Aqueous zinc ion battery electrolyte additive as well as preparation method and application thereof

Abstract

The invention discloses an aqueous zinc ion battery electrolyte additive as well as a preparation method and application thereof, and the electrolyte additive is a mixture of one or more than two of biological type isomeride saccharide molecules, monosaccharide molecules, disaccharide molecules and polysaccharide molecules, and the monosaccharide molecules, the disaccharide molecules and the polysaccharide molecules comprise diastereomer and enantiomer structures. The amount-of-substance concentration of the additive in the electrolyte solution is 0.01 M to 1 M. The carbonyl and hydroxyl functional groups in the additive provided by the invention can coordinate with Zn < 2 + > to change the solvation structure of zinc ions; and meanwhile, directional and uniform deposition of zinc can be induced by changing the position of carbonyl and the spatial three-dimensional configuration of hydroxyl, so that side reactions such as dendritic crystal growth, hydrogen evolution and corrosion are effectively inhibited, and the cycling stability of the zinc negative electrode is remarkably improved. In addition, the additive disclosed by the invention is rich in source, low in cost and environment-friendly, and accords with the development direction of the electrolyte additive.

Description

Technical Field

[0001] The invention belongs to the technical field of zinc ion battery electrolyte, and specifically relates to an aqueous zinc ion battery electrolyte additive and a preparation method and application thereof. Background Art

[0002] Aqueous zinc-ion batteries have attracted much attention due to their high theoretical capacity, low redox potential, high safety and environmental friendliness, especially in the field of large-scale energy storage. However, the dendrite growth and side reactions occurring at the interface between zinc anode and electrolyte severely limit the coulombic efficiency and cycle life of aqueous zinc-ion batteries, restricting the commercial application prospects of aqueous zinc-ion batteries. Therefore, how to solve the problems faced by zinc anode and improve its coulombic efficiency and cycle life is crucial to the development of aqueous zinc-ion batteries.

[0003] In order to improve the performance of zinc-ion batteries, researchers have proposed a variety of strategies, including constructing 3D zinc anodes, modifying zinc anode surfaces, and electrolyte engineering. Among them, electrolyte engineering is particularly important for improving zinc anode problems and improving the performance of zinc-ion batteries because it is simple, efficient, and can effectively improve the interface between zinc anode and electrolyte. Electrolyte engineering includes the design of high-concentration electrolytes, gel electrolytes, and electrolyte additives. Among them, high-concentration electrolytes and gel electrolytes can greatly promote the uniformity of zinc anodes by changing solvation and desolvation. However, their increased viscosity reduces the ionic conductivity of the electrolyte, which can lead to a decline in battery performance at high current density. Electrolyte additives can effectively improve the stability of the zinc anode and inhibit dendrite growth and corrosion. At the same time, it has attracted widespread attention due to its simple operation, low cost, and ease of large-scale application.

[0004] Although great progress has been made in the research of electrolyte additives, most of the research focuses on the regulation of the zinc solvation structure by polar functional groups in the additives, while ignoring the effect of the molecular spatial configuration on the performance of aqueous zinc-ion batteries. Therefore, it is crucial to explore the relationship between the spatial configuration of the additive molecules in the electrolyte system and the electrochemical performance of the zinc anode to achieve high-performance aqueous zinc-ion batteries. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide an aqueous zinc ion battery electrolyte additive.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: an aqueous zinc ion battery electrolyte additive, characterized in that: the aqueous zinc ion battery electrolyte additive comprises one or more of sugar isomer compounds;

[0009] Among them, sugar isomer compounds include diastereomers and enantiomers of fructose, glucose, galactose, sucrose, maltose and lactose.

[0010] As a preferred embodiment of the aqueous zinc ion battery electrolyte additive of the present invention, the molar concentration of the aqueous zinc ion battery electrolyte additive is 0.01M to 1M.

[0011] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an aqueous zinc ion battery electrolyte additive for use in an aqueous zinc ion battery.

[0012] To solve the above technical problems, the present invention provides the following technical solutions: an aqueous zinc ion battery electrolyte, characterized in that the aqueous zinc ion battery electrolyte comprises deionized water, a zinc salt electrolyte and the aqueous zinc ion battery electrolyte additive.

[0013] As a preferred embodiment of the aqueous zinc ion battery electrolyte of the present invention, the zinc salt electrolyte includes one or more of zinc sulfate, zinc chloride, zinc perchlorate and zinc trifluoromethanesulfonate.

[0014] As a preferred embodiment of the aqueous zinc ion battery electrolyte of the present invention, the concentration of the aqueous zinc ion battery electrolyte is 0.5-3M.

[0015] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an aqueous zinc ion battery electrolyte for use in an aqueous zinc ion battery.

[0016] To solve the above technical problems, the present invention provides the following technical solutions: an aqueous zinc ion battery, characterized in that the aqueous zinc ion battery consists of a positive electrode, a negative electrode, a diaphragm and the aqueous zinc ion electrolyte.

[0017] As a preferred embodiment of the aqueous zinc ion battery of the present invention, the positive electrode of the aqueous zinc ion battery is a zinc sheet, the negative electrode is a zinc sheet, and the separator is glass fiber.

[0018] As a preferred embodiment of the aqueous zinc ion battery of the present invention, the diameter of the positive electrode is 14 mm, and the diameter of the negative electrode is 15 mm.

[0019] Beneficial effects of the present invention:

[0020] (1) The present invention selects sugar isomers as electrolyte additives. During zinc deposition, they can be preferentially adsorbed on the surface of the zinc anode, reducing the direct contact between free water and the zinc anode, thereby inhibiting the occurrence of side reactions such as hydrogen evolution and corrosion of the zinc anode. At the same time, the aqueous zinc ion battery containing sugar molecules has a larger nucleation overpotential, and a large nucleation overpotential is conducive to the formation of a more fine and uniform zinc deposition layer, thereby achieving the purpose of inhibiting dendrite growth.

[0021] (2) The electrolyte prepared by the present invention has obvious effects in inhibiting corrosion at the zinc anode of aqueous zinc ion batteries, and has a significant difference in the effect on the orientation of zinc deposition; the additives are all natural organic molecules, which are green and environmentally friendly, low in cost, and suitable for large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0023] Figure 1 The electrolytes prepared in Example 1, Example 2, Example 3 and the comparative example of the present invention were assembled into button-type batteries to obtain cycle performance graphs.

[0024] Figure 2 The ion migration graphs obtained for the electrolytes prepared in Example 1, Example 2, Example 3 and the comparative example of the present invention.

[0025] Figure 3 Linear sweep voltammetry curves were measured for the electrolytes prepared in Example 1, Example 2, Example 3 and the comparative example of the present invention.

[0026] Figure 4 Liquid NMR images were obtained for Example 1, Example 2, Example 3 and the additives used in the present invention.

[0027] Figure 5 The electrolytes prepared in Example 1, Example 2, Example 3 and the comparative example of the present invention were assembled into button cells and X-ray diffraction patterns were measured after 100 cycles. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] Unless otherwise specified, all raw materials used in the examples of the present invention are commercially available, as shown in Table 1 for details.

[0032] Table 1

[0033] name Commercial channels Part Number Zinc sulfate heptahydrate Greagent 7446-20-0 Zinc chloride Adamas 7646-85-7 Zinc perchlorate hexahydrate Sigma-Aldrich 10025-64-6 Zinc trifluoromethanesulfonate TCI 54010-75-2 glucose Aladdin 50-99-7 Galactose Adamas 96-23-4 fructose Merck 57-48-7 sucrose Adamas 57-50-1 Maltose Monohydrate Adamas 6363-53-7 lactose Adamas 5989-81-1

[0034] Example 1

[0035] This embodiment provides a method for preparing an aqueous zinc ion battery electrolyte additive:

[0036] (1) Dissolve 20 mM ZnSO4·7H2O in water and prepare 10 mL of 2M zinc sulfate electrolyte using a volumetric flask.

[0037] (2) Add 5 mM sucrose to the above solution and stir for 30 min to obtain the target electrolyte.

[0038] Example 2

[0039] The difference from Example 1 is that the sucrose in step (2) is replaced by maltose.

[0040] Example 3

[0041] The difference from Example 1 is that the sucrose in step (2) is replaced by lactose.

[0042] Example 4

[0043] (1) Dissolve 20 mM ZnSO4·7H2O in water and prepare 10 mL of 2M zinc sulfate electrolyte using a volumetric flask.

[0044] (2) Add 2 mM glucose to the above solution and stir for 30 min to obtain the target electrolyte.

[0045] Example 5

[0046] The difference from Example 4 is that the glucose in step (2) is replaced by fructose.

[0047] Example 6

[0048] The difference from Example 4 is that the glucose in step (2) is replaced by galactose.

[0049] Example 7

[0050] The difference from Example 1 is that the sucrose in step (2) is replaced by a mixture of 2 mM galactose and 2 mM fructose.

[0051] Example 8

[0052] The difference from Example 1 is that the sucrose in step (2) is replaced by a mixture of 0.1 mM glucose and 0.2 mM fructose.

[0053] Example 9

[0054] The difference from Example 1 is that the sucrose in step (2) is replaced by a mixture of 0.1 mM sucrose and 0.1 Mm lactose.

[0055] Example 10

[0056] The difference from Example 1 is that the sucrose in step (2) is replaced by a mixture of 0.5 mM sucrose and 0.5 mM lactose.

[0057] Comparative Example 1

[0058] (1) Dissolve 20 mmol ZnSO4·7H2O in water and prepare 10 mL of 2M zinc sulfate electrolyte using a volumetric flask.

[0059] Comparative Example 2

[0060] (1) Dissolve 10 mmol ZnSO4·7H2O in water and prepare 10 mL of 1 M zinc sulfate electrolyte using a volumetric flask.

[0061] Comparative Example 3

[0062] The difference from Comparative Example 1 is that the ZnSO4·7H2O in step (1) is replaced by 20 mmol of zinc chloride.

[0063] Comparative Example 4

[0064] The difference from Comparative Example 1 is that the ZnSO4·7H2O in step (1) is replaced by 20 mmol of zinc perchlorate.

[0065] Comparative Example 5

[0066] The difference from Comparative Example 1 is that the ZnSO4·7H2O in step (1) is replaced by 20 mmol of zinc trifluoromethanesulfonate.

[0067] Assembly of aqueous zinc ion zinc|zinc symmetrical battery: the positive electrode uses a zinc sheet with a diameter of 14 mm, the negative electrode uses a zinc sheet with a diameter of 15 mm, and the separator is glass fiber (GF / D), and the battery is assembled symmetrically.

[0068] Constant current charge and discharge test of aqueous zinc ion zinc-zinc symmetrical battery: Use BST-5V model NEWARE battery test system. Keep the battery to be tested at 25℃, set the charge and discharge time to 1 hour per time, and obtain cycle life data through different current densities and number of cycles. Explore the change of voltage over time.

[0069] Table 2 shows the cycle life of symmetrical button cells in different types / concentrations of electrolytes.

[0070] Table 2

[0071]

[0072] Table 3 shows the cycle life of symmetrical button cells in 2M zinc sulfate electrolyte with different types of additives.

[0073] Table 3

[0074]

[0075]

[0076] As can be seen from Tables 2 and 3, the use of the zinc sulfate battery electrolyte containing different types of additives of the present invention can significantly increase the cycle life of the aqueous zinc ion symmetrical button battery, especially when the disaccharide additive is used, the cycle life of the aqueous zinc ion symmetrical button battery is the longest. This fully demonstrates the positive effect of the additives provided by the present invention, especially maltose, on enhancing the performance of aqueous zinc ion batteries.

[0077] In the present invention, the electrolytes containing additives prepared in Example 1, Example 2, and Example 3 and the electrolytes prepared in the comparative example are respectively assembled into zinc ion symmetric batteries for cycle performance testing. Figure (1) is a long cycle performance diagram of a zinc|zinc symmetric battery. Figure (2) is a diagram of the ion migration number measured by assembling the electrolytes containing additives prepared in Example 1, Example 2, and Example 3 and the electrolytes prepared in the comparative example into zinc|zinc symmetric batteries. The ion migration numbers measured in Examples 1, 2, and 3 are 0.52, 0.80, and 0.66, respectively, which are all higher than 0.31 measured in the comparative example. Among them, the ion migration number of the electrolyte in Example 2 is the largest, indicating that it can more effectively alleviate concentration polarization, thereby reducing dendrite growth and achieving uniform zinc deposition. Figure (3) shows the linear sweep voltammetry (LSV) curves of button cells assembled with the electrolytes containing additives prepared in Example 1, Example 2, and Example 3 and the electrolyte prepared in the comparative example. It can be seen from the figure that the hydrogen evolution overpotentials measured by the button cells assembled in the examples are -0.14V, -0.13V, and -0.12V, respectively, which are higher than the -0.09V measured by the button cells assembled in the comparative example. In addition, for the three isomeric electrolyte additives in Example 1, Example 2, and Example 3, due to their different spatial configurations, their inhibitory effects on the hydrogen evolution reaction are also different. Figure (4) shows the liquid nuclear magnetic hydrogen spectra of the examples and pure sugar molecules ( 1 HNMR), compared with pure sugar molecules without ZnSO4 electrolyte, the sugar molecules in the examples 1 The HNMR spectrum shifts significantly toward high field strength. This is because the sugar molecules interact with zinc ions, which increases the electron density around the sugar hydrogen atoms and reduces the chemical shift, indicating that the addition of sugar molecules can effectively regulate [Zn(D2O)6] 2+ The solvation structure of zinc anode. Figure (5) shows the X-ray diffraction (XRD) patterns of zinc anode after 100 cycles of zinc-|-zinc symmetric batteries assembled with electrolytes containing additives prepared in Example 1, Example 2, and Example 3 and the comparative example. It can be seen from the figure that different electrolytes have different effects on the orientation of zinc deposition. When sucrose is used as an additive, zinc is preferentially deposited on the (101) crystal plane. When lactose is used as an additive, zinc is preferentially deposited on the (002) crystal plane. When maltose is used as an additive, the growth rates of the (002) crystal plane and the (101) crystal plane are comparable.

[0078] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. An aqueous zinc ion battery electrolyte additive, characterized in that: It includes one or more of the carbohydrate isomer compounds; wherein the carbohydrate isomer compounds include diastereomers and enantiomers of fructose, glucose, galactose, sucrose, maltose and lactose.

2. The aqueous zinc ion battery electrolyte additive as claimed in claim 1, characterized in that: The molar concentration of the aqueous zinc ion battery electrolyte additive is 0.01M to 1M.

3. Use of the aqueous zinc ion battery electrolyte additive according to claims 1 to 2 in aqueous zinc ion batteries.

4. An aqueous zinc ion battery electrolyte, characterized in that: The aqueous zinc ion battery electrolyte comprises deionized water, a zinc salt electrolyte and the aqueous zinc ion battery electrolyte additive according to claims 1 to 2.

5. The aqueous zinc ion battery electrolyte as claimed in claim 4, characterized in that: The zinc salt electrolyte includes one or more of zinc sulfate, zinc chloride, zinc perchlorate and zinc trifluoromethanesulfonate.

6. The aqueous zinc ion battery electrolyte according to claim 4, characterized in that: The aqueous zinc ion battery electrolyte concentration is 0.5-3M.

7. Use of the aqueous zinc ion battery electrolyte as claimed in claims 4 to 6 in an aqueous zinc ion battery.

8. An aqueous zinc ion battery, characterized in that: The aqueous zinc ion battery consists of a positive electrode, a negative electrode, a separator and the aqueous zinc ion electrolyte according to any one of claims 4 to 6.

9. The aqueous zinc ion battery according to claim 8, characterized in that: The aqueous zinc ion battery comprises a positive electrode of a zinc sheet, a negative electrode of a zinc sheet, and a separator of glass fiber.

10. The aqueous zinc ion battery according to claim 9, characterized in that: The diameter of the positive electrode is 14 mm, and the diameter of the negative electrode is 15 mm.

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