Niobium-based chalcogenide functionalized MXene zinc negative electrode protection layer and preparation method and application thereof

Abstract

The invention relates to a niobium-based chalcogenide functionalized MXene zinc negative electrode protection layer as well as a preparation method and application thereof, and belongs to the technical field of aqueous zinc ion batteries. According to the niobium-based chalcogenide functionalized MXene zinc negative electrode protection layer disclosed by the invention, the niobium-based chalcogenide functionalized MXene zinc negative electrode protection layer is prepared from the following components in percentage by mass: 90 percent of a chalcogenide functionalized niobium-based MXene material and 10 percent of polyvinylidene fluoride. When the chalcogenide functionalized niobium-based MXene zinc negative electrode protective layer provided by the invention is used as a negative electrode material of an aqueous zinc ion battery, side reactions such as dendrite growth and hydrogen evolution can be inhibited, so that the cycling stability of the whole battery is improved, and the chalcogenide functionalized niobium-based MXene zinc negative electrode protective layer has potential application prospects in the energy related field.

Description

Technical Field

[0001] This application relates to the field of aqueous zinc-ion battery technology, and in particular to a niobium-based sulfide-functionalized MXene zinc anode protective layer, its preparation method, and its application. Background Technology

[0002] Zinc, with its outstanding theoretical capacity and suitable electrochemical potential, is considered an ideal anode material for high-safety aqueous zinc-ion batteries (AZIBs). However, the dynamic instability of the electrolyte / electrode interface leads to uncontrolled dendrite growth and harmful side reactions induced by water, such as hydrogen evolution, corrosion, and byproduct formation, posing a serious challenge to its practical application. Notably, constructing an artificial interface layer (AIL) can regulate zinc deposition behavior and establish a physical barrier to prevent interfacial side reactions, which is crucial for the development of high-performance AZIBs.

[0003] As emerging two-dimensional layered materials, transition metal carbides or nitrides (MXenes) have been explored as anode materials (AILs) for aqueous or non-aqueous metals (such as lithium, sodium, and zinc) due to their unique layered structure, rich surface chemistry, and high mechanical strength. However, traditional etching methods for MXenes rely on fluorinated aqueous solutions, and when MXene-based films or composite polymers are used as modifying layers for metal anodes, the hydrophilicity of their oxygen-containing end groups (F- / O- / OH-) may affect the durability and stability of the material in aqueous environments. Furthermore, the specific mechanisms by which MXene-modified layers regulate zinc deposition behavior and suppress side reactions, especially the role of surface chemical effects, remain to be clarified.

[0004] Chinese patent publication number 115347139A discloses a method for preparing CNF / MXene@Zn anodes and a full cell. The CNF / Ti3C2Tx@Zn composite material prepared using a traditional wet chemical method (in-situ generation of HF from HCl / LiF) inevitably introduces hydrophilic oxygen-containing end groups (-O / -OH ratio > 65%) during the etching process, leading to the following fundamental defects: the hydrophilic interface exacerbates hydrogen evolution reaction and zinc corrosion; zinc deposition kinetics become unbalanced; and different oxygen-containing end groups interact with Zn... 2+ Differences in binding energy lead to local ion aggregation, increasing deposition overpotential. Summary of the Invention

[0005] In view of this, this application provides a niobium-based sulfide-functionalized MXene zinc anode protective layer, its preparation method and application, which solves the problems of uncontrollable dendrite growth and water-induced hydrogen evolution side reactions in zinc metal anodes during cycling, thereby enabling aqueous zinc-ion batteries to have high cycle stability.

[0006] The first aspect of this application provides a niobium-based sulfide-functionalized MXene zinc anode protective layer, expressed as a percentage by mass, wherein the niobium-based sulfide-functionalized MXene zinc anode protective layer is composed of 90% sulfide-functionalized niobium-based MXene material and 10% polyvinylidene fluoride.

[0007] This application employs molten salt etching of MXene to avoid introducing oxygen-containing functional groups: the Nb2AlC precursor is dealuminized under a high-temperature inert atmosphere, completely avoiding H2O / O2 intervention and eliminating oxygen-containing functional groups from the source; sulfide-oriented functionalization: covalent bonding of sulfur / selenium / tellurium atoms with exposed Nb sites is achieved simultaneously, forming an intrinsic zinc-loving hydrophobic interface, which can effectively avoid side reactions such as hydrogen evolution, while inducing rapid and uniform zinc deposition.

[0008] Preferably, the sulfide-functionalized niobium-based MXene material is selected from Nb2CS. x Nb2CSe x Nb2CTe x One of them.

[0009] A second aspect of this application also provides a method for preparing the above-mentioned niobium-based chalcogenide-functionalized MXene zinc anode protective layer, comprising the following steps:

[0010] The sulfide-functionalized niobium-based MXene material and polyvinylidene fluoride were dissolved in N-methylpyrrolidone and stirred to obtain a uniform composite slurry, namely the niobium-based sulfide-functionalized MXene zinc anode protective layer.

[0011] Preferably, the preparation process of the chalcogenide-functionalized niobium-based MXene material is as follows:

[0012] Nb2AlC, halide etchant, chalcogenide powder and molten salt were uniformly mixed to obtain a mixture. The mixture was placed in a ceramic crucible and etched at high temperature under a tube furnace protective atmosphere to obtain an etched product. The etched product was dissolved in a mixed solution of ammonium chloride and ammonia to remove metal impurities and stirred at 40°C for 6 hours. Then it was washed several times with deionized water and alcohol and dried in a vacuum drying oven at 40°C for 24 hours to obtain chalcogenide-functionalized niobium-based MXene material.

[0013] Preferably, the halide etchant is selected from at least one of CuCl, AgCl, and CuI; the sulfur element powder is S powder, Se powder, or Te powder; and the molten salt is a mixed salt of sodium chloride and potassium chloride.

[0014] Specifically, Nb2AlC, CuCl, S, NaCl, and KCl are used as reactants to obtain Nb2CS. x Nb2CSe was obtained by using Nb2AlC, AgCl, Se, NaCl and KCl as reactants. xNb2CTe was obtained by using Nb2AlC, CuI, Te, NaCl, and KCl as reactants. x .

[0015] Preferably, the protective atmosphere is nitrogen or argon, the high-temperature etching temperature is 650-900℃, and the high-temperature etching time is 5-12h.

[0016] Preferably, the stirring time is 6 hours.

[0017] A third aspect of this application also provides a method for preparing a zinc anode for an aqueous zinc-ion battery using the aforementioned niobium-based sulfide-functionalized MXene zinc anode protective layer, comprising the following steps:

[0018] The niobium-based sulfide-functionalized MXene zinc anode protective layer was placed in an ultrasonic spraying machine and uniformly sprayed onto commercial zinc foil. After spraying, it was dried in a vacuum oven at 60°C for 12 hours to obtain a zinc anode with a niobium-based sulfide-functionalized MXene protective layer.

[0019] The fourth aspect of this application also provides a zinc anode, which is a niobium-based sulfide-functionalized MXene zinc anode prepared by the above method.

[0020] The fifth aspect of this application also provides a full cell assembled from the above-mentioned niobium-based sulfide-functionalized MXene zinc anode and V2O3 cathode.

[0021] Compared with the prior art, this application has the following advantages:

[0022] 1. The sulfide-functionalized niobium-based MXene zinc anode protective layer prepared in this application can suppress side reactions such as dendrite growth and hydrogen evolution when used as an anode material in aqueous zinc-ion batteries, thereby improving the cycle stability of the whole battery and showing potential application prospects in energy-related fields.

[0023] 2. The anode material of this application exhibits excellent electrochemical performance: based on Nb2CS x @Zn assembled symmetrical cell at 5mA cm -2 1mAh cm -2 Under high current densities, it can cycle stably for over 2000 hours, highlighting its excellent cycle stability and anti-dendrying ability; Nb2CS x After 3500 cycles, the average coulombic efficiency of the @Zn / / Cu asymmetric cell remains above 99.5%, confirming its highly efficient zinc deposition / stripping reversibility and interface stability; particularly noteworthy is the Nb2CS... xThe @Zn / / V2O3 pouch cell can still cycle stably for more than 70 times under harsh conditions, with an actual capacity output of nearly 300mAh and a negative / positive capacity ratio (N / P ratio) as low as 2.9. This fully demonstrates the great potential of this protective layer technology in practical applications and provides an effective solution for improving the cycle life, rate performance and safety of aqueous zinc-ion batteries. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 The Nb2CS obtained in Example 1 x Nb2CSe x Nb2CTe x X-ray diffraction (XRD) pattern;

[0026] Figure 2 The Nb2CS obtained in Example 1 x Scanning electron microscope and corresponding elemental mapping diagrams;

[0027] Figure 3 The Nb2CSe obtained in Example 1 x Scanning electron microscope and corresponding elemental mapping diagrams;

[0028] Figure 4 The Nb2CTe obtained in Example 1 x Scanning electron microscope and corresponding elemental mapping diagrams;

[0029] Figure 5 The Nb2CS obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer;

[0030] Figure 6 The Nb2CSe obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer;

[0031] Figure 7 The Nb2CTe obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer;

[0032] Figure 8 The Nb2CS obtained in Example 3 x @Zn、Nb2CSex @Zn、Nb2CTe x Symmetric cells assembled with Zn and bare zinc, at 5 mA / cm² -2 1mAh cm -2 Cyclic stability plot under the tested conditions;

[0033] Figure 9 The Nb2CS obtained in Example 3 x @Zn||Cu、Nb2CSe x @Zn||Cu、Nb2CTe x @Zn||Cu and Zn||Cu asymmetric cells, at 2mAcm -2 1mAh cm -2 Cyclic stability plot under the tested conditions;

[0034] Figure 10 The Nb2CSe obtained in Example 3 x @Zn||V₂O₃ and Zn||V₂O₃ full cells, in 0.1-20 Ag -1 Rate performance graph tested at current density;

[0035] Figure 11 The Nb2CSe obtained in Example 3 x @Zn||V₂O₃ and Zn||V₂O₃ full cells, at 10Ag -1 Long-cycle energy plot measured at current density;

[0036] Figure 12 The Nb2CS obtained in Example 3 x @Zn / / V2O3 pouch cell, at 0.5Ag -1 Cyclic stability plot under current density test. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.

[0039] In the following examples, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.

[0040] Example 1

[0041] In this embodiment, Nb2CS x Nb2CSe x Nb2CTe x The preparation method is carried out according to the following steps:

[0042] First, Nb₂AlC, halide etchant CuCl, sulfur powder, and molten salts (NaCl and KCl) were weighed in a glove box at a molar ratio of 1:2:2:1. The mixture was then ground in an agate mortar for 30 minutes to achieve uniform dispersion of the multiphase raw materials, forming a precursor composite powder. The mixture was transferred to an alumina ceramic crucible and heated to the target temperature (650-900℃) at a controlled rate of 5℃ / min in a tube furnace under an argon atmosphere. The temperature was held for 5-12 hours, cooled to room temperature, and then removed. Metal impurities were removed using a 1:1 volume ratio of ammonium chloride and ammonia. The mixture was stirred at 40℃ for 6 hours, followed by washing several times with deionized water and alcohol. Finally, the obtained sample was dried in a vacuum drying oven at 40℃ for 24 hours to obtain Nb₂CS. x .

[0043] First, Nb₂AlC, halide etchant AgCl, Se powder, and molten salts (NaCl and KCl) were weighed in a glove box at a molar ratio of 1:2:2:1. The mixture was then ground in an agate mortar for 30 minutes to achieve uniform dispersion of the multiphase raw materials, forming a precursor composite powder. The mixture was transferred to an alumina ceramic crucible and heated to the target temperature (650-900℃) at a controlled rate of 5℃ / min in a tube furnace under an argon atmosphere. The temperature was held for 5-12 hours, cooled to room temperature, and then removed. Metal impurities were removed using a 1:1 volume ratio of ammonium chloride and ammonia water, and the mixture was stirred at 40℃ for 6 hours. Subsequently, the sample was washed several times with deionized water and alcohol. Finally, the obtained sample was dried in a vacuum drying oven at 40℃ for 24 hours to obtain Nb₂CSe. x .

[0044] First, Nb₂AlC, halide etchant CuI, Te powder, and molten salts (NaCl and KCl) were weighed in a glove box at a molar ratio of 1:2:2:1. The mixture was then ground in an agate mortar for 30 minutes to achieve uniform dispersion of the multiphase raw materials, forming a precursor composite powder. The mixture was transferred to an alumina ceramic crucible and heated to the target temperature (650-900℃) at a controlled rate of 5℃ / min in a tube furnace under an argon atmosphere. The temperature was held for 5-12 hours, cooled to room temperature, and then removed. Metal impurities were removed using a 1:1 volume ratio of ammonium chloride and ammonia. The mixture was stirred at 40℃ for 6 hours, followed by washing several times with deionized water and alcohol. Finally, the obtained sample was dried in a vacuum drying oven at 40℃ for 24 hours to obtain Nb₂CTe. x .

[0045] Example 2

[0046] In this embodiment, Nb2CS x @Zn、Nb2CSe x @Zn、Nb2CTe x @Zn anode preparation:

[0047] Weigh out (Nb2CS) at a mass ratio of 9:1. x Nb2CSe x Nb2CTe x The mixture was prepared by adding polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (NMP) at a ratio of 0.1 mg / mL and stirring for 6 hours. The homogenized slurry was then placed in an ultrasonic spraying machine and ultrasonically sprayed onto the surface of commercial zinc foil. After spraying, the zinc foil was dried in a vacuum drying oven at 60°C for 12 hours to obtain Nb2CS. x @Zn、Nb2CSe x @Zn、Nb2CTe x @Zn.

[0048] Example 3

[0049] Battery assembly and electrochemical performance testing:

[0050] The Nb2CS obtained from Implementation Case 2 x @Zn、Nb2CSe x @Zn、Nb2CTe x @Zn is cut into 12mm diameter circular electrodes and assembled into a symmetrical cell (Nb2CS). x @Zn / / Nb2CS x @Zn、Nb2CSe x @Zn / / Nb2CSe x @Zn、Nb2CTe x @Zn / / Nb2CTe x @Zn、Zn / / Zn), asymmetric cell (Nb2CS) x @Zn / / Cu、Nb2CSe x @Zn / / Cu、Nb2CTe x @Zn / / Cu) and full cell (Nb2CS) x @Zn / / V2O3, Zn / / V2O3), all coin cells are R2032 type cells. Symmetric and asymmetric cells are tested in the Blue Electricity testing system at 2mAcm. -2 Current density, 1mAh cm -2 Capacity was tested, with the full battery yielding 0.1-20 Ag. -1 Rate performance testing was performed using current density at 10Ag. -1 Cyclic stability was measured using current density. The Nb2CS obtained from Implementation Case 2 was then used.x @Zn was cut into square electrodes with a diameter of 5×8cm. A 5.5×8.5cm glass fiber was used as the separator, and a 4.5×7.5cm V2O3 electrode was used as the positive electrode to assemble a pouch cell. After standing for 6 hours, 0.5Ag was used as the positive electrode. -1 Cyclic stability was measured using current density.

[0051] The upper and lower limits of the process parameters (such as temperature, time, etc.) and the range values ​​of this application can all achieve the method of this application, and the embodiments are not listed one by one here.

[0052] Figure 1 The Nb2CS obtained in Example 1 x Nb2CSe x Nb2CTe x The X-ray diffraction (XRD) pattern of Nb2CS shows that, compared to the characteristic peaks of Nb2AlC, Nb2CS... x Nb2CSe x Nb2CTe x Significant changes occurred, indicating that the Al layer atoms were successfully removed; Figure 2 The Nb2CS obtained in Example 1 x Scanning electron microscopy and the corresponding elemental mapping images show an accordion-like morphology, with uniform distribution of Nb, C, and S elements, indicating Nb₂CS x Successfully prepared; Figure 3 The Nb2CSe obtained in Example 1 x Scanning electron microscopy and the corresponding elemental mapping images show an accordion-like morphology, with uniform distribution of Nb, C, and Se elements, indicating Nb₂CSe. x Successfully prepared; Figure 4 The Nb2CTe obtained in Example 1 x Scanning electron microscopy and the corresponding elemental mapping images show an accordion-like morphology, with uniform distribution of Nb, C, and Te elements, indicating Nb₂CTe. x Successfully prepared; Figure 5 The Nb2CS obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer, Nb2CS x Uniformly distributed on the surface of the zinc negative electrode; Figure 6 The Nb2CSe obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer, Nb2CSe x Uniformly distributed on the surface of the zinc negative electrode; Figure 7 The Nb2CTe obtained in Example 2 x Scanning electron microscope image of the zinc anode surface with protective layer, Nb2CTe x Uniformly distributed on the surface of the zinc negative electrode; Figure 8 The Nb2CS obtained in Example 3 x @Zn、Nb2CSe x @Zn、Nb2CTe x Symmetric cells assembled from Zn and bare zinc, at 5 mA cm⁻¹ -2 1mAhcm -2 Cyclic stability plots tested under the condition of Nb2CS x Nb2CSe x Nb2CTe x The protective layer greatly improves the stability of symmetrical cells; Figure 9 The Nb2CS obtained in Example 3 x @Zn||Cu、Nb2CSe x @Zn||Cu、Nb2CTe x @Zn||Cu and Zn||Cu asymmetric cells, at 2mAcm -2 1mAh cm -2 Cyclic stability plots tested under the condition of Nb2CS x Nb2CSe x Nb2CTe x After the protective layer is applied, the Zn deposition / stripping efficiency reaches 100% and can achieve stable cycling for more than 3,500 cycles; Figure 10 The Nb2CSe obtained in Example 3 x @Zn||V₂O₃ and Zn||V₂O₃ full cells, in 0.1-20 Ag -1 Rate performance plot tested at current density, with Nb2CSe x After the protective layer was applied, the rate performance of the full cell was significantly improved. Figure 11 The Nb2CSe obtained in Example 3 x @Zn||V₂O₃ and Zn||V₂O₃ full cells, at 10Ag -1 Long-cycle energy map of Nb2CSe tested at current density x The protective layer significantly improves the stability of the entire battery; Figure 12 The Nb2CSe obtained in Example 3 x @Zn / / V2O3 pouch cell, at 0.5Ag -1 The cycling stability graph tested at current density shows that, under harsh conditions with an actual capacity output close to 300mAh and a negative / positive capacity ratio (N / P ratio) as low as 2.9, it can still cycle stably for more than 70 cycles.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A niobium-based sulfide-functionalized MXene zinc anode protective layer, characterized in that, Expressed as a percentage by mass, the niobium-based sulfide-functionalized MXene zinc anode protective layer is composed of 90% sulfide-functionalized niobium-based MXene material and 10% polyvinylidene fluoride.

2. The niobium-based chalcogenide-functionalized MXene zinc anode protective layer according to claim 1, characterized in that, The sulfide-functionalized niobium-based MXene material is selected from Nb2CS. x Nb2CSe x Nb2CTe x One of them.

3. A method for preparing the niobium-based chalcogenide-functionalized MXene zinc anode protective layer as described in claim 1 or 2, characterized in that, Includes the following steps: The sulfide-functionalized niobium-based MXene material and polyvinylidene fluoride were dissolved in N-methylpyrrolidone and stirred to obtain a uniform composite slurry, namely the niobium-based sulfide-functionalized MXene zinc anode protective layer.

4. The method for preparing the niobium-based chalcogenide-functionalized MXene zinc anode protective layer according to claim 3, characterized in that, The preparation process of the chalcogenide-functionalized niobium-based MXene material is as follows: Nb2AlC, halide etchant, chalcogenide powder and molten salt were uniformly mixed to obtain a mixture. The mixture was placed in a ceramic crucible and etched at high temperature under a tube furnace protective atmosphere to obtain an etched product. The etched product was dissolved in a mixed solution of ammonium chloride and ammonia to remove metal impurities and stirred at 40°C for 6 hours. Then it was washed several times with deionized water and alcohol and dried in a vacuum drying oven at 40°C for 24 hours to obtain chalcogenide-functionalized niobium-based MXene material.

5. The method for preparing the niobium-based chalcogenide-functionalized MXene zinc anode protective layer according to claim 4, characterized in that, The halide etchant is selected from at least one of CuCl, AgCl, and CuI; the sulfur element powder is S powder, Se powder, or Te powder; and the molten salt is a mixed salt of sodium chloride and potassium chloride.

6. The method for preparing the niobium-based chalcogenide-functionalized MXene zinc anode protective layer according to claim 4, characterized in that, The protective atmosphere is nitrogen or argon, the high-temperature etching temperature is 650-900℃, and the high-temperature etching time is 5-12 hours.

7. The method for preparing the niobium-based chalcogenide-functionalized MXene zinc anode protective layer according to claim 3, characterized in that, The stirring time is 6 hours.

8. A method for preparing a zinc anode for an aqueous zinc-ion battery using the niobium-based sulfide-functionalized MXene zinc anode protective layer as described in claim 1 or 2, characterized in that, Includes the following steps: The niobium-based sulfide-functionalized MXene zinc anode protective layer was placed in an ultrasonic spraying machine and uniformly sprayed onto commercial zinc foil. After spraying, it was dried in a vacuum oven at 60°C for 12 hours to obtain a zinc anode with a niobium-based sulfide-functionalized MXene protective layer.

9. A zinc negative electrode, characterized in that, The niobium-based sulfide-functionalized MXene zinc anode was prepared by the method described in claim 8.

10. A full battery, characterized in that, It is assembled from the niobium-based sulfide-functionalized MXene zinc anode and the V2O3 cathode as described in claim 9.

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