Water-based sodium-ion battery negative electrode and preparation method thereof

Abstract

This invention discloses an aqueous sodium-ion battery negative electrode, comprising: a negative electrode sheet or a negative electrode current collector, the negative electrode sheet comprising a negative electrode active material; and a ZnS layer comprising ZnS, the ZnS layer being disposed on at least a portion of the surface of the negative electrode sheet or the negative electrode current collector. This invention adds a ZnS layer to the surface of the battery negative electrode to achieve protection of the negative electrode, effectively suppressing dendrite growth and volume expansion, and improving the cycle stability of the battery under high current density.

Description

Technical Field

[0001] This invention relates to the field of storage battery technology, specifically to an aqueous sodium-ion battery negative electrode and its preparation method, and an aqueous sodium-ion battery. Background Technology

[0002] In recent years, sodium-ion batteries have attracted close attention from scholars both domestically and internationally due to their numerous advantages; however, compared to lithium-ion batteries, related reports are still relatively few. As a completely new system, the development of novel high-performance positive and negative electrode materials and matching electrolytes is key to sodium-ion battery research. Considering safety and environmental protection, aqueous sodium-ion batteries have attracted widespread attention from researchers for energy storage applications. It is well known that the electrochemical performance of sodium-ion batteries is mainly determined by their electrode materials. While research on positive electrode materials for sodium-ion batteries has been relatively extensive, negative electrode materials have become a current research hotspot. Currently reported sodium-ion negative electrode materials mainly include carbon-based materials, metal or alloy materials, organic materials, and metal sulfide materials.

[0003] Traditional methods for preparing aqueous sodium-ion battery anode materials typically involve directly coating a substrate with pure-phase NaTi2(PO4)3 and pressing it in place. This achieves a reversible capacity of 40–50 mA·h / g, releasing 70% of the reversible capacity at a high rate of 100C. However, its conductivity is poor, requiring carbon coating to improve it, which significantly increases costs. Furthermore, aqueous sodium-ion battery systems struggle to form a stable solid electrolyte interphase (SEI) film, leading to continuous interfacial reactions, dendrite growth, and reduced cycle life. Therefore, there is an urgent need for a simple, high-performance aqueous sodium-ion battery anode material to improve electrolyte and interfacial stability, reduce dendrite growth, and enhance battery cycle stability. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes an aqueous sodium-ion battery anode, its preparation method, and an aqueous sodium-ion battery. This invention adds a ZnS layer to the surface of the battery anode to protect it, effectively suppressing dendrite growth and volume expansion, and improving the battery's cycle stability at high current densities.

[0005] Therefore, in a first aspect, the present invention provides an aqueous sodium-ion battery negative electrode, comprising:

[0006] Negative electrode sheet or negative electrode current collector, the negative electrode sheet including negative electrode active material; and

[0007] The ZnS layer comprises ZnS and is disposed on at least a portion of the surface of the negative electrode sheet or the negative electrode current collector.

[0008] This invention adds a ZnS layer to the surface of the negative electrode. During battery charging, the ZnS is reduced to metallic Zn, forming a dynamic electrode protective layer to protect the negative electrode. This dynamic ZnS solid electrolyte interface layer allows the negative electrode to operate stably for a long time under high current density conditions, extending the battery's cycle life and meeting the application requirements of high-energy-density aqueous sodium-ion batteries. Furthermore, ZnS material exhibits excellent stability in aqueous electrolytes, and the formed solid electrolyte interface layer is not easily detached. Therefore, the negative electrode of this invention effectively suppresses dendrite growth and volume expansion, improving the battery's cycle stability under high current density.

[0009] In some embodiments, the negative electrode active material includes at least one of titanium dioxide, sodium titanium phosphate, sodium titanium manganese phosphate, and sodium vanadium fluorophosphate.

[0010] In some embodiments, the negative current collector includes at least one of copper foil, copper foam, graphite paper, nickel current collector, stainless steel current collector, or polyethylene film.

[0011] In some embodiments, the loading of ZnS on the negative electrode sheet or negative electrode current collector is 0.2 to 1 mg.

[0012] In some embodiments, the ZnS in the ZnS layer is in the form of nanorods.

[0013] In some embodiments, the negative electrode further includes a conductive agent and a binder.

[0014] In some embodiments, the conductive agent includes at least one of carbon black, graphite, or carbon fiber.

[0015] In some embodiments, the adhesive includes at least one of polyvinylidene fluoride, styrene-butadiene rubber, sodium carboxymethyl cellulose, polyvinyl alcohol, polytetrafluoroethylene, polyolefins, modified SBR rubber, fluorinated rubber, polyurethane, or polymethacrylate.

[0016] In a second aspect, the present invention provides a method for preparing the negative electrode of an aqueous sodium-ion battery as described in the first aspect, comprising:

[0017] At least a portion of the surface of the negative electrode sheet or negative electrode current collector is coated with ZnS, the negative electrode sheet comprising a negative electrode active material, in order to obtain an aqueous sodium-ion battery negative electrode.

[0018] In some embodiments, the negative electrode sheet is obtained by mixing the negative electrode active material, conductive agent, and binder in a solvent.

[0019] In some embodiments, ZnS is pre-dispersed in an acetone solution.

[0020] The preparation method of this invention is simple to operate, low in cost, and easy to scale up for mass production, thus improving production efficiency. Pre-dispersing ZnS in an acetone solution improves the dispersibility of ZnS in the solution, avoids agglomeration, and results in a more uniform dispersion system, facilitating subsequent processing steps such as coating and drying. Furthermore, acetone has good volatility and can evaporate rapidly at room temperature, leaving uniformly distributed ZnS nanoparticles. Therefore, a high-performance aqueous sodium-ion battery anode material can be prepared.

[0021] In a third aspect of the invention, an aqueous sodium-ion battery is provided, comprising: a positive electrode, a separator, and a negative electrode according to the first aspect or a negative electrode prepared according to the second aspect, wherein the separator is immersed in a sulfur-containing electrolyte.

[0022] Therefore, this aqueous sodium-ion battery can effectively suppress dendrite growth and volume expansion of the negative electrode, and improve the cycle stability of the battery under high current density.

[0023] In some embodiments, the sulfur-containing electrolyte includes at least one of thiosulfate ions or sulfate ions.

[0024] In some embodiments, the electrolyte includes sodium sulfate, sodium bisulfate, or a dilute sulfuric acid solution.

[0025] In some embodiments, the positive electrode includes copper foil, sodium vanadate electrode, or sodium manganate electrode. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the in-situ formation of a dynamic solid electrolyte interface layer on the negative electrode inside the battery according to the present invention.

[0027] Figure 2 Figure A is a schematic diagram comparing the morphology of the battery before and after cycling according to the present invention. Figure B is a schematic diagram of dendrites formed on the surface of the battery negative electrode after multiple cycles. Figure B is a schematic diagram of the surface of the battery negative electrode containing the ZnS layer after multiple cycles.

[0028] Figure 3 Figure A shows the ZnS layer morphology on the negative electrode surface of the battery before and after charging, according to Embodiment 1 of the present invention. Figure B shows the ZnS layer morphology on the negative electrode surface before charging and the ZnS layer morphology on the negative electrode surface after charging.

[0029] Figure 4 The XRD pattern of the ZnS layer on the negative electrode of the battery after charging is shown in Embodiment 2 of the present invention.

[0030] Figure 5 This is a topographic image of the ZnS layer on the negative electrode of the battery after charging, according to Embodiment 2 of the present invention.

[0031] Figure 6Figure A shows the morphology of ZnS before and after heat treatment in Embodiment 3 of the present invention, where Figure A is the morphology of ZnS without heat treatment and Figure B is the morphology of ZnS after heat treatment.

[0032] Figure 7 This is a topographic image of the ZnS layer on the negative electrode of the battery after charging, according to Embodiment 3 of the present invention.

[0033] Figure 8 The image shows the XRD pattern of the ZnS negative electrode after charging in Embodiment 3 of the present invention, where A is the ZnS pattern before charging, B is the ZnS pattern after charging for 24 hours, and C is the ZnS pattern after charging for 10 hours.

[0034] Figure 9 This is a battery cycle performance diagram of Embodiment 4 of the present invention;

[0035] Figure 10 This is a battery cycle performance diagram of Embodiment 5 of the present invention;

[0036] Figure 11 This is a battery cycle performance diagram of Comparative Example 1 of the present invention. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0038] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0040] In this document, the terms “comprising” or “including” are open-ended expressions, meaning they include the contents specified in this invention but do not exclude other aspects.

[0041] In a first aspect of the present invention, the present invention provides an aqueous sodium-ion battery negative electrode, comprising:

[0042] Negative electrode sheet or negative electrode current collector, the negative electrode sheet including negative electrode active material; and

[0043] The ZnS layer comprises ZnS and is disposed on at least a portion of the surface of the negative electrode sheet or the negative electrode current collector.

[0044] This invention protects the negative electrode by adding a ZnS layer to the surface of the negative electrode. During battery charging, the ZnS is reduced to metallic Zn, forming a dynamic electrode protective layer. Figure 1 This dynamic ZnS solid electrolyte interface layer enables the negative electrode to operate stably for extended periods under high current density conditions, prolonging the battery's cycle life and meeting the application requirements of high-energy-density aqueous sodium-ion batteries. Furthermore, ZnS material exhibits excellent stability in aqueous electrolytes, and the formed solid electrolyte interface layer is not easily detached. Therefore, the negative electrode of this aqueous sodium-ion battery effectively suppresses dendrite growth and volume expansion, improving the battery's cycle stability under high current density.

[0045] In some embodiments of the present invention, the negative electrode active material includes at least one of titanium dioxide, sodium titanium phosphate, sodium titanium manganese phosphate, and sodium vanadium fluorophosphate.

[0046] The negative electrode active material, as a carrier of sodium ions and electrons during battery charging, plays a role in energy storage and release. When used in conjunction with the ZnS layer of this invention, it can effectively improve the cycle stability of the battery under high current density.

[0047] In some embodiments of the present invention, the negative electrode current collector includes at least one of copper foil, copper foam, graphite paper, nickel current collector, stainless steel current collector, or polyethylene film.

[0048] In some embodiments of the present invention, the loading of ZnS on the negative electrode sheet or negative electrode current collector is 0.2 to 1 mg.

[0049] This allows for the formation of a high-performance dynamic electrode protective layer, which protects the negative electrode, effectively suppresses dendrite growth and volume expansion, and improves the cycle stability of the battery under high current density.

[0050] In some embodiments of the present invention, the ZnS in the ZnS layer is in the form of nanorods.

[0051] According to an embodiment of the present invention, after heat treatment, ZnS material is shaped into nanorods. After charging, the heat-treated ZnS forms a porous solid electrolyte interface layer on the negative electrode surface.

[0052] In some embodiments of the present invention, the negative electrode sheet further includes a conductive agent and a binder.

[0053] In some embodiments of the present invention, the conductive agent includes at least one of carbon black, graphite, or carbon fiber.

[0054] In some embodiments of the present invention, the adhesive includes at least one of polyvinylidene fluoride, styrene-butadiene rubber, sodium carboxymethyl cellulose, polyvinyl alcohol, polytetrafluoroethylene, polyolefins, modified SBR rubber, fluorinated rubber, polyurethane, or polymethacrylate.

[0055] In a second aspect of the present invention, the present invention provides a method for preparing the negative electrode of an aqueous sodium-ion battery as described in the first aspect, comprising:

[0056] At least a portion of the surface of the negative electrode sheet or negative electrode current collector is coated with ZnS, the negative electrode sheet comprising a negative electrode active material, in order to obtain an aqueous sodium-ion battery negative electrode.

[0057] In some embodiments of the present invention, the negative electrode sheet is obtained by mixing the negative electrode active material, conductive agent and binder in a solvent.

[0058] In some embodiments of the present invention, ZnS is pre-dispersed in an acetone solution.

[0059] The preparation method of this invention is simple to operate, low in cost, and easy to scale up for mass production, thus improving production efficiency. Pre-dispersing ZnS in an acetone solution improves the dispersibility of ZnS in the solution, avoids agglomeration, and results in a more uniform dispersion system, facilitating subsequent processing steps such as coating and drying. Furthermore, acetone has good volatility and can evaporate rapidly at room temperature, leaving uniformly distributed ZnS nanoparticles. Therefore, a high-performance aqueous sodium-ion battery anode material can be prepared.

[0060] In some embodiments of the present invention, the method for preparing the aqueous sodium-ion battery anode of the first aspect further includes: heat-treating the ZnS material, wherein the heat treatment controls parameters to satisfy at least one of the following:

[0061] (1) The sintering temperature of the heat treatment is 200~1000℃;

[0062] (2) The heat treatment time is 1 to 4 hours;

[0063] (3) The gaseous environment for heat treatment includes at least one of air or an inert gas.

[0064] The heat-treated ZnS material takes the form of nanorods and, after charging, forms a porous solid electrolyte interface layer on the negative electrode surface. This is beneficial for constructing a dynamic electrode protective layer, achieving protection of the negative electrode and dendrite suppression.

[0065] In a third aspect of the present invention, the present invention provides an aqueous sodium-ion battery comprising: a positive electrode, a separator, and a negative electrode according to the first aspect or a negative electrode prepared according to the second aspect, wherein the separator is immersed in a sulfur-containing electrolyte.

[0066] In some embodiments of the present invention, the sulfur-containing electrolyte includes at least one of thiosulfate ions or sulfate ions.

[0067] The electrolyte of this invention introduces thiosulfate ions (S2O3). 2- (or sulfate ions) can enable a reversible solid-solid transformation reaction between ZnS and Zn at the solid electrolyte interface layer, i.e. This avoids the formation of dendritic crystals and volume expansion at the negative electrode, and the S2O3 content in the electrolyte can be adjusted. 2- Concentration, to a certain extent, improves the morphology of ZnS after conversion, keeping the electrode surface smooth (e.g., Figure 2 (As shown), this further optimizes the electrochemical performance of the negative electrode. This facilitates the construction of a dynamic electrode protective layer, achieving protection of the negative electrode and dendrite suppression, and improving the cycle stability of the battery at high current densities.

[0068] In some embodiments of the present invention, the electrolyte includes sodium sulfate, sodium bisulfate, or a dilute sulfuric acid solution.

[0069] In some embodiments of the present invention, the positive electrode includes copper foil, sodium vanadate electrode, or sodium manganate electrode.

[0070] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0071] Example 1: A method for preparing a negative electrode solid electrolyte interface layer

[0072] (1) Anode Preparation: NaTi2(PO4)3 material, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 80:10:10 and added to the solvent N-methylpyrrolidone (NMP). After stirring to form a uniform slurry, a NaTi2(PO4)3 anode sheet was prepared. Commercial ZnS was dispersed in an acetone solution and coated onto the surface of the NaTi2(PO4)3 anode sheet using a suspension coating method. The mass of the anode material was approximately 2 mg, the mass ratio of ZnS to NaTi2(PO4)3 was 1:4, and the ZnS loading was 0.5 mg.

[0073] (2) Positive electrode preparation: The positive electrode uses copper foil (12 mm in diameter and 0.05 mm in thickness).

[0074] (3) Battery assembly and testing: A single-layer 0.4 mm AGM separator was used, and 140 μL of 0.5 mol / L Na2SO4 electrolyte was added. The positive electrode, negative electrode and separator were assembled into a coin cell and charged at a current density of 25 mA / g.

[0075] Battery test results: At room temperature (25℃), the battery was charged at a current density of 25 mA / g for 10 hours and then removed. The material morphology on the negative electrode was observed to be nanosheet-like. Figure 3 ).

[0076] Example 2: A verification method for the conversion of ZnS to Zn in the interface layer of a dynamic solid electrolyte at the negative electrode.

[0077] (1) Negative electrode preparation: Commercial ZnS and acetylene black were dispersed in acetone solution and coated onto a conductive PE film (current collector) by suspension coating. The mass ratio of ZnS to acetylene black was 90:10, and the ZnS loading was 1 mg.

[0078] (2) Preparation of positive electrode: Same as in Example 1.

[0079] (3) Battery assembly and testing: Same as in Example 1.

[0080] Battery test results: At room temperature (25℃), the battery was charged at a current density of 25 mA / g for 10 hours and then removed. It was observed that some of the ZnS component on the negative electrode was converted into elemental Zn metal. Figure 4 (with dashed lines in the middle) The morphology of the ZnS material after charging is similar to that of Example 1. Figure 5 The results show that during charging, the solid electrolyte interface layer on the negative electrode is reduced from ZnS to Zn metallic element in situ.

[0081] Example 3: A method for preparing a porous negative electrode solid electrolyte interface layer

[0082] (1) ZnS heat treatment: Commercial ZnS was calcined at 1000℃ in air for 2 hours to obtain nanorod-shaped ZnS products. Figure 6 ).

[0083] (2) Anode preparation: Same as in Example 2, except that Example 3 uses heat-treated ZnS.

[0084] (3) Preparation of positive electrode: Same as in Example 2.

[0085] (4) Battery assembly and testing: Same as in Example 2.

[0086] Battery test results: At room temperature (25℃), the battery was charged at a current density of 25 mA / g for 10 hours and 24 hours, respectively, before being removed. After charging, the material morphology on the negative electrode showed a porous structure. Figure 7 ), and most of the ZnS on the negative electrode ( Figure 8 (The dashed box in the middle) is reduced to elemental Zn.

[0087] Example 4: A verification method for the reversible reaction of ZnS and Zn in the interface layer of a dynamic solid electrolyte at the negative electrode.

[0088] (1) Preparation of positive and negative electrodes: This example is a symmetrical battery. Both the positive and negative electrodes are made of the nanosheet Zn+ZnS material obtained in Example 2. The preparation method is the same as in Example 2.

[0089] (2) Symmetrical cell assembly and testing: The electrolyte was a mixture of 0.5 mol / L Na₂SO₄ solution and 0.5 mol / L Na₂S₂O₃ solution at a mass ratio of 0.99:1.10. A single-layer 0.4 mm AGM membrane was used as the separator, and 140 μL of electrolyte was added dropwise. A symmetric cell was assembled. At room temperature of 25℃, the cell operated at 0.5 mA / cm². 2 Charging and discharging at current density.

[0090] Battery test results: At room temperature (25℃), the initial overpotential of the symmetric battery was approximately 0.25V, and the operating time exceeded 280 hours. This indicates that the solid electrolyte interface layer relies on S2O3 in the electrolyte. 2- The ions achieved a reversible solid-solid reaction between ZnS and Zn. Battery cycle performance is as follows: Figure 9 As shown.

[0091] Example 5: Fabrication of a long-life symmetric battery

[0092] (1) Preparation of positive and negative electrodes: This example is a symmetrical battery with the same positive and negative electrodes. The positive and negative electrode materials are both NaTi2(PO4)3 and ZnS material after heat treatment in Example 3, and the preparation method is the same as in Example 1.

[0093] (2) Symmetrical battery assembly and testing: The symmetric battery assembly and testing conditions are the same as in Example 4.

[0094] Battery test results: At room temperature (25℃), the initial overpotential of the symmetrical battery is approximately 0.18V, and the cycle life exceeds 280 hours, demonstrating stable cycle performance. The battery cycle performance is as follows: Figure 10 As shown.

[0095] Comparative Example 1: Fabrication of an aqueous sodium-ion symmetric cell without a ZnS layer

[0096] (1) Preparation of positive and negative electrodes: The positive and negative electrodes are the same, both using NaTi2(PO4)3 material, without the use of a ZnS layer. The preparation method is the same as in Example 1.

[0097] (2) Symmetrical cell assembly and testing: The electrolyte, symmetric cell assembly and testing conditions are the same as in Example 4.

[0098] Battery test results: At room temperature (25℃), the symmetric battery without a ZnS layer exhibits a high overpotential and poor cycle stability. Battery cycle performance is as follows: Figure 11 As shown.

[0099] Comparative Example 2: Preparation of Aqueous Sodium-Ion Full Cells Without ZnS Layers

[0100] (1) Anode preparation: The anode was made of NaTi2(PO4)3 material, without the ZnS layer. The preparation method was the same as in Example 1.

[0101] (2) Preparation of positive electrode: Sodium vanadate material, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 70:20:10, N-methylpyrrolidone (NMP) solvent is added, and the mixture is stirred into a uniform slurry and then drawn to form sodium vanadate positive electrode sheet.

[0102] (3) Full cell assembly and testing: The electrolyte and battery assembly were the same as in Example 4. Constant current charging and discharging were performed at current densities of 10–500 mA / g. The voltage range was 0.6–1.2 V.

[0103] Battery test results: At room temperature of 25℃, the symmetric battery without the ZnS layer has a large overpotential and poor cycle stability.

[0104] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0105] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A water-based sodium-ion battery negative electrode, characterized in that, include: A negative electrode sheet or a negative electrode current collector, wherein the negative electrode sheet comprises a negative electrode active material; as well as A ZnS layer comprising ZnS is disposed on at least a portion of the surface of the negative electrode sheet or the negative electrode current collector.

2. The negative electrode according to claim 1, characterized in that, The negative electrode active material includes at least one of titanium dioxide, sodium titanium phosphate, sodium titanium manganese phosphate, and sodium vanadium fluorophosphate.

3. The negative electrode according to claim 1, characterized in that, The negative electrode current collector includes at least one of copper foil, copper foam, graphite paper, nickel current collector, stainless steel current collector, or polyethylene film.

4. The negative electrode according to claim 1, characterized in that, The ZnS loading on the negative electrode or negative electrode current collector is 0.2–1 mg.

5. The negative electrode according to claim 1, characterized in that, The ZnS in the ZnS layer is in the form of nanorods.

6. The negative electrode according to claim 1, characterized in that, The negative electrode sheet also includes a conductive agent and a binder; Optionally, the conductive agent includes at least one selected from carbon black, graphite, or carbon fiber; Optionally, the adhesive comprises at least one selected from polyvinylidene fluoride, styrene-butadiene rubber, sodium carboxymethyl cellulose, polyvinyl alcohol, polytetrafluoroethylene, polyolefins, modified SBR rubber, fluorinated rubber, polyurethane, or polymethacrylate.

7. A method for preparing the aqueous sodium-ion battery negative electrode according to any one of claims 1 to 6, characterized in that, include: At least a portion of the surface of the negative electrode sheet or negative electrode current collector is coated with ZnS, the negative electrode sheet comprising a negative electrode active material, in order to obtain the negative electrode of the aqueous sodium-ion battery; Optionally, the negative electrode sheet is obtained by mixing the negative electrode active material, conductive agent and binder in a solvent; Optionally, the ZnS is pre-dispersed in an acetone solution.

8. An aqueous sodium-ion battery, characterized in that, include: The positive electrode, the separator, and the negative electrode according to any one of claims 1 to 6 or the negative electrode prepared according to claim 7, wherein the separator is immersed in a sulfur-containing electrolyte.

9. The aqueous sodium-ion battery according to claim 8, characterized in that, The sulfur-containing electrolyte includes at least one of thiosulfate ions or sulfate ions; Optionally, the electrolyte includes sodium sulfate, sodium bisulfate, or a dilute sulfuric acid solution.

10. The battery according to claim 8, characterized in that, The positive electrode includes copper foil, sodium vanadate electrode, or sodium manganate electrode.

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