Super-wetting zinc ion battery electrolyte as well as preparation method and application thereof

Abstract

The invention provides a super-wetting zinc ion battery electrolyte as well as a preparation method and application thereof. The method comprises the following steps: preparing a zinc ion solution; adding an electrolyte wetting agent into the zinc ion solution in the air under the conditions of normal temperature and normal pressure; stirring the zinc ion solution until the solid is completely dissolved or uniformly dispersed to obtain the super-wet zinc ion battery electrolyte; and the electrolyte wetting agent is a wetting agent with double hydrophobic tails and hydrophilic branched chains. The wetting agent with double hydrophobic tails and hydrophilic branched chains is used as an electrolyte additive, and can be adsorbed on the surface of a zinc negative electrode, so that the interface free energy is remarkably reduced, the aqueous electrolyte can completely wet the surface of zinc metal, the zinc ion flow is uniform, and the growth of dendritic crystals is effectively inhibited. And the adsorption layer can generate a coordination effect with zinc ions, so that the nucleation overpotential is increased, grains are refined, the nucleation density is increased, and compact and flat zinc deposition is facilitated, so that the corrosivity of zinc in the super-wetting aqueous electrolyte is remarkably improved, and the cycling stability of the zinc ion battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aqueous zinc-ion batteries, and particularly to a super-wetting zinc-ion battery electrolyte and a preparation method and application thereof. Background Art

[0002] With the increasing demand for energy in society, more and more researchers are committed to the development of renewable energy and the research of sustainable energy storage technologies. Among them, aqueous zinc-ion batteries are considered to be one of the most promising large-scale grid energy storage batteries due to their high safety, environmental friendliness, low cost, and high ion diffusion kinetics. In addition, aqueous zinc-ion batteries also have advantages such as high theoretical volume / mass capacity (5855 mAh cm –3 / 820 mAh g – 1 ) and low redox potential (-0.76 V vs standard hydrogen electrode), and have received extensive attention.

[0003] However, the poor reversibility of the zinc anode remains a problem that hinders the further development of aqueous zinc-ion batteries. On the one hand, due to the non-uniformity of the zinc electrode-electrolyte interface, zinc deposition is uneven. Under the non-uniform electric field and concentration gradient, zinc ions are deposited faster at the tips of dendrites. In addition, zinc ions can also be transferred from flat parts to active parts through two-dimensional diffusion, resulting in the preferential growth of zinc dendrites and "dead zinc". On the other hand, in a weakly acidic (pH = 3-7) ZnSO 4 electrolyte solution, the reaction between zinc and water is thermodynamically spontaneous, and the hydrogen evolution reaction (HER) competes with zinc deposition. The OH – generated by the hydrogen evolution reaction raises the local pH value of the electrode and induces the formation of insulating Zn 4 (OH) 6 SO 4 ·xH 2 O by-products and passivation, thereby reducing the Coulombic efficiency (CE) and capacity of aqueous zinc-ion batteries. Summary of the Invention

[0004] The purpose of the present invention is to provide a super-wetting zinc-ion battery electrolyte and a preparation method and application thereof, aiming to solve the problems of local wetting of the electrode and uneven distribution of zinc ions in the traditional aqueous battery electrolyte, resulting in rampant growth of zinc dendrites.

[0005] In the first aspect, the present invention provides a preparation method of a super-wetting zinc-ion battery electrolyte, and the preparation method includes:

[0006] Preparing a zinc ion solution;

[0007] In air, under normal temperature and pressure conditions, an electrolyte wetting agent is added to a zinc ion solution; the zinc ion solution is stirred until the solid is completely dissolved or evenly dispersed to obtain a super-wetting zinc ion battery electrolyte.

[0008] The electrolyte wetting agent is a wetting agent with a double hydrophobic tail and a hydrophilic branched chain.

[0009] According to the above preparation method, by using a wetting agent with a double hydrophobic tail and a hydrophilic branched chain as an electrolyte additive, this type of additive can adsorb on the surface of the zinc negative electrode, thereby significantly reducing the interfacial free energy at the electrode / electrolyte interface, enabling the electrolyte to completely wet the zinc metal surface, uniform the zinc ion flow, and effectively inhibit the growth of dendrites. And the adsorption layer can have a coordination effect with zinc ions, increasing the nucleation overpotential of zinc, effectively refining the crystal grains and increasing the nucleation density, which is beneficial to dense and flat zinc deposition, thereby significantly enhancing the corrosion resistance of zinc metal in the super-wetting aqueous electrolyte and improving the cycle stability of the zinc ion battery. In addition, this type of wetting agent is low-cost, green and environmentally friendly, and is suitable for industrial production.

[0010] In some preferred embodiments, the electrolyte wetting agent at least includes one of sodium dioctyl sulfosuccinate, sodium dodecyl sulfate, disodium lauroiminodipropionate, sodium dodecylbenzenesulfonate, sodium 3-mercapto-1-propanesulfonate, and sodium p-ethylbenzenesulfonate.

[0011] In some preferred embodiments, the concentration of the electrolyte wetting agent in the super-wetting zinc ion battery electrolyte is 0.005 - 0.5 M.

[0012] In some preferred embodiments, the solute in the zinc ion solution at least includes one of zinc sulfate heptahydrate, zinc bromide, and zinc chloride.

[0013] In some preferred embodiments, the zinc ion concentration in the zinc ion electrolyte is 1 - 3 M.

[0014] In a second aspect, the present invention also provides a super-wetting zinc ion battery electrolyte, which is prepared according to the above preparation method of the super-wetting zinc ion battery electrolyte.

[0015] In a third aspect, the present invention also provides the application of the above super-wetting electrolyte in an aqueous zinc battery, and the aqueous zinc battery includes a super-wetting electrolyte, a positive electrode, a negative electrode, and a separator.

[0016] In some preferred embodiments, the positive electrode is any one of vanadium-based oxides, manganese-based oxides, iodine positive electrodes, Prussian blue analogs, carbon felt, and graphite felt.

[0017] In some preferred embodiments, the negative electrode is zinc or a zinc alloy.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The wetting agent with double hydrophobic tails and hydrophilic branched chains proposed by the present invention is used as an electrolyte additive to make the electrolyte reach a super-wetting state, which is not only simple to operate but also low in cost, and can effectively improve the cycle stability of the aqueous zinc-ion battery and extend the battery life.

[0020] 2. The anionic part of the wetting agent in the present invention can effectively reduce the surface tension of the electrolyte and the interfacial free energy at the interface between the electrolyte and the negative electrode at an appropriate concentration. It can refine the crystal grains, uniform the zinc ion flow, and induce uniform and dense deposition. At the same time, this anion can adsorb on the surface of the negative electrode, significantly improving the corrosion resistance of the negative electrode and inhibiting the occurrence of side reactions.

[0021] 3. The cationic part of the electrolyte wetting agent in the present invention has the function of "electrostatic shielding", which can well uniform the zinc ion flow and relieve the aggregation of zinc ions at the tips, thereby inhibiting the growth of zinc dendrites. Under the combined action of the anion and cation, the zinc-ion battery realizes stable and reversible ultra-long cycling. In addition, this electrolyte wetting agent additive has the advantages of adjustable properties, low volatility, non-toxic and harmless, and has good application prospects in the field of aqueous zinc-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 are the molecular structures of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium dioctyl sulfosuccinate and the corresponding contact angles;

[0024] Figure 2 are the electrochemical performance diagrams of symmetric batteries assembled with electrolytes containing the same concentration of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium dioctyl sulfosuccinate under the test conditions of 1 mA cm – 2 , 1 mAh cm – 2 ;

[0025] Figure 3 are the photos and SEM diagrams of the electrolyte zinc sheets soaked for different times prepared in Example 1 of the present invention;

[0026] Figure 4 are the in-situ optical microscopes of the zinc negative electrode deposited for different times in the electrolyte prepared in Example 1 of the present invention;

[0027] Figure 5It is the cyclic voltammetry curve of the zinc-titanium battery assembled with the electrolyte prepared in Example 1 of the present invention;

[0028] Figure 6 It is the SEM images of the electrolyte prepared in Example 1 of the present invention deposited at different current densities at a surface capacity of 0.25 mAh cm – 2 ;

[0029] Figure 7 It is the relationship diagram of the calculated binding energy with different groups and the influence of the nucleation overpotential and surface free energy on the nucleation behavior.

[0030] Figure 8 It is the electrochemical performance diagram and the partial enlarged diagram of the zinc-zinc symmetric battery assembled with the electrolyte prepared in Example 1 of the present invention under the test conditions of 5 mAh cm – 2 , 5 mA cm – 2 ;

[0031] Figure 9 It is the electrochemical performance diagram and the corresponding specific capacity-voltage curve of the zinc-copper battery assembled with the electrolyte prepared in Example 1 of the present invention under the test conditions of 5 mA cm – 2 , 1 mAh cm – 2 ;

[0032] Figure 10 It is the electrochemical performance diagram and the corresponding specific capacity-voltage curve of the zinc-ammonium vanadate full battery assembled with the electrolyte prepared in Example 1 of the present invention under the test conditions of 1 A g –1 ;

[0033] Figure 11 It is the electrochemical performance diagram of the zinc-ammonium vanadate soft-pack battery assembled with the electrolyte prepared in Example 1 of the present invention under the test conditions of 0.5 A g –1 ; Detailed Description of the Invention

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0035] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0036] Example 1

[0037] Dissolve 11.5 g of zinc sulfate heptahydrate powder in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.445 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare a 0.05 M electrolyte solution.

[0038] Example 2

[0039] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.272 g of sodium dodecyl sulfate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare a 0.05 M electrolyte solution.

[0040] Example 3

[0041] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.348 g of sodium dodecylbenzenesulfonate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare a 0.05 M electrolyte solution.

[0042] Example 4

[0043] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.373 g of disodium N-lauroyliminodipropionate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare a 0.05 M electrolyte solution.

[0044] Example 5

[0045] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.178 g of 3-sulfanyl-1-propanesulfonate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare a 0.05 M electrolyte solution.

[0046] Example 6

[0047] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in the air, weigh 0.206 g of sodium p - ethylbenzenesulfonate and dissolve it in the prepared zinc sulfate solution. Stir until it is completely dissolved to prepare a 0.05 M electrolyte solution.

[0048] Example 7

[0049] Weigh 17.25 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 3 M zinc sulfate solution. Under normal temperature and pressure in the air, weigh 0.445 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution. Stir until it is completely dissolved to prepare a 0.05 M electrolyte solution.

[0050] Example 8

[0051] Weigh 5.75 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 1 M zinc sulfate solution. Under normal temperature and pressure in the air, weigh 0.445 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution. Stir until it is completely dissolved to prepare a 0.05 M electrolyte solution.

[0052] Comparative Example 1

[0053] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 2 M zinc sulfate hydrolysis solution.

[0054] Comparative Example 2

[0055] Weigh 5.44 g of zinc chloride powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in the air, weigh 0.445 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution. Stir until it is completely dissolved to prepare a 0.05 M electrolyte solution.

[0056] Comparative Example 3

[0057] Weigh 11.5 g of zinc sulfate heptahydrate powder and dissolve it in 20 mL of deionized water. Stir it until the solution becomes clear to prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in the air, weigh 0.41 g of sodium lauryl sulfosuccinate and dissolve it in the prepared zinc sulfate solution. Stir until it is completely dissolved to prepare a 0.05 M electrolyte solution.

[0058] Comparative Example 4

[0059] Dissolve 2.875 g of zinc sulfate heptahydrate powder in 20 mL of deionized water, stir it until the solution is clear, and prepare a 0.5 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.445 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare an electrolyte solution with a concentration of 0.05 M.

[0060] Comparative Example 5

[0061] Dissolve 11.5 g of zinc sulfate heptahydrate powder in 20 mL of deionized water, stir it until the solution is clear, and prepare a 2 M zinc sulfate solution. Under normal temperature and pressure in air, weigh 0.0045 g of sodium dioctyl sulfosuccinate and dissolve it in the prepared zinc sulfate solution, stir until completely dissolved, and prepare an electrolyte solution with a concentration of 0.0005 M.

[0062] It can be seen from Figure 1 that the addition of the electrolyte wetting agent can significantly reduce the surface tension of the liquid, making the wet liquid easier to wet the surface. It can be seen from Figure 3 that the addition of the electrolyte wetting agent exhibits excellent corrosion resistance. The zinc sheet remains shiny after being immersed in the electrolyte prepared in Example 1 for 15 days. It can be seen from Figure 4 that the addition of the electrolyte wetting agent can uniform the zinc ion flow at the electrode / electrolyte interface, promote uniform zinc deposition, and inhibit the growth of dendrites. Figure 5 、 Figure 6 It can be seen from Figure 7 that the electrolyte wetting agent can increase the nucleation overpotential of zinc ions, reduce the free energy at the electrode / electrolyte interface, and promote the fine-grained deposition of zinc. It can be seen from

[0063] Test Example 1

[0064] Assemble a zinc-zinc symmetric battery in air: Use a Whatman diaphragm, unmodified pure zinc as the zinc negative electrode, and unmodified pure zinc as the positive electrode. Use the zinc-zinc symmetric battery assembled with the electrolyte prepared in Example 1 as the experimental sample, and use the zinc-zinc symmetric batteries assembled with the electrolytes prepared in Example 2 and Example 3 as the control groups. As Figure 2 shown; Charge and discharge test the above-assembled symmetric batteries under the conditions of a current density of 1 mA cm – 2 、1 mAh cm – 2 as Figure 2As shown; in contrast, the zinc-zinc symmetric battery assembled with the electrolyte configured in Example 1 exhibits more excellent long-cycle stability, capable of stable cycling for up to 3700 h, while the zinc-zinc batteries assembled with the electrolytes configured in Example 2 and Example 3 only cycled for 900 h and 2600 h, respectively. It can be seen that the anion part of the electrolyte wetting agent has a greater impact on the cycling duration of the zinc-zinc symmetric battery, and the dioctyl sulfosuccinate ion is the best.

[0065] Test Example 2

[0066] Assemble a zinc-zinc symmetric battery in air: Use a Whatman separator, unmodified pure zinc as the negative electrode, and unmodified pure zinc as the positive electrode. And use the zinc-zinc symmetric battery assembled with the electrolyte configured in Example 1 as the experimental sample, and the zinc-zinc symmetric battery assembled with the zinc sulfate electrolyte configured in Comparative Example 1 as the control group. Charge and discharge the above-assembled symmetric batteries under the conditions of a current density of 5 mA cm – 2 and 5 mAh cm – 2 , as shown in Figure 8 ; in contrast, the zinc-zinc symmetric battery assembled with the electrolyte configured in Example 1 exhibits more excellent long-cycle stability, capable of stable cycling for up to 1100 h, while the zinc-zinc battery assembled with the electrolyte configured in Comparative Example 1 short-circuited and failed after only 40 h of cycling.

[0067] Test Example 3

[0068] Assemble a zinc-copper symmetric battery in air: Use a Whatman separator, unmodified pure zinc as the negative electrode, and unmodified copper foil as the positive electrode. And use the zinc-copper battery assembled with the electrolyte configured in Example 1 as the experimental sample, and the zinc-copper battery assembled with the zinc sulfate electrolyte configured in Comparative Example 1 as the control group. Charge and discharge the above-assembled symmetric batteries under the conditions of a current density of 5 mA cm – 2 and 1 mAh cm – 2 , as shown in Figure 9 ; in contrast, the zinc-copper battery assembled with the electrolyte configured in Example 1 exhibits more excellent reversibility, maintaining a Coulombic efficiency of 99.5% after 2400 cycles, while the zinc-copper battery assembled with the electrolyte configured in Comparative Example 1 short-circuited and failed after only 880 cycles.

[0069] Test Example 4

[0070] Assembly of Zinc-Ammonium Vanadate All-Battery in Air: Mix ammonium vanadate with oxalic acid. Add the powder to 200 mL of deionized water and stir until a homogeneous solution is formed. Heat the solution in a 250-Teflon autoclave at 140 °C for 24 h to carry out a hydrothermal reaction. After the reaction is completed, collect the precipitate and wash it repeatedly with deionized water. Using isopropanol as a dispersant, mix the obtained powder with Ketjen black and polytetrafluoroethylene emulsion in a mass ratio of 8:1:1 to prepare a slurry and roll it onto a stainless steel mesh with a mesh number of 300. After drying overnight at 60 °C in air, an ammonium vanadate electrode containing 3 - 4 mg cm – 2 is obtained, and then a positive electrode plate is obtained after rolling. Use a Whatman separator and unmodified pure zinc as the negative electrode, and the fabricated ammonium vanadate electrode plate as the positive electrode. Use the zinc-ammonium vanadate battery assembled with the electrolyte prepared in Example 1 as the experimental sample, and the zinc-ammonium vanadate battery assembled with the zinc sulfate electrolyte prepared in Comparative Example 1 as the control group. Charge and discharge test the above-assembled symmetric battery under the condition of a current density of 1 A g – 1 , as shown in Figure 10 . In contrast, the zinc-ammonium vanadate battery assembled with the electrolyte prepared in Example 1 exhibits more excellent long-cycle stability and can still maintain 78.9% of its capacity after 1100 cycles. The capacity retention rate of the zinc-ammonium vanadate all-battery assembled with the electrolyte prepared in Comparative Example 1 is 0% after 600 cycles.

[0071] Test Example 5

[0072] Assembly of Zinc-Ammonium Vanadate Soft Pack Battery in Air: Mix ammonium vanadate with oxalic acid. Add the powder to 200 mL of deionized water and stir until a homogeneous solution is formed. Heat the solution in a 250-Teflon autoclave at 140 °C for 24 h to carry out a hydrothermal reaction. After the reaction is completed, collect the precipitate and wash it repeatedly with deionized water. Using isopropanol as a dispersant, mix the obtained powder with Ketjen black and polytetrafluoroethylene emulsion in a mass ratio of 8:1:1 to prepare a slurry and roll it onto a stainless steel mesh with a mesh number of 300. After drying overnight at 60 °C in air, an ammonium vanadate electrode containing 3 - 4 mg cm – 2 is obtained, and then a positive electrode plate is obtained after rolling. Use a Whatman separator and unmodified pure zinc as the negative electrode, and the fabricated ammonium vanadate electrode plate as the positive electrode. Use the zinc-ammonium vanadate soft pack battery assembled with the electrolyte prepared in Example 1 as the experimental sample, and the zinc-ammonium vanadate soft pack battery assembled with the zinc sulfate electrolyte prepared in Comparative Example 1 as the control group. Charge and discharge test the above-assembled zinc-ammonium vanadate soft pack battery under the condition of a current density of 0.5 A g – 1 , as shown in Figure 11As shown; in contrast, the zinc-ammonium vanadate soft-pack battery assembled with the electrolyte configured in Example 1 exhibits more excellent long-cycle stability, with an initial specific capacity of 320.2 mAh g – 1 , and it can still maintain 83.3% of the capacity after 200 cycles. While the zinc-ammonium vanadate soft-pack battery assembled with the electrolyte configured in Proportion 1 has an initial specific capacity of 267.0 mAh g – 1 , and the battery only maintains 58.2% of the capacity after 45 cycles.

[0073] In addition, the batteries assembled with the electrolytes obtained from each of Examples 2-8 and Comparative Examples 1-5 were tested for their performance using the same methods as in Test Example 1, Test Example 2, Test Example 3, Test Example 4, and Test Example 5. The performance data is shown in Table 1 below:

[0074] Table 1

[0075]

[0076]

[0077] Result analysis. From Test Examples 1-5 and Table 1, it can be seen that the super-wetting zinc-ion battery electrolytes prepared in Examples 1-8 have good performance in zinc-zinc symmetric batteries, zinc-copper symmetric batteries, zinc-ammonium vanadate full batteries, and zinc-ammonium vanadate soft-pack batteries. Specifically, for the zinc-zinc symmetric battery, the cycle duration is greatly improved under the conditions of 1 mA cm -2 , 1 mAh cm -2 and 5 mA cm -2 , 5 mAh cm -2 . For the zinc-copper symmetric battery, the Coulombic efficiency remains above 99% after 2400 cycles. For the zinc-ammonium vanadate full battery, the capacity retention rate after 1100 cycles is greatly improved. For the zinc-ammonium vanadate soft-pack battery, the initial specific heat capacity is improved, and the capacity retention rate after 200 cycles is also greatly improved. That is to say, the super-wetting zinc-ion battery electrolytes prepared in the embodiments of the present application are applicable to various batteries and can maintain good performance.

[0078] In addition, from Example 1 and Examples 2-8, it can be seen that in the embodiments of the present application, when sodium dioctyl sulfosuccinate is used as the wetting agent, and the concentration of the electrolyte wetting agent is 0.05 M and the zinc ion concentration is 2 M, the overall performance of the various batteries is the best.

[0079] In addition, it can be seen from Examples 1-6 and Comparative Example 1 that in the case of not adding a wetting agent, the electrolytes obtained show poor performance when applied to zinc-zinc symmetric batteries, zinc-copper symmetric batteries, zinc-ammonium vanadate full batteries, and zinc-ammonium vanadate soft-pack batteries. This shows that the electrolyte prepared by adding a specific wetting agent in this application has an obvious effect on improving the performance of various batteries.

[0080] In addition, it can be seen from Example 1 and Comparative Example 2 that when the electrolyte is replaced from zinc sulfate heptahydrate with zinc chloride and the zinc ion concentration is kept equal, the electrolytes obtained in Comparative Example 2 show poor performance when applied to zinc-zinc symmetric batteries, zinc-copper symmetric batteries, zinc-ammonium vanadate full batteries, and zinc-ammonium vanadate soft-pack batteries. Thus, it can be seen that the selection of specific zinc sulfate heptahydrate as the electrolytic salt and sodium dioctyl sulfosuccinate as the wetting agent in this application has a synergistic effect.

[0081] In addition, it can be seen from Example 1 and Comparative Example 3 that when changing the anion of the wetting agent, that is, also a sodium salt, but using sodium lauryl sulfosuccinate as the wetting agent, the electrolytes obtained show poor performance when applied to zinc-zinc symmetric batteries, zinc-copper symmetric batteries, zinc-ammonium vanadate full batteries, and zinc-ammonium vanadate soft-pack batteries. This further illustrates the particularity of the wetting agent selected in the examples of this application, and it is not sufficient to be similar to the wetting agent selected in this application.

[0082] In addition, it can be seen from Example 1 and Comparative Examples 4 and 5 that too low or too high an amount of sodium dioctyl sulfosuccinate added during the preparation of the electrolyte will affect the effect of the electrolyte when applied to zinc-zinc symmetric batteries, zinc-copper symmetric batteries, zinc-ammonium vanadate full batteries, and zinc-ammonium vanadate soft-pack batteries.

[0083] It is known by common technical knowledge that the present invention can be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and are not the only ones. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A preparation method of a super-wetting zinc-ion battery electrolyte, characterized in that, the preparation method includes: Preparing a zinc-ion electrolyte; Adding an electrolyte wetting agent to the zinc-ion electrolyte under normal temperature and pressure in the air; stirring the zinc-ion electrolyte until the solid is completely dissolved or evenly dispersed to obtain a super-wetting zinc-ion battery electrolyte; The electrolyte wetting agent is a wetting agent with a double hydrophobic tail and a hydrophilic branched chain.

2. The preparation method of the super-wetting zinc-ion battery electrolyte according to claim 1, characterized in that, The electrolyte wetting agent at least includes one of sodium dioctyl sulfosuccinate, sodium dodecyl sulfate, disodium lauryldiiminodipropionate, sodium dodecylbenzenesulfonate, sodium 3-mercapto-1-propanesulfonate, and sodium p-ethylbenzenesulfonate.

3. The preparation method of the super-wetting zinc-ion battery electrolyte according to claim 2, characterized in that, The concentration of the electrolyte wetting agent in the super-wetting zinc-ion battery electrolyte is 0.005 - 0.5 M.

4. The preparation method of the super-wetting zinc-ion battery electrolyte according to claim 1, characterized in that, The solute in the zinc-ion solution at least includes one of zinc sulfate heptahydrate, zinc bromide, and zinc chloride.

5. The preparation method of the super-wetting zinc-ion battery electrolyte according to claim 4, characterized in that, The zinc-ion concentration in the zinc-ion solution is 1 - 3 M.

6. A super-wetting zinc-ion battery electrolyte, characterized in that, The super-wetting zinc-ion battery electrolyte is prepared according to the preparation method of the super-wetting zinc-ion battery electrolyte according to any one of claims 1 - 5.

7. An application of the super-wetting zinc-ion battery electrolyte according to claim 6 in an aqueous zinc battery, characterized in that, The aqueous zinc battery includes a super-wetting zinc-ion battery electrolyte, a positive electrode, a negative electrode, and a separator.

8. The application according to claim 7, characterized in that, The positive electrode is any one of vanadium-based oxides, manganese-based oxides, iodine positive electrodes, Prussian blue analogs, carbon felt, and graphite felt.

9. The application according to claim 7, characterized in that, The negative electrode is zinc or a zinc alloy.

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