CN-122025853-A - Aqueous zinc ion battery electrolyte, aqueous zinc ion battery and application thereof

Abstract

The invention discloses a water-based zinc ion battery electrolyte, a water-based zinc ion battery and application thereof, and belongs to the technical field of water-based zinc ion batteries. The electrolyte comprises a compound with the concentration of 0.02-0.4 mol/L, wherein a and c are integers of 1-6, and b is an integer of 0-5, the additive is preferentially adsorbed on the surface of a zinc negative electrode to form a protective layer through amino groups, meanwhile, the hydroxyl groups can regulate and control a solvation structure of Zn 2+ , the water content of a Helmholtz plane in an electrode/electrolyte interface is obviously reduced through synergistic effect, and side reactions are effectively inhibited from sources.

Inventors

• WANG MENGLEI
• RAO ZHIQIANG
• ZHANG MENG
• GUO SHAOZHENG
• Shang Cancan

Assignees

• 河南工业大学
• 济源星翰新材料科技有限公司

Dates

Publication Date

20260512

Application Date

20260116

Claims (10)

1. 1. The aqueous zinc ion battery electrolyte comprises a solvent, a soluble zinc salt and an additive, and is characterized in that the concentration of the additive in the electrolyte is 0.02-0.4 mol/L, and the additive is a compound with the following general formula: HO-(CH 2 ) a -CH(-(CH 2 ) b -NH 2 )-(CH 2 ) c -OH wherein a and c are integers of 1 to 6, and b is an integer of 0 to 5.
2. 2. The aqueous zinc-ion battery electrolyte according to claim 1, wherein the additive is serinol.
3. 3. The aqueous zinc-ion battery electrolyte according to claim 2, wherein the concentration of serinol in the electrolyte is 0.05-0.2 mol/L.
4. 4. The aqueous zinc-ion battery electrolyte according to claim 1 to 3, wherein the soluble zinc salt is at least one of zinc sulfate, zinc trifluoromethane sulfonate, zinc chloride and zinc nitrate.
5. 5. The aqueous zinc-ion battery electrolyte according to claim 4, wherein the concentration of the soluble zinc salt in the electrolyte is 0.2 to 7mol/L.
6. 6. A water-based zinc ion battery comprises a positive electrode, a negative electrode, a diaphragm and a battery electrolyte, and is characterized in that the battery electrolyte is the water-based zinc ion battery electrolyte according to any one of claims 2-5.
7. 7. The aqueous zinc-ion battery according to claim 6, wherein the active material of the positive electrode is at least one of a vanadium-based compound, a manganese-based compound, a Prussian blue analog, and a carbon material.
8. 8. The aqueous zinc-ion battery according to claim 7, wherein the active material of the positive electrode is cesium-doped ammonium vanadate.
9. 9. The aqueous zinc-ion battery according to claim 6, wherein the separator is one selected from the group consisting of a glass fiber separator, a polypropylene separator, a polyethylene separator and a nanopore separator.
10. 10. Use of the aqueous zinc-ion battery of claims 6-8 in an energy storage system, an electric vehicle or a portable electronic device.

Description

Aqueous zinc ion battery electrolyte, aqueous zinc ion battery and application thereof Technical Field The invention belongs to the technical field of electrochemical energy storage, and particularly relates to a water-based zinc ion battery electrolyte, a water-based zinc ion battery and application thereof. Background The water-based zinc ion battery (AZIBs) has the advantages of low cost, high safety, environmental friendliness and the like, and is paid attention to the field of large-scale energy storage. However, during the cycling of its practical application, uneven deposition of zinc ions tends to cause dendrite growth, possibly penetrating the separator to cause cell shorting, and at the same time, hydrogen Evolution Reactions (HER) involving active water molecules in the electrolyte, corrosion and by-products associated with the formation (e.g., basic zinc sulfate) irreversibly consume the active species and degrade the electrode interface, which together lead to rapid decay of cell capacity and reduced cycle life. To address the above challenges, the introduction of functional additives into electrolytes is an effective and easily industrialized strategy. The research of the existing additives is mainly focused on two main categories: The first class of additives focuses on regulating the solvation structure of zinc ions in bulk electrolytes to reduce the number of reactive water molecules. For example, small molecule alcohol additives (e.g., propylene glycol, tripropylene glycol, etc.) form hydrogen bonds with water molecules through their hydroxyl groups, competitively enter the solvating sheath of Zn 2+, partially replace the coordinated water therein, and thereby inhibit side reactions such as hydrogen evolution to some extent (see CN116365067A, CN114725537 a). Propylene Glycol (PG) has been demonstrated to reconstruct Zn 2+ solvated sheaths and stabilize hydrogen bond networks, achieving a cycle life of 3500 hours in symmetric cells (j.li et al, adv.function. Mater 2023, 2307201). However, such molecules have weak adsorption to the zinc anode surface, limited active guiding and interfacial protection capabilities for zinc deposition orientation, resulting in bottlenecks in battery cycle life improvement, which is often difficult to break through for 2000 hours under moderate test conditions (0.5-1 mA/cm 2,0.25-1mAh/cm2), and the improvement effect often depends on higher additive concentrations. The second type of additive is focused on enhancing interfacial adsorption and protection on the surface of the zinc anode. For example, amino acid additives (e.g., serine, methionine, etc.) can strongly adsorb to zinc surface by virtue of their polar groups such as amino groups, carboxyl groups, etc., forming a protective layer, inhibiting interfacial side reactions (see CN116544530A, CN120637630 a). Recent studies have also found that methionine (Met) can build a water-poor interface on the zinc surface by synergistic adsorption of amino groups and methylthio groups, and exert pH buffering effects, inhibiting by-product formation, and achieving cycle life of symmetrical cells over 3200 hours (l. Pen et al, chip. J. Struct. Chem. 2025, 100542). However, the mechanism of action of such additives often depends on the strong coordination ability of the carboxyl groups, which have a relatively weak tuning effect on the bulk solvated structure, and while some studies have led to a symmetrical cell life extension of more than 3000 hours by using such additives, higher addition concentrations are often required to achieve significant effects, which may increase costs and negatively impact ion conductivity. There have also been studies attempting to optimize zinc deposition behavior by adjusting deposition overpotential. For example, tripropylene Glycol (TG) as a bifunctional additive can participate in zn2+ solvation sheath modulation as well as form an adsorbed layer on the zinc surface, promoting uniform deposition by adjusting the appropriate overpotential, achieving a coulombic efficiency of 99.8% in Zn/Cu cells (z.liu et al, adv.funct, mate, 2024, 2214538). However, the addition amount thereof needs to be precisely controlled, and excessive amount may cause decrease in ionic conductivity and excessive overpotential, which are rather unfavorable for long-term circulation. More intensive studies have shown that many key side reactions occur centrally in the helmholtz plane (IHP) of the innermost layer of the electrode/electrolyte interface. The water molecule content of the IHP region directly determines the interfacial water activity and the severity of side reactions. The ideal electrolyte additive can cooperatively realize dual functions of (1) preferentially adsorbing on the surface of a zinc anode, constructing a physical barrier and directly reducing water molecule contact in an IHP region, (2) effectively regulating and controlling the bulk solvation structure of Zn 2+ and reducing the number of