the button battery made of the electrolyte prepared in Example 4 has a high charge specific capacity and discharge specific capacity at different rates, indicating that the rate performance is relatively excellent.

[0050] Experimental Example 2: The preparation of the positive electrode was the same as that in Experimental Example 1.

[0051] Assembly of button cells: In a glove box, the positive electrode sheet was used as the positive electrode, PP was used as the separator, and the metal sodium sheet was used as the negative electrode. The electrolyte prepared in Example 4 was added in an amount of 50 μL.

[0052] Determination of cycle performance: The cycle performance of button batteries is tested by a battery tester.

[0053] The results are as follows Figure 3 As shown, the button battery made of the electrolyte prepared in Example 4 can be stably cycled under the charge and discharge conditions of 1.5C, indicating that it can support 1.5C fast charging.

[0054] Experimental Example 3: The preparation of the positive electrode was the same as that in Experimental Example 1.

[0055] Assembly of button cells: In a glove box, the positive electrode sheet was used as the positive electrode, PP was used as the separator, and the metal sodium sheet was used as the negative electrode. The electrolyte prepared in Examples 4, 6-9 and Comparative Examples 1-2 was added, and the amount of electrolyte added was 50 μL.

[0056] Determination of first discharge specific capacity: The first discharge specific capacity of the button battery at 1C is tested by a battery tester.

[0057] Table 1 Results of first discharge specific capacity determination

[0058] The button cells made of the electrolytes prepared in Examples 4, 6-9 and Comparative Examples 1-2, the results of the first discharge specific capacity measurement are shown in Table 1. Compared with Example 6, Example 4 shows that the use of isodecyl diphenyl phosphate and trineopentyl phosphite can improve the first discharge specific capacity of the button cells made of the prepared electrolytes; compared with Example 7, Example 6 shows that increasing the amount of isodecyl diphenyl phosphate within a certain range can also improve the first discharge specific capacity of the button cells made of the prepared electrolytes; compared with Example 8, Example 6 shows that the use of isodecyl diphenyl phosphate and trineopentyl phosphite can improve the first discharge specific capacity of the button cells made of the prepared electrolytes. In the above, the use of diethylene glycol dimethanesulfonate can further improve the initial discharge specific capacity of the button cell made of the prepared electrolyte; Example 8, compared with Example 9, shows that increasing the amount of diethylene glycol dimethanesulfonate used within a certain range can also improve the initial discharge specific capacity of the button cell made of the prepared electrolyte; Example 6, compared with Comparative Examples 1 and 2, shows that isodecyl diphenyl phosphate and trineopentyl phosphite need to be used together, and the use of either isodecyl diphenyl phosphate or trineopentyl phosphite alone has no obvious effect on improving the initial discharge specific capacity of the button cell made of the prepared electrolyte.

[0059] Experimental Example 4: The preparation of the positive electrode was the same as that in Experimental Example 1.

[0060] Assembly of button cells: In a glove box, the positive electrode sheet was used as the positive electrode, PP was used as the separator, and the metal sodium sheet was used as the negative electrode. The electrolyte prepared in Examples 4, 6-9 and Comparative Examples 1-2 was added, and the amount of electrolyte added was 50 μL.

[0061] Determination of capacity retention rate: The capacity retention rate of the button battery after 100 cycles at 0.5C was measured.

[0062] Table 2 Capacity retention rate measurement results

[0063] The button cells made of the electrolytes prepared in Examples 4, 6-9 and Comparative Examples 1-2, the results of the first coulombic efficiency measurement are shown in Table 2. Compared with Example 6, Example 4 shows that the use of isodecyl diphenyl phosphate and trineopentyl phosphite can improve the capacity retention rate of the button cells made of the prepared electrolytes; compared with Example 7, Example 6 shows that increasing the amount of isodecyl diphenyl phosphate within a certain range can also improve the capacity retention rate of the button cells made of the prepared electrolytes; compared with Example 8, Example 6 shows that on the basis of using isodecyl diphenyl phosphate and trineopentyl phosphite, the capacity retention rate of the button cells made of the prepared electrolytes can be improved. In the above, the use of diethylene glycol dimethanesulfonate can further improve the capacity retention rate of the button battery made of the prepared electrolyte; Example 8, compared with Example 9, shows that increasing the amount of diethylene glycol dimethanesulfonate used within a certain range can also improve the capacity retention rate of the button battery made of the prepared electrolyte; Example 6, compared with Comparative Examples 1 and 2, shows that isodecyl diphenyl phosphate and trineopentyl phosphite need to be used together, and the use of either isodecyl diphenyl phosphate or trineopentyl phosphite alone has no obvious effect on improving the capacity retention rate of the button battery made of the prepared electrolyte.

[0064] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and do not impose any form of limitation on the implementation methods of the technology of the present invention. Any person skilled in the art may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0065] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A sodium ion battery fast charge electrolyte comprising: Main film formers, additives, solvents and sodium salts; The mass ratio of the main film-forming agent to the solvent is 1:47-65.

2. A sodium ion battery fast charge electrolyte according to claim 1, characterized in that: The main film-forming agent is fluoroethylene carbonate, the additives include at least one of triphenyl phosphate, isodecyl diphenyl phosphate, tripentyl phosphite and 4-aminophenylboronic acid pinacol ester, the solvent includes propylene carbonate and ethyl methyl carbonate, and the sodium salt includes at least one of sodium hexafluorophosphate and sodium bis(trifluoromethanesulfonyl)imide.

3. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to triphenyl phosphate is 1:0.4-0.

65.

4. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to isodecyl diphenyl phosphate is 1:0.25-0.

8.

5. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to trineopentyl phosphite is 1:0.2-0.

45.

6. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to 4-aminophenylboronic acid pinacol ester is 1:0.5-2.

5.

7. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to the propylene carbonate is 1:12-20.

8. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to ethyl methyl carbonate is 1:35-45.

9. A sodium ion battery fast charge electrolyte according to claim 2, characterized in that: The mass ratio of the fluoroethylene carbonate to sodium hexafluorophosphate is 1:7-14, and the mass ratio of the fluoroethylene carbonate to sodium bis(trifluoromethanesulfonyl)imide is 1:1-1.

5.

10. Use of the sodium ion battery fast-charge electrolyte according to any one of claims 1 to 9 in preparing a battery.

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