CN-121974915-A - Aqueous zinc battery electrolyte based on organic amine cage additive and application thereof

Abstract

The invention provides a water-based zinc battery electrolyte based on an organic amine cage additive and application thereof, belonging to the field of electrochemical energy storage. The organic amine cage additive is a three-dimensional molecule with a permanent molecular cavity, and simultaneously, the three-dimensional molecule contains a secondary amine group, and the internal area of the three-dimensional molecule cavity is spatially separated from the external area of the cavity. The organic amine cage additive provided by the invention can be adsorbed on the surface of a zinc electrode to form an interface regulation layer, so that zinc ions at an interface are enriched, water molecules or anions at the interface are reduced, and then zinc deposition or stripping processes are improved, so that zinc deposition uniformity is improved, hydrogen evolution, corrosion or byproduct generation is reduced, and the electrolyte is simple and convenient in preparation process and easy to be compatible with the existing electrolyte system, and can be simultaneously applied to water-based zinc button cells, soft package cells and redox flow batteries.

Inventors

• CHENG HAO
• LI LAIXI
• LU YINGYING

Assignees

• 浙江大学杭州国际科创中心

Dates

Publication Date

20260505

Application Date

20260403

Claims (10)

1. 1. An organic amine cage additive, which is characterized in that the chemical structural formula of the organic amine cage additive is shown as the following formula: 。
2. 2. The method for preparing the organic amine cage additive according to claim 1, wherein the organic amine cage additive is obtained by reduction reaction of an organic imine cage.
3. 3. The preparation method according to claim 2, wherein the organic imine cage is obtained by reacting 1,3, 5-trimethylbenzene with ethylenediamine in an inert atmosphere; Wherein the mass ratio of the 1,3, 5-trimethylbenzene to the ethylenediamine is 9:5-3:2, and the reaction time is at least 24 h.
4. 4. The preparation method according to claim 3, wherein the reducing agent used in the reduction reaction is sodium borohydride, and the mass ratio of 1,3, 5-trimethylbenzene to sodium borohydride is 5:4-1:1; the temperature of the reduction reaction is room temperature for a period of at least 12 h a.
5. 5. An aqueous zinc cell electrolyte comprising a zinc salt, water and an additive, wherein the additive comprises the organic amine cage additive of claim 1.
6. 6. The aqueous zinc cell electrolyte according to claim 5, wherein the zinc salt is one or more selected from zinc sulfate, zinc acetate, zinc bromide, zinc chloride, zinc nitrate, zinc perchlorate, zinc tetrafluoroborate, zinc trifluoromethane sulfonate, and zinc bis (trifluoromethane sulfonyl) imide.
7. 7. The aqueous zinc cell electrolyte of claim 5, wherein the concentration of zinc salt in the aqueous zinc cell electrolyte is from 0.1 to 3.0M.
8. 8. The aqueous zinc cell electrolyte of claim 5, wherein the concentration of the organic amine cage additive in the aqueous zinc cell electrolyte is from 0.02 to 0.2 mM.
9. 9. The aqueous zinc cell electrolyte of claim 8, wherein the concentration of the organic amine cage additive in the aqueous zinc cell electrolyte is from 0.05 to 0.1 mM.
10. 10. The use of the aqueous zinc cell electrolyte according to any one of claims 5-9 in an aqueous zinc cell energy storage device comprising a button cell, a pouch cell and a redox flow cell.

Description

Aqueous zinc battery electrolyte based on organic amine cage additive and application thereof Technical Field The invention belongs to the field of electrochemical energy storage, and particularly relates to a water-based zinc battery electrolyte based on an organic amine cage additive and application thereof. Background In the practical charging and discharging process of the water-based zinc battery, a series of adverse reactions are easy to occur at the interface of the zinc cathode, and the cycle life and the energy efficiency of the water-based zinc battery are severely limited. The concrete steps are as follows: (1) Dendrite growth during zinc deposition can easily cause short circuit of the battery; (2) The participation of water molecules initiates hydrogen evolution reaction; (3) Electrode surface corrosion and byproduct generation; (4) Interface passivation layer formation results in increased polarization; (5) Deposition non-uniformity is exacerbated at high current or high surface capacity conditions. The root of the above problems is closely related to the electric double layer structure at the interface of the zinc electrode and the electrolyte. In the aqueous solution, the surface of the zinc electrode forms an electric double layer structure, and zinc ions, water molecules and anions in the interface area are in a certain space distribution state. When water molecules or anions are locally enriched at the interface, side reactions are easy to induce, and when zinc ions are unevenly distributed, electric field concentration is easy to form in local areas, so that dendrite growth is induced. In order to improve the interface stability of the zinc cathode, the following strategies are mainly adopted in the prior art: (1) Increasing the electrolyte salt concentration to reduce water activity; (2) Introducing a cosolvent to regulate a zinc ion solvation structure; (3) Adding organic or inorganic functional additives; (4) Coating or structural modification is carried out on the surface of the electrode. Among them, additive strategies are widely studied due to their simplicity of operation, ease of integration. For example, cui et al (Nature Energy, 2024, 9, 1350-1359) add surfactant at a concentration of 0.1 mM to the zinc battery electrolyte, which significantly improves the coulombic efficiency of the zinc anode to 99.9%. Jiang et al (SCIENCE ADVANCES, 2024, 10, eadn, 2265) introduced additives into the zinc battery electrolyte that could be self-contained on the surface of the zinc anode, achieved an orderly zinc deposition and stripping process that increased the depth of dischargeable batteries to above 90%. Zhi et al (Nature Communications, 2025, 16, 1800) introduced a threshold level of additives in the electrolyte and verified its versatility in static and flow cell systems. However, existing additives generally rely on their functional groups chemically interacting with zinc ions or electrode surfaces to improve deposition behavior. The additive regulates and controls the chemical environment of an interface mainly through local coordination or adsorption, and is difficult to reconstruct the microscopic distribution state of an electric double layer on the space structure level. Under the condition of high multiplying power or high capacity, the interface regulation and control capability is often limited. The prior art is lack of an electrolyte system which realizes zinc ion enrichment and water molecule/anion rejection by constructing a structured regulating layer with a space separation function at a zinc electrode interface through the space topological feature of a molecular structure. Therefore, how to form a stable and controllable space regulation layer on the interface through the molecular structure design so as to reconstruct the electric double layer structure and improve the reversibility of the zinc cathode is still a technical problem to be solved in the field. Disclosure of Invention Aiming at the problems that side reactions such as zinc dendrite growth, hydrogen evolution/corrosion and the like and interface passivation are easy to occur in the charge and discharge process of a water-based zinc battery to cause the limitation of cycle life and energy efficiency in the prior art, the invention provides a water-based zinc battery electrolyte based on an organic amine cage additive. The invention provides an organic amine cage additive, which has a chemical structural formula as follows: 。 The organic amine cage additive provided by the invention has a permanent molecular cavity, wherein the cavity inner area and the cavity outer area are spatially and relatively separated, the cavity inner area is a zinc-philic environment, the inner surface of the cavity inner area contains zinc ion affinity sites for coordinating with zinc ions or performing electrostatic attraction and the like, the cavity outer area is a hydrophilic environment for forming interaction with water molec