Aqueous zinc ion battery electrolyte, preparation method and application thereof

Abstract

The application discloses a water-based zinc ion battery electrolyte, a preparation method and application thereof. The water-based zinc ion battery electrolyte contains a zinc salt, ethylene glycol ether and water. The zinc salt is selected from at least one of ZnSO4, ZnCl2 and Zn(OTf)2. In the water-based zinc ion battery electrolyte, the mass content of the ethylene glycol ether is 1-20 wt%. The concentration of the zinc salt is 3M.

Description

Technical Field

[0001] This application relates to an aqueous zinc-ion battery electrolyte, its preparation method, and its application, belonging to the field of zinc-ion waste batteries. Background Technology

[0002] For decades, fossil fuels have been the primary source of energy production. Overconsumption to meet high energy demands has brought them to the brink of depletion, resulting in insufficient battery life. Adopting cleaner energy production methods is essential. In recent decades, advancements in mobile devices and electric vehicles have driven the widespread adoption of lithium-ion batteries. Electrochemical energy storage devices, particularly lithium batteries, have revolutionized the electronics industry. However, safety concerns have arisen due to the potential for explosions caused by the flammable and toxic electrolytes used in lithium-ion batteries. To address these safety issues, rechargeable aqueous batteries using non-flammable aqueous electrolytes have emerged as potential candidates and better alternatives to lithium-ion batteries. Among these aqueous batteries, zinc-ion batteries stand out due to their environmental friendliness, low cost, high safety, high zinc content, and impressive 820mAh capacity. -1 The zinc anode has attracted widespread attention due to its theoretical gravimetric capacity and low electrochemical potential of 0.762 V compared to SHE (using a zinc metal anode). However, its practical implementation remains challenging due to limited cycle durability caused by corrosion and uneven dendrite growth on the zinc metal anode, as well as hydrogen evolution reactions caused by side reactions. Significant efforts have been made to address this challenge, including electrolyte modification, electrode structure design, and surface coating. Among these, electrolyte modification is one of the most effective methods for suppressing zinc dendrite growth and side reactions on the zinc metal anode. Summary of the Invention

[0003] The purpose of this invention is to provide an application of an electrolyte ether cosolvent in zinc-ion batteries. The ether oxygen group of the cosolvent can regulate the solvation structure of the electrolyte, and the terminal hydroxyl oxygen can effectively induce the growth of the (002) crystal plane, so that the (101) crystal plane is preferentially adsorbed, effectively inhibiting zinc foil corrosion and zinc dendrite growth, so that the aqueous zinc-ion battery has excellent electrochemical performance and long cycle stability.

[0004] According to one aspect of this application, an aqueous zinc-ion battery electrolyte is provided, the aqueous zinc-ion battery electrolyte containing zinc salt, ethylene glycol ethyl ether and water;

[0005] The zinc salt is selected from at least one of ZnSO4, ZnCl2, and Zn(OTf)2;

[0006] The aqueous zinc-ion battery electrolyte contains 1-20 wt% ethylene glycol ethyl ether.

[0007] The concentration of the zinc salt is 3M.

[0008] According to another invention of this application, a method for preparing the above-mentioned aqueous zinc-ion battery electrolyte is provided, comprising the following steps:

[0009] Zinc salt, water, and ethylene glycol ethyl ether are mixed and sonicated to obtain the aqueous zinc-ion battery electrolyte.

[0010] The temperature of the ultrasound is 20–25°C;

[0011] Optionally, the temperature of the ultrasound is independently selected from any value of 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, or a range between any two of the above.

[0012] The ultrasound session lasted 5 to 10 minutes.

[0013] Optionally, the ultrasound duration is independently selected from any value of 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or a range between any two of the above.

[0014] According to another invention of this application, an aqueous zinc-ion battery is provided, comprising a positive electrode, a negative electrode and the above-described aqueous zinc-ion battery electrolyte.

[0015] This application provides an organic additive for solving corrosion and uneven dendrite growth on zinc metal anodes. Specifically, by adding an ether co-solvent to the electrolyte of a zinc-ion battery, the ether oxygen group of the co-solvent can regulate the solvation structure of the electrolyte, and the terminal hydroxyl oxygen can effectively induce the growth of (002) crystal planes, so that (101) crystal planes are preferentially adsorbed, effectively inhibiting zinc foil corrosion and zinc dendrite growth, so that the aqueous zinc-ion battery has excellent electrochemical performance and long cycle stability.

[0016] The beneficial effects that this application can produce include:

[0017] 1) The cosolvent provided in this application can be used as a medium to regulate the solvation structure of the electrolyte and reduce dendrite growth on the surface of the zinc metal anode.

[0018] 2) The terminal hydroxyl oxygen provided in this application can effectively induce the growth of the (002) crystal plane, so that the (101) crystal plane is preferentially adsorbed, thereby inhibiting the corrosion of zinc foil.

[0019] 3) The aqueous zinc-ion battery provided in this application has excellent electrochemical performance and long cycle stability. Attached Figure Description

[0020] Figure 1 For the comparison of long-cycle curves of Example 1 and Comparative Example 1 of this application, the current density is 1 mA cm⁻¹. -2 The capacity is limited to 1mAh cm -2 .

[0021] Figure 2 For the comparison of long-cycle curves of Example 1 and Comparative Example 1 of this application, the current density is 7 mA / cm². -2 The capacity is limited to 7mAh cm -2 .

[0022] Figure 3 This is a comparison of the rate electrochemical performance of Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0023] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0024] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0025] The chemical reagents used in the examples, such as zinc sulfate (ZnSO4) and ethylene glycol ethyl ether (2-ethoxyethanol), were all purchased from CASMA Mall, and the manufacturers were Shanghai Test and Aladdin.

[0026] Constant current charge / discharge test was conducted using the LAND CT3001A battery system (Wuhan Landian Electronics Co., Ltd.) (current density 1 mA cm⁻¹). -2 The capacity is limited to 1mAh cm -2 ).

[0027] Comparative Example 1

[0028] 1) Take 8.6268g of ZnSO4·7H2O into a sample vial, add 10ml of deionized water to the vial using a pipette, and sonicate in an ultrasonic cleaner for 5 minutes. Prepare a 3M ZnSO4 electrolyte and let it stand for later use.

[0029] 2) Assemble the battery using the prepared electrolyte, zinc sheets, positive and negative electrodes, and compact them.

[0030] 3) The installed batteries are subjected to electrochemical performance testing in a constant temperature chamber.

[0031] Example 1

[0032] 1) Take 8.6268g of ZnSO4·7H2O into a sample vial, add 0.1ml of ethoxyethanol and 9.9ml of deionized water into the sample vial using a pipette, and sonicate in an ultrasonic cleaner for 5min. Prepare a 1% 2-ethoxyethanol-3MZnSO4 electrolyte solution and let it stand for later use.

[0033] 3) Assemble the battery using the prepared electrolyte, zinc sheets, positive and negative electrodes, and compact them.

[0034] The installed batteries were subjected to electrochemical performance testing in a constant temperature chamber.

[0035] Example 1 Performance Test

[0036] The electrolytes prepared in Comparative Example 1 and Example 1 were assembled into batteries, and their electrical performance was tested. Battery assembly: Then, the negative electrode zinc sheet was combined with the positive electrode to obtain the test battery.

[0037] Charge and discharge performance test

[0038] The test parameters are: 1 mAcm -2 Constant current charge / discharge, limited capacity 1mAh cm -2 7mAcm -2 Constant current charge and discharge, limited capacity 7mAh cm -2 The voltage range is -2V to 2V. Test results are as follows: Figure 1 The figure shows the 1 mA cm of Comparative Example 1 and Experimental Example 1. -2 1mAh cm -2 Comparison of charge-discharge electrochemical performance, such as Figure 2 The figure shows the 7mA cm of Comparative Example 1 and Experimental Example 1. -2 7mAh cm -2 The comparison of charge-discharge electrochemical performance shows that Experiment 1 significantly reduced the charge-discharge overpotential and the system exhibited high cycle stability. Figure 3 The above are the charge-discharge curves for Comparative Example 1 and Experimental Example 1 of this invention. Experimental Example 1 can reach a rate of 12 mA cm⁻¹. -2 It has excellent rate performance.

[0039] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An aqueous zinc-ion battery electrolyte, characterized in that, The aqueous zinc-ion battery electrolyte contains zinc salt, ethylene glycol ethyl ether, and water. The zinc salt is selected from at least one of ZnSO4, ZnCl2, and Zn(OTf)2; The aqueous zinc-ion battery electrolyte contains 1-20 wt% ethylene glycol ethyl ether. The concentration of the zinc salt is 3M.

2. A method for preparing the aqueous zinc-ion battery electrolyte according to claim 1, characterized in that, Includes the following steps: Zinc salt, water, and ethylene glycol ethyl ether are mixed and sonicated to obtain the aqueous zinc-ion battery electrolyte.

3. The preparation method according to claim 2, characterized in that, The temperature of the ultrasound is 20–25°C; The ultrasound session lasted 5 to 10 minutes.

4. An aqueous zinc-ion battery, characterized in that, Includes the aqueous zinc-ion battery electrolyte as described in claim 1.

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