A zinc metal negative electrode zincophilic hydrophobic interface modification layer, a preparation method and applications thereof

Abstract

The application belongs to the technical field of energy storage materials, and relates to a zinc metal negative electrode zincophilic hydrophobic interface modification layer, a preparation method and application. The interface modification layer is an M-XF nanolayer constructed on the surface of the zinc negative electrode. M is zincophilic metal nanoparticles with solid solubility with zinc metal, and XF is fluoride nanoparticles with hydrophobicity. In the preparation, the zincophilic metal M and the hydrophobic fluoride XF are co-sputtered and deposited on the metal zinc by radio frequency magnetron sputtering. The target material in the sputtering is the zincophilic metal M and the fluoride XF target material. The zincophilic hydrophobic interface modification layer can be used for preparing a water-based zinc ion battery. The metal M in the modification layer homogenizes the current density distribution on the surface of the zinc negative electrode, forms a dendrite-free negative electrode / electrolyte interface, and the XF nanoparticles isolate the zinc metal negative electrode and free water molecules, thereby inhibiting the hydrogen evolution side reaction and the self-corrosion side reaction. The zincophilic hydrophobic dual-function interface modification layer of the application induces uniform zinc deposition and inhibits side reactions such as hydrogen evolution on the electrode surface.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of energy storage materials, and relates to a zincophilic hydrophobic interface modification layer of a zinc metal negative electrode, a preparation method and application. BACKGROUND

[0002] Under the background of global climate warming and the increasingly serious oil crisis, renewable energy, including solar energy, geothermal energy, wind energy, and tidal energy, is considered to be one of the most important energies for solving the energy crisis and environmental problems. However, the unevenness of space-time distribution and deployment of renewable resources hinders their development in actual energy storage applications. Therefore, the development of large-scale electrochemical energy storage systems has very important social significance and economic benefits, and can make renewable energy a stable and adjustable energy. At present, lithium-based electrochemical systems are widely used in portable electronic products, electric / hybrid vehicles, and power grid energy storage equipment. However, the inherent problems of lithium ion batteries, such as the shortage and high cost of battery materials, and the flammable and explosive nature of organic electrolyte, seriously limit their application in large-scale energy storage equipment. Therefore, the research on finding electrochemical systems that can replace lithium ion batteries has attracted widespread attention. Among them, water-based zinc ion batteries based on aqueous electrolyte have attracted much attention. Compared with the standard hydrogen electrode, metal zinc (Zn) has a theoretical capacity of up to 820 mA h g -1 and a reduction potential as low as -0.76V, and its good natural abundance makes the water-based zinc ion battery (ZIBs) with zinc metal as the negative electrode have superior safety performance, lower economic cost, and environmental friendliness, and has great potential to be applied in large-scale power grid energy storage equipment. However, the zinc battery system still faces great challenges: dendrite growth of the core material zinc negative electrode, hydrogen evolution reaction caused by aqueous electrolyte, and corrosion byproducts generated by local alkalinity, which will cause battery performance degradation or even failure. At present, achieving uniform zinc deposition on the surface of the zinc metal negative electrode, inhibiting the hydrogen evolution reaction and reducing the side reaction, achieving stable zinc deposition / detachment cycle of the electrode / electrolyte interface to realize ultra-long cycle life has become an urgent demand in the field of water-based zinc batteries. Therefore, people tend to focus on how to improve the stability of the zinc metal negative electrode / electrolyte interface.

[0003] At present, for improving the stability of zinc metal anode / electrolyte interface, a series of in-depth research and discussion have been carried out at home and abroad, which can be roughly divided into three directions; (1) constructing a layer of in-situ SEI (solid electrolyte interface) film on the surface of zinc anode through electrolyte additive; (2) forming an artificial SEI film on the surface of zinc anode through interface engineering modification; (3) optimizing the composition or structure of the electrode. Among them, for the interface engineering modification strategy, scholars try to deposit different artificial interface modification layers on the surface of zinc metal anode through physical coating or chemical induction, such as conductive carbon interface, metal nanoparticle coating, inorganic coating. These interface modification strategies have improved the dendrite growth and side reaction problem of zinc metal anode and electrolyte interface to some extent.

[0004] Although the existing modification methods have improved the operation performance of aqueous zinc ion battery from different angles to some extent, there are still some problems: (1) single interface modification strategy can only solve the problem on one side, and may even exacerbate other interface problems; (2) most of the zinc anode interface modification strategies have the problem of poor controllability; (3) the mechanism research of interface strategy is still lacking.

[0005] Therefore, it is very important to study the zinc metal anode / electrolyte interface from the micro-mechanism, explore a new controllable interface modification layer, and effectively improve the interface stability and improve the long-term operation stability of zinc ion battery. SUMMARY

[0006] The purpose of the present application is to solve the problems of the prior art, based on the interface engineering theory, to provide a practical and effective aqueous zinc ion battery zinc metal anode / electrolyte interface modification strategy and its preparation method, and a zinc ion battery using the interface modification strategy. The method co-sputters a nanoscale zincophilic metal having a certain solubility with zinc element and a hydrophobic fluoride particle capable of inhibiting hydrogen evolution side reaction on the surface of zinc metal anode sheet (Zn, 99.99%) by magnetron sputtering film technology, to form a dual-functional nanoscale interface modification layer with zincophilic and hydrophobic properties, change the double-layer structure of zinc metal anode / electrolyte interface, and control the uniform deposition of zinc ions while inhibiting the hydrogen evolution side reaction from the root, and realize a long-time cycle highly reversible zinc metal anode through synergistic effect, and improve the cycle life and coulombic efficiency of aqueous zinc ion battery.

[0007] The technical scheme adopted by the present application to solve the technical problem is: a zinc metal negative electrode zincophilic hydrophobic interface modification layer, the interface modification layer is an M-XF nanolayer constructed on the surface of the zinc metal negative electrode, M in the M-XF nanolayer is a zincophilic metal nanoparticle having solid solubility with zinc metal, and XF in the M-XF nanolayer is a hydrophobic fluoride nanoparticle; the thickness of the M-XF nanolayer is 20-500 nm;

[0008] The zincophilic metal (M) particles can uniformly distribute the current density on the electrode surface to regulate uniform zinc metal deposition, and the hydrophobic fluoride (XF) particles can inhibit the side reaction at the electrode interface, the nanoscale particles are uniformly attached to both sides of the positive and negative electrodes of the aqueous zinc battery and one side, a zinc metal electrode with a double-sided deposition modification layer is prepared to test the electrochemical performance of a symmetric battery, and a zinc metal negative electrode with a single-sided deposition modification layer is prepared to test the electrochemical performance of a full battery; the element M having a certain solubility with zinc as a component of the interface modification layer can form a solid solution alloy with zinc and homogenize the electric field distribution on the surface of the zinc negative electrode, thereby promoting uniform dendrite-free zinc deposition; the fluoride having good hydrophobicity, corrosion resistance and excellent ionic conductivity as a component of the interface modification layer.

[0009] Preferably, M in the M-XF nanolayer includes one or more of copper, silver, tantalum, bismuth, scandium, yttrium, titanium, zirconium, hafnium, niobium, chromium, molybdenum, technetium, nickel, aluminum, indium, tin, and lead.

[0010] Preferably, XF in the M-XF nanolayer includes one or more of lithium fluoride, cerium fluoride, lanthanum fluoride, praseodymium fluoride, and iron fluoride.

[0011] Preferably, the thickness of the M-XF nanolayer is 50-200 nm.

[0012] The present application also discloses a preparation method of a zinc metal negative electrode zincophilic hydrophobic interface modification layer, which is used to prepare the above-mentioned interface modification layer; the preparation method comprises the following steps: co-sputtering depositing zincophilic metal M and hydrophobic fluoride XF on metal zinc by radio frequency magnetron sputtering, and the target material during sputtering is zincophilic metal M and fluoride XF target material.

[0013] Preferably, the purity of the metal zinc is greater than or equal to 99.99%, and the metal zinc includes zinc foil.

[0014] Preferably, the background vacuum degree in the radio frequency magnetron sputtering process is 0.1*10 -4 Pa-9.9*10 -4 Pa, the working gas pressure is 0.40-0.50 Pa, the working bias is 90 V, and the purity of the target material is greater than or equal to 99.99%.

[0015] Preferably, in the radio frequency magnetron sputtering process, the target distance is 8-12 cm, the sputtering temperature is 20-30℃, and the sputtering time is 2-10 min.

[0016] The application also discloses an application of the zincophilic and hydrophobic interface modification layer of the zinc metal negative electrode. 10 The application is used for preparing a water-based zinc ion battery, and the water-based zinc ion battery comprises a positive electrode, a diaphragm, a negative electrode and a water-based electrolyte.

[0017] The preparation process of the positive electrode of the water-based zinc ion battery comprises the following steps: 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) is dissolved in deionized water, and stirred in a 80℃ water bath for 40 min, and the color of the solution changes from white to light yellow; 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder is added into the ammonium metavanadate solution, and the stirring is continued in a 80℃ water bath for 30 min, and the color of the solution changes from white to light blue-green; the solution is poured into a 50 ml high-pressure reaction kettle, heated at 180℃ for 8 h, and after cooling, repeatedly washed with deionized water, and dried at room temperature overnight to obtain ammonium vanadate NH4V4O 10 powder; the NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) are dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture is cast on a 316 stainless steel mesh, and dried in a 70℃ temperature oven overnight to obtain a positive electrode.

[0018] Preferably, the thickness of the diaphragm is 0.5-0.8 mm; and the concentration of zinc sulfate ZnSO4 in the electrolyte solution is 1-3 mol / L.

[0019] The application has the following beneficial effects:

[0020] 1、The zinc negative electrode surface modified by the application is co-sputtered with nano-sized metal M particles and XF particles by a radio frequency power magnetron sputtering. The metal M has good zinc affinity, can form a stable solid solution with zinc, homogenizes the current density distribution of the zinc negative electrode surface, and serves as a nucleation site to induce uniform deposition of zinc ions, forming a dendrite-free negative electrode / electrolyte interface. The other component XF nanoparticles in the modification layer have good hydrophobicity and corrosion resistance, isolate the zinc metal negative electrode from free water molecules in an acidic electrolyte environment, thereby inhibiting the hydrogen evolution side reaction and the self-corrosion side reaction at the zinc negative electrode / electrolyte interface. Therefore, the zincophilic and hydrophobic dual-functional interface modification layer of the application induces uniform zinc deposition and inhibits side reactions such as hydrogen evolution on the electrode surface.

[0021] 2、The application realizes the uniform and dendrite-free zinc ion deposition by optimizing the double electric layer structure of the zinc negative electrode surface through the composition regulation of the double functional nano-particle modification layer by the radio frequency co-sputtering technology, and the free water molecules in the double electric layer of the zinc negative electrode surface are isolated to inhibit the side reaction, so that the application improves the reversibility and stability of the zinc metal negative electrode, improves the coulomb efficiency and cycle stability of the zinc ion battery, and reduces the capacity attenuation.

[0022] 3、The application forms the metal M nano-particle modification layer doped with a small amount of XF nano-particles and having a certain solid solubility with zinc on the surface of the zinc negative electrode by the radio frequency magnetron co-sputtering; therefore, the application realizes the uniform and dense modification nano-particle modification layer, and induces the uniform deposition of zinc. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is the cycle stability diagram of the zinc symmetric battery assembled by the zinc electrode with the introduced nano-Ag-LiF interface modification layer of the zinc metal negative electrode of the application at the current density of 5 mA cm -2 ;

[0024] Fig. 2 is the cycle stability diagram of the zinc symmetric battery assembled by the zinc electrode with the introduced nano-Ag-LiF interface modification layer of the application when the current density is changed;

[0025] Fig. 3 is the cycle stability diagram of the full battery obtained by assembling the zinc metal negative electrode with the introduced nano-Ag-LiF modification layer of the application and the ammonium vanadate positive electrode at different rates. DETAILED DESCRIPTION

[0026] The related technologies in the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by the ordinary skilled in the art without creative labor are within the protection scope of the application.

[0027] REFERENCE Figs. 1-3The interface modification layer prepared by co-sputtering through the magnetron sputtering method and the optimized zinc metal negative electrode based on the modification layer in the embodiment. The modification layer is deposited on the high-purity zinc foil (Zn≥99.99%) substrate by radio frequency co-sputtering, zincophilic metal (M) nanoparticles with a certain solid solubility with zinc metal, and fluorinated compound (XF) nanoparticles with hydrophobicity. Among them, the zincophilic metal M can induce the uniform deposition of zinc ions on the zinc electrode, inhibit the growth of zinc dendrites, prevent capacity attenuation, and even prevent short circuit caused by dendrite piercing the separator; the hydrophobic fluorinated compound XF can reduce the amount of free water on the surface of the zinc metal negative electrode, thereby inhibiting the occurrence of hydrogen evolution reaction and preventing performance impact or even failure caused by battery bulging; at the same time, the multifunctional modification layer co-sputtered as a physical shielding layer prevents direct contact between the zinc negative electrode and the electrolyte, and inhibits various interface side reactions.

[0028] The zinc battery structure applied by the zinc negative electrode based on the multifunctional modification layer also includes a positive electrode, a separator, and an electrolyte. Among them, the positive electrode is a stainless steel mesh with attached ammonium vanadate, the separator is a glass fiber membrane, the electrolyte is a zinc sulfate solution, and the side of the zinc metal with the attached multifunctional modification layer faces the separator.

[0029] The specific preparation steps of the zinc metal negative electrode with the multifunctional modification layer and the assembled aqueous zinc ion battery include:

[0030] Step 1, cut the high-purity zinc foil (Zn≥99.99%) with a thickness of 0.05mm, clean with alcohol and dry;

[0031] Step 2, fix the zinc foil prepared in step 1 on the magnetron sputtering sample disc with conductive tape, clean the sample with alcohol on a cotton swab and dry thoroughly; fix the sample disc with the zinc foil in the magnetron sputtering equipment cavity and cover it with a baffle; polish the selected target material (purity≥99.99%) with sandpaper, then wash it with alcohol and dry thoroughly; after the cavity is pumped to a background vacuum, pre-sputter the target material for five minutes to clean the surface impurities and oxides, ensuring the purity of the modification layer; after pre-sputtering, adjust the vacuum to the working gas pressure, open the sample baffle for co-sputtering. The process parameters of radio frequency magnetron sputtering are: background vacuum (0.1-9.9) ×10 -4 Pa, working gas pressure 0.4-0.5 Pa, target distance 8-12 cm, sputtering bias -90 V, sputtering power is optimized according to different target materials, sputtering temperature 20-30℃, sample disc rotation speed 16 rpm, sputtering time 1-10 min;

[0032] Step 3, under the optimized magnetron sputtering process in step 2, deposit two substances: metal M and fluorinated compound XF simultaneously through the radio frequency power supply, obtain a zinc foil with a 50-200 nm nano-modification layer, and cut it with a tablet press as a battery negative electrode;

[0033] Step 4, Preparation of the separator: A glass fiber film with a thickness of 0.68 mm was cut by a tablet press as the battery separator;

[0034] Step 5, Preparation of the ammonium vanadate positive electrode: 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water, and stirred in a water bath at 80°C for 40 minutes. The color of the solution changed from white to light yellow. 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder was added to the ammonium metavanadate solution, and stirring was continued in a water bath at 80°C for 30 minutes. The color of the solution changed from white to light blue-green. The solution was poured into a 50 ml high-pressure reaction kettle, heated at 180°C for 8h, and after cooling, repeatedly washed with deionized water and dried overnight at room temperature to obtain ammonium vanadate NH4V4O 10 powder; NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) were dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture was cast on a cut 316 stainless steel mesh and dried in a temperature oven at 70°C overnight to obtain a positive electrode.

[0035] Step 6, Preparation of the electrolyte solution: Zinc sulfate heptahydrate (Aladdin, 99.995%) powder was dissolved in deionized water to obtain an electrolyte solution with a concentration of 2 mol / L;

[0036] Step 7, Assembly of the ammonium vanadate / modified zinc metal full battery: At room temperature, the modified zinc metal negative electrode, glass fiber membrane, and ammonium vanadate positive electrode were placed in a standard CR2032 type button cell shell, and 100 μL of electrolyte was dropped on both sides of the separator. The full battery was assembled using a button cell sealing machine. The modified layer of the zinc metal negative electrode faced the glass fiber separator.

[0037] The prepared full battery was tested for charge and discharge performance, and cycled at different rates in the range of 0.1-3 A / g at 26°C. The test voltage range for each cycle was 1.2 V to 2.0 V.

[0038] Example 1

[0039] A zinc metal negative electrode with an Ag-LiF multifunctional modification layer was prepared and applied in a water-based zinc ion full battery;

[0040] A thoroughly cleaned and dried high-purity zinc foil (Zn≥99.99%) was fixed to the magnetron sputtering sample tray using conductive tape, placed inside the sputtering chamber, and covered with a baffle. Ag and LiF targets with a purity of 99.99% were sanded, cleaned with alcohol, and dried before a five-minute pre-sputtering process to remove surface oxides and irrelevant impurities, ensuring the purity of the Ag-LiF modified layer. After pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters for RF magnetron sputtering were: background vacuum 6.0 × 10⁻⁶. -4 The working pressure after introducing 99.99% pure argon gas is 0.45 Pa, the target distance is 10 cm, the sputtering bias is ~90 V, the sputtering power is 80 W, the sputtering temperature is 26 °C, the sample disk rotation speed is 16 rpm, and the sputtering time is 1 min.

[0041] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water and stirred in an 80°C water bath for 40 minutes, during which the solution color changed from white to pale yellow. 0.85 g of oxalic acid powder (H2C2O4·2H2O, Aladdin, 99%) was added to the ammonium metavanadate solution, and stirring was continued in an 80°C water bath for 30 minutes, during which the solution color changed from white to pale blue-green. The solution was poured into a 50 ml high-pressure reactor and heated at 180°C for 8 hours. After cooling, it was repeatedly washed with deionized water and dried overnight at room temperature to obtain ammonium metavanadate NH4VO3. 10 Powder; NH4V4O 10 Powder, Ketjen Black (KB), and polytetrafluoroethylene (PTFE, dispersed in water at 60% by mass) were dissolved in isopropanol at a mass ratio of 75:15:10 to form a mixture. The mixture was cast onto a cut 316 stainless steel mesh, dried overnight in an oven at 70°C, and then cut to obtain the positive electrode.

[0042] The modified zinc metal anode, glass fiber membrane, and ammonium vanadate cathode were placed into a standard CR2032 coin cell casing. 100 μL of 2 mol / L zinc sulfate electrolyte was then dropped onto both sides of the separator. The entire cell was assembled using a coin cell sealing machine. The modified zinc metal anode layer faced the glass fiber separator.

[0043] Comparative charge-discharge tests were conducted on the batteries prepared in the comparative example and Example 1. The results showed that after introducing the multifunctional modified layer proposed in this embodiment into the zinc metal anode, at a current density of 5 mA cm⁻¹, [the battery performance improved]. -2 The assembled zinc symmetric battery showed significantly improved cycle stability, reversibility, and cycle life; the assembled ammonium vanadate / zinc metal full cell showed improved reversibility and stability during cycling at different rates at 26℃, and the capacity retention rate was as high as 97% after 45 cycles at different rates.

[0044] Example 2

[0045] Preparation of zinc metal anode with Cu-LiF multifunctional modification layer and its application in aqueous zinc-ion full battery;

[0046] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The Cu target and LiF target with a purity of 99.99% were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Cu-LiF modification layer; after pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: base vacuum degree 6.0x10 -4 Pa, working gas pressure after introducing 99.99% pure argon 0.45 Pa, target distance 10 cm, sputtering bias -90 V, sputtering power 80 W, sputtering temperature 26°C, sample disc rotation speed 16 rpm, sputtering time 1 min.

[0047] Dissolve 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) in deionized water, stir in a 80°C water bath for 40 minutes, the color of the solution changes from white to light yellow; add 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder to the ammonium metavanadate solution, continue to stir in a 80°C water bath for 30 minutes, the color of the solution changes from white to light blue-green; pour the solution into a 50 ml high-pressure reaction kettle, heat at 180°C for 8h, after cooling, wash repeatedly with deionized water, dry overnight at room temperature, to obtain ammonium vanadate NH4V4O 10 powder; dissolve NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at 60% mass fraction) in isopropanol at a mass ratio of 75:15:10 to form a mixture; cast the mixture on a cut 316 stainless steel mesh, dry in a 70°C temperature oven overnight and cut to obtain a positive electrode.

[0048] Put the modified zinc metal anode, glass fiber membrane and ammonium vanadate positive electrode into a standard CR2032 type button cell shell, and co-drip 100 μL of 2 mol / L zinc sulfate electrolyte on both sides of the diaphragm, and assemble the full battery using a button cell sealing machine. Among them, the modified layer of the zinc metal anode faces the glass fiber diaphragm.

[0049] Example 3

[0050] Preparation of zinc metal anode with Ta-LiF multifunctional modification layer and its application in aqueous zinc-ion full battery;

[0051] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The Ta target and LiF target with a purity of 99.99% were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Ta-LiF modified layer; after the pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: the base vacuum degree was 6.0x10 -4 Pa, the working gas pressure after the introduction of 99.99% pure argon was 0.45 Pa, the target distance was 10 cm, the sputtering bias was -90 V, the sputtering power was 80 W, the sputtering temperature was 26°C, the sample disc rotation speed was 16 rpm, and the sputtering time was 1 min.

[0052] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water, stirred in a 80°C water bath for 40 minutes, and the color of the solution changed from white to light yellow; 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder was added to the ammonium metavanadate solution, and the solution was continuously stirred in a 80°C water bath for 30 minutes, and the color of the solution changed from white to light blue-green; the solution was poured into a 50 ml high-pressure reaction kettle, heated at 180°C for 8h, cooled, washed repeatedly with deionized water, and dried at room temperature overnight to obtain ammonium vanadate NH4V4O 10 powder; the NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) were dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture was cast on a cut 316 stainless steel mesh, dried in a 70°C temperature oven overnight, and cut to obtain a positive electrode.

[0053] The modified zinc metal negative electrode, glass fiber membrane and ammonium vanadate positive electrode were placed in a standard CR2032 type button cell shell, and 100 μL of 2 mol / L zinc sulfate electrolyte was dropped on both sides of the diaphragm, and the button cell sealing machine was used to complete the assembly of the full cell. Among them, the modified layer of the zinc metal negative electrode faces the glass fiber diaphragm.

[0054] Example 4

[0055] A zinc metal negative electrode with a Bi-LiF multifunctional modified layer was prepared and applied in a water-based zinc ion full cell;

[0056] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The Bi target and LiF target with a purity of 99.99% were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Bi-LiF modified layer; after the pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: the base vacuum degree was 6.0x10 -4 Pa, the working gas pressure after introducing argon with a purity of 99.99% was 0.45 Pa, the target distance was 10 cm, the sputtering bias was -90 V, the sputtering power was 80 W, the sputtering temperature was 26°C, the sample disc rotation speed was 16 rpm, and the sputtering time was 1 min.

[0057] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water, stirred in a 80°C water bath for 40 minutes, and the color of the solution changed from white to light yellow; 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder was added to the ammonium metavanadate solution, and the solution was continuously stirred in a 80°C water bath for 30 minutes, and the color of the solution changed from white to light blue-green; the solution was poured into a 50 ml high-pressure reaction kettle, heated at 180°C for 8h, cooled, washed repeatedly with deionized water, and dried at room temperature overnight to obtain ammonium vanadate NH4V4O 10 powder; the NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) were dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture was cast on a cut 316 stainless steel mesh, dried in a 70°C temperature oven overnight, and cut to obtain a positive electrode.

[0058] The modified zinc metal negative electrode, glass fiber membrane and ammonium vanadate positive electrode were placed in a standard CR2032 type button cell shell, and 100 μL of zinc sulfate electrolyte with a concentration of 2 mol / L was dropped on both sides of the diaphragm, and a button cell sealing machine was used to complete the assembly of the full cell. Among them, the modified layer of the zinc metal negative electrode faces the glass fiber diaphragm.

[0059] Example 5

[0060] A zinc metal negative electrode with an Ag-ZnF2 multifunctional modified layer was prepared and applied in a water-based zinc ion full cell;

[0061] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The 99.99% pure Ag target and ZnF2 target were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Ag-ZnF2 modified layer; after pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: base vacuum degree 6.0x10 -4 Pa, working gas pressure after 99.99% pure argon was introduced 0.45 Pa, target distance 10 cm, sputtering bias -90 V, sputtering power 80 W, sputtering temperature 26 °C, sample disc rotation speed 16 rpm, sputtering time 1 min.

[0062] Dissolve 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) in deionized water, stir in a 80 °C water bath for 40 minutes, the color of the solution changes from white to light yellow; add 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder to the ammonium metavanadate solution, continue to stir in a 80 °C water bath for 30 minutes, the color of the solution changes from white to light blue-green; pour the solution into a 50 ml high-pressure reaction kettle, heat at 180 °C for 8 h, after cooling, wash repeatedly with deionized water, dry overnight at room temperature, to obtain ammonium vanadate NH4V4O 10 powder; dissolve NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at 60% mass fraction) in isopropanol at a mass ratio of 75:15:10 to form a mixture; cast the mixture on a cut 316 stainless steel mesh, dry in a 70 °C temperature oven overnight and cut to obtain a positive electrode.

[0063] Put the modified zinc metal negative electrode, glass fiber membrane and ammonium vanadate positive electrode into a standard CR2032 type button cell shell, and co-drip 100 μL of 2 mol / L zinc sulfate electrolyte on both sides of the diaphragm, and assemble the full cell using a button cell sealing machine. Among them, the modified layer of the zinc metal negative electrode faces the glass fiber diaphragm.

[0064] Example 6

[0065] Prepare a zinc metal negative electrode with a Cu-ZnF2 multifunctional modified layer and apply it in a water-based zinc ion full cell;

[0066] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The Cu target and ZnF2 target with a purity of 99.99% were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Cu-ZnF2 modified layer; after the pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: the base vacuum degree was 6.0x10 -4 Pa, the working gas pressure after introducing 99.99% pure argon was 0.45 Pa, the target distance was 10 cm, the sputtering bias was -90 V, the sputtering power was 80 W, the sputtering temperature was 26°C, the sample disc rotation speed was 16 rpm, and the sputtering time was 1 min.

[0067] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water, stirred in a 80°C water bath for 40 minutes, and the color of the solution changed from white to light yellow; 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder was added to the ammonium metavanadate solution, and the solution was continuously stirred in a 80°C water bath for 30 minutes, and the color of the solution changed from white to light blue-green; the solution was poured into a 50 ml high-pressure reaction kettle, heated at 180°C for 8h, cooled, washed repeatedly with deionized water, and dried at room temperature overnight to obtain ammonium vanadate NH4V4O 10 powder; the NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) were dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture was cast on a cut 316 stainless steel mesh, dried in a 70°C temperature oven overnight, and cut to obtain a positive electrode.

[0068] The modified zinc metal negative electrode, glass fiber membrane and ammonium vanadate positive electrode were placed in a standard CR2032 type button cell shell, and 100 μL of 2 mol / L zinc sulfate electrolyte was dropped on both sides of the diaphragm, and a button cell sealing machine was used to complete the assembly of the full cell. Among them, the modified layer of the zinc metal negative electrode faces the glass fiber diaphragm.

[0069] Example 7

[0070] A zinc metal negative electrode with a Ta-ZnF2 multifunctional modified layer was prepared and applied in a water-based zinc ion full cell;

[0071] The clean and completely dried high-purity zinc foil (Zn≥99.99%) was fixed on the magnetron sputtering sample disc with conductive tape, loaded into the sputtering chamber and covered with a baffle. The Ta target and ZnF2 target with a purity of 99.99% were polished with sandpaper and cleaned with alcohol and dried, then pre-sputtered for five minutes to clean the surface oxides and irrelevant impurities, to ensure the purity of the Ta-ZnF2 modified layer; after the pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters of the radio frequency magnetron sputtering were as follows: the base vacuum degree was 6.0x10 -4 Pa, the working gas pressure after the introduction of 99.99% pure argon was 0.45 Pa, the target distance was 10 cm, the sputtering bias was -90 V, the sputtering power was 80 W, the sputtering temperature was 26°C, the sample disc rotation speed was 16 rpm, and the sputtering time was 1 min.

[0072] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water, stirred in a 80°C water bath for 40 minutes, and the color of the solution changed from white to light yellow; 0.85 g of oxalic acid (H2C2O4·2H2O, Aladdin, 99%) powder was added to the ammonium metavanadate solution, and the solution was continuously stirred in a 80°C water bath for 30 minutes, and the color of the solution changed from white to light blue-green; the solution was poured into a 50 ml high-pressure reaction kettle, heated at 180°C for 8 h, cooled, washed repeatedly with deionized water, and dried at room temperature overnight to obtain ammonium vanadate NH4V4O 10 powder; the NH4V4O 10 powder, Ketjen black (KB) and polytetrafluoroethylene (PTFE, dispersed in water at a mass fraction of 60%) were dissolved in isopropanol at a mass fraction ratio of 75:15:10 to form a mixture; the mixture was cast on a cut 316 stainless steel mesh, dried in a 70°C temperature oven overnight, and cut to obtain a positive electrode.

[0073] The modified zinc metal negative electrode, glass fiber membrane and ammonium vanadate positive electrode were placed in a standard CR2032 type button cell shell, and 100 μL of 2 mol / L zinc sulfate electrolyte was dropped on both sides of the diaphragm, and the button cell sealing machine was used to complete the assembly of the full cell. Among them, the modified layer of the zinc metal negative electrode faces the glass fiber diaphragm.

[0074] Example 8

[0075] A zinc metal negative electrode with a Bi-ZnF2 multifunctional modified layer was prepared and applied in a water-based zinc ion full cell;

[0076] A thoroughly cleaned and dried high-purity zinc foil (Zn≥99.99%) was fixed to the magnetron sputtering sample tray using conductive tape, placed inside the sputtering chamber, and covered with a baffle. Bi and ZnF2 targets with a purity of 99.99% were sanded, cleaned with alcohol, and dried before a five-minute pre-sputtering process to remove surface oxides and irrelevant impurities, ensuring the purity of the Bi-ZnF2 modified layer. After pre-sputtering, the sample baffle was opened for co-sputtering. The process parameters for RF magnetron sputtering were: background vacuum 6.0 × 10⁻⁶. -4 The working pressure after introducing 99.99% pure argon gas is 0.45 Pa, the target distance is 10 cm, the sputtering bias is ~90 V, the sputtering power is 80 W, the sputtering temperature is 26 °C, the sample disk rotation speed is 16 rpm, and the sputtering time is 1 min.

[0077] 0.85 g of ammonium metavanadate (NH4VO3, Aladdin, 99%) was dissolved in deionized water and stirred in an 80°C water bath for 40 minutes, during which the solution color changed from white to pale yellow. 0.85 g of oxalic acid powder (H2C2O4·2H2O, Aladdin, 99%) was added to the ammonium metavanadate solution, and stirring was continued in an 80°C water bath for 30 minutes, during which the solution color changed from white to pale blue-green. The solution was poured into a 50 ml high-pressure reactor and heated at 180°C for 8 hours. After cooling, it was repeatedly washed with deionized water and dried overnight at room temperature to obtain ammonium metavanadate NH4VO3. 10 Powder; NH4V4O 10 Powder, Ketjen Black (KB), and polytetrafluoroethylene (PTFE, dispersed in water at 60% by mass) were dissolved in isopropanol at a mass ratio of 75:15:10 to form a mixture. The mixture was cast onto a cut 316 stainless steel mesh, dried overnight in an oven at 70°C, and then cut to obtain the positive electrode.

[0078] The modified zinc metal anode, glass fiber membrane, and ammonium vanadate cathode were placed into a standard CR2032 coin cell casing. 100 μL of 2 mol / L zinc sulfate electrolyte was then dropped onto both sides of the separator. The entire cell was assembled using a coin cell sealing machine. The modified zinc metal anode layer faced the glass fiber separator.

[0079] This embodiment is performed at 26°C and 5mA cm. -2 The constant current cycling curve under high current density, such as Fig. 1 As shown, compared to the control sample's overpotential of ~80mV, the modified symmetrical battery's operating overpotential is stable at ~50mV, and its operational and cycle stability are significantly improved, enabling stable operation for over 1000 hours. Fig. 2The symmetric battery was operated at current densities of 1, 2, 3, 5, 10, and then gradually reduced one by one, so as to characterize the rate performance of the battery. The modified battery showed good cycle stability and reversibility, while the control sample failed in the middle.

[0080] In this embodiment, the zinc anode with M-XF interfacial modification layer and the ammonium vanadate cathode were assembled into a full battery, and were operated at different current densities in turn, as shown in the following table. Fig. 3 As shown, the ammonium vanadate / M-XF interfacial modification layer zinc metal battery has good capacity retention rate and good cycle performance, and maintains a high discharge capacity after the current density is changed back to 0.1 A / g.

[0081] The principle of the M-XF interfacial modification layer in this embodiment to improve the stability and reversibility of the symmetric battery and the full battery is as follows: 1) The zincophilic nanometal M uniformly deposited in the modification layer can form a solid solution with zinc, homogenize the current density distribution on the surface of the zinc electrode, induce uniform deposition of zinc, and inhibit dendrite growth; 2) The fluoride (XF) nanoparticles in the modification layer have hydrophobicity, which reduces the number of free water molecules in the double electric layer and inhibits the hydrogen evolution reaction; 3) The introduction of the multifunctional modification layer forms a protective layer on the surface of the zinc electrode, reducing the side reactions caused by the direct contact between zinc metal and electrolyte in the double electric layer.

[0082] The ultimate goal of this embodiment is to improve the uneven zinc dendrite growth at the zinc electrode / electrolyte interface and inhibit the side reactions such as hydrogen evolution and self-corrosion at the interface. Therefore, a multifunctional zincophilic and hydrophobic modification layer is introduced at the zinc anode / electrolyte interface in this embodiment, which is uniformly composed of nanoscale metal M and fluoride XF. Among them, the metal M can form a solid solution with zinc with a certain solid solubility, and the uniformly zincophilic metal M at the interface can induce uniform zinc deposition, thereby inhibiting the growth of zinc dendrites; the hydrophobic fluoride (XF) particles can reduce the free water molecules at the zinc anode / electrolyte interface, thereby inhibiting the hydrogen evolution reaction; at the same time, the multifunctional modification layer acts as a physical barrier layer to hinder the direct contact between zinc metal and electrolyte, and inhibit the generation of interface side reactions such as self-corrosion. The introduction of the multifunctional modification layer improves the stability and reversibility of the zinc anode, and is confirmed to improve the battery operation performance and life in practical application.

[0083] In summary, the zinc negative electrode surface after modification is co-sputtered with nano-sized metal M particles and XF particles by a radio frequency power magnetron sputtering. The metal M has good affinity for zinc and can form a stable solid solution with zinc. The metal M homogenizes the current density distribution on the surface of the zinc negative electrode and acts as a nucleation site to induce uniform deposition of zinc ions, forming a dendrite-free negative electrode / electrolyte interface. The other component XF nanoparticles in the modified layer have good hydrophobicity and corrosion resistance, which isolate the zinc metal negative electrode from free water molecules in the acidic electrolyte environment, thereby inhibiting the hydrogen evolution side reaction and the self-corrosion side reaction at the zinc negative electrode / electrolyte interface. Therefore, the zincophilic and hydrophobic bifunctional interface modification layer of the present application induces uniform zinc deposition and inhibits side reactions such as hydrogen evolution on the electrode surface.

[0084] It should be emphasized that: the above is only the preferred embodiment of the present application, not any form of limitation on the present application, any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application still belongs to the scope of the technical scheme of the present application.

Claims

1. A zinc metal negative electrode with a zincophilic hydrophobic interfacial modification layer, characterized in that, The interface modification layer is an M-XF nanolayer constructed on the surface of the zinc metal negative electrode, M in the M-XF nanolayer is a zincophilic metal nanoparticle having solid solubility with zinc metal, and XF in the M-XF nanolayer is a hydrophobic fluoride nanoparticle; the thickness of the M-XF nanolayer is 20-200 nm; M in the M-XF nanolayer includes one or more of copper, silver, tantalum, bismuth, scandium, yttrium, titanium, zirconium, hafnium, niobium, chromium, molybdenum, technetium, nickel, aluminum, indium, tin, and lead; XF in the M-XF nanolayer includes one or more of lithium fluoride, cerium fluoride, lanthanum fluoride, praseodymium fluoride, and iron fluoride; The M-XF nanolayer is prepared by co-sputtering deposition of the zincophilic metal M and the hydrophobic fluoride XF on the metal zinc through radio frequency magnetron sputtering.

2. A method for producing a zincophilic hydrophobic interfacial modification layer of a zinc metal negative electrode, characterized by, The preparation method is used for preparing the interface modification layer of claim 1, and the preparation method comprises co-sputtering deposition of the zincophilic metal M and the hydrophobic fluoride XF on the metal zinc through radio frequency magnetron sputtering, and the target material during sputtering is the zincophilic metal M and the fluoride XF target material. The purity of the metal zinc is ≥ 99.99%, and the metal zinc includes zinc foil. The background vacuum degree in the radio frequency magnetron sputtering process is 0.1×10 -4 Pa~9.9×10 -4 Pa, the working pressure is 0.40~0.50Pa, the working bias is 90V, and the purity of the target material is ≥99.99%. During the radio frequency magnetron sputtering process, the target electrode distance is 8-12 cm, the sputtering temperature is 20-30 ℃, and the sputtering time is 2-10 min.

3. Use of a zincophilic hydrophobic interfacial modification layer of a zinc metal negative electrode, characterized in that, The application adopts the interface modification layer of claim 1, and is used for preparing a water-based zinc ion battery, the water-based zinc ion battery comprising: a positive electrode, a diaphragm, a negative electrode and a water-based electrolyte, the positive electrode comprising ammonium vanadate powder NH4V4O 10 , the diaphragm comprising a glass fiber membrane, the negative electrode comprising zinc metal after interface modification, and the water-based electrolyte comprising a zinc sulfate solution. The thickness of the separator is 0.5-0.8 mm, and the concentration of zinc sulfate in the aqueous electrolyte is 1-3 mol / L.

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