High-entropy electrolyte of aqueous zinc ion battery capable of being used in high-temperature environment

Abstract

The invention belongs to the technical field of water-based rechargeable batteries, and particularly relates to a high-entropy electrolyte of a water-based zinc ion battery capable of being used in a high-temperature environment. Any one or a combination of two of phenanthroline and hydroxylamine hydrochloride is added into the high-entropy electrolyte, and the concentration of the phenanthroline and the hydroxylamine hydrochloride is 0.01-3 g / L. The phenanthroline in the high-entropy electrolyte can strongly interact with the zinc ions, so that the solvation structure of the hydrated zinc ions is changed, the problems of hydrogen evolution and corrosion caused by high-temperature desolvation of the hydrated zinc ions are relieved, and the deposition / stripping kinetics of the zinc ions is enhanced, so that the generation of dendritic crystals is inhibited. The hydroxylamine hydrochloride has a hydroxyl functional group and can interact with the solvent water, so that the hydrogen bond strength of the water is changed. The aqueous zinc ion battery assembled by using the high-entropy electrolyte can be used in a severe high-temperature environment, the safety problems of liquid leakage, gas expansion, explosion and the like of the battery at an extremely high temperature can be effectively relieved, the cycling stability of the battery is improved, and the service life of the battery is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aqueous rechargeable batteries, and particularly relates to a high-entropy electrolyte for an aqueous zinc ion battery applicable to a high-temperature environment. BACKGROUND

[0002] Developing sustainable energy has become the core direction of energy transformation. However, renewable energy such as solar energy and wind energy has inherent volatility, and its large-scale application highly depends on reliable and efficient energy storage technology. As one of the mainstream energy storage solutions, batteries have achieved remarkable commercialization in the field of energy storage, among which lithium ion batteries have been widely used in smart phones, wearable devices, electric vehicles and other fields due to their high energy density and good stability, and have become the core choice of current energy storage devices. However, the further development of lithium ion batteries is limited by their inherent defects: on the one hand, the scarcity of lithium resources exacerbates the supply pressure of raw materials, pushing up the long-term application cost; on the other hand, the organic electrolyte used by lithium ion batteries is volatile, toxic and flammable, which not only requires strict production environment, but also limits its application in scenarios with high safety requirements.

[0003] Under this background, aqueous zinc ion batteries (AZIBs) have become a promising alternative solution due to their significant advantages: zinc is abundant in the earth's crust, and the cost of raw materials is low; the use of aqueous electrolyte has the characteristics of non-toxicity and non-flammability, and the safety is greatly improved, and the production process does not require strict water and oxygen-free environment, which meets the demand of large-scale preparation, and is expected to be widely used in future energy storage scenarios. However, the industrialization process of aqueous zinc ion batteries still faces key technical bottlenecks, especially as human activities expand, the global climate warms up, and the demand for batteries in high-temperature conditions gradually increases. However, under high-temperature conditions, the interface problem between zinc anode and electrolyte is significantly worsened, and the inhomogeneous deposition of ions leads to the growth of zinc dendrites, which pierces the separator and causes short circuit of the battery; at the same time, high temperature accelerates the water decomposition reaction and induces the hydrogen evolution side reaction, which greatly reduces the zinc ion deposition / exfoliation efficiency, and seriously weakens the cycle stability and service life of the battery system. Existing solutions such as constructing surface coating and using high-concentration electrolyte have problems such as short cycle life, limited modification effect, complex operation process and high cost, which are difficult to meet the actual application requirements. Therefore, developing a simple and efficient interface optimization strategy to solve the stability problem of zinc anode in high-temperature environment has become the key to promoting the industrialization of aqueous zinc ion batteries. Relatively, the present application proposes a high-entropy electrolyte strategy, which studies the mechanism of stabilizing zinc anode under high temperature, effectively alleviates the problems of zinc dendrite growth and hydrogen evolution of zinc anode in high-temperature environment, and provides technical support for the stable application of aqueous zinc ion batteries in high-temperature environment. SUMMARY

[0004] The application aims to provide a high-entropy electrolyte applicable to a high-temperature environment and an application thereof in a water-based zinc ion battery, aiming to solve the problem of significant deterioration between a zinc anode and an electrolyte interface of the water-based zinc ion battery under high-temperature conditions.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the application is:

[0006] The high-entropy electrolyte of the water-based zinc ion battery applicable to the high-temperature environment is composed of a solvent, an electrolyte and an additive; the additive is any one or a combination of the other two of o-dinitrogen phenyl and hydroxylamine hydrochloride.

[0007] Further, the concentration of the additive in the high-entropy electrolyte is 0.01-3 g / L.

[0008] Further, the solvent is deionized water.

[0009] Further, the deionized water is ultrapure water with a resistance of 18-25 MΩ.

[0010] Further, the electrolyte is any one or a combination of two or more of zinc sulfate, zinc trifluoromethane sulfonate and zinc chloride.

[0011] Further, the concentration of the electrolyte in the high-entropy electrolyte is 1-3 mol / L.

[0012] The application of the high-entropy electrolyte in any one of the above-mentioned to a zinc ion electrochemical energy storage device.

[0013] Further, the application of the high-entropy electrolyte in the water-based zinc ion battery.

[0014] The application has the following beneficial effects:

[0015] 1. The electrolyte additive in the high-entropy electrolyte contains o-dinitrogen phenyl, which can strongly interact with zinc ions, thereby changing the solvation structure of hydrated zinc ions and relieving the problems of hydrogen evolution and corrosion caused by high-temperature desolvation. In addition, o-dinitrogen phenyl molecules can be electrostatically adsorbed on the surface of the zinc anode, improve the wettability of the electrolyte on the electrode, increase the nucleation overpotential, strengthen the mass transfer effect of zinc ions, and enhance the deposition / detachment kinetics of zinc ions, thereby inhibiting the generation of dendrites.

[0016] 2. The high-entropy electrolyte provided by the application contains hydroxylamine hydrochloride, which has a hydroxyl functional group and can interact with solvent water, thereby changing the hydrogen bond strength of water and avoiding the decomposition of water at high temperatures, so as to effectively inhibit the problems such as swelling, leakage and explosion of the battery during use in a high-temperature environment, improve the safety, cycle stability and service life of the battery.

[0017] 3. The high-entropy electrolyte provided by the application has the characteristics of low cost, safety, environmental protection and simple operation, has an effective inhibitory effect on the corrosion reaction and hydrogen evolution reaction of a zinc anode, makes the electrolyte have good reversibility during deposition / peeling at high temperatures, and significantly improves the electrochemical performance of the aqueous zinc ion battery in an extremely high-temperature environment. Therefore, the aqueous zinc ion battery and other potential new energy batteries have great prospects and research value in the high-temperature field. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The high-entropy electrolyte provided by the application for Example 1 is used in a zinc ion symmetrical button cell, and a constant potential of-150 mV is applied to both ends of the Zn||Zn symmetrical cell, and the maintenance time is 1000 s.

[0019] Figure 2 The high-entropy electrolyte provided by the application for Example 1 is used in an asymmetric button cell with a current density of 2 mA cm -2 and an area capacity of 0.5 mAh cm -2 .

[0020] Figure 3 The in-situ optical microscopic imaging diagram of the zinc negative electrode surface of the zinc ion symmetrical button cell (marked as ZSO) provided by the 2 mol / L zinc sulfate aqueous solution electrolyte of Comparative Example 1 after cycling.

[0021] Figure 4 The in-situ optical microscopic imaging diagram of the zinc negative electrode surface of the zinc ion symmetrical button cell (marked as 1P1H) provided by the zinc sulfate mixed solution electrolyte containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride of Example 1 of the application after cycling. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the application more clear and explicit, the application will be further described in detail through specific examples. The specific examples described herein are only used to explain the application and do not limit the application.

[0023] Example 1: A high-entropy electrolyte for an aqueous zinc ion battery that can be used in a high-temperature environment

[0024] (I) High-entropy electrolyte for aqueous zinc ion battery in high-temperature environment, the preparation method comprising the following steps:

[0025] 1. Prepare a 2 mol / L zinc sulfate solution.

[0026] Take a certain amount of ultrapure water with a resistance of 18 MΩ as a solvent, add the weighed zinc sulfate heptahydrate particles into the ultrapure water and stir to dissolve, and finally prepare a 2 mol / L zinc sulfate aqueous solution.

[0027] 2. Prepare a zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as a high-entropy electrolyte.

[0028] Take 2 mol / L zinc sulfate aqueous solution, add phenanthroline and hydroxylamine hydrochloride into it and stir to dissolve, to obtain a zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as a high-entropy electrolyte.

[0029] (II) Application of zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as a high-entropy electrolyte in aqueous zinc ion battery

[0030] Cut the high-purity zinc foil (99.99%) with a thickness of 0.01 mm into a circular sheet with a diameter of 12 mm, and store it for later use; cut the glass fiber separator into a circular sheet with a diameter of 16 mm, and store it for later use; cut the copper foil with a thickness of 0.002 mm into a circular sheet with a diameter of 12 mm, and store it for later use.

[0031] The button cell used in this example is CR2032.

[0032] 1. Assemble a symmetric button cell

[0033] The high-purity zinc foil with a thickness of 0.01 mm is used as the positive and negative electrode sheets of the button cell. First, the negative electrode sheet is placed in the negative electrode shell, then the glass fiber separator is added, 120 μL of the prepared zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride is taken as the electrolyte using a pipette, then the positive electrode sheet is placed, followed by the gasket and the spring, and finally the positive electrode shell is closed. The battery is assembled using a battery packaging machine, and the zinc sulfate mixed solution containing phenanthroline and hydroxylamine hydrochloride is used as the electrolyte of the aqueous zinc ion symmetric button cell, which is marked as 1P1H symmetric cell.

[0034] Comparative Example 1 - Take 2 mol / L zinc sulfate solution as electrolyte to obtain aqueous zinc ion symmetric cell. The assembly method of the battery is the same as above, except that the electrolyte is 2 mol / L zinc sulfate solution, which is marked as ZSO symmetric cell.

[0035] 2. Assembling asymmetric button cell

[0036] The cut copper foil disc was used as the positive electrode sheet of the button cell, and the high-purity zinc foil was used as the negative electrode sheet of the button cell. First, the negative electrode sheet was placed in the negative electrode shell of the battery, then the glass fiber diaphragm was placed, and then 120 μL of the prepared zinc sulfate solution containing 1 g / L of phenanthroline and 1 g / L of hydroxylamine hydrochloride was taken by a pipette gun, and then the positive electrode sheet was placed above the diaphragm, followed by the gasket and the spring, and finally the positive shell was closed, the battery was sealed by using a battery packaging machine, and finally a water-based zinc ion asymmetric button cell with a zinc sulfate solution containing phenanthroline and hydroxylamine hydrochloride as the electrolyte was obtained, which was marked as 1P1H asymmetric battery.

[0037] Comparative Example 2 - A water-based zinc ion asymmetric battery was obtained using a 2 mol / L zinc sulfate solution as the electrolyte. The assembly method was the same as above, except that the electrolyte was a 2 mol / L zinc sulfate solution, which was marked as ZSO asymmetric battery.

[0038] 3. Performance test of the battery

[0039] The water-based zinc ion symmetric battery and the water-based zinc ion asymmetric battery were tested by chronopotentiometry, cyclic voltammetry, and constant current charge and discharge test under controlled high temperature conditions (60°C).

[0040] 3.1 The symmetric button cell was tested by chronopotentiometry, and a single potential step was used, a constant potential of -150 mV was applied to the Zn||Zn symmetric battery, the maintenance time was 1000 s, and the current-time curve was recorded. The results are shown in Figure 1 As shown in the figure, when a overpotential of -150 mV is applied, the response current in the ZSO electrolyte continues to increase for about 200 s, indicating that the nucleation sites of zinc ions continue to increase, which will induce the selective lateral migration process of zinc ions, corresponding to the 2D diffusion process of zinc ions. This disordered two-dimensional diffusion process leads to a porous structure of the deposited layer, providing topological induction sites for the nucleation of dendrites. In the 1P1H electrolyte, the response current rapidly increases in the early stage (<10 s) and remains stable, which indicates the rapid nucleation and uniform growth of zinc ions, corresponding to the transient nucleation stage of zinc ions, and then the stable current indicates the uniform diffusion process of zinc ions along the electrode surface, that is, the 3D diffusion process. The above indicates that the 1P1H electrolyte has good regulation effect on the diffusion and deposition process of zinc ions at high temperature.

[0041] 3.2 The water-based zinc ion asymmetric button cell was tested by constant current charge and discharge at a current density of 2 mA cm -2 and an area capacity of 0.5 mAh cm -2 Figure 2 ​As shown. We further evaluated the reversibility of the zinc anode plating / stripping at high temperatures by testing the cycle life and coulombic efficiency (CE) of the Zn||Cu asymmetric cell. From Figure 2 As can be seen from this, at 2 mA cm -2 / 0.5 mAh cm -2 Furthermore, under high-temperature conditions of 60 °C, the 1P1H electrolyte can stably cycle for 150 cycles with an average coulombic efficiency of 97.95%, while the ZSO electrolyte exhibits a short circuit after only 45 cycles. This indicates that the high-entropy electrolyte of this invention is beneficial for regulating the deposition behavior of zinc ions at the zinc anode / electrolyte interface, inducing uniform deposition of zinc ions, thereby enhancing the reversibility of the zinc anode cycle and ultimately achieving excellent cycle performance of the aqueous zinc-ion asymmetric battery under high-temperature conditions.

[0042] 4. Characterization

[0043] Figure 3 In-situ optical microscopic image of the zinc anode surface after cycling of a zinc-ion symmetric button cell (labeled ZSO) with a 2 mol / L zinc sulfate aqueous electrolyte provided in Comparative Example 1. Figure 4 This is an in-situ optical microscopic image of the zinc anode surface after cycling of a zinc-ion symmetric button cell (labeled 1P1H) containing a zinc sulfate mixed solution electrolyte of 1 g / L o-phenanthroline and 1 g / L hydroxylamine hydrochloride, as provided in Example 1 of this invention. To accurately capture the interfacial behavior of zinc ions, this experiment used an in-situ optical microscopic imaging system to monitor the evolution of zinc deposition morphology under different electrolytes in real time. Figure 3 As shown, at 5 mAcm -2 Under constant current deposition conditions, after 20 minutes of deposition in ZSO electrolyte, micron-sized protrusions appeared on the zinc substrate surface. The subsequent deposition morphology exhibited an uneven, moss-like appearance with noticeable protrusions at the edges. These sharp protrusions subsequently formed dendrites, which easily penetrated the separator, causing battery short circuits and performance failure. Figure 4 As shown, the 1P1H electrolyte system exhibited a significant improvement effect. No obvious zinc deposit protrusions were detected during the 20-minute deposition process, and the deposition interface remained smooth, indicating that the 1P1H electrolyte modulated the zinc ion deposition behavior at the electrode / electrolyte interface. This demonstrates that the high-entropy electrolyte of this invention can effectively improve the zinc anode surface of zinc-ion batteries, thereby enhancing electrochemical performance.

[0044] Example 2: Effect of different electrolyte additive concentrations on the electrical performance of aqueous zinc-ion batteries

[0045] 1. Prepare a mixed solution of zinc sulfate containing different concentrations of o-phenanthroline and hydroxylamine hydrochloride as the electrolyte.

[0046] Take 2 mol / L zinc sulfate aqueous solution, add phenanthroline and hydroxylamine hydrochloride into it and stir to dissolve, respectively obtain 0.3 g / L phenanthroline and 0.3 g / L hydroxylamine hydrochloride zinc sulfate mixed solution, 0.5 g / L phenanthroline and 0.5 g / L hydroxylamine hydrochloride zinc sulfate mixed solution and 0.7 g / L phenanthroline and 0.7 g / L hydroxylamine hydrochloride zinc sulfate mixed solution as electrolyte.

[0047] 2、Symmetric battery assembly

[0048] The experimental method is the same as the assembly method of 1P1H symmetric battery in Example 1, the electrolyte of the electrolyte remains unchanged, only 120 μL of 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride zinc sulfate mixed solution is replaced by 0.3 g / L phenanthroline and 0.3 g / L hydroxylamine hydrochloride zinc sulfate mixed solution, 0.5 g / L phenanthroline and 0.5 g / L hydroxylamine hydrochloride zinc sulfate mixed solution and 0.7 g / L phenanthroline and 0.7 g / L hydroxylamine hydrochloride zinc sulfate mixed solution, respectively.

[0049] 3、Asymmetric battery assembly

[0050] The experimental method is the same as the assembly method of 1P1H full battery in Example 1, the electrolyte of the electrolyte remains unchanged, only 120 μL of 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride zinc sulfate mixed solution is replaced by 0.3 g / L phenanthroline and 0.3 g / L hydroxylamine hydrochloride zinc sulfate mixed solution, 0.5 g / L phenanthroline and 0.5 g / L hydroxylamine hydrochloride zinc sulfate mixed solution and 0.7 g / L phenanthroline and 0.7 g / L hydroxylamine hydrochloride zinc sulfate mixed solution, respectively.

[0051] 4、Battery performance test

[0052] The experimental method is the same as the test method of aqueous zinc ion symmetric battery and aqueous zinc ion asymmetric battery in Example 1.

[0053] Example 3 Influence of different electrolytes on the performance of aqueous zinc ion battery

[0054] 1、Preparation of 2 mol / L zinc trifluoromethanesulfonate solution.

[0055] The experimental method is the same as the preparation method of 2 mol / L zinc sulfate solution in Example 1, only the electrolyte is replaced from zinc sulfate to zinc trifluoromethanesulfonate.

[0056] 2、Preparation of 2 mol / L zinc chloride solution.

[0057] The experimental method is the same as the preparation method of 2 mol / L zinc sulfate solution in Example 1, except that the electrolyte is replaced from zinc sulfate to zinc chloride.

[0058] 3. Prepare a zinc trifluoromethanesulfonate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as an electrolyte.

[0059] Take 2 mol / L zinc trifluoromethanesulfonate solution, add phenanthroline and hydroxylamine hydrochloride to it and stir to dissolve, to obtain a zinc trifluoromethanesulfonate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as an electrolyte.

[0060] 4. Prepare a zinc chloride mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as an electrolyte.

[0061] Take 2 mol / L zinc chloride solution, add phenanthroline and hydroxylamine hydrochloride to it and stir to dissolve, to obtain a zinc chloride mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride as an electrolyte.

[0062] 5. Symmetric battery assembly

[0063] The experimental method is the same as the assembly method of 1P1H symmetric battery in Example 1, and the electrolyte additive remains unchanged, except that 120 μL of zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride is respectively replaced by zinc trifluoromethanesulfonate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride and zinc chloride mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride.

[0064] 6. Asymmetric battery assembly

[0065] The experimental method is the same as the assembly method of 1P1H full battery in Example 1, and the electrolyte additive remains unchanged, except that 120 μL of zinc sulfate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride is respectively replaced by zinc trifluoromethanesulfonate mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride and zinc chloride mixed solution containing 1 g / L phenanthroline and 1 g / L hydroxylamine hydrochloride.

[0066] 7. Battery performance test

[0067] The experimental method is the same as the test method of aqueous zinc ion symmetric battery and aqueous zinc ion asymmetric battery in Example 1.

[0068] Among the three aqueous zinc ion batteries assembled according to the above Examples 1-3, we get the best electrochemical performance of Example 1, with a current density of 2 mA cm -2 , and an area capacity of 0.5 mAh cm-2 As shown below, Figure 2 As shown below, 2+ In Example 1, the high-entropy aqueous zinc-ion electrolyte system, as a typical π-π conjugated heterocyclic ligand, ortho-phenanthroline can form a stable chelate with Zn 2+ solvation sheath. And the constructed high-entropy electrolyte can significantly inhibit the spontaneous zinc corrosion reaction, increase the hydrogen evolution overpotential to inhibit the hydrogen evolution reaction, effectively regulate the deposition behavior of zinc ions at the zinc anode / electrolyte interface, induce uniform deposition of zinc ions, and thus improve the electrochemical performance.

Claims

1. A high-entropy electrolyte for aqueous zinc-ion batteries that can be used in high-temperature environments, characterized in that, The high-entropy electrolyte is composed of a solvent, an electrolyte, and an additive; the additive is any one or a combination of two of o-phenanthroline and hydroxylamine hydrochloride.

2. The high-entropy electrolyte for aqueous zinc-ion batteries suitable for high-temperature environments according to claim 1, characterized in that, The concentration of the additive in the high-entropy electrolyte is 0.01–3 g / L.

3. The high-entropy electrolyte for aqueous zinc-ion batteries suitable for high-temperature environments according to claim 1, characterized in that, The solvent is deionized water.

4. The high-entropy electrolyte for aqueous zinc-ion batteries suitable for high-temperature environments according to claim 3, characterized in that, The deionized water is ultrapure water with a resistance of 18-25 MΩ.

5. The high-entropy electrolyte for aqueous zinc-ion batteries suitable for high-temperature environments according to claim 1, characterized in that, The electrolyte is any one or a combination of two or more of zinc sulfate, zinc trifluoromethanesulfonate, and zinc chloride.

6. The high-entropy electrolyte for aqueous zinc-ion batteries suitable for high-temperature environments according to claim 5, characterized in that, The concentration of the electrolyte in the high-entropy electrolyte is 1–3 mol / L.

7. The application of the high-entropy electrolyte according to any one of claims 1-6 in a zinc ion electrochemical energy storage device.

8. The application according to claim 7, characterized in that, Application of the high-entropy electrolyte in aqueous zinc-ion batteries.

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