Preparation method of reducing phosphate solid electrolyte interface layer and application thereof in anode of aqueous zinc ion battery

Abstract

The application relates to a preparation method of a reducing phosphate solid electrolyte interface layer and application thereof to an anode of a water-based zinc ion battery, and belongs to the field of water-based zinc ion batteries. The application aims to solve the problems of easy generation of dendrites, corrosion and passivation of the anode in the existing water-based zinc ion battery. The method comprises the following steps: I. preparation of a surfactant layer; II. thin film growth. Application: the interface protection layer of the anode in the water-based zinc ion battery. The application is used for the preparation of a reducing phosphate solid electrolyte interface layer and the application thereof to the anode of a water-based zinc ion battery.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aqueous zinc ion battery. BACKGROUND

[0002] Aqueous battery is one of the ideal systems in the future scale energy storage field. Compared with fuel cells, energy storage batteries pay more attention to its cost, self-discharge, safety and cycle life. At present, lithium ion battery is the most widely studied, but lithium ion battery has problems such as expensive lithium metal price and flammable and explosive organic electrolyte. Compared with lithium battery, zinc battery uses aqueous electrolyte, has higher safety, and zinc metal has low price, abundant reserves, and high capacity density and energy density.

[0003] However, the anode in aqueous zinc ion battery also has a series of problems, such as easy to produce dendrite, corrosion and passivation, which seriously hinder the development of aqueous zinc ion battery in long cycle and high efficiency charging and discharging. SUMMARY

[0004] The present application solves the problems of easy to produce dendrite, corrosion and passivation of the anode in the existing aqueous zinc ion battery, and further provides a preparation method of a reducing phosphate solid electrolyte interface layer and its application in the anode of aqueous zinc ion battery.

[0005] A preparation method of a reducing phosphate solid electrolyte interface layer, which is carried out according to the following steps:

[0006] I. Preparation of surfactant layer:

[0007] Drop chloroform solution of perfluorotetradecanoic acid on the surface of metal sulfate solution to form a single layer of surfactant layer, and obtain a sulfate solution with surfactant layer on the surface;

[0008] II. Thin film growth:

[0009] Inject sodium phosphate solution under the liquid surface of the sulfate solution with surfactant layer on the surface, then stand at room temperature, and obtain a reducing phosphate thin film at the water-air interface, that is, complete the preparation method of the reducing phosphate solid electrolyte interface layer;

[0010] The reducing phosphate thin film is a copper phosphate thin film; the molar ratio of sodium phosphate in the sodium phosphate solution to sulfate in the sulfate solution with surfactant layer on the surface is 1:(1-2).

[0011] The application of the reducing phosphate solid electrolyte interface layer in the anode of aqueous zinc ion battery is used as an interface protection layer for the anode in aqueous zinc ion battery.

[0012] The beneficial effects of the present application are:

[0013] The addition of the reducing phosphate solid electrolyte interface layer can effectively protect the zinc anode surface from direct contact with the electrolyte. Since the solid electrolyte interface layer has reducing metal ions, the original reduction reaction is changed during the deposition process, so that a new metal element is generated. The strong adsorption between zinc metal and the newly generated metal element reduces the migration energy barrier of zinc ions; the newly generated metal element provides new sites for the nucleation of zinc metal, thereby reducing the nucleation energy barrier of zinc ions. In addition, during the entire synthesis process, the perfluorotetradecanoic acid used has hydrophobic ability, so that the reducing phosphate solid electrolyte interface layer also has a certain desolvation ability, which can inhibit the occurrence of hydrogen evolution, corrosion and passivation reaction.

[0014] The solid electrolyte interface layer prepared by the application is simple, safe and environmentally friendly, and is easy to scale up. The prepared reducing phosphate solid electrolyte interface layer can inhibit the generation of dendrites and reduce the generation of hydrogen evolution, corrosion and passivation reaction, thereby promoting the development of long cycle and high efficiency of water-based zinc ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 XPS analysis diagram of anode interface layer in Zn||Zn symmetric battery assembled by zinc electrode protected by solid electrolyte interface layer (Example 1), a is Cu 2p orbit, b is P 2p orbit;

[0016] Figure 2 Comparison diagram of overpotential test of Zn||Zn symmetric battery assembled by zinc electrode protected by solid electrolyte interface layer (Example 1, Comparative Experiment 1 to 3) and bare zinc respectively;

[0017] Figure 3 Anode polarization voltage test diagram in Zn||Cu half-cell of zinc electrode protected by solid electrolyte interface layer (Example 1, Comparative Experiment 1 to 3) and bare zinc respectively assembled;

[0018] Figure 4 Zinc ion loading number test diagram of Zn||Zn symmetric battery assembled by zinc electrode protected by solid electrolyte interface layer (Example 1, Comparative Experiment 1 to 3) and bare zinc respectively;

[0019] Figure 5 Hydrogen evolution potential test diagram of Zn||Cu half-cell of zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc respectively assembled;

[0020] Figure 6 Long cycle performance diagram of Zn||Cu half-cell of zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc respectively assembled under the condition that the current density is 10 mA / cm 2 and the surface capacity is 1 mAh / cm 2 .

[0021] Figure 7 To achieve a current density of 1 mA / cm 2 ~50mA / cm 2 The surface capacity is 1mAh / cm² 2 Cyclic diagrams of Zn||Zn symmetric cells assembled with zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc respectively under the following conditions;

[0022] Figure 8 Optical photographs of the morphology of the anode surface of the zinc electrode protected by the solid electrolyte interface layer (Example 1) and the Zn||Cu half-cell assembled with bare zinc after cycling. a1 to a3 are the zinc deposition process, and a3 to a5 are the zinc stripping process.

[0023] Figure 9 This is a schematic diagram of the cycling of a Zn||I2 full cell assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1) and bare zinc, respectively, under a current density of 5 A / g.

[0024] Figure 10 The CV comparison diagram shows the Zn||I2 full cells assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1) and bare zinc at 0.3V to 1.8V.

[0025] Figure 11 For Co 2+ Ni 2+ Cu 2+ Zn 2+ and Cd 2+ Comparison chart of restoration capabilities;

[0026] Figure 12 To achieve a current density of 5 mA·cm -2 and a capacity of 1mAh·cm -2 Cyclic test diagrams of Zn||Zn symmetric cells assembled with zinc electrodes protected by a solid electrolyte interface layer (Example 1) and bare zinc, respectively;

[0027] Figure 13 Corrosion test images of a zinc electrode protected by a solid electrolyte interface layer (Example 1) and bare zinc;

[0028] Figure 14 To achieve a current density of 10 mA / cm 2 and a capacity of 1mAh / cm 2 Under the conditions described, XRD test images of the anode of a Zn||Zn symmetric cell assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1) and bare zinc respectively after 600 cycles. Detailed Implementation

[0029] Embodiment 1: The present embodiment is a preparation method of a reducing phosphate solid electrolyte interface layer, which is carried out according to the following steps:

[0030] I. Preparation of the surfactant layer:

[0031] A chloroform solution of perfluorotetradecanoic acid is added dropwise on the surface of the metal sulfate solution to form a monolayer surfactant layer, and a sulfate solution covered with a surfactant layer is obtained;

[0032] II. Thin film growth:

[0033] The sodium phosphate solution is injected below the surface of the sulfate solution covered with a surfactant layer, and then left at room temperature, so that a reducing phosphate thin film is obtained at the water-air interface, i.e. the preparation method of the reducing phosphate solid electrolyte interface layer is completed.

[0034] The reducing phosphate thin film is a copper phosphate thin film; and the molar ratio of sodium phosphate in the sodium phosphate solution to sulfate in the sulfate solution covered with a surfactant layer is 1:(1-2).

[0035] Mechanism:

[0036] Firstly, XPS test is performed on the surface of a zinc anode deposited for 10 min (10 mA cm -2 ) to find that, in addition to the phosphate, elemental metal also appears on the surface of the zinc anode, which means that the presence of the phosphate causes a new reduction reaction to occur during the deposition process, and a new elemental metal is generated. The new elemental metal and zinc ions have different adsorption capacities, so that zinc has new nucleation sites during the deposition process, which can reduce the migration energy barrier by relying on the adsorption energy of the newly generated elemental metal, and can also reduce the nucleation energy barrier by using the newly generated metal sites.

[0037] Secondly, according to the XPS, it can be known that the presence of the phosphate solid electrolyte interface layer causes a new reduction reaction to occur during the deposition process. Through comparison of the standard reduction potentials, it can be found that Cu 2+ has the strongest reducing capacity relative to other metal ions, and will be reduced to an elemental metal before zinc ions during the deposition process, thereby inducing uniform deposition of zinc and accelerating the migration of zinc ions. This further explains that the phosphate thin film has a certain reducing property, which changes the reduction reaction during the deposition process.

[0038] Finally, the reducing copper phosphate solid electrolyte interface layer also has a certain desolvation ability. Hydrogen evolution reaction test is performed on the zinc anode protected by the reducing copper phosphate. The results show that, relative to the unprotected zinc anode, the hydrogen evolution potential changes from -121 mV to -140 mV, and the hydrogen evolution potential is effectively widened.

[0039] The zinc anode with the protective layer of the reduced phosphate solid electrolyte interface has reduced nucleation energy barrier of zinc ions, reduced migration energy barrier of zinc ions and desolvation ability. Under the three protective effects, the reduced phosphate solid electrolyte interface effectively improves the cycle life and high-efficiency charge-discharge efficiency of the battery.

[0040] The beneficial effects of the embodiment are:

[0041] The addition of the reduced phosphate solid electrolyte interface layer in the embodiment can effectively protect the direct contact of the zinc anode surface with the electrolyte. Since the solid electrolyte interface layer has reduced metal ions, the original reduction reaction is changed during the deposition process, so that a new metal element is generated. The strong adsorption between zinc metal and the newly generated metal element reduces the migration energy barrier of zinc ions; the newly generated metal element provides new sites for the nucleation of zinc metal, thereby reducing the nucleation energy barrier of zinc ions. In addition, during the entire synthesis process, the perfluorotetradecanoic acid used has hydrophobic ability, so that the reduced phosphate solid electrolyte interface layer also has a certain desolvation ability, which can inhibit the occurrence of hydrogen evolution, corrosion and passivation reaction.

[0042] The solid electrolyte interface layer prepared in the embodiment is simple, safe and environmentally friendly, easy to scale up, and can inhibit the generation of dendrites and reduce the occurrence of hydrogen evolution, corrosion and passivation, thereby promoting the development of long cycle and high-efficiency charge-discharge of aqueous zinc ion batteries.

[0043] Specific implementation method two: The difference between the embodiment and the specific implementation method one is that the concentration of the metal sulfate solution in step one is 10 mmol / L-50 mmol / L. The others are the same as the specific implementation method one.

[0044] Specific implementation method three: The difference between the embodiment and the specific implementation method one or two is that the metal sulfate solution in step one is copper sulfate solution. The others are the same as the specific implementation method one or two.

[0045] Specific implementation method four: The difference between the embodiment and the specific implementation method one to three is that the concentration of the chloroform solution of perfluorotetradecanoic acid in step one is 0.5 mmol / L-2.5 mmol / L. The others are the same as the specific implementation method one to three.

[0046] Specific implementation method five: The difference between the embodiment and the specific implementation method one to four is that the chloroform solution of perfluorotetradecanoic acid is added on the surface of the metal sulfate solution at a dropping speed of 1 μL / s-3 μL / s in step one. The others are the same as the specific implementation method one to four.

[0047] Sixth embodiment: the difference between this embodiment and the first to fifth embodiments is that: in step one, the chloroform solution of perfluorotetradecanoic acid is added dropwise on the surface of the metal sulfate solution, so that the amount of perfluorotetradecanoic acid on the air-liquid interface is 0.6 nmol / cm 2 ~1.2 nmol / cm 2 , forming a monolayer surfactant layer. The others are the same as the first to fifth embodiments.

[0048] Seventh embodiment: the difference between this embodiment and the first to sixth embodiments is that: in step two, the concentration of the sodium phosphate solution is 5 mmol / L~50 mmol / L. The others are the same as the first to sixth embodiments.

[0049] Eighth embodiment: the difference between this embodiment and the first to seventh embodiments is that: in step two, the sodium phosphate solution is injected under the surface of the surfactant layer-covered sulfate solution at an injection rate of 0.05 mL / s~0.15 mL / s. It is the same as the first to seventh embodiments.

[0050] Ninth embodiment: the difference between this embodiment and the first to eighth embodiments is that: in step two, the room temperature is kept for 7h~30h. The others are the same as the first to eighth embodiments.

[0051] Tenth embodiment: the application of the reductive phosphate solid electrolyte interface layer in the anode of the aqueous zinc ion battery, which is used as an interface protection layer for the anode in the aqueous zinc ion battery.

[0052] The following examples are used to verify the beneficial effects of the present application:

[0053] Example one:

[0054] A preparation method of a reductive phosphate solid electrolyte interface layer, which is carried out according to the following steps:

[0055] I. Preparation of surfactant layer:

[0056] Under the condition that the dropping speed is 2 μL / s, the chloroform solution of perfluorotetradecanoic acid is added dropwise on the surface of the metal sulfate solution, so that the amount of perfluorotetradecanoic acid on the air-liquid interface is 1.0 nmol / cm 2 , forming a monolayer surfactant layer, and obtaining a surfactant layer-covered sulfate solution;

[0057] II. Thin film growth:

[0058] The sodium phosphate solution is injected into the surface-surfactant layer covered sulfate solution under the surface at an injection speed of 0.1 mL / s, and then is left at room temperature for 24 hours to obtain a reduced phosphate film, i.e. a solid electrolyte interface layer, at the water-air interface;

[0059] The reduced phosphate film is a copper phosphate film; and the molar ratio of sodium phosphate in the sodium phosphate solution to sulfate radical in the surface-surfactant layer covered sulfate solution is 1:1.

[0060] The concentration of the metal sulfate solution in step one is 24 mmol / L.

[0061] The metal sulfate solution in step one is a copper sulfate solution.

[0062] The concentration of the perfluorotetradecanoic acid chloroform solution in step one is 1.8 mmol / L.

[0063] The concentration of the sodium phosphate solution in step two is 24 mmol / L.

[0064] Comparative experiment one: the difference between the comparative experiment and example one is that the metal sulfate solution in step one is a cobalt sulfate solution. The others are the same as example one.

[0065] Comparative experiment two: the difference between the comparative experiment and example one is that the metal sulfate solution in step one is a nickel sulfate solution. The others are the same as example one.

[0066] Comparative experiment three: the difference between the comparative experiment and example one is that the metal sulfate solution in step one is a chromium sulfate solution. The others are the same as example one.

[0067] Water is injected under the solid electrolyte interface layer prepared in example one and comparative experiments one to three, so that the reduced phosphate film floats in pure water, then a zinc sheet (200 μm in thickness) or a copper foil (30 μm in thickness) with a smooth surface is obliquely inserted into the film, and is gently lifted, so that the film uniformly covers the surface of the zinc sheet or the copper foil, and the zinc electrode and the copper electrode protected by the solid electrolyte interface layer are obtained by drying at room temperature, and battery assembly is carried out:

[0068] Zn / / Zn symmetric battery:

[0069] A CR2032 button cell, i.e. a Zn / / Zn symmetric battery, is prepared by taking the zinc electrode protected by the solid electrolyte interface layer as a cathode and an anode respectively, taking glass fiber as a separator, and adding 2M zinc sulfate aqueous solution as an electrolyte.

[0070] Zn||Cu half-cell:

[0071] A button cell, or Zn||Cu half cell, was prepared by using a copper electrode protected by a solid electrolyte interface layer as the cathode, a zinc electrode protected by a solid electrolyte interface layer as the anode, glass fiber as the separator, and adding 2M zinc sulfate aqueous solution as the electrolyte.

[0072] Zn||I2 full battery:

[0073] ① Mix activated carbon, Super P, and polytetrafluoroethylene in a mass ratio of 8:1:1 until homogeneous to form a putty-like consistency. Apply this mixture to one side of a titanium mesh and allow it to dry. Then, use a tablet press to press it into a disc with a diameter of 1 cm. Finally, add iodine solution to make the concentration 20 mg / cm³. 2 Finally, it is dried to obtain the cathode current collector; the iodine solution is specifically prepared by dissolving 0.5g of I2 in 500mL of ethanol;

[0074] ② A button cell was prepared by using a cathode current collector as the cathode, a zinc electrode protected by a solid electrolyte interface layer as the anode, glass fiber as the separator, and adding 2M zinc sulfate aqueous solution as the electrolyte, thus obtaining a Zn||I2 full cell.

[0075] At 10mA·cm -2 At a current density, a Zn||Zn symmetric cell assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1) was deposited, and X-ray photoelectron spectroscopy (XPS) was performed on the zinc anode surface under deposition times of 0 min, 3 min, and 10 min. Figure 1 XPS analysis of the anode interface layer in a Zn||Zn symmetric cell assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1). a represents Cu 2p orbitals, and b represents P 2p orbitals. Compared with the control group at 0 min, a new peak position of elemental copper appears. Furthermore, it can be observed that the peak position of elemental copper gradually increases with increasing deposition time, while Cu... 2+ The peak position gradually decreases. This indicates that during the deposition process, Cu... 2+ Gradually transforms into Cu 0 Therefore, it can be concluded that a new reduction reaction occurred during the deposition process. (Cu) 2+ Prior to Zn 2+ It gains electrons and becomes Cu 0 Cu 0 Accelerating the migration rate of zinc ions and lowering the nucleation energy barrier of zinc ions further improves the stability and cycle life of the battery.

[0076] Figure 2 Comparative overpotential tests of Zn||Zn symmetric cells assembled with a zinc electrode protected by a solid electrolyte interface layer (Example 1, Comparative Experiments 1 to 3) and bare zinc, respectively; at 10 mA·cm -2current density of 10 mA / cm -2 The electrolyte interface layer protected by the reducing phosphate solid electrolyte interface layer showed a lower overpotential relative to bare zinc under the test of current density of 10 mA / cm

[0077] The polarization voltage of the Zn||Cu half-cell was tested under the condition of current density of 10 mA / cm -2 and capacity of 1 mAh / cm -2 Figure 3 The anode polarization voltage test diagram of the Zn||Cu half-cell assembled by the zinc electrode protected by the solid electrolyte interface layer (Example 1, Comparative Experiments 1 to 3) and bare zinc; the results show that the zinc anode protected by the copper phosphate prepared in Example 1 has the lowest polarization voltage (140 mV). This indicates that the presence of the copper phosphate solid electrolyte interface layer effectively accelerates the migration rate of zinc ions and reduces the migration energy barrier of zinc ions.

[0078] Figure 4 The zinc ion transport number test diagram of the Zn||Zn symmetric cell assembled by the zinc electrode protected by the solid electrolyte interface layer (Example 1, Comparative Experiments 1 to 3) and bare zinc; it can be found that the zinc ion transport number of the Zn||Zn symmetric cell protected by the phosphate solid electrolyte interface layer is increased. Among them, the zinc ion transport number of the symmetric cell protected by the copper phosphate prepared in Example 1 is the highest (0.77), indicating that the prepared phosphate can reduce the migration energy barrier of zinc ions, accelerate the transmission of zinc ions, and the protection effect of copper phosphate is the most advantageous.

[0079] The hydrogen evolution potential of the Zn||Cu half-cell was tested under the voltage of 0V-3V; Figure 5 The hydrogen evolution potential test diagram of the Zn||Cu half-cell assembled by the zinc electrode protected by the solid electrolyte interface layer (Example 1) and bare zinc; it is found that the hydrogen evolution potential changes from -121 mV to -140 mV relative to the unprotected zinc anode, and the hydrogen evolution potential is effectively widened.

[0080] Figure 6 The hydrogen evolution potential of the Zn||Cu half-cell was tested under the voltage of 0V-3V; 2 and surface capacity of 1 mAh / cm 2 ​Figure 6 is a graph showing the long cycle performance of Zn||Cu half-cells assembled with zinc electrodes protected by the solid electrolyte interphase layer (Example 1) and bare zinc, respectively, under the condition that the current density is 1 mA / cm2~ 50 mA / cm2and the surface capacity is 1 mAh / cm2; as can be seen from the figure, the Zn||Cu half-cell with the solid electrolyte interphase layer can be cycled for more than 10,000 cycles, and the average coulombic efficiency is 99.98%. In the control group, the Zn||Cu cell shows unstable cycling, and the fluctuation of coulombic efficiency is mainly due to the formation of zinc dendrites and the generation of H2.

[0081] Figure 7 Figure 7 is a graph showing the cycle of Zn||Zn symmetric cells assembled with zinc electrodes protected by the solid electrolyte interphase layer (Example 1) and bare zinc, respectively, under the condition that the current density is 1 mA / cm2~ 50 mA / cm2and the surface capacity is 1 mAh / cm2; as can be seen from the figure, under the current density of 1 mA / cm2~ 50 mA / cm2, the overpotential of the symmetric cell with the reduced phosphate solid electrolyte interphase layer of Example 1 is less than that of bare zinc, indicating that the addition of the reduced phosphate solid electrolyte interphase layer effectively reduces the migration energy barrier and the nucleation energy barrier on the surface of the zinc anode. 2 2 2 2 2

[0082] Figure 8 Figure 8 is an optical photograph showing the morphology of the anode surface after cycling of Zn||Cu half-cells assembled with zinc electrodes protected by the solid electrolyte interphase layer (Example 1) and bare zinc, respectively; a1 to a3 are the deposition process of zinc, and a3 to a5 are the stripping of zinc; as can be seen from the figure, during the deposition and stripping processes, the zinc deposition or stripping on the zinc anode surface with the reduced phosphate solid electrolyte interphase layer of Example 1 is smooth and uniform, and no obvious dendrites are generated.

[0083] Figure 9 Figure 9 is a cycle schematic diagram of Zn||I2 full cells assembled with zinc electrodes protected by the solid electrolyte interphase layer (Example 1) and bare zinc, respectively, under the condition that the current density is 5 A / g; as can be seen from the figure, the addition of the reduced phosphate solid electrolyte interphase layer of Example 1 enables the Zn||I2 full cell to be cycled for more than 12,000 cycles, while the bare zinc fails after 375 cycles.

[0084] Figure 10 ​​​​​CV comparison chart of Zn||I2 full cell assembled by zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc under 0.3V-1.8V; as can be seen from the chart, the addition of the reducing phosphate solid electrolyte interface layer of Example 1 makes the polarization voltage of the Zn||I2 full cell 0.15V, compared with 0.21V of bare zinc, which may be due to the addition of the reducing phosphate solid electrolyte interface layer which enhances the anode electrochemical kinetics.

[0085] Figure 11 reduction ability comparison chart of Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ and Cd 2+ ; as can be seen from the chart, Cu 2+ has strong reduction ability, 0.336V, which can be converted into Cu 2+ prior to Zn 0 , thereby inducing uniform deposition of zinc and accelerating migration of zinc ions.

[0086] Figure 12 is the cycle test chart of Zn||Zn symmetric cell assembled by zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc under the condition of current density of 5mA·cm -2 and capacity of 1mAh·cm -2 . The Zn||Zn symmetric cell can be stably cycled for 2700h under the protection of the copper phosphate solid electrolyte interface layer, and the overpotential is stable. In contrast, under the same current density, the unprotected zinc electrode can only be cycled for 200h, a short circuit occurs, and the overpotential gradually increases with time. It is shown that the addition of the copper phosphate solid electrolyte interface layer inhibits the generation of dendrites, so that the cycle life of the battery can be effectively increased.

[0087] The corrosion test was carried out under three electrodes with Ag / AgCl as the reference electrode and the zinc electrode protected by the solid electrolyte interface layer (Example 1) (or bare zinc) as the counter electrode and working electrode. Figure 13 is the corrosion test chart of zinc electrode protected by solid electrolyte interface layer (Example 1) and bare zinc; the Tafel chart further reveals the optimization effect of the solid electrolyte interface layer on the corrosion reaction, and the zinc electrode protected by the solid electrolyte interface layer has a smaller corrosion current density (4.62×10 - 6 mA / cm 2 ) and a higher corrosion potential (-993.03mV) than bare zinc, indicating that it has better corrosion resistance in aqueous electrolyte.

[0088] Figure 14at a current density of 10 mA / cm 2 and a capacity of 1 mAh / cm 2 The XRD characterization results of the anode of the Zn||Zn symmetric cell assembled with the zinc electrode protected by the solid electrolyte interphase layer (Example 1) and the bare zinc electrode respectively after 600 cycles under the conditions of a current density of 10 mA / cm 2+ and a capacity of 1 mAh / cm 2- showed that the strong diffraction peaks of Zn4SO4(OH)6·5H2O corrosion, passivation and by-products appeared on the surface of the bare zinc electrode after the cycle, which was derived from the irreversible reaction of Zn - with SO4 -2 and OH -2 in the electrolyte; while the formation of these by-products was significantly inhibited in the zinc electrode protected by the solid electrolyte interphase layer (Example 1).

[0089] From the above test results, it can be seen that the addition of the copper phosphate solid electrolyte interphase layer prepared in Example 1 has the lowest overpotential on the surface of the zinc anode in the battery cycle, and the zinc deposition has better zinc plating and stripping performance. Under the conditions of a current density of 5 mA·cm -2 and a capacity of 1 mAh·cm -2 , the cycle length of the Zn||Zn symmetric cell exceeds 2700 hours. Under the conditions of a current density of 10 mA / cm 2 and a capacity of 1 mAh / cm 2 , the Zn||Cu half-cell cycle exceeds 10,000 cycles, and the coulombic efficiency can still be maintained at 99.9%. In the Zn||I2 full cell, it can be cycled more than 12,000 cycles at a current density of 5 A / g. This all shows that the addition of the copper phosphate solid electrolyte interphase layer can maintain the stability of the zinc anode surface, reduce the migration energy barrier and nucleation energy barrier of zinc ions, and also has a certain desolvation ability, which can avoid the direct contact of the zinc anode with water and inhibit the hydrogen evolution.

Claims

1. A method for producing a reduced phosphoric acid salt solid electrolyte interface layer, characterized by It is carried out according to the following steps: I. Preparation of the surfactant layer: A chloroform solution of perfluorotetradecanoic acid is added dropwise on the surface of the metal sulfate solution to form a monolayer surfactant layer, and a sulfate solution covered with a surfactant layer is obtained; II. Thin film growth: A sodium phosphate solution is injected below the surface of the sulfate solution covered with a surfactant layer, and then the solution is left to stand at room temperature, so that a reducing phosphate thin film is obtained at the water-air interface, i.e. the preparation method of the reducing phosphate solid electrolyte interface layer is completed; The reducing phosphate thin film is a copper phosphate thin film; the molar ratio of sodium phosphate in the sodium phosphate solution to sulfate in the sulfate solution covered with a surfactant layer is 1:(1-2).

2. The method of producing a reducing phosphate solid electrolyte interface layer according to claim 1, characterized by The concentration of the metal sulfate solution in step I is 10-50 mmol / L.

3. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by The metal sulfate solution in step I is a copper sulfate solution.

4. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by The concentration of the chloroform solution of perfluorotetradecanoic acid in step I is 0.5-2.5 mmol / L.

5. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by In step I, the chloroform solution of perfluorotetradecanoic acid is added dropwise on the surface of the metal sulfate solution at a speed of 1-3 μL / s.

6. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by In step one the chloroform solution of perfluorotetradecanoic acid is added dropwise to the surface of the metal sulphate solution such that the amount of perfluorotetradecanoic acid at the air and liquid interface is 0.6 nmol / cm 2 ~ 1.2 nmol / cm 2 forming a monolayer surfactant layer.

7. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by The concentration of the sodium phosphate solution in step II is 5-50 mmol / L.

8. The method of producing a reduced-phosphate solid-electrolyte interphase layer according to claim 1, characterized by In step II, the sodium phosphate solution is injected below the surface of the sulfate solution covered with a surfactant layer at a speed of 0.05-0.15 mL / s.

9. The method of claim 1, wherein the method is characterized by In step II, the solution is left to stand at room temperature for 7-30 h.

10. The use of a reduced phosphate solid electrolyte interphase layer prepared according to claim 1 at the anode of an aqueous zinc-ion battery, characterized in that It is used as an interface protection layer for the anode in a water-based zinc ion battery.

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