CN-122025856-A - Electrolyte for water-based zinc ion battery, preparation method of electrolyte and water-based zinc ion battery

Abstract

The invention discloses an electrolyte for a water-based zinc ion battery, a preparation method thereof and the water-based zinc ion battery, wherein the electrolyte for the water-based zinc ion battery comprises zinc salt, water and a cationic surfactant; the cationic surfactant is octyl trimethyl ammonium chloride or dodecyl trimethyl ammonium chloride. The cationic surfactant used in the electrolyte of the water-based zinc ion battery forms an ion channel interface layer on the surface of the zinc anode, blocks water erosion, inhibits side reaction, increases zinc ion nucleation overpotential, and limits two-dimensional diffusion of zinc ions on the surface of the anode, thereby inducing uniform directional deposition and inhibiting dendrite growth. The water-based zinc ion battery has long cycle life and high coulombic efficiency.

Inventors

• WANG YUNXIAO
• ZHU KUNJIE
• LI CHENGFENG
• YAO LONG
• Ni Chaotian

Assignees

• 上海理工大学

Dates

Publication Date

20260512

Application Date

20260303

Claims (10)

1. 1. An electrolyte for an aqueous zinc ion battery, comprising zinc salt, water and a cationic surfactant; the cationic surfactant is octyl trimethyl ammonium chloride or dodecyl trimethyl ammonium chloride.
2. 2. The electrolyte for an aqueous zinc-ion battery according to claim 1, wherein the zinc salt is one of zinc sulfate heptahydrate and zinc trifluoromethane sulfonate.
3. 3. The electrolyte for an aqueous zinc-ion battery according to claim 2, wherein the concentration of the zinc salt is 0.5 to 3mol/L.
4. 4. The electrolyte for an aqueous zinc ion battery according to claim 1, wherein the concentration of the cationic surfactant is 0.1 to 10mmol/L.
5. 5. The method for preparing the electrolyte for the aqueous zinc-ion battery according to any one of claims 1 to 4, characterized by comprising the following steps: dissolving a cationic surfactant in water to obtain a cationic surfactant solution; Dissolving zinc salt in water to obtain zinc salt solution; And adding the cationic surfactant solution into the zinc salt solution, and stirring to obtain the electrolyte for the water-based zinc ion battery.
6. 6. An aqueous zinc ion battery, characterized by comprising the electrolyte for an aqueous zinc ion battery according to any one of claims 1 to 4.
7. 7. The aqueous zinc-ion battery according to claim 6, further comprising a positive electrode, a negative electrode, and a separator.
8. 8. The aqueous zinc-ion battery of claim 7, wherein the positive electrode comprises a positive electrode active material, a conductive agent, a binder, and a current collector; and/or, the negative electrode is zinc foil; And/or, the separator is a glass fiber film.
9. 9. The aqueous zinc-ion battery according to claim 8, wherein the positive electrode active material is one of vanadium dioxide and polymerized 2, 3-diaminophenazine; and/or the conductive agent is one of ketjen black, conductive carbon black, super P and acetylene black; and/or the binder is one of polytetrafluoroethylene and polyvinylidene fluoride; and/or the current collector is one of a titanium mesh and a titanium foil; And/or the mass ratio of the positive electrode active material to the conductive agent to the binder is (7-8): 1-2): 1.
10. 10. The aqueous zinc-ion battery according to claim 8, wherein the positive electrode is prepared by mixing a positive electrode active material, a conductive agent and a binder, and then coating the mixture on a current collector.

Description

Electrolyte for water-based zinc ion battery, preparation method of electrolyte and water-based zinc ion battery Technical Field The invention belongs to the technical field of batteries, and particularly relates to an electrolyte for a water-based zinc ion battery, a preparation method of the electrolyte and the water-based zinc ion battery. Background The water-based zinc ion battery (AZIBs) is widely focused on the application of energy storage on the scale of a power grid due to low cost, nonflammability and simple manufacturing process. However, dendrite growth and interfacial side reactions of zinc metal anodes during cycling have greatly limited the use of aqueous zinc ion batteries. Dendrite formation is accompanied by zinc deposition/dissolution non-uniformity, and part of the zinc cannot participate in the reaction, resulting in a decrease in coulombic efficiency. In severe cases dendrites can puncture the separator, resulting in the cell not being operational. Deposition of zinc ions occurs in the Electric Double Layer (EDL) region of the electrode/electrolyte interface. The zinc ions hydrate (Zn (H 2O)62+)) in the electrolyte are desolvated and diffuse freely from the outer helmholtz layer into the inner helmholtz layer, close to the electrode surface. At present, some electrolyte modification strategies have been reported to optimize the EDL environment, however, the existing modification strategies are costly or poorly optimized, and therefore it is highly necessary to develop a low-cost high-performance electrolyte. Disclosure of Invention In order to solve the problems set forth in the background art, the invention aims to provide an electrolyte for an aqueous zinc ion battery, a preparation method thereof and the aqueous zinc ion battery. The cationic surfactant used in the electrolyte of the water-based zinc ion battery forms an ion channel interface layer on the surface of the zinc anode, blocks water erosion, inhibits side reaction, increases zinc ion nucleation overpotential, and limits two-dimensional diffusion of zinc ions on the surface of the anode, thereby inducing uniform directional deposition and inhibiting dendrite growth. The water-based zinc ion battery has long cycle life and high coulombic efficiency. In order to achieve the aim, the invention adopts the technical scheme that on one hand, the invention provides an electrolyte for a water-based zinc ion battery, which comprises zinc salt, water and cationic surfactant; the cationic surfactant is octyl trimethyl ammonium chloride (C8) or dodecyl trimethyl ammonium chloride (C10). Further, the zinc salt is one of zinc sulfate heptahydrate (ZnSO 4·7H2 O) and zinc trifluoromethane sulfonate (Zn (OTf) 2). Further, the concentration of the zinc salt is 0.5-3 mol/L, preferably 2mol/L. Further, the concentration of the cationic surfactant is 0.1-10 mmol/L, preferably 0.5mmol/L. In another aspect, the present invention provides a method for preparing the electrolyte for an aqueous zinc-ion battery, which comprises the following steps: dissolving a cationic surfactant in water to obtain a cationic surfactant solution; Dissolving zinc salt in water to obtain zinc salt solution; And adding the cationic surfactant solution into the zinc salt solution, and stirring to obtain the electrolyte for the water-based zinc ion battery. In another aspect, the invention provides an aqueous zinc-ion battery comprising any one of the electrolytes for aqueous zinc-ion batteries described above. Further, a positive electrode, a negative electrode, and a separator are included. Further, the positive electrode includes a positive electrode active material, a conductive agent, a binder, and a current collector; and/or, the negative electrode is zinc foil; And/or, the separator is a glass fiber film. Further, the positive electrode active material is one of vanadium dioxide (VO 2) and polymeric 2, 3-diaminophenazine (p-DAP); and/or the conductive agent is one of ketjen black, conductive carbon black, super P and acetylene black; And/or the binder is one of Polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF); and/or the current collector is one of a titanium mesh and a titanium foil; And/or the mass ratio of the positive electrode active material to the conductive agent to the binder is (7-8): 1-2): 1. The preparation method of the positive electrode comprises the steps of mixing a positive electrode active material, a conductive agent and a binder, and then coating the mixture on a current collector to prepare the positive electrode. Further, the model of the water-based zinc ion battery comprises CR2032 and a soft package battery) Etc. The mechanism of the invention is that the cationic surfactant can be adsorbed on the zinc anode during the operation process of the water system zinc ion battery, so as to construct a stable ion channel, widen the EDL and optimize the electrode/electrolyte interface. Zinc ions in the double electric layer are