CN-122026004-A - Application of covalent organic framework material in lithium metal battery

Abstract

The invention belongs to the technical field of electrochemistry, and discloses an application of a covalent organic framework material in a lithium metal battery, wherein the covalent organic framework material is prepared through Schiff base polycondensation reaction, has an ordered porous structure, is rich in Co-N 2 O 2 and C=O active sites, and the lithium metal battery composite diaphragm prepared by using the covalent organic framework material can optimize a lithium ion migration path, optimize a lithium ion local coordination environment, inhibit growth of lithium dendrites, promote formation of a stable SEI layer, realize a stable lithium deposition/stripping process, remarkably improve coulombic efficiency and improve stability and safety of the lithium metal battery.

Inventors

• WU MANMAN
• ZHANG HAO
• ZHOU ZHEN

Assignees

• 郑州大学

Dates

Publication Date

20260512

Application Date

20260123

Claims (5)

1. 1. Use of a covalent organic framework material in a lithium metal battery, characterized in that the covalent organic framework material has the structural formula: 。
2. 2. The method for preparing the covalent organic framework material according to claim 1, wherein the preparation method comprises the steps of adding 2, 5-dihydroxyterephthalaldehyde, 2,3,5, 6-tetra (amino) p-benzoquinone and cobalt acetate tetrahydrate into a container, adding N-methylpyrrolidone, carrying out ultrasonic treatment for 0.5h, transferring into a hydrothermal reaction kettle, carrying out sealing reaction for 48-96 h at 100-150 ℃, naturally cooling to room temperature after the reaction is finished, filtering and collecting obtained precipitate, washing, and carrying out vacuum drying at 60-120 ℃ to obtain the covalent organic framework material.
3. 3. The use according to claim 2, wherein the molar ratio of 2, 5-dihydroxyterephthalaldehyde, 2,3,5, 6-tetra (amino) p-benzoquinone and cobalt acetate tetrahydrate is 2:1:2-6.
4. 4. The use according to claim 1, characterized in that the separator of the lithium metal battery is coated with a hybrid coating consisting of covalent organic framework material, conductive carbon black and polyvinylidene fluoride.
5. 5. The use according to claim 4, wherein the mass ratio of the covalent organic framework material, the conductive carbon black and the polyvinylidene fluoride is 5-8:4-1:1.

Description

Application of covalent organic framework material in lithium metal battery Technical Field The invention belongs to the technical field of electrochemistry, and relates to application of a covalent organic framework material in a lithium metal battery. Background Lithium metal batteries are considered as important candidates for next generation high energy density batteries due to their high theoretical capacity (3830 mAh g -1) and low operating potential (-3.04V vs. SHE). However, the problems of uncontrolled growth of lithium dendrites and instability of Solid Electrolyte Interfaces (SEI) severely limit practical applications. Commercial polyolefin separators (e.g., PP) have good mechanical strength, but poor electrolyte wettability and lack of functional sites, resulting in high ion transport resistance, exacerbating lithium deposition non-uniformity. Covalent organic frameworks (Covalent Organic Frameworks, COFs) exhibit potential in membrane functionalization due to their ordered porous structure and regulatable active sites. The unique one-dimensional ordered channels not only provide an effective transmission path for lithium ions, but also enable active functional groups in the structure to anchor the lithium ions through coordination interaction, adjust solvation structures, induce uniform nucleation and deposition and improve the performance of the lithium metal battery. Disclosure of Invention Aiming at the technical problems of the diaphragm for the lithium metal battery, the invention provides application of a covalent organic frame material in the lithium metal battery, wherein the covalent organic frame material has an ordered porous structure and is rich in Co-N 2O2 and C=O active sites, and the lithium metal battery composite diaphragm prepared by using the covalent organic frame material can optimize a lithium ion migration path, optimize a lithium ion local coordination environment, inhibit growth of lithium dendrites, promote formation of a stable SEI layer, realize a stable lithium deposition/stripping process, remarkably improve coulomb efficiency and improve stability and safety of the lithium metal battery. In order to achieve the above purpose, the present invention adopts the following technical scheme: In a first aspect, the present invention provides the use of a covalent organic framework material in a lithium metal battery, the covalent organic framework material having the structural formula: 。 According to the technical scheme, the preparation method of the covalent organic framework material comprises the following steps of adding 2, 5-dihydroxyterephthalaldehyde, 2,3,5, 6-tetra (amino) p-benzoquinone and cobalt acetate tetrahydrate into a container, then adding N-methylpyrrolidone, transferring the container into a hydrothermal reaction kettle after ultrasonic treatment for 0.5h, carrying out sealing reaction for 48-96 h at 100-150 ℃, naturally cooling to room temperature after the reaction is finished, filtering and collecting obtained precipitate, washing, and carrying out vacuum drying at 60-120 ℃ to obtain the covalent organic framework material. In the technical scheme, the molar ratio of the 2, 5-dihydroxyterephthalaldehyde to the 2,3,5, 6-tetra (amino) p-benzoquinone to the cobalt acetate tetrahydrate is 2:1:2-6. In the technical scheme, the separator of the lithium metal battery is coated with a mixed coating consisting of a covalent organic frame material, conductive carbon black and polyvinylidene fluoride. Preferably, the separator is a commercial polypropylene separator. In the technical scheme, the mass ratio of the covalent organic framework material to the conductive carbon black to the polyvinylidene fluoride is 5-8:4-1:1. Compared with the prior art, the invention has the beneficial effects that: According to the invention, 2, 5-dihydroxyterephthalaldehyde (HBC) and 2,3,5, 6-tetra (amino) p-benzoquinone (TABQ) are used as organic ligands, cobalt acetate tetrahydrate is simultaneously introduced to jointly perform Schiff base polycondensation reaction, and a covalent organic framework material Co-COF is constructed through molecular design. Compared with the traditional COFs, the covalent organic framework material Co-COF has an ordered porous structure and is rich in Co-N 2O2 and C=O active sites. The PP diaphragm modified by the covalent organic framework material Co-COF can be used for constructing a functional coating on the surface of the diaphragm, optimizing a lithium ion migration path through a highly ordered one-dimensional channel of the Co-COF, improving electrolyte wettability and ion transmission efficiency of the diaphragm, combining with a lithium-philic site (Co-N 2O2 and C=O), selectively anchoring lithium ions, optimizing a local coordination environment of the lithium ions, and inhibiting lithium dendrite growth. Thanks to the characteristics, the Li symmetric battery assembled by the composite diaphragm Co-COF@PP realizes stable lithium