Sodium-ion battery negative electrode pre-sodium modification method and sodium-ion battery negative electrode pre-sodium modification device

Abstract

The invention relates to a sodium ion battery negative electrode pre-sodium modification method and device, the pre-sodium modification operation is carried out in inert gas, and the method comprises the following steps: heating a negative electrode plate; spraying a sodium metal powder solution on the heated negative pole piece; and pressurizing the negative pole piece. The method has the advantages that the negative pole piece is heated, so that the organic solvent can be quickly removed, and the influence of residues on the electrochemical performance of the negative pole piece is reduced; the pole piece compounded with the sodium metal is rolled, so that the electric contact between the sodium metal and the pole piece can be increased, and the pre-sodium modification effect is improved; in the process that sodium metal powder is in direct contact with a pole piece for pre-sodium modification, if the added sodium metal powder is too little, the pre-sodium modification effect is not obvious, and if the added sodium metal powder is too much, excessive sodium can promote growth of sodium dendrites and cause safety problems, so that the adding amount of the sodium metal is very important; the pre-sodium modification degree can be quantitatively controlled by controlling the concentration of the sodium metal powder solution.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium ion batteries, and in particular to a method and device for pre-sodiumization of a negative electrode of a sodium ion battery. Background Art

[0002] Based on the current situation of energy shortage and the need for environmental protection, people pay more and more attention to the use of clean energy. In the process of collecting, transporting and efficiently utilizing clean energy such as solar energy and wind energy, energy storage technology is crucial. Lithium-ion batteries are widely used in electronic products, electric vehicles and large-scale energy storage due to their high energy density, high output voltage and excellent cycle performance. At present, the shortage of lithium resources has become the biggest obstacle to its large-scale application. Sodium-ion batteries are considered to be the most promising powerful supplement and reserve of lithium-ion batteries due to their highly competitive cost advantages and sustainable resource supply. Many negative electrode materials such as conversion materials, embedded materials and alloy materials have shown high sodium storage specific capacity and excellent cycle stability. However, the common problem of low initial coulombic efficiency of negative electrode materials has always restricted the improvement of the energy density of sodium-ion batteries. Pre-sodiumization can compensate for the loss of active sodium in negative electrode materials, effectively improve the initial coulombic efficiency of negative electrode materials, and thus achieve a significant increase in the energy density and cycle life of the whole battery.

[0003] In the prior art, the patent application number is 2020800562248, and the patent name is "A method for pre-sodiumization of a negative electrode, a pre-sodiumized negative electrode, and a lithium secondary battery comprising the pre-sodiumized negative electrode". It is proposed that a battery be composed of a negative electrode plate and metallic sodium, and the negative electrode plate be pre-sodiumized through charging and discharging. This method involves the assembly and disassembly of the battery and the cleaning of the plate. The operation is complicated and the pre-sodiumization operation cannot be performed continuously.

[0004] Application number 2022110536429, patent name "High initial efficiency hard carbon negative electrode for sodium ion battery" proposes that the negative electrode material precursor is mixed with a sodium-containing compound, and a pre-sodiumized negative electrode material is obtained after a series of chemical reactions. This method involves a chemical reaction process, and pre-sodiumization is only applicable to substances that will undergo chemical reactions, so its scope of application is relatively narrow. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for pre-sodiumization of the negative electrode of a sodium ion battery, wherein the sodium metal particles are directly physically compounded with the electrode plate, and the missing active sodium is pre-buried in the electrode, thereby achieving the purpose of pre-sodiumization, which is simple and efficient, has a wide range of applications, and can be pre-sodiumized continuously. To achieve the above purpose, the present invention is implemented by the following technical solutions:

[0006] A method for pre-sodiumization of a negative electrode of a sodium ion battery, wherein the pre-sodiumization operation is performed in an inert gas, comprising:

[0007] S1, heating the negative electrode;

[0008] S2, spraying a sodium metal powder solution on the heated negative electrode sheet;

[0009] S3. Pressurizing the negative electrode plate.

[0010] In S1, the heating method of the negative electrode plate is heating by a heating device or gas heating, and the heating temperature of the negative electrode plate is 40 to 90°C.

[0011] In S2, the size of the sodium metal powder is 0.05-100 μm, the concentration of the sodium metal powder solution is 0.1-70 wt%, and the solvent used in the sodium metal powder solution is a volatile organic solvent, including one or a combination of methanol, ethanol, n-hexane, n-pentane, acetone, benzene, tetrahydrofuran, toluene, and ethyl acetate.

[0012] In S3, the negative electrode plate includes one or a composite of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, and negative electrode coke, and the pressurization treatment includes roller pressing and pressurization, and the applied pressure intensity is 0.01 to 20 MPa.

[0013] The inert gas is one of nitrogen, argon and helium.

[0014] The device of the method for pre-sodiumization of the negative electrode of a sodium ion battery comprises a nozzle, a negative electrode sheet, a reel, a heating device, a pair of rollers, an infrared thermometer, a sheet pressing roller, and a sheet winding shaft. The negative electrode sheet passes through the reel, the sheet pressing roller, and the pair of rollers in sequence, and is finally wound on the sheet winding shaft. A sodium metal powder solution is contained in the nozzle, and a valve is provided at the bottom of the nozzle. The nozzle is located above the negative electrode sheet and close to one end of the reel. The heating device is located below the negative electrode sheet and is close to the negative electrode sheet and is used to heat the negative electrode sheet. The infrared thermometer is located above the heating device and close to one end of the pair of rollers.

[0015] The reel is used to wind the negative electrode sheet that has not been pre-sodiumized. The length of the reel is greater than the width of the negative electrode sheet, and the difference between the length of the reel and the width of the negative electrode sheet is 2 to 20 cm. The electrode sheet pressing roller is fixedly installed above the heating device by a bracket, and a gap is left between the electrode sheet pressing roller and the heating device, and the gap range is 0.1 to 10 mm. The electrode sheet pressing roller is used to support the negative electrode sheet and rotates with the movement of the negative electrode sheet.

[0016] The length of the pole sheet pressing roller is greater than the width of the negative pole sheet, and the difference between the length of the pole sheet pressing roller and the width of the negative pole sheet is 1 to 10 cm, the length of the counter-roller is greater than the width of the negative pole sheet, and the difference between the length of the counter-roller and the width of the negative pole sheet is 2 to 20 cm, the length of the pole sheet winding axis is greater than the width of the negative pole sheet, and the difference between the length of the pole sheet winding axis and the width of the negative pole sheet is 2 to 20 cm.

[0017] The negative electrode sheet has a side with active material facing upward, and the active material includes one or more of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, and negative electrode coke.

[0018] The infrared thermometer is used to detect the surface temperature of the negative electrode piece, and the heating device is used to heat the negative electrode piece; the heating device includes a heating plate and a heater, the heating plate is closely attached to the negative electrode piece, and the heater is used to heat the heating plate.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Heating the negative electrode can quickly remove the organic solvent and reduce the impact of the residue on the electrochemical performance of the negative electrode;

[0021] 2. The use of sodium metal powder organic solution is conducive to the spraying process. At the same time, the sodium metal powder organic solution avoids direct contact between metallic sodium and moisture and air, thereby improving the safety during storage and operation;

[0022] 3. Rolling the composite sodium metal pole piece can increase the electrical contact between the sodium metal and the pole piece and improve the pre-sodiumization effect;

[0023] 4. In the process of pre-sodiumization in which sodium metal powder is in direct contact with the electrode, if too little sodium metal powder is added, the pre-sodiumization effect is not obvious. If too much sodium metal powder is added, the excess sodium will promote the growth of sodium dendrites and cause safety problems. Therefore, the amount of sodium metal added is very important. By controlling the concentration of the sodium metal powder solution, the degree of pre-sodiumization can be quantitatively controlled.

[0024] 5. Sodium metal powder solution is sprayed onto the pole piece through the nozzle, the heating plate heats the pole piece to volatilize the solvent, and the roller applies pressure to the pole piece to complete the pre-sodium treatment. The rotation of the reel and the roller can continuously allow the pole piece that has not been pre-sodiumized to enter under the nozzle, and the above-mentioned pre-sodiumization operation is continuously performed, realizing continuous pre-sodiumization with simple structure and easy operation;

[0025] 6. Sodium metal particles are directly physically compounded with the negative electrode plate, the missing active sodium is pre-buried in the electrode, and the electrode plate is pre-sodiumized to supplement the sodium consumed by the formation of the solid electrolyte membrane, thereby improving the initial coulombic efficiency of the material without compromising the battery capacity and cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the pre-sodiumization device for the negative electrode of a sodium ion battery.

[0027] Figure 2 It is a top view of the relative position of the pressure roller and the negative electrode.

[0028] Figure 3This is a schematic diagram of the electrical principle of the pre-sodiumization device for the negative electrode of a sodium-ion battery.

[0029] In the figure: 1-nozzle 2-sodium metal powder solution 3-negative electrode plate 4-reel 5-heating device 6-pair of rollers 7-valve 8-infrared thermometer 9-electrode plate pressure roller 10-electrode plate winding shaft 11-connecting line 12-heater control console. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0031] The following examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0032] A pre-sodiumization device for a negative electrode of a sodium ion battery comprises a nozzle 1, a negative electrode sheet 3, a reel 4, a heating device 5, a pair of rollers 6, an infrared thermometer 8, a sheet pressing roller 9, and a sheet winding shaft 10. The negative electrode sheet 3 passes through the reel 4, the sheet pressing roller 9, and the pair of rollers 6 in sequence, and is finally wound on the sheet winding shaft 10. The sheet pressing roller 9 is fixedly installed above the heating device 5 by a bracket. A gap is left between the sheet pressing roller 9 and the heating device 5, and the gap range is 0.1-10mm. The negative electrode sheet 3 passes through the gap between the heating device 5 and the sheet pressing roller 9. The sheet pressing roller 9 is used to support the negative electrode sheet 3 and rotates with the movement of the negative electrode sheet 3. The sheet pressing roller 9 helps the negative electrode sheet 3 and the heating device 5 to be closer. The tight fit can improve the heating effect and prevent the negative electrode plate 3 from curling during movement. The length of the plate pressing roller 9 is 1 to 10 cm greater than the width of the negative electrode plate 3. The negative electrode plate 3 has an active material side facing upward, and the active material includes one or a combination of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, and negative electrode coke. A valve 7 is installed at the bottom of the nozzle 1. The nozzle 1 is used to hold the sodium metal powder solution 2. The spraying of the sodium metal powder solution 2 is controlled by the valve 7. When the valve 7 is opened, the sodium metal powder solution 2 can be sprayed onto the negative electrode plate 3. The flow rate of the sodium metal powder solution 2 is controlled by the size of the valve 7 opening. The valve 7 is connected to the control unit.

[0033] The nozzle 1 is located above the negative electrode sheet 3, close to one end of the reel 4. The heating device 5 is located below the negative electrode sheet 3, close to the negative electrode sheet 3. The heating device includes a heating plate and a heater. The heating plate is close to the negative electrode sheet 3. The heater is used to heat the heating plate. The infrared thermometer 8 is located above the heating device 5, close to one end of the roller 6; the infrared thermometer 8 is used to detect the surface temperature of the negative electrode sheet 3. The heater control console 12 is provided with a contactor KM1, which is closed / disconnected by the contactor KM1 to heat the negative electrode sheet 3. The reel 4 is used to wind the negative electrode sheet 3 that has not been pre-sodiumized; the roller 6 can rotate to apply pressure to the negative electrode sheet 3 to increase the electrical contact between the sodium metal and the sheet; the sheet winding shaft 10 can rotate to wind and collect the pre-sodiumized negative electrode sheet 3. The heating device, infrared thermometer, and valve are connected to the PLC.

[0034] The present invention and the device provide a simple and easy-to-operate continuous pre-sodiumization method.

[0035] A method for pre-sodiumization of a negative electrode of a sodium ion battery, wherein the pre-sodiumization operation is performed in an inert gas, wherein the inert gas is one of nitrogen, argon, and helium, and specifically comprises:

[0036] (1) Heating the negative electrode

[0037] The negative electrode sheet includes one or a combination of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, negative electrode coke, coal, and graphene;

[0038] The heating method of the negative electrode plate is heating by a heating device, the heating device includes a heating table or a heating plate, and the heating temperature of the negative electrode plate is 40-90°C, preferably 50-85°C, or 60-80°C; heating the plate is conducive to the rapid volatilization of the organic solvent in the sodium metal particle solution, shortening the operation time, and reducing the residual organic solvent. If the heating temperature is too low, the organic solvent will not evaporate completely, and if the heating temperature is too high, the risk of side reactions will increase.

[0039] (2) Spraying sodium metal powder solution on the heated negative electrode

[0040] The size of the sodium metal powder is 0.05-100 μm, preferably 0.1-50 μm, or 0.5-20 μm; the smaller the size of the sodium metal particles, the more conducive it is to the penetration of the sodium metal in the negative electrode, and the better the pre-sodiumization effect, but if the size of the sodium metal particles is too small, the risk of increased production costs increases; the solvent used in the sodium metal particle solution is a volatile organic solvent, including methanol, ethanol, n-hexane, n-pentane, acetone, benzene, tetrahydrofuran, toluene, ethyl acetate, or a combination of several thereof;

[0041] The concentration of the sodium metal particle solution is 0.1 to 70 wt%, preferably 5 to 50 wt%, or 15 to 40 wt%; if the concentration of the sodium metal particle solution is too low, the amount of sodium metal participating in the reaction is small, and the pre-sodiumization effect is weakened. If the concentration of the sodium metal particle solution is too high, the sodium metal particles are easy to agglomerate and have poor dispersion, which is not conducive to the penetration of sodium metal in the negative electrode, and the pre-sodiumization effect becomes poor. At the same time, excessive sodium will promote the growth of sodium dendrites, causing safety problems.

[0042] (3) Pressurizing the above-mentioned pole piece

[0043] A certain pressure is applied to the negative electrode plate, and the applied pressure intensity is 0.01 to 50 MPa, preferably 2 to 40 MPa, or 10 to 30 MPa; rolling can increase the electrical contact between the sodium metal and the plate, improve the reaction activity, and enhance the pre-sodiumization effect.

[0044] Sodium metal particles are directly physically compounded with the electrode plates to pre-bury the missing active sodium in the electrode, thereby achieving the purpose of pre-sodiumization; heating the plate can quickly remove the organic solvent and reduce the impact of the residue on the electrochemical properties of the plate. The use of sodium metal powder organic solution is conducive to the spraying process. At the same time, the sodium metal particle organic solution avoids the direct contact between metallic sodium and moisture and air, and improves the safety during storage and operation; rolling the composite sodium metal plate can increase the electrical contact between the sodium metal and the plate and improve the pre-sodiumization effect; in the process of pre-sodiumization in direct contact between the sodium metal powder and the plate, if too little sodium metal powder is added, the pre-sodiumization effect is not obvious. If too much sodium metal powder is added, the excess sodium will promote the growth of sodium dendrites and cause safety problems. Therefore, the amount of sodium metal added is very important. In the present invention, the degree of pre-sodiumization can be quantitatively controlled by controlling the concentration of the sodium metal particle solution; the method and device provided by the present invention spray the sodium metal powder solution onto the electrode through a nozzle, the heating device heats the electrode to volatilize the solvent, and the roller applies pressure to the electrode to complete the pre-sodiumization treatment; the rotation of the reel and the roller can continuously allow the electrode that has not been pre-sodiumized to enter under the nozzle, and continuously perform the above-mentioned pre-sodiumization operation.

[0045] [Example]

[0046] The present invention is described in more detail by way of examples. These examples are merely descriptions of the best mode for carrying out the present invention and do not limit the scope of the present invention in any way.

[0047] Table 1 lists the introduction of the pre-sodiumization implementation method of the embodiment, and the first coulombic efficiency (first efficiency) of the material after the corresponding pre-sodiumization is completed. Table 2 lists the introduction of the pre-sodiumization implementation method of the comparative example, and the first efficiency of the material after the corresponding pre-sodiumization is completed;

[0048] Table 1 is a brief introduction to the embodiment method and the corresponding first effect

[0049]

[0050] In Table 1, Example 1: Under an argon atmosphere, the hard carbon negative electrode material is heated to 70-80°C, and then a n-hexane solution of sodium metal powder (sodium metal powder size 1 μm, solution concentration 35wt%) is sprayed on the hard carbon negative electrode material at this temperature. After the spraying is completed, the electrode sheet is rolled at a pressure of 20-30MPa; after the pre-sodiumization is completed, a button cell is assembled with the sodium metal sheet as the counter electrode, and the first efficiency of the negative electrode material is tested, and the first efficiency of the material is 97%.

[0051] Example 2: Compared with Example 1, other conditions remain unchanged, and the size of the sodium metal powder is changed to 30 μm; after pre-sodiumization, the initial efficiency of the material is 92%.

[0052] Example 3: Compared with Example 1, other conditions remain unchanged, and the size of the sodium metal powder is changed to 80 μm; after pre-sodiumization, the initial efficiency of the material is 88%.

[0053] Example 4: Under a nitrogen atmosphere, the hard carbon negative electrode material is heated to 70-80°C, and then a n-hexane solution of sodium metal powder (sodium metal powder size 1 μm, solution concentration 65wt%) is sprayed on the hard carbon negative electrode material at this temperature. After spraying, the electrode sheet is roll-pressed at a pressure of 20-30 MPa. After pre-sodiumization, button cells are assembled with the sodium metal sheet as the counter electrode, and the first efficiency of the negative electrode material is tested. The first efficiency of the material is 94%.

[0054] Example 5: Compared with Example 4, other conditions remain unchanged, and the concentration of the sodium metal powder solution is changed to 35wt%; after pre-sodiumization, the first efficiency of the material is 97%.

[0055] Example 6: Compared with Example 4, other conditions remain unchanged, and the concentration of the sodium metal powder solution is changed to 14wt%; after pre-sodiumization, the first efficiency of the material is 93%.

[0056] Example 7: Compared with Example 4, other conditions remain unchanged, and the concentration of the sodium metal powder solution is changed to 3wt%; after pre-sodiumization, the first efficiency of the material is 90%.

[0057] Example 8: Compared with Example 5, other conditions remain unchanged, and the rolling pressure is changed to 5 MPa; after pre-sodiumization, the initial efficiency of the material is 91%.

[0058] Example 9: Under an argon atmosphere, the soft carbon negative electrode material is heated to 55°C, and then an ethanol solution of sodium metal powder (sodium metal powder size 5μm, solution concentration 15wt%) is sprayed on the soft carbon negative electrode material at this temperature. After spraying, the electrode sheet is roll-pressed at a pressure of 15MPa. After pre-sodiumization, button batteries are assembled with the sodium metal sheet as the counter electrode, and the first efficiency of the negative electrode material is tested. The first efficiency of the material is 92%.

[0059] Table 2 is a brief introduction to the comparative implementation method and the corresponding first effect

[0060]

[0061] In Table 2, Comparative Example 1: The hard carbon negative electrode material is not subjected to the pre-sodium treatment of the present invention; a button cell is assembled using a sodium metal sheet as a counter electrode, and the first efficiency of the negative electrode material is tested, and the first efficiency of the material is 75%.

[0062] Comparative Example 2: Under a nitrogen atmosphere, a n-hexane solution of sodium metal powder (sodium metal powder size 200 μm, solution concentration 0.01 wt%) was sprayed onto the hard carbon negative electrode material at room temperature. After spraying, the electrode sheet was not rolled. After pre-sodiumization, button cells were assembled using the sodium metal sheet as the counter electrode, and the first efficiency of the negative electrode material was tested, and the first efficiency of the material was 79%.

[0063] As can be seen from the above, in Examples 1-3, the size of the sodium metal powder is reduced, and the first effect of the negative electrode material is increased, because the smaller the size of the sodium metal particles, the more conducive it is to the penetration of sodium metal in the negative electrode, and the better the pre-sodiumization effect. Comparison of Examples 5-7 shows that increasing the concentration of the sodium metal powder solution within a certain range can improve the first effect of the material, because in the process of pre-sodiumization in which the sodium metal powder is in direct contact with the pole piece, if the concentration of the added sodium metal powder solution is too low, the amount of sodium metal powder is too small, resulting in an insignificant pre-sodiumization effect and an insignificant increase in the first effect; Comparison of Examples 4 and 5 shows that if the concentration of the sodium metal powder solution is too high, the first effect of the negative electrode material may not increase significantly, because if the concentration of the sodium metal particle solution is too high, the sodium metal particles are easy to agglomerate and have poor dispersion, which is not conducive to the penetration of sodium metal in the negative electrode, and the pre-sodiumization effect becomes worse. At the same time, excessive sodium will promote the growth of sodium dendrites, causing safety problems. In Examples 1 and 5, different types of inert gases can achieve the pre-sodiumization effect. In Examples 5 and 8, increasing the rolling pressure can improve the pre-sodiumization effect and improve the first effect of the negative electrode material; rolling can increase the electrical contact between the sodium metal and the electrode sheet, improve the reaction activity, and enhance the pre-sodiumization effect. In summary, in Examples 1-9, the pre-sodiumization method of the present invention can be applied to a variety of negative electrode materials.

[0064] By comparing Comparative Example 1 with Examples 1-8, if the pre-sodiumization method of the present invention is not used to treat the negative electrode material, the initial efficiency of the material is low; by comparing Comparative Example 2 with Examples 1-8, if the pre-sodiumization parameters recommended by the present invention are not used to treat the negative electrode material, the initial efficiency of the material is low.

[0065] The present invention heats the negative electrode plate, which can quickly remove the organic solvent and reduce the influence of the residue on the electrochemical performance of the negative electrode plate; the use of sodium metal powder organic solution is conducive to the spraying process, and at the same time, the sodium metal powder organic solution avoids the direct contact of metallic sodium with moisture and air, thereby improving the safety during storage and operation; the composite sodium metal plate is rolled, which can increase the electrical contact between the sodium metal and the plate and improve the pre-sodiumization effect; in the process of pre-sodiumization in which the sodium metal powder is in direct contact with the plate, if too little sodium metal powder is added, the pre-sodiumization effect is not obvious, and if too much sodium metal powder is added, the excessive sodium will promote the growth of sodium dendrites, causing safety problems, so the sodium metal The amount of sodium added is very important. By controlling the concentration of the sodium metal powder solution, the degree of pre-sodiumization can be quantitatively controlled; the sodium metal powder solution is sprayed onto the electrode through a nozzle, the heating plate heats the electrode to evaporate the solvent, and the roller applies pressure to the electrode to complete the pre-sodiumization treatment. The rotation of the reel and the roller can continuously allow the unpre-sodiumized electrode to enter under the nozzle, and continuously perform the above-mentioned pre-sodiumization operation, thereby achieving continuous pre-sodiumization with a simple structure and easy operation; the sodium metal particles are directly physically compounded with the negative electrode electrode, and the missing active sodium is pre-buried in the electrode to pre-sodiumize the electrode, replenish the sodium consumed by the formation of the solid electrolyte membrane, and improve the material's first coulombic efficiency without damaging the battery capacity and cycle stability.

Claims

1. A method for pre-sodiumization of a negative electrode of a sodium ion battery, characterized in that: The pre-sodiumization operation is carried out in an inert gas and includes: S1, heating the negative electrode; S2, spraying a sodium metal powder solution on the heated negative electrode sheet; S3. Pressurizing the negative electrode plate.

2. The method for pre-sodiumization of a negative electrode of a sodium ion battery according to claim 1, wherein: In S1, the heating method of the negative electrode plate is heating by a heating device or gas heating, and the heating temperature of the negative electrode plate is 40 to 90°C.

3. The method for pre-sodiumization of a negative electrode of a sodium ion battery according to claim 1, characterized in that: In S2, the size of the sodium metal powder is 0.05-100 μm, the concentration of the sodium metal powder solution is 0.1-70 wt%, and the solvent used in the sodium metal powder solution is a volatile organic solvent, including one or a combination of methanol, ethanol, n-hexane, n-pentane, acetone, benzene, tetrahydrofuran, toluene, and ethyl acetate.

4. The method for pre-sodiumization of a negative electrode of a sodium ion battery according to claim 1, characterized in that: In S3, the negative electrode plate includes one or a composite of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, and negative electrode coke, and the pressurization treatment includes roller pressing and pressurization, and the applied pressure intensity is 0.01 to 20 MPa.

5. The method for pre-sodiumization of a negative electrode of a sodium ion battery according to claim 1, characterized in that: The inert gas is one of nitrogen, argon and helium.

6. A device for implementing the method for pre-sodiumization of a negative electrode of a sodium ion battery as claimed in any one of claims 1 to 5, characterized in that: It includes a nozzle, a negative electrode sheet, a reel, a heating device, a pair of rollers, an infrared thermometer, a sheet pressing roller, and a sheet winding shaft. The negative electrode sheet passes through the reel, the sheet pressing roller, and the pair of rollers in sequence, and is finally wound on the sheet winding shaft. The nozzle is filled with a sodium metal powder solution, and a valve is provided at the bottom of the nozzle. The nozzle is located above the negative electrode sheet, close to one end of the reel. The heating device is located below the negative electrode sheet, close to the negative electrode sheet, and is used to heat the negative electrode sheet. The infrared thermometer is located above the heating device, close to one end of the pair of rollers.

7. The pre-sodiumization device for the negative electrode of a sodium ion battery according to claim 6, characterized in that: The reel is used to wind the negative electrode sheet that has not been pre-sodiumized, the length of the reel is greater than the width of the negative electrode sheet, and the difference between the length of the reel and the width of the negative electrode sheet is 2 to 20 cm; the electrode sheet pressing roller is fixedly installed above the heating device by a bracket, and a gap is left between the electrode sheet pressing roller and the heating device, and the gap range is 0.1 to 10 mm. The electrode sheet pressing roller is used to support the negative electrode sheet and rotates with the movement of the negative electrode sheet.

8. The pre-sodiumization device for the negative electrode of a sodium ion battery according to claim 6, characterized in that: The length of the pole sheet pressing roller is greater than the width of the negative pole sheet, and the difference between the length of the pole sheet pressing roller and the width of the negative pole sheet is 1 to 10 cm, the length of the counter-roller is greater than the width of the negative pole sheet, and the difference between the length of the counter-roller and the width of the negative pole sheet is 2 to 20 cm, the length of the pole sheet winding axis is greater than the width of the negative pole sheet, and the difference between the length of the pole sheet winding axis and the width of the negative pole sheet is 2 to 20 cm.

9. The pre-sodiumization device for the negative electrode of a sodium ion battery according to claim 6, characterized in that: The negative electrode sheet has a side with active material facing upward, and the active material includes one or more of hard carbon, soft carbon, artificial graphite, natural graphite, needle coke, petroleum coke, and negative electrode coke.

10. The pre-sodiumization device for the negative electrode of a sodium ion battery according to claim 6, characterized in that: The infrared thermometer is used to detect the surface temperature of the negative electrode sheet, and the heating device is used to heat the negative electrode sheet; the heating device includes a heating plate and a heater, the heating plate is close to the negative electrode sheet, and the heater is used to heat the heating plate.

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