Aqueous electrolyte, preparation method and battery

Abstract

The water-based electrolyte provided in the application comprises an additive, and the additive comprises fluorine-containing alcohol hydroxyl-terminated organic matter. The application introduces a small amount of fluorine-containing alcohol hydroxyl-terminated organic matter into the water-based electrolyte, so that the hydroxyl in the additive and hydrogen in water form intermolecular hydrogen bonds, the original hydrogen bond network of water molecules is broken, the effect of inhibiting the occurrence of hydrogen evolution side reactions is achieved, and the existence of part of free water in the hydrogen bond network is ensured, so that the electrolyte has high ionic conductivity. The water-based electrolyte can be applied to ion batteries, realizes long cycle life under large current density and deposition capacity, and has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ion batteries, in particular to a water-based electrolyte, a preparation method and a battery. BACKGROUND

[0002] Nowadays, the commercialization of lithium ion batteries has brought great convenience to people's life, but one of its shortcomings is that lithium ion batteries usually use organic system electrolyte, which has the problem of flammability and safety, and the reserves of lithium ore resources are small, which determines that the cost of lithium ion batteries is relatively high, and it is difficult to realize the application in the field of large-scale energy storage. Therefore, it is urgent to find a battery system with low price, high safety and good cycle stability to meet the demand of large-scale energy storage. Rechargeable water-based zinc ion battery is considered as a practical remedy for lithium ion battery, which can be used for large-scale energy storage. This is because zinc metal has many advantages, such as: high theoretical capacity and volume capacity (820mAh g -1 and 5855mAh cm -3 ), low electrochemical potential (compared with standard hydrogen electrode (SHE) -0.762V), good compatibility with water-based electrolyte, rich content, low cost, safety and environmental protection, relatively easy to manufacture, etc. However, during the charging and discharging process of water-based zinc-based battery, the hydrolysis of [Zn(H2O) x ] 2+ ion and the free water molecules outside the Zn 2+ solvation shell will have serious interfacial side reactions, leading to problems such as zinc corrosion, hydrogen evolution and uneven zinc deposition.

[0003] In order to solve these problems, people have explored various strategies to modify the zinc negative electrode or design the electrolyte, such as surface coating modification, negative electrode structure optimization, and electrolyte modification. Compared with coating modification and structure optimization, the measure of introducing multifunctional additives into the electrolyte not only has simple process and low cost, but also can greatly improve the coulombic efficiency and cycle stability of water-based zinc-based battery, which is one of the key ideas to alleviate the problems of negative electrode and its interface. On the one hand, a small amount of fluorine-containing long-chain alcohol is introduced into the water-based electrolyte. Since alcohol and water can form hydrogen bonds, the addition of this additive reduces the activity of water, thereby inhibiting the occurrence of hydrogen evolution reaction. On the other hand, by changing the Zn[H2O]6 2+ solvation structure in the water-based electrolyte, the fluorine-containing alcohol solvent replaces part of the water to form Zn[[H2O] n [fluorine-containing alcohol solvent] m ] 2+ and squeeze into the solvation shell of Zn 2+ , participate in the formation of solid-state electrolyte layer on the electrode surface.

[0004] It has been reported that the electrolyte developed by introducing additives has high ionic conductivity, good compatibility with the electrolyte interface, etc. However, these electrolyte systems are generally difficult to ensure the ultra-long cycle life of the zinc negative electrode (about 800 hours at 5 mA cm -2 Large current density and 5mAh cm -2 Only about 800 hours at large deposition capacity), which seriously reduces the large rate and long life characteristics of the rechargeable aqueous zinc battery. In addition, the function of the additives introduced in the general electrolyte is relatively single, such as, while playing a role in relieving the hydrogen evolution reaction, the ionic conductivity of the electrolyte is reduced; while the 002 crystal face zinc deposition is controlled, the electrolyte causes serious hydrogen evolution side reaction; while the interface compatibility with the zinc negative electrode is good, the dissolution of the positive electrode material is caused, including the dissolution of V in vanadium-based materials and the dissolution of Mn in manganese-based materials. Therefore, it is urgent to develop a low-cost, low-concentration, high-ionic-conductivity aqueous electrolyte for zinc-based batteries. SUMMARY

[0005] Therefore, it is necessary to provide a low-concentration, high-ionic-conductivity aqueous electrolyte, a preparation method and a battery in view of the defects in the prior art.

[0006] To solve the above problems, the technical scheme adopted by the present application is as follows:

[0007] One of the purposes of the present application is to provide an aqueous electrolyte, which comprises an additive, and the additive comprises a fluorine-containing alcohol hydroxyl-terminated organic matter.

[0008] In some embodiments, the fluorine-containing alcohol hydroxyl-terminated organic matter comprises a long-chain fluorine-containing alcohol-terminated organic matter and / or a short-chain fluorine-containing alcohol-terminated organic matter.

[0009] In some embodiments, the long-chain fluorine-containing alcohol-terminated organic matter comprises at least one of perfluorooctanol, perfluorooctanediol, perfluorodecanol, perfluorodecanediol, and the short-chain fluorine-containing alcohol-terminated organic matter comprises at least one of perfluorobutanol, perfluorohexanediol, fluorine-containing pentanol, and perfluoropentanediol.

[0010] In some embodiments, the fluorine-containing alcohol hydroxyl-terminated organic matter further comprises a hydroxyl-terminated organic matter containing F, S or sulfonic acid group at the same time.

[0011] In some embodiments, the additive in the aqueous electrolyte is added in an amount of 0.001-0.01 mol / L.

[0012] The second purpose of the present application is to provide a preparation method of the aqueous electrolyte, which comprises the following steps:

[0013] The additive is mixed with deionized water, stirred at 25-50 DEG C for 1-8 hours, then a metal salt is added to the mixed solution, and stirring is continued at 25-60 DEG C to obtain the aqueous electrolyte, wherein the additive comprises fluorine-containing alcohol hydroxyl-terminated organic matter.

[0014] In some embodiments, the metal salt comprises a lithium salt or a sodium salt or a calcium salt or a potassium salt or an aluminum salt.

[0015] In some embodiments, the zinc salt comprises at least one of zinc sulfate, zinc methanesulfonate, zinc trifluoromethanesulfonate, zinc bis-trifluoromethanesulfonimide, zinc chloride, zinc hexafluorosilicate, zinc perchlorate or zinc nitrate.

[0016] In some embodiments, the concentration of the zinc salt is 0.5-3 mol / L.

[0017] In some embodiments, the additive is added in the aqueous electrolyte in an amount of 0.001-0.01 mol / L.

[0018] The third object of the present application provides a battery comprising the aqueous electrolyte.

[0019] The technical scheme of the present application has the following beneficial effects:

[0020] The aqueous electrolyte provided by the present application comprises an additive, and the additive comprises fluorine-containing alcohol hydroxyl-terminated organic matter. The introduction of a small amount of fluorine-containing alcohol hydroxyl-terminated organic matter in the aqueous electrolyte can promote the formation of intermolecular hydrogen bonds between the hydroxyl groups in the additive and hydrogen in water, break the original hydrogen bond network of water molecules, thereby achieving the effect of inhibiting the occurrence of hydrogen evolution side reactions. At the same time, the presence of part of free water in the hydrogen bond network can ensure the high ionic conductivity of the electrolyte. The aqueous electrolyte can be applied in an ionic battery to achieve long cycle life under large current density and deposition capacity, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application or the prior art description. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 Raman spectrum of the electrolyte with 2M zinc sulfate electrolyte and fluorine-containing alcohol hydroxyl-terminated organic matter as an additive provided for Example 1;

[0023] Figure 2Fourier transform infrared spectra of the electrolyte provided for Example 1 with 2M zinc sulfate electrolyte and the electrolyte with the fluorine-containing alcohol hydroxyl-terminated organic compound as an additive;

[0024] Figure 3 Voltage-time plot of a zinc-zinc symmetric cell assembled with the electrolyte provided for Example 3 with the fluorine-containing alcohol hydroxyl-terminated organic compound as an additive;

[0025] Figure 4 Cycle-capacity plot of a zinc-zinc iodide full cell assembled with the electrolyte provided for Example 3 with the fluorine-containing alcohol hydroxyl-terminated organic compound as an additive. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described below in detail with reference to the accompanying drawings, in which like or similar elements are denoted by the same or similar reference signs throughout the drawings. The embodiments described below are examples in which the present application is applied, and are intended to explain the present application, and should not be understood as limiting the present application.

[0027] In the description of the present application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application.

[0028] In addition, the terms "first", "second" are only for the purpose of description, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features referred to. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0029] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0030] The water-based electrolyte provided by the present application includes an additive, and the additive is an organic compound terminated by a fluorine-containing alcohol hydroxyl group.

[0031] In some embodiments, the organic compound terminated by a fluorine-containing alcohol hydroxyl group includes a long-chain fluorine-containing alcohol-terminated organic compound and / or a short-chain fluorine-containing alcohol-terminated organic compound.

[0032] Further, the long-chain fluorine-containing alcohol-terminated organic compound includes at least one of perfluorooctanol, perfluorooctanediol, perfluorodecanol, perfluorodecanediol, and the short-chain fluorine-containing alcohol-terminated organic compound includes at least one of perfluorobutanol, perfluorohexanbutanol, fluorine-containing pentanol, and perfluoropentanediol.

[0033] In some embodiments, the fluorine-containing alcohol-hydroxyl-terminated organic compound further includes a hydroxyl-terminated organic compound containing F, S or sulfonic acid group at the same time. The hydroxyl-terminated organic compound containing F, S or sulfonic acid group at the same time not only has more hydrogen bond acceptors, but also has a strong electron-withdrawing group, which forms intermolecular hydrogen bonds with water and reduces the activity of water.

[0034] It can be understood that the fluorine-containing alcohol-hydroxyl-terminated organic compound mentioned in the above embodiments of the present application as an additive is not limited to long-chain and short-chain fluorine-containing alcohol-terminated organic compounds and hydroxyl-terminated organic compounds containing F, S or sulfonic acid group at the same time. As long as the fluorine-containing alcohol-hydroxyl-terminated organic compound contains alcohol hydroxyl group, whether or not there are other elements in the organic compound to replace hydrogen, such as Br, I, -COOH, -SO3, etc., it all belongs to the protection scope of the present patent.

[0035] It can be understood that the types and quantities of the fluorine-containing alcohol-hydroxyl-terminated additive provided in the above embodiments of the present application can be randomly combined, such as two or more short-chain fluorine-containing alcohol-terminated organic compounds, two or more long-chain fluorine-containing alcohol-terminated organic compounds, one or more long-chain and one or more short-chain fluorine-containing alcohol-terminated organic compounds, two or more short-chain hydroxyl-terminated organic compounds containing F, S or sulfonic acid group at the same time, two or more long-chain hydroxyl-terminated organic compounds containing F, S or sulfonic acid group at the same time, one or more long-chain and one or more short-chain hydroxyl-terminated organic compounds containing F, S or sulfonic acid group at the same time, one or more long-chain or short-chain fluorine-containing alcohol-terminated organic compounds and one or more long-chain or short-chain hydroxyl-terminated organic compounds containing F, S or sulfonic acid group at the same time. The electrolyte with the fluorine-containing alcohol-hydroxyl-terminated organic compound as an additive designed in this way all belongs to the protection scope of the present patent. It should be noted that when adding different types of fluorine-containing alcohol-hydroxyl-terminated additives, the solubility in the aqueous electrolyte is different, and one, multiple or two types are preferably used in combination.

[0036] In some embodiments, the amount of the additive added in the aqueous electrolyte is 0.001-0.01 mol / L.

[0037] It can be understood that the amount of the additive added in the aqueous electrolyte is 0.001-0.01 mol / L.

[0038] The water-based electrolyte provided in the application adopts an organic matter with a fluorine-containing alcohol hydroxyl end-capped as an additive to configure the water-based electrolyte, which can better alleviate the problems of hydrogen evolution side reaction and poor stability of zinc metal anode interface caused by the water-based electrolyte in the reduction process under the premise of ensuring high ionic conductivity, low cost and environmental protection of the pure water-based electrolyte; the introduction of a small amount of the organic matter with the fluorine-containing alcohol hydroxyl end-capped into the water-based electrolyte can promote the formation of intermolecular hydrogen bonds between the hydroxyl groups in the additive and hydrogen in water, and break the original hydrogen bond network of water molecules, so as to achieve the effect of inhibiting the occurrence of the hydrogen evolution side reaction, and at the same time, can ensure the existence of part of free water in the hydrogen bond network, and ensure the high ionic conductivity of the electrolyte.

[0039] The application further provides a preparation method of the water-based electrolyte, comprising the following steps:

[0040] The additive is mixed with deionized water, and then stirred at 25-50 DEG C for 1-8 hours; then a metal salt is added into the above mixed solution, and the stirring is continued at 25-60 DEG C to obtain the water-based electrolyte; the additive comprises the organic matter with the fluorine-containing alcohol hydroxyl end-capped.

[0041] In the embodiment, the deionized water is ultrapure water with a resistance of 18-25 MΩ.

[0042] In the embodiment, the metal salt comprises lithium salt or sodium salt or calcium salt or potassium salt or aluminum salt.

[0043] Further, the zinc salt comprises at least one of zinc sulfate, zinc methanesulfonate, zinc trifluoromethanesulfonate, zinc bis-trifluoromethanesulfonimide, zinc chloride, zinc hexafluorosilicate, zinc perchlorate or zinc nitrate. It can be understood that the above-mentioned zinc salt has high solubility in the water-based electrolyte and does not react with the organic matter with the fluorine-containing alcohol hydroxyl end-capped.

[0044] It can be understood that the introduction of the organic matter with the fluorine-containing alcohol hydroxyl end-capped into the water-based electrolyte can be dissolved in water, which can change the solvation structure of Zn[H2O]6 2+ in the water-based electrolyte, so that the hydrogen bond capturing agent replaces part of water Zn[[H2O] n [organic matter] m ] 2+ and squeezes into the solvation shell of Zn 2+ , reduces the activity of water, participates in the formation of the solid-state electrolyte layer on the electrode surface, and improves the stability of the water-based battery electrode; at the same time, the introduction of the organic matter with the fluorine-containing alcohol hydroxyl end-capped into the water-based electrolyte can be dissolved in water, and the organic matter additive molecules have high adsorption energy to the Zn(002) crystal surface, which can induce the zinc to deposit in a hexagonal close-packed structure, which fundamentally destroys the "tip effect" and "accumulation effect" in the deposition process, and the morphology can effectively avoid the generation of zinc dendrites during the battery cycle, and improve the cycle stability and life of the battery.

[0045] Further, the concentration of the zinc salt is 0.5-3 mol / L, so as to reduce the cost and viscosity of the electrolyte under the condition of ensuring high ionic conductivity.

[0046] Further, the additive is added in the electrolyte in an amount of 0.001-0.01 mol / L.

[0047] It can be understood that, in the embodiment, by screening the type, amount and addition amount of the fluorine-containing alcohol hydroxyl-terminated organic matter, the method for adjusting the solvation structure of zinc ions, directional control of zinc deposition and promotion of the generation of the interface protection layer rich in inorganic fluorine-containing materials is achieved, the growth of dendrites is inhibited, the occurrence of hydrogen evolution and corrosion reaction is inhibited, and the cycle life of the aqueous zinc-based battery under large current density and large deposition capacity is improved.

[0048] The preparation method of the aqueous electrolyte provided in the above embodiment has simple preparation process, wide raw material source, low cost, good safety and wide application prospect.

[0049] The application further provides a battery comprising the aqueous electrolyte.

[0050] In the embodiment, a zinc ion battery is provided, which comprises zinc metal or zinc alloy as an anode, an organic matter or inorganic material with high stability and capacity as a cathode, an electrolyte added with 70-240 μL of fluorine-containing alcohol hydroxyl-terminated organic matter as an additive, and a suitable separator, so as to assemble an aqueous zinc-based battery with low cost and high safety.

[0051] Further, the zinc metal or zinc alloy is used as the anode of the zinc-based battery, and zinc sheet, zinc powder, zinc mesh or zinc alloy is preferred. Since the zinc sheet, zinc powder, zinc mesh or zinc alloy has low overpotential, reversible intercalation and deintercalation of zinc ions can be realized under certain conditions, and can be used for large-scale preparation.

[0052] Further, the organic matter or inorganic material with high stability and capacity is used as the cathode, and manganese dioxide, vanadium pentoxide, zinc iodide, sodium vanadate, ammonium vanadate, double metal sulfide, nitrogen-oxygen-containing organic matter and the like are preferred. The above-mentioned cathode material has low cost, easy preparation, stable structure and good rate performance.

[0053] Further, the suitable separator is used to separate the anode and cathode materials, and glass fiber separator, cellulose separator, filter paper, pp separator and the like are preferred. The above-mentioned separator can remain stable during the charging and discharging process of the battery, and has electronic insulation and high ionic conductivity.

[0054] In the embodiment, an aqueous zinc-based battery is provided, which comprises the aqueous electrolyte of the fluorine-containing alcohol hydroxyl-terminated organic matter.

[0055] It is understood that this application applies an aqueous electrolyte containing the fluorinated alcohol hydroxyl-terminated organic compound to a rechargeable aqueous zinc-based battery, achieving a long cycle life under high current density and deposition capacity, and has broad application prospects in low-cost, high-safety and large-scale zinc-based batteries.

[0056] It is understood that by changing the type of salt in the electrolyte composed of fluorinated alcohol hydroxyl-terminated organic compounds, such as lithium salt, sodium salt, calcium salt, potassium salt, aluminum salt, etc., it can be applied to different ion batteries, such as lithium-ion batteries, sodium-ion batteries, calcium-ion batteries, potassium-ion batteries, aluminum-ion batteries, etc. The field of aqueous ion batteries is within the protection scope of this patent.

[0057] The battery provided in the above embodiments of this application includes an aqueous electrolyte, which includes an additive containing an organic compound with fluorinated alcohol hydroxyl-terminated capping. Introducing a small amount of fluorinated alcohol hydroxyl-terminated organic compound into the aqueous electrolyte can promote the formation of intermolecular hydrogen bonds between the hydroxyl groups in the additive and hydrogen in the water, thereby breaking the original hydrogen bond network of water molecules. This achieves the effect of inhibiting the occurrence of hydrogen evolution side reactions, while also ensuring the presence of some free water in the hydrogen bond network, guaranteeing the high ionic conductivity of the electrolyte, and achieving a long cycle life under high current density and deposition capacity, which has broad application prospects.

[0058] The technical solutions described above in this application will be explained in detail below with reference to specific embodiments.

[0059] Example 1

[0060] This embodiment provides a method for preparing an electrolyte using an organic compound with fluorinated alcohol hydroxyl-terminated capping as an additive, comprising the following steps:

[0061] Add 5 mmol L to 4 ml of deionized water. -1 1H,1H,9H,9H-perfluoro-1,9-nonanediol (TDFND, a fluorinated alcohol-terminated organic compound) was stirred at 40°C for 5 hours, and then 2 mol L was added to the above mixed solution. -1 Zinc sulfate was added and stirred overnight at 30°C to obtain a homogeneous aqueous electrolyte with fluorinated alcohol-hydroxyl-terminated organic compounds as additives. This aqueous electrolyte with fluorinated alcohol-hydroxyl-terminated organic compounds as additives and 2 mol L... -1 Raman peaks of zinc sulfate, such as Figure 1 As shown, after adding the additive, the temperature is between 3100 and 3600 cm⁻¹ -1 The OH bonds belonging to water are weakened and slightly shifted, indicating a decrease in free water content in the electrolyte containing additives. Its Fourier transform infrared spectral data are as follows: Figure 2 This further confirms the reduction of free water in the electrolyte.

[0062] Example 2

[0063] Example 2 provides a preparation of electrolyte with fluorine-containing alcohol hydroxyl-terminated organic additive, including the following steps:

[0064] The difference between Example 2 and Example 1 is that only one kind of fluorine-containing alcohol hydroxyl-terminated organic additive is selected in step (1) of Example 2, while 3 mmol L -1 of 1H, 1H, 10H, 10H-perfluoro-1, 10-decanediol (fluorine-containing alcohol-terminated organic) is selected in Example 2. -1 1H, 1H, 10H, 10H-perfluoro-1, 10-decanediol (fluorine-containing alcohol-terminated organic) is stirred at 60°C for 6 hours, and then 1 mol L -1 of zinc triflate is added to the above mixed solution, and the stirrer continues to stir overnight at 30°C. The mass of zinc salt in step (1) is higher, and the zinc salt is an inorganic salt. In Example 2, a low-molar organic zinc triflate is selected as the zinc salt, which can ensure a high addition amount of fluorine-containing alcohol hydroxyl-terminated organic additive and obtain a uniform aqueous electrolyte with multiple fluorine-containing alcohol hydroxyl-terminated organic additives as additives.

[0065] Example 3

[0066] Example 3 provides the application of an electrolyte with fluorine-containing alcohol hydroxyl-terminated organic additive in a secondary aqueous zinc-based battery and performance testing thereof.

[0067] (1) Assemble the battery: the first battery is a zinc-zinc symmetric battery, both the anode and the cathode are selected to be zinc sheets, and the second battery is a zinc-zinc iodide full battery, the anode is selected to be a zinc sheet, the cathode is selected to be a high-stability zinc iodide, the separator is selected to be a glass fiber, and the electrolyte is selected to be the electrolyte with a zinc ion concentration of 2 mol L -1 of 1H, 1H, 9H, 9H-perfluoro-1, 9-nonanediol prepared by the present application in Example 1, and assembled into a CR2032 type button cell. The structure of the assembled battery is: positive shell, zinc sheet / positive sheet, electrolyte, separator, electrolyte, zinc sheet, gasket, spring, and negative shell.

[0068] (2) Electrochemical testing: at room temperature, the assembled button cell is subjected to charge-discharge testing on a new battery testing system, the testing conditions of the zinc-zinc symmetric battery are that the current density is 5 mA cm -2 , the deposition capacity is 5 mAh cm -2 , and the cycle performance graph is as shown in Figure 3 , and under the above conditions, the overpotential of the symmetric battery after 600 hours of cycling is only 87 mV. The testing conditions of the zinc-zinc iodide full battery are that the charge-discharge voltage interval is 0.3-1.8 V, and the charge-discharge testing is carried out at a current density of 1 A g -1 , and the cycle-capacity graph is as shown in Figure 4As shown, the specific capacity of the electrode material can reach 130 mAh g -1 , which can be stably cycled for more than 1000 cycles, and the coulombic efficiency is as high as 99.66%.

[0069] It can be understood that the technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, and as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure.

[0070] The above is only a preferred embodiment of the present application, and only the technical principles of the present application are specifically described, and these descriptions are only for the purpose of explaining the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanation here, any modification, equivalent replacement and improvement made within the spirit and principle of the present application, and other specific embodiments of the present application which can be easily conceived by those skilled in the art without creative labor, should be included in the protection scope of the present application.

Claims

1. An aqueous electrolyte, characterized in that, The aqueous electrolyte includes additives, which are fluorinated alcohol hydroxyl-terminated organic compounds. These fluorinated alcohol hydroxyl-terminated organic compounds include long-chain and / or short-chain fluorinated alcohol hydroxyl-terminated organic compounds. The long-chain fluorinated alcohol hydroxyl-terminated organic compounds include at least one of perfluorononanol, perfluorononanediol, perfluorodecaneol, and perfluorodecanediol. The short-chain fluorinated alcohol hydroxyl-terminated organic compounds include at least one of perfluorobutanol, perfluorohexanebutanol, fluorinated pentanol, and perfluoropentanediol.

2. The aqueous electrolyte as described in claim 1, characterized in that, The fluorinated alcohol hydroxyl-terminated organic compounds also include hydroxyl-terminated organic compounds that simultaneously contain F, S, or sulfonic acid groups.

3. The aqueous electrolyte as described in claim 1, characterized in that, The amount of the additive added to the aqueous electrolyte is 0.001-0.01 mol / L.

4. A method for preparing an aqueous electrolyte as described in any one of claims 1 to 3, characterized in that, Includes the following steps: The additive is mixed with deionized water and stirred at 25–50°C for 1–8 hours. Then, a metal salt is added to the mixture and stirred at 25–60°C to obtain the aqueous electrolyte. The additive includes an organic compound with fluorinated alcohol hydroxyl-terminated capping.

5. The method for preparing the aqueous electrolyte as described in claim 4, characterized in that, The metal salts include lithium salts, sodium salts, calcium salts, potassium salts, aluminum salts, or zinc salts.

6. The method for preparing the aqueous electrolyte as described in claim 5, characterized in that, The zinc salt includes at least one of zinc sulfate, zinc methanesulfonate, zinc trifluoromethanesulfonate, zinc bis(trifluoromethanesulfonate)imide, zinc chloride hexafluorosilicate, zinc perchlorate, or zinc nitrate.

7. The method for preparing the aqueous electrolyte as described in claim 6, characterized in that, The concentration of the zinc salt is 0.5–3 mol / L.

8. The method for preparing the aqueous electrolyte as described in claim 4, characterized in that, The amount of the additive added to the aqueous electrolyte is 0.001-0.01 mol / L.

9. A battery, characterized in that, Includes the aqueous electrolyte as described in any one of claims 4 to 8.

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