CN-117673240-B - Preparation method and application of monocrystal metal zinc negative electrode

Abstract

A preparation method and application of a monocrystal metallic zinc cathode are provided, and a polycrystal metallic zinc foil with the purity of more than 98wt% arranged between two inert heat conducting materials is subjected to melting recrystallization in vacuum or inert atmosphere to prepare a Zn (002) monocrystal zinc foil with the closest packing surface. Compared with single crystals of polycrystal or other crystal faces, the metal zinc anode prepared by the method has the advantages that side reactions on an electrolyte/anode interface are obviously inhibited, the formation of corrosion bubbles and passivation layers on the surface of the anode can be effectively relieved, the circulation stability is improved, meanwhile, single crystal zinc plays a role of an epitaxial template within a certain deposition capacity range, conformal deposition behavior of zinc is guided, dendrite-free growth is realized, and the cycle life of a battery is prolonged.

Inventors

• LUO JIAYAN
• REN LINGXIAO

Assignees

• 上海交通大学

Dates

Publication Date

20260512

Application Date

20220830

Claims (3)

1. 1. A preparation method of a monocrystal metallic zinc cathode is characterized in that a polycrystal metallic zinc foil with the purity of more than 98 percent and wt percent, which is arranged between two pieces of inert heat conducting materials, is subjected to melting recrystallization in vacuum or inert atmosphere to prepare a monocrystal zinc foil with the closest packing surface Zn (002); The melt recrystallization is that in vacuum or inert atmosphere, the temperature is raised to 20-200 ℃ above the melting point and then the temperature is kept constant, the temperature is reduced at a constant speed and the temperature is kept constant and annealed at 20-50 ℃ below the melting point, and then the temperature is cooled to room temperature along with the furnace; the inert heat conduction material is graphite; the temperature is raised at a rate of 5-10 ℃ per minute, and the temperature is lowered at a rate of 5-10 ℃ per minute; the constant temperature is maintained for 1-10 min; and the annealing time is more than or equal to 30 min.
2. 2. The method for producing a single crystal metallic zinc anode according to claim 1, wherein the thickness of the polycrystalline metallic zinc foil is 10 μm or more.
3. 3. The method of claim 1, wherein the inert atmosphere is injected into the chamber at a rate of 1 sccm to 500 sccm.

Description

Preparation method and application of monocrystal metal zinc negative electrode Technical Field The invention relates to a technology in the field of zinc ion batteries, in particular to a preparation method of a monocrystal metal zinc anode material and application of the monocrystal metal zinc anode material in a water-based battery. Background The performance of the existing zinc metal electrode is mainly limited by low Coulombic Efficiency (CE), high voltage polarization and failure tendency (Energy & Environmental Science 2021,14,5669) caused by dendrite growth, in order to solve the problems, researchers carry out certain improvements by surface modification, structural design, electrolyte optimization, non-metal negative electrode and other methods (Energy & Environmental Materials 2020,2,146), but most of current research strategies can only temporarily inhibit or slow down dendrite growth and interfacial side reaction to a certain extent, and adverse factors cannot be fundamentally avoided or eliminated. Therefore, developing an intrinsic high-stability metal zinc anode is important to prolonging the service life of a battery and realizing the practical development of a zinc ion battery. Disclosure of Invention Aiming at the defects of the prior art, such as gas/liquid/solid three-phase transformation and oxidation reaction and complex operation, the invention provides a preparation method and application of a monocrystal metallic zinc negative electrode, wherein the prepared metallic zinc negative electrode has stronger corrosion resistance in electrolyte and higher deposition/dissolution reversibility, compared with polycrystal or monocrystal with other crystal faces, the side reaction on the interface of the electrolyte/negative electrode is obviously inhibited, the formation of corrosion bubbles and passivation layers on the surface of the negative electrode can be effectively relieved, the circulation stability is improved, meanwhile, monocrystal zinc plays the role of an epitaxial template within a certain deposition capacity range, the conformal deposition behavior of zinc is guided, the growth without dendrite is realized, and the cycle life of a battery is prolonged. The invention is realized by the following technical scheme: the invention relates to a preparation method of a monocrystal metallic zinc cathode, which comprises the step of carrying out melting recrystallization on a polycrystal metallic zinc foil with the purity of more than 98wt% arranged between two inert heat conducting materials in vacuum or inert atmosphere to prepare a Zn (002) monocrystal zinc foil with the closest packing surface. The melt recrystallization is that in vacuum or protective atmosphere, the temperature is raised to 20-200 ℃ above the melting point and then the temperature is kept constant, the temperature is reduced at a constant speed and the temperature is kept constant and annealed at 20-50 ℃ below the melting point, and then the temperature is cooled to room temperature along with the furnace. The thickness of the polycrystalline zinc foil is preferably greater than or equal to 10 micrometers. The inert atmosphere is preferably injected into the chamber at 1sccm to 500 sccm; The inert heat conducting material is a material which does not have alloying and other interactions with molten metal zinc at high temperature and has excellent heat conducting property, and is preferably graphite. The temperature is increased at a rate of 5-10 ℃ per minute, and the temperature is decreased at a rate of-5-10 ℃ per minute. The constant temperature is preferably kept for 1-10 min. The annealing is preferably performed for 30min or more. The invention relates to an application of a monocrystal metal zinc negative electrode prepared based on the method, which is used as a metal zinc secondary battery negative electrode, enables zinc to be conformally deposited along a specific orientation, and inhibits interface side reaction. The step of inhibiting the interface side reaction is that the prepared monocrystal metal zinc cathode assembled symmetrical battery is placed in a zinc sulfate aqueous solution electrolyte system, and the monocrystal metal zinc cathode assembled symmetrical battery shows the circulation stability obviously superior to that of polycrystalline zinc foil under different multiplying powers. Technical effects Compared with the existing technical methods for preparing single crystals, such as a Czochralski method, a crucible descent method, a zone melting method and the like, the product is generally rod-shaped or columnar, is unfavorable for subsequent treatment and processing, and can not maintain the original single crystal structure after processing. In a zinc sulfate aqueous solution electrolyte system, the monocrystal metal zinc foil cathode prepared by the method plays a guiding role in the deposition and dissolution behaviors of zinc ions, effectively inhibits interface side reactions, an