Use of a sulfide-based hollow nanobrick heterojunction anode coating material and method of preparation thereof

Abstract

The application belongs to the technical field of electrochemical energy storage materials, and discloses application of a sulfide-based hollow nanobrick heterojunction anode coating material and a preparation method thereof, in particular, application of the sulfide-based hollow nanobrick heterojunction anode coating material to an aqueous zinc ion battery, wherein the sulfide-based hollow nanobrick heterojunction comprises an X metal sulfide and a Y metal sulfide, and the heterojunction is represented as XS-YS n , 0 < n < 3, X is Zn, and Y is selected from one of Sn, Co, Cu or Mo; the preparation method comprises the following steps: mixing a zinc salt and a fluoride etchant, and one of a tin salt, a cobalt salt, a copper salt or a molybdenum salt, and then performing a hydrothermal reaction to obtain a bimetal-based hollow nanobrick precursor; and then performing sulfurization calcination to obtain the XS-YS n . The sulfide-based hollow nanobrick heterojunction can effectively inhibit zinc dendrite growth and interface side reactions, thereby significantly improving the electrochemical stability of the material, and further prolonging the cycle life of the aqueous zinc ion battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical energy storage materials, and particularly relates to application of a sulfide-based hollow nanobrick heterojunction anode coating material and a preparation method thereof. BACKGROUND

[0002] Aqueous zinc-ion batteries have broad application prospects in large-scale energy storage due to their high safety, low cost, environmental friendliness, and high theoretical capacity. Anode materials, as a core component of aqueous zinc-ion batteries, directly determine the cycle stability, rate performance, and energy density of the batteries. Currently, commercial aqueous zinc-ion batteries mostly use metal zinc foil as the anode. However, the metal zinc anode is prone to zinc dendrite growth, hydrogen evolution reaction, and interface side reactions during charging and discharging, which leads to short cycle life and low coulombic efficiency of the battery, seriously hindering the industrialization process of aqueous zinc-ion batteries.

[0003] To solve the above problems, researchers actively explore the use of heterojunction materials for zinc anode protection. Heterojunctions, especially Type-II heterojunctions, can significantly promote charge separation and transport by means of built-in electric field effect, and optimize electrochemical kinetics, becoming an important direction for improving the stability of zinc anodes. In the prior art, a variety of heterojunction materials have been tried for zinc negative electrode protection. However, non-sulfide heterojunction materials still have limitations, and single-component sulfides (such as WS2, NiS2, FeS x , etc.) have inherent defects such as significant volume expansion, poor conductivity, and insufficient cycle stability, although they have been used in battery fields due to their unique layered structure and excellent ion conduction performance.

[0004] Sulfide-based heterojunction materials combine the structural advantages of sulfides and the charge regulation ability of heterojunctions. However, in the prior art, ZnS-CdS and ZnS-CuS have been confirmed as Type-II heterojunctions, but their applications are mostly concentrated in the field of photocatalysis (for example, Chinese Patent No. CN120662338A discloses a photocatalyst based on sulfide heterojunction, which is a heterojunction formed by twin sulfur cadmium manganese and transition metal sulfide, used for degrading H2S to produce hydrogen. And Chinese Patent No. CN107469834A discloses that when copper sulfide (CuS) / zinc sulfide (ZnS) bimetallic sulfide is used as a photocatalyst, it can effectively separate photo-generated carriers and effectively improve the photocatalytic activity.). They have not been developed for anode protection in aqueous zinc-ion batteries. At the same time, the reported sulfide-based heterojunction materials have problems such as difficulty in morphology control, loose combination of heterojunction interfaces, poor dispersion, etc. during preparation, and are mostly solid particles or irregular shapes, which cannot fully expose active sites, making it difficult to alleviate volume expansion during charging and discharging, resulting in insufficient cycle stability.

[0005] To sum up, there is no report on the construction of sulfide-based Type-II heterostructure into a specific hollow morphology and its application as anode coating for aqueous zinc-ion batteries. Therefore, it is still a technical problem to be solved in the field to develop a sulfide-based anode coating material with unique microstructure and heterojunction electronic structure advantages, and to realize the dual inhibition of zinc dendrites and side reactions. SUMMARY

[0006] The application aims to provide a sulfide-based hollow nanobrick heterojunction anode coating material and a preparation method thereof. The structure of the sulfide-based hollow nanobrick heterojunction makes full use of the built-in electric field effect of Type-II heterojunction to promote ion migration, and combines the high specific surface area and buffer space provided by the hollow nanobrick morphology to effectively inhibit zinc dendrite growth and interface side reactions, thereby significantly improving the electrochemical stability of the material and prolonging the cycle life of the aqueous zinc-ion battery.

[0007] To achieve the above application purposes, the application provides the following technical solutions.

[0008] The application relates to an application of a sulfide-based hollow nanobrick heterojunction anode coating material in an aqueous zinc-ion battery. The sulfide-based hollow nanobrick heterojunction anode coating material comprises an A metal sulfide and a B metal sulfide, and the heterojunction is represented as XS-YS n , 0 < n < 3, X is Zn, and Y is selected from one of Sn, Co, Cu or Mo.

[0009] In the application, when the sulfide-based hollow nanobrick heterojunction anode coating material is applied to the negative electrode of the aqueous zinc-ion battery, hydrogen evolution, corrosion and byproduct generation can be effectively inhibited. The heterojunction promotes charge transfer and ion diffusion by means of the built-in electric field, enhances the electrochemical performance and zinc anode interface stability, and thus improves the overall performance of the battery. Specifically, the hollow nanobrick morphology can effectively relieve the volume strain (volume expansion) in the charging and discharging process, avoid the collapse of the protective layer structure, and provide a rich active interface. The Type-II heterojunction composed of XS-YS n can establish a built-in electric field, promote rapid charge transfer, and guide the uniform deposition of zinc ions on the zinc anode surface, thereby significantly inhibiting dendrite growth, hydrogen evolution, corrosion and other side reactions. The ZnS component enhances the interface stability, and YS n provides an efficient ion transmission channel. Therefore, when the sulfide-based hollow nanobrick heterojunction anode coating material is coated on the surface of a zinc foil to construct a modified aqueous zinc anode, the structure and component synergistic advantages can be fully utilized, the key problems such as zinc dendrite growth, hydrogen evolution reaction, electrode corrosion and surface passivation in the aqueous zinc-ion battery can be significantly inhibited, the electrochemical reversibility and cycle stability of the zinc anode can be greatly improved, and the service life of the aqueous zinc-ion battery can be prolonged.

[0010] In the present application, the anode coating is also called anode protection layer.

[0011] In the present application, the sulfide-based hollow nanobrick heterojunction can be ZnS-SnS2, ZnS-CoS2, ZnS-CuS or ZnS-MoS2.

[0012] The molar ratio of the X metal sulfide and the Y metal sulfide in the sulfide-based hollow nanobrick heterojunction is (0.5-1.3):1.

[0013] As preferred, the sulfide-based hollow nanobrick heterojunction is ZnS-SnS2, and the molar ratio of the X metal sulfide and the Y metal sulfide in the sulfide-based hollow nanobrick heterojunction is (0.5-0.9):1. When Y is Sn and the above molar ratio is used, the component synergistic advantage of the heterojunction can be fully exerted, and the service life of the aqueous zinc ion battery is further prolonged.

[0014] As preferred, the sulfide-based hollow nanobrick heterojunction is a Type-II heterojunction.

[0015] In the present application, the morphology of the sulfide-based hollow nanobrick heterojunction is hollow nanobrick.

[0016] The sulfide-based hollow nanobrick heterojunction is mixed with a binder after being dissolved in a solvent (such as NMP) and is spin-coated on a zinc foil as a negative electrode of an aqueous zinc ion battery.

[0017] Further, the prepared ZnS-SnS2, ZnS-CoS2, ZnS-CuS or ZnS-MoS2 is mixed with polyvinylidene fluoride at a ratio of 9:1, and is uniformly spin-coated on a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and is dried in a vacuum oven at 60 ℃ for 12 h to obtain ZnS-SnS2@Zn, ZnS-CoS2@Zn, ZnS-CuS@Zn and ZnS-MoS2 electrodes, respectively.

[0018] The binder in the aqueous zinc ion battery is polyvinylidene fluoride or sodium carboxymethyl cellulose, the electrolyte includes ZnSO4, and the positive electrode is a carbon paper coated with ammonium vanadate.

[0019] The present application also provides a preparation method of the above sulfide-based hollow nanobrick heterojunction, which comprises:

[0020] (1) Hollow nanobrick precursor preparation: zinc salt and another metal salt are used as metal sources, dissolved in deionized water with a fluoride etchant, stirred to form a mixed solution, and a double-metal-based hollow nanobrick precursor is obtained through a hydrothermal reaction.

[0021] (2) Sulfidation reaction: the bimetallic hollow nanobrick precursor powder and sulfur source are calcined at high temperature under inert atmosphere to make the metal source sulfidize and build heterojunction at the same time, and a sulfide-based hollow nanobrick heterojunction material inheriting the precursor morphology is obtained.

[0022] The preparation principle of the application is to build a ZnS-SnS2 hollow nanobrick heterojunction material with Type-II type energy band structure by a controllable hydrothermal-calcination sulfidation two-step method, and apply it as a high-performance anode protection layer to a water-based zinc ion battery. In terms of material preparation, ammonium fluoride is used as a key morphology control agent to guide the formation of a hollow structure through coordination etching and Ostwald ripening mechanism. The precursor is calcined and sulfidized with a sulfur source under a nitrogen atmosphere, and finally converted into a ZnS-SnS2 hollow nanobrick heterojunction material inheriting the precursor hollow brick morphology. n heterojunction material.

[0023] In step (1), 1-16 mmol of a zinc salt and 10-120 mmol of a fluoride etchant, and 1-20 mmol of one of a tin salt, a cobalt salt, a copper salt, and a molybdenum salt are added to deionized water; the molar ratio of the zinc salt to the other metal salt is (0.5-1.3):1.

[0024] In step (1), the zinc salt is zinc nitrate hexahydrate or zinc acetate dihydrate; the fluoride etchant is one of ammonium fluoride, sodium fluoride, potassium fluoride, or sodium tetrafluoroborate; the tin salt is tin chloride dihydrate or sodium stannate tetrahydrate; the cobalt salt is cobalt chloride hexahydrate or cobalt nitrate hexahydrate; the copper salt is copper chloride dihydrate or copper nitrate trihydrate; and the molybdenum salt is ammonium heptamolybdate tetrahydrate or sodium molybdate dihydrate.

[0025] As a preference, in step (1), the zinc salt is zinc acetate dihydrate; the fluoride etchant is ammonium fluoride; the tin salt is sodium stannate tetrahydrate; the cobalt salt is cobalt chloride hexahydrate; the copper salt is copper chloride dihydrate; and the molybdenum salt is sodium molybdate dihydrate.

[0026] By further regulating the types and proportions of metals in the sulfide-based hollow nanobrick heterojunction material, the application can further uniformly build the hollow nanobrick morphology, so that the sulfide-based hollow nanobrick heterojunction anode coating material prepared can effectively regulate the electric field distribution when applied to a water-based zinc ion battery, promote charge transport and ion diffusion, enhance the electrochemical performance and zinc anode interface stability, and improve the cycle life of the battery.

[0027] As a preference, step (1) is specifically:

[0028] (1-1) 1-16 mmol of zinc acetate dihydrate and 10-120 mmol of ammonium fluoride, and 1-20 mmol of one of sodium stannate tetrahydrate, 1-20 mmol of cobalt chloride hexahydrate, 1-20 mmol of copper chloride dihydrate, 1-20 mmol of sodium molybdate dihydrate are added to 10-100 mL of deionized water, stirred at room temperature at a speed of 400-800 r / min for 20-60 min to obtain a mixed solution A for standby use; wherein the molar ratio of the zinc acetate dihydrate to the sodium stannate tetrahydrate or the cobalt chloride hexahydrate or the copper chloride dihydrate or the sodium molybdate dihydrate is (0.5-1.3):1;

[0029] (1-2) The mixed solution A is transferred to a 20-100 ml stainless steel high-pressure reaction kettle, and after hydrothermal reaction at 120-180 ℃ for 1-8 h, the bimetallic-based hollow nanobrick precursor B is obtained by centrifugation, washing and drying; wherein the drying method is vacuum drying, the temperature is 60-100 ℃, and the time is 12-36 h.

[0030] The preparation method provided by the present application can make the formation of the bimetallic-based hollow nanobrick precursor B more uniform through appropriate molar ratio and reaction time.

[0031] In step (2), the sulfur source is one or more of sulfur powder, thiourea, ammonium sulfide, and L-cysteine; and the inert atmosphere is nitrogen, argon or a mixture thereof. In step (2), the bimetallic-based hollow nanobrick precursor B prepared in step (1) is calcined with the sulfur source at a mass ratio of 1:2-1:8 under a nitrogen atmosphere at 200-600 ℃ for 1-5 hours, and the heating rate is 1-6 ℃ / min.

[0032] In the preparation method provided by the present application, the appropriate calcination temperature, calcination time and heating rate make the metal source sulfide and build a heterojunction at the same time, which is conducive to the preparation of sulfide-based hollow nanobrick Type-II heterojunction material inheriting the morphology of the precursor; the built-in electric field in the heterojunction can promote ion migration, combined with the high specific surface area and buffer space of the hollow nanobrick, can effectively inhibit zinc dendrite and side reaction, significantly enhance the electrochemical stability, and further prolong the cycle life of the aqueous zinc ion battery.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] (1) Structural advantage: the present application successfully prepares a heterojunction material with a hollow nanobrick morphology. The unique hollow structure can expose more active sites, provide sufficient space for zinc deposition, effectively alleviate the volume expansion during charging and discharging, and also effectively reduce the local current density, uniformize the Zn 2+ flow, promote electron transfer and zinc ion diffusion, and significantly reduce the charge transfer resistance.

[0035] (2) Heterojunction effect: the type-II heterojunction structure formed between ZnS and another sulfide (YS n ) can generate a built-in electric field pointing from YS n to ZnS at the interface. This electric field can effectively guide the directional migration of Zn 2+ and preferentially deposit on the heterojunction interface and the ZnS side, thus realizing uniform nucleation and growth of zinc and fundamentally inhibiting the formation of dendrites.

[0036] (3) Synergistic enhancement: ZnS has good chemical stability and mechanical strength, and can act as a strong barrier to isolate water molecules from direct contact with the zinc anode, thereby inhibiting side reactions; while another sulfide (YS n ) provides excellent ion / electron conductivity or unique layered ion transport channels. The combination of the two achieves the dual functions of "dendrite inhibition" and "side reaction isolation".

[0037] (4) Social value: the preparation method of the invention is simple, low-cost and reproducible, and is easy to scale up, providing a new idea for the development of anode materials for aqueous zinc ion batteries, and has important industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a morphology image of the ZnS-SnS2 (molar ratio of 0.9:1) hollow nanobrick heterojunction material prepared in Example 1 observed by a field emission scanning electron microscope (FE-SEM) of S-4800 type of Hitachi Company of Japan;

[0039] Figure 2 is an X-ray diffraction (XRD) spectrum of the ZnS-SnS2 (molar ratio of 0.9:1) hollow nanobrick heterojunction material prepared in Example 1 measured by a D8 type X-ray diffractometer of Bruker Company of the United States, wherein: the abscissa X is the diffraction angle (2θ), and the ordinate Y is the relative diffraction intensity;

[0040] Figure 3 is an X-ray photoelectron spectroscopy (XPS) spectrum of the ZnS-SnS2 (molar ratio of 0.9:1) hollow nanobrick heterojunction material prepared in Example 1 measured by an X-ray photoelectron spectrometer of ESCALAB MKΙI type, wherein: the abscissa X is the binding energy (eV), and the ordinate Y is the relative intensity (a.u.);

[0041] Figure 4 is a cross-sectional element distribution map of the ZnS-SnS2 (molar ratio of 0.9:1) hollow nanobrick heterojunction material prepared in Example 1 after spin coating on the surface of a zinc foil observed by a field emission scanning electron microscope (FE-SEM) of S-4800 type of Hitachi Company of Japan.

[0042] Figure 5 is the ZnS-SnS2(molar ratio of 0.9:1) hollow nanobrick heterojunction material prepared in Example 1 of the application, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm 2 , with an area capacity of 0.25 mAh / cm 2 , the time-voltage graph of the aqueous zinc ion battery symmetrical cell is as follows:

[0043] Figure 6 is the ZnS-SnS2(molar ratio of 0.5:1) material of Example 2, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm 2 , with an area capacity of 0.25 mAh / cm 2 , the time-voltage graph of the aqueous zinc ion battery symmetrical cell is as follows:

[0044] Figure 7 is the ZnS-SnS2(molar ratio of 1.2:1) material of Example 3, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm 2 , with an area capacity of 0.25 mAh / cm 2 , the time-voltage graph of the aqueous zinc ion battery symmetrical cell is as follows:

[0045] Figure 8 is the ZnS-CoS2(molar ratio of 0.9:1) material of Example 4, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm 2 , with an area capacity of 0.25 mAh / cm 2 , the time-voltage graph of the aqueous zinc ion battery symmetrical cell is as follows:

[0046] Figure 9 is the ZnS-CuS(molar ratio of 0.9:1) material of Example 7, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm 2 , with an area capacity of 0.25 mAh / cm 2 , the time-voltage graph of the aqueous zinc ion battery symmetrical cell is as follows:

[0047] Figure 10 is the ZnS-MoS2(molar ratio of 0.9:1) material of Example 10, assembled into a button cell, tested on a Wuhan Lanlike CT3001A electrochemical workstation at a current density of 0.25 mA / cm2 0.25 mAh / cm 2 Time-voltage plot of the symmetric cell of the aqueous zinc-ion battery under the following conditions:

[0048] Figure 11 The button cell assembled with the ZnS material of Comparative Example 1 was tested by a CHI 660D electrochemical workstation of Wuhan Lanlike Corporation, and the current density was 0.25 mA / cm 2 0.25 mAh / cm 2 Time-voltage plot of the symmetric cell of the aqueous zinc-ion battery under the following conditions:

[0049] Figure 12 The button cell assembled with the SnS2 material of Comparative Example 2 was tested by a CHI 660D electrochemical workstation of Wuhan Lanlike Corporation, and the current density was 0.25 mA / cm 2 0.25 mAh / cm 2 Time-voltage plot of the symmetric cell of the aqueous zinc-ion battery under the following conditions:

[0050] Figure 13 The button cell assembled with the ZnS-SnS2 (molar ratio of 1.5:1) material of Comparative Example 3 was tested by a CHI 660D electrochemical workstation of Wuhan Lanlike Corporation, and the current density was 0.25 mA / cm 2 0.25 mAh / cm 2 Time-voltage plot of the symmetric cell of the aqueous zinc-ion battery under the following conditions:

[0051] Figure 14 The button cell assembled with the unmodified zinc foil directly as the negative electrode of Comparative Example 4 was tested by a CHI 660D electrochemical workstation of Wuhan Lanlike Corporation, and the current density was 0.25 mA / cm 2 0.25 mAh / cm 2 Time-voltage plot of the symmetric cell of the aqueous zinc-ion battery under the following conditions. DETAILED DESCRIPTION

[0052] The above content of the present application is further described in detail through the following examples, but this should not be understood as the scope of the above subject matter of the present application is limited to the following examples only, and all the technologies realized based on the above content of the present application belong to the scope of the present application.

[0053] Example 1

[0054] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 10.13 mmol of sodium stannate tetrahydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The above bimetallic-based hollow nanobrick precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tubular furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product was collected, which is the ZnS-SnS2 hollow nanobrick heterojunction material. Finally, the prepared ZnS-SnS2 hollow nanobrick heterostructure material was mixed with polyvinylidene fluoride in NMP solvent at a ratio of 9:1 and ground into a uniform slurry. This slurry was then uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-SnS2@Zn electrode (molar ratio of 0.9:1), which is the modified zinc anode.

[0055] SEM images of the obtained products are shown below. Figure 1 It can be observed that the ZnS-SnS2 (molar ratio of 0.9:1) heterojunction material exhibits a hollow nanobrick morphology; Figure 2 XRD confirmed the coexistence of ZnS and SnS2 phases in ZnS-SnS2; according to Figure 3 The XPS figures further demonstrate this. Furthermore, as... Figure 4 As shown, the thickness of the prepared zinc anode coating material is 28 μm, and the elements Zn, Sn, and S are uniformly distributed. The electrochemical performance of the ZnS-SnS2@Zn (molar ratio of 0.9:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 The assembled symmetrical battery can cycle stably for 4580 hours; Zn 2+ The number of migrations was as high as 0.6.

[0056] Example 2

[0057] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 18.24 mmol of sodium stannate tetrahydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to a hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The bimetallic-based hollow nanobrick precursor powder and a sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder positioned upstream of the gas flow in a tubular furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product, ZnS-SnS2 hollow nanobrick heterojunction material, was collected. Finally, the prepared ZnS-SnS2 hollow nanobrick heterostructure material was mixed with polyvinylidene fluoride in NMP solvent at a ratio of 9:1 and ground into a uniform slurry. This slurry was then uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-SnS2@Zn electrode (molar ratio of 0.5:1), which is the modified zinc anode.

[0058] The electrochemical performance of the ZnS-SnS2@Zn (molar ratio 0.5:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 3160 hours.

[0059] Example 3

[0060] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 7.6 mmol of sodium stannate tetrahydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The above bimetallic-based hollow nanobrick precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product, ZnS-SnS2 hollow nanobrick heterojunction material, was collected. Finally, the prepared ZnS-SnS2 hollow nanobrick heterojunction material was mixed with polyvinylidene fluoride in a 9:1 ratio in NMP solvent and ground into a homogeneous slurry. The electrode was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-SnS2@Zn electrode (molar ratio of 1.2:1), which is the modified zinc anode.

[0061] The electrochemical performance of the ZnS-SnS2@Zn (molar ratio 1.2:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 1769 hours.

[0062] Example 4

[0063] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 10.13 mmol of cobalt chloride hexahydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The above bimetallic-based hollow nanobrick precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product was collected, which is the ZnS-CoS2 hollow nanobrick heterojunction material. Finally, the prepared ZnS-CoS2 hollow nanobrick heterojunction material was mixed with polyvinylidene fluoride in a 9:1 ratio in NMP solvent and ground into a homogeneous slurry. The electrode was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-CoS2@Zn electrode (molar ratio of 0.9:1), which is the modified zinc anode.

[0064] The electrochemical performance of the ZnS-CoS2@Zn (molar ratio 0.9:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical cells can cycle stably for 2019 hours.

[0065] Example 5

[0066] The difference from Example 4 is that the molar amount of cobalt chloride hexahydrate is 18.24 mmol, resulting in a ZnS-CoS2@Zn electrode (molar ratio of 0.5:1).

[0067] The electrochemical performance of the ZnS-CoS2@Zn (molar ratio 0.5:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical cells can cycle stably for 1313 hours.

[0068] Example 6

[0069] The difference from Example 4 is that the molar amount of cobalt chloride hexahydrate is 7.6 mmol, resulting in a ZnS-CoS2@Zn electrode (molar ratio of 1.2:1).

[0070] The electrochemical performance of the ZnS-CoS2@Zn (molar ratio 1.2:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 1280 hours.

[0071] Example 7

[0072] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 10.13 mmol of copper chloride dihydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The above bimetallic-based hollow nanobrick precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product was collected, which is the ZnS-CuS hollow nanobrick heterojunction material. Finally, the prepared ZnS-CuS hollow nanobrick heterojunction material was mixed with polyvinylidene fluoride in NMP solvent at a ratio of 9:1 and ground into a homogeneous slurry. The electrode was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-CuS@Zn electrode (molar ratio of 0.9:1), which is the modified zinc anode.

[0073] The electrochemical performance of the ZnS-CuS@Zn (molar ratio 0.9:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical cells can cycle stably for 1521 hours.

[0074] Example 8

[0075] The difference from Example 7 is that the number of moles of copper chloride dihydrate is 18.24 mmol, resulting in a ZnS-CuS@Zn electrode (molar ratio of 0.5:1).

[0076] The electrochemical performance of the ZnS-CuS@Zn (molar ratio 0.5:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2Under these conditions, the assembled symmetrical battery can cycle stably for 1233 hours.

[0077] Example 9

[0078] The difference from Example 7 is that the number of moles of copper chloride dihydrate is 7.6 mmol, resulting in a ZnS-CuS@Zn electrode (molar ratio of 1.2:1).

[0079] The electrochemical performance of the ZnS-CuS@Zn (molar ratio 1.2:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 1185 hours.

[0080] Example 10

[0081] 9.12 mmol of zinc acetate dihydrate, 60 mmol of ammonium fluoride, and 10.13 mmol of sodium molybdate dihydrate were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, bimetallic-based hollow nanobrick precursor powder was obtained. The above bimetallic-based hollow nanobrick precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tubular furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product was collected, which is the ZnS-MoS2 hollow nanobrick heterojunction material. Finally, the prepared ZnS-MoS2 hollow nanobrick heterojunction material was mixed with polyvinylidene fluoride in a 9:1 ratio in NMP solvent and ground into a homogeneous slurry. The electrode was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS-MoS2@Zn electrode (molar ratio of 0.9:1), which is the modified zinc anode.

[0082] The electrochemical performance of the ZnS-MoS2@Zn (molar ratio 0.9:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 1307 hours.

[0083] Example 11

[0084] The difference from Example 10 is that the number of moles of sodium molybdate dihydrate is 18.24 mmol, resulting in a ZnS-MoS2@Zn electrode (molar ratio of 0.5:1).

[0085] The electrochemical performance of the ZnS-MoS2@Zn (molar ratio 0.5:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 1194 hours.

[0086] Example 12

[0087] The difference from Example 10 is that the number of moles of sodium molybdate dihydrate is 7.6 mmol, resulting in a ZnS-MoS2@Zn@Zn electrode (molar ratio of 1.2:1).

[0088] The electrochemical performance of the ZnS-MoS2@Zn (molar ratio 1.2:1) electrode prepared in this embodiment is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 986 hours.

[0089] Comparative Example 1

[0090] 9.12 mmol of zinc acetate dihydrate and 60 mmol of ammonium fluoride were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, the precursor powder was obtained. The above precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product, ZnS material, was collected. Finally, the prepared ZnS material was mixed with polyvinylidene fluoride in NMP solvent at a ratio of 9:1 and ground into a homogeneous slurry. The coating was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm, and dried in a vacuum oven at 60 °C for 12 h to obtain a ZnS@Zn electrode, which is the modified zinc anode.

[0091] The electrochemical performance of the ZnS@Zn electrode prepared in this comparative example is as follows: at a current density of 0.25 mA / cm², 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 908 hours.

[0092] Comparative Example 2

[0093] 10.13 mmol of sodium stannate tetrahydrate and 60 mmol of ammonium fluoride were added to 35 mL of deionized water and stirred at 500 r / min for 30 min at room temperature to obtain a mixed solution. The mixed solution was transferred to a 50 mL stainless steel high-pressure reactor and subjected to hydrothermal reaction at 150 °C for 2 h. After centrifugation, washing, and drying, the precursor powder was obtained. The above precursor powder and sulfur source were placed in ceramic boats at a mass ratio of 1:5, with the sulfur powder located upstream of the gas flow in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 500 °C at 2 °C / min and held for 3 h, followed by natural cooling to room temperature. The final product, SnS2 material, was collected. Finally, the prepared SnS2 was mixed with polyvinylidene fluoride in NMP solvent at a ratio of 9:1 and ground into a homogeneous slurry. The SnS2@Zn electrode was uniformly spin-coated onto a zinc foil with a thickness of 100 μm and a diameter of 1 cm and dried in a vacuum oven at 60 °C for 12 h to obtain the modified zinc anode.

[0094] The electrochemical performance of the SnS2@Zn electrode prepared in this comparative example is as follows: at a current density of 0.25 mA / cm², 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical cells can cycle stably for 653 hours.

[0095] Comparative Example 3

[0096] The difference from Example 1 is that the number of moles of sodium stannate tetrahydrate is 6.08 mmol, resulting in a ZnS-SnS2@Zn electrode (molar ratio of 1.5:1).

[0097] The electrochemical performance of the ZnS-SnS2@Zn electrode (molar ratio 1.5:1) prepared in this comparative example is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can cycle stably for 408 hours.

[0098] Comparative Example 4

[0099] The only difference between the method for assembling an aqueous zinc-ion symmetric button cell with unmodified zinc foil electrodes and the example is that both the positive and negative electrode sheets use unmodified zinc foil.

[0100] The electrochemical performance of the symmetrical coin cell obtained in this comparative example is as follows: at a current density of 0.25 mA / cm²... 2 The dough mixing capacity is 0.25 mAh / cm³. 2It can cycle stably for 288 hours.

[0101] Application examples

[0102] Electrochemical testing

[0103] The materials obtained in Examples 1-12 were used for electrochemical tests and compared with Comparative Examples 1-4. All electrochemical tests were performed in button cells.

[0104] Carbon paper and unmodified zinc foil were cut into electrode sheet sizes using a cutting machine. The sulfide-based hollow nanobrick heterojunction anode coating material prepared in the previous example was spin-coated onto the unmodified zinc foil as the negative electrode. Ammonium vanadate-coated carbon paper served as the positive electrode, glass fiber as the separator, and 2M ZnSO4 as the electrolyte to assemble a CR2032 type button cell. In Comparative Example 4, the symmetrical button cell was assembled using unmodified zinc foil for both positive and negative electrodes. The current density was 0.25 mA / cm². 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Next, a symmetrical charge-discharge test of the button cell was conducted, such as... Figures 5 to 14 As shown. Example 1 exhibits the best performance, with a maximum cycle life of 4580 hours, significantly enhancing the cycle durability of aqueous zinc-ion batteries (e.g., Figure 6 (As shown).

[0105] The zinc anode protected by the ZnS-SnS2 (molar ratio 0.5:1) coating provided by this invention operates at a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can stably cycle for 3160 hours; the zinc anode protected by the ZnS-SnS2 (molar ratio of 0.9:1) coating provided by this invention can operate at a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can stably cycle for 4580 hours; the zinc anode protected by the ZnS-SnS2 (molar ratio of 1.2:1) coating provided by this invention can operate at a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can stably cycle for 1769 hours. Therefore, the optimal molar ratio of the metal elements Zn and Sn in the raw materials is determined to be 0.9:1, and the optimal structural formula is ZnS-SnS2. This optimal scheme is extended to elements such as Co, Cu, and Mo: the zinc anode protected by the ZnS-CoS2 (molar ratio of 0.9:1) coating provided by this invention can achieve a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25 mAh / cm³.2 Under these conditions, the assembled symmetrical battery can stably cycle for 2019 hours; the zinc anode protected by the ZnS-CuS (molar ratio of 0.9:1) coating provided by this invention can operate at a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25mAh / cm³. 2 Under these conditions, the assembled symmetrical battery can stably cycle for 1521 hours; the zinc anode protected by the ZnS-MoS2 (molar ratio of 0.9:1) coating provided by this invention can operate at a current density of 0.25 mA / cm². 2 The dough mixing capacity is 0.25 mAh / cm³. 2 Under these conditions, the assembled symmetrical cells can cycle stably for 1307 hours; the cycle life is higher than that at a current density of 0.25 mA / cm². 2 The lower surface capacity is 0.25 mAh / cm². 2 The cycle life of the symmetric cell assembled with a zinc anode protected by a monometallic sulfide-based ZnS coating is 908 hours, the cycle life of the symmetric cell assembled with a zinc anode protected by a monometallic sulfide-based SnS2 coating is 653 hours, and the cycle life of the symmetric cell assembled with unmodified zinc foil is 288 hours.

[0106] The above results indicate that the XS-YS prepared by this invention... n Hollow nanobrick heterojunction coating material, applied to the anode protective layer of aqueous zinc-ion batteries, benefits from the synergistic effect of its Type-II heterojunction interface and hollow nanobrick morphology. This effectively regulates the interfacial electric field distribution, uniformizes zinc ion flow, promotes rapid zinc ion migration, and significantly enhances the stability of the zinc metal anode / electrolyte interface, thereby effectively suppressing dendrite growth and side reactions, and extending battery cycle life. This invention not only advances the XS-YS... n The research on the application of hollow nanobrick heterojunction coating materials in the field of aqueous zinc-ion batteries has broken through the performance bottleneck of traditional sulfide coating materials through the functional design of Type-II heterojunctions, providing key technical support for the development of high-performance aqueous zinc-ion battery anode protection materials, and has significant practical application value.

Claims

1. The application of a sulfide-based hollow nanobrick heterojunction anode coating material in an aqueous zinc-ion battery, characterized in that, The sulfide-based hollow nanobrick heterojunction as an anode coating material includes an X metal sulfide and a Y metal sulfide, and the heterojunction is denoted as XS-YS n , where 0 < n < 3, X is Zn, and Y is selected from one of Sn, Co, Cu, or Mo.

2. The application according to claim 1, characterized in that, The molar ratio of metal sulfide X to metal sulfide Y in the sulfide-based hollow nanobrick heterostructure is (0.5–1.3):

1.

3. The application according to claim 1, characterized in that, The sulfide-based hollow nanobrick heterojunction is a Type-II heterojunction, and the morphology of the sulfide-based hollow nanobrick heterojunction is a hollow nanobrick.

4. The application according to claim 1, characterized in that, The sulfide-based hollow nanobrick heterostructure and binder are mixed in a solvent and then spin-coated onto zinc foil to serve as the negative electrode of an aqueous zinc-ion battery.

5. The application according to claim 4, characterized in that, The binder is polyvinylidene fluoride or sodium carboxymethyl cellulose.

6. The application according to claim 1, characterized in that, The electrolyte in the aqueous zinc-ion battery includes ZnSO4, the separator is a glass fiber membrane, and the positive electrode is carbon paper coated with ammonium vanadate.

7. A method for preparing a sulfide-based hollow nanobrick heterojunction anodic coating material for any of the applications described in claims 1-6, characterized in that, The preparation method includes: (1) Preparation of hollow nanobrick precursor: Zinc salt and another metal salt are used as metal sources, and dissolved in deionized water with fluoride etchant. Stirring is used to form a mixed solution, and bimetallic hollow nanobrick precursor powder is obtained by hydrothermal reaction. (2) Sulfidation reaction: The bimetallic hollow nanobrick precursor powder and the sulfur source are calcined in an inert atmosphere to sulfidate the metal source and simultaneously construct a heterojunction, thereby obtaining a sulfide-based hollow nanobrick heterojunction material that inherits the morphology of the precursor.

8. The method for preparing the sulfide-based hollow nanobrick heterojunction anodic coating material according to claim 7, characterized in that, In step (1), 1-16 mmol of zinc salt and 10-120 mmol of fluoride etchant, and one of 1-20 mmol of tin salt, 1-20 mmol of cobalt salt, 1-20 mmol of copper salt or 1-20 mmol of molybdenum salt are added to deionized water; the molar ratio of the zinc salt to the other metal salt is (0.5-1.3):

1.

9. The method for preparing the sulfide-based hollow nanobrick heterojunction anodic coating material according to claim 7, characterized in that, In step (1), the temperature of the hydrothermal reaction is 120–180 °C; the time of the hydrothermal reaction is 1–8 h.

10. The method for preparing the sulfide-based hollow nanobrick heterojunction anodic coating material according to claim 7, characterized in that, In step (2), the mass ratio of the bimetallic hollow nanobrick precursor powder to the sulfur source is 1:2 to 1:8; the sulfur source is one or more of sulfur powder, thiourea, ammonium sulfide, and L-cysteine; the inert atmosphere is nitrogen, argon, or a mixture thereof; the calcination temperature is 200 to 600°C, the calcination time is 1 to 5 hours, and the heating rate is 1 to 6°C / min.

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