CN-117865292-B - Polar plate for extracting lithium through electrodeionization and preparation method and application thereof

Abstract

The invention provides a polar plate for extracting lithium by electric desorption, a preparation method and application thereof, wherein the polar plate for extracting lithium by electric desorption comprises a porous current collector and slurry coatings at two sides of the porous current collector, the slurry coating on both sides of the porous current collector is connected through the pores of the porous current collector, and the slurry coating comprises a structural agent. The polar plate for extracting lithium by electrodialyzing is embedded into the current collector through the slurry coating containing the structural agent, so that the polar plate with the three-dimensional conductive net structure and line contact is formed, the erosion resistance of the polar plate can be improved, and the conductivity and the lithium extraction capability of the polar plate can be improved.

Inventors

• CHEN DINGFANG
• RUAN DINGSHAN
• LU ZHIYUAN
• QIAO YANCHAO
• LI JIAMING
• LI CHANGDONG

Assignees

• 广东邦普循环科技有限公司
• 湖南邦普循环科技有限公司

Dates

Publication Date

20260505

Application Date

20240220

Claims (17)

1. 1. The electrode plate for extracting lithium through electrical separation is characterized by comprising a porous current collector and slurry coatings at two sides of the porous current collector, wherein the slurry coatings at two sides of the porous current collector are connected through holes of the porous current collector, and the slurry coatings comprise a structural agent; the slurry coating also comprises a conductive agent, a binder, a hydrophilic agent and an active material after lithium removal; The structural agent comprises a conductive high-molecular structural agent and a conductive fiber structural agent; The conductive high molecular structural agent comprises any one or a combination of at least two of polyacetylene, polyaniline, polypyrrole, polyaromatic hydrocarbon, polyheteroaromatic hydrocarbon or phthalocyanine chelate; The conductive fiber structurant comprises carbon fibers; in the preparation raw materials of the slurry coating, the content of the structural agent is 1.5-5.5wt% based on 100% of solid mass fraction, and the content of the conductive fiber structural agent is 20-80% of the conductive polymer structural agent.
2. 2. The electrode plate for extracting lithium by electrodeionization according to claim 1, wherein the porous current collector comprises a surface-treated porous current collector.
3. 3. The electrode plate for extracting lithium by electrodeionization according to claim 2, wherein the porous current collector is a frosted surface-treated porous current collector.
4. 4. The electrode plate for extracting lithium by electrodeionization according to claim 1, wherein the thickness of the porous current collector is 0.6 to 1.3mm.
5. 5. The electrode plate for extracting lithium by electrodeionization according to claim 1, wherein the porous current collector has a diamond shape or a triangle shape.
6. 6. The electrode plate for extracting lithium by electrodeionization according to claim 1, wherein the porous current collector comprises any one or a combination of at least two of ruthenium-plated iridium-titanium mesh, porous graphite plate, carbon-plated copper mesh, or carbon-plated aluminum mesh.
7. 7. The electrode plate for extracting lithium by electrodeionization according to claim 1, wherein the slurry coating is prepared from the raw materials of 65 to 90wt% of active material, 4 to 10wt% of conductive agent, 4 to 15wt% of binder and 2 to 10wt% of hydrophilic agent by solid mass fraction of 100%.
8. 8. The electrode plate for electrodeionization and extraction of lithium of claim 7, wherein the active material comprises lithium iron phosphate.
9. 9. The electrode plate for lithium intercalation/deintercalation according to claim 7, wherein the conductive agent comprises any one or a combination of at least two of SP, KS-6 or ketjen black.
10. 10. The electrode plate for extracting lithium by electrodeionization according to claim 7, wherein the binder comprises any one or a combination of at least two of PVDF, VW770, and HSV 900.
11. 11. The electrode plate for lithium electrodeintercalation according to claim 7, wherein the hydrophilic agent comprises any one or a combination of at least two of PEG, polydopamine, chitosan, and polyvinyl alcohol.
12. 12. A method for preparing the electrode plate for extracting lithium by electrodeionization according to any one of claims 1 to 11, comprising the steps of: and coating the coating slurry on two sides of the porous current collector, and drying and removing lithium to obtain the polar plate for extracting lithium through electrodeionization.
13. 13. The method of claim 12, wherein the porous current collector is subjected to a frosted surface treatment prior to the coating on both sides of the porous current collector.
14. 14. The method of claim 13, wherein the sanded surface treatment comprises sand blasting and/or shot blasting.
15. 15. The method of claim 12, wherein the coating slurry is applied to a thickness of 1-2mm and the coating slurry is applied to a mass of 1.5-3g.
16. 16. The method of claim 12, wherein the method of preparing the coating slurry comprises mixing the hydrophilic agent with the solvent in the amount of the formulation, adding the binder, adding the conductive agent and the active material, stirring and mixing, and adding the structurant and mixing.
17. 17. An electrical lithium extraction device, characterized in that the electrical lithium extraction device comprises the electrode plate for electrical lithium extraction according to any one of claims 1-11.

Description

Polar plate for extracting lithium through electrodeionization and preparation method and application thereof Technical Field The invention belongs to the technical field of electrochemical lithium extraction, and relates to a polar plate for extracting lithium through electrodeionization and a preparation method and application thereof. Background With the rapid development of new energy industry, the significance of lithium resources is more important. Aiming at the lithium extraction of salt lakes, the existing mature salt lake brine lithium extraction industrial technology such as an adsorbent adsorption method, a solvent extraction method, an ionic membrane electrodialysis method, a calcination method and a solar cell method has the problems of low lithium extraction efficiency, serious environmental pollution, high cost and the like although the technology has the characteristics. At present, new lithium extraction processes such as an electrochemical deintercalation method, a novel extraction and adsorption method, a coupling membrane method and the like appear. The electrochemical deintercalation method lithium extraction technology is development of the traditional lithium extraction method, is suitable for a low-grade and complex salt lake brine system, and has the advantages of strong adaptability to raw materials, modularization of a lithium extraction device, high lithium extraction efficiency, low cost and the like. The electrochemical deintercalation lithium extraction technology comprises the steps of carrying out electric deintercalation lithium extraction on salt lake brine by adopting a salt lake brine water deintercalation lithium extraction device, wherein the salt lake brine water deintercalation lithium extraction device comprises an electrolytic tank, an anion exchange membrane, an anode and a cathode, the anion exchange membrane is arranged in the electrolytic tank to vertically divide the electrolytic tank into a cathode chamber and an anode chamber, the anode is arranged in the anode chamber, the cathode is arranged in the cathode chamber, voltage is applied to the cathode and the anode to carry out electric deintercalation lithium extraction, and the anode electrolyte is added in the anode chamber in the electric deintercalation lithium extraction process. Therefore, taking a LiFePO 4/FePO4 electrode system as an example, an anion selective exchange membrane is used for dividing an electrolytic cell into two compartments, liFePO 4 is used as a lithium-rich electrode and is placed in a recovery chamber, fePO 4 is used as a lithium-poor electrode and is placed in raw material brine, a forward electric field is applied in the electrolytic cell, the lithium-rich electrode performs oxidation (lithium removal) reaction, the lithium-poor electrode performs reduction (lithium intercalation) reaction, but a polar plate is continuously flushed in the electrolytic cell, the integrity and the service life of the polar plate seriously influence the lithium extraction efficiency, and the lithium extraction density of the current electric deintercalation lithium extraction technology is lower. Based on the above research, although the electric deintercalation lithium extraction has obvious advantages, the aspect of water flushing resistance of the polar plate still needs to be improved, and optimization and improvement are needed, so that the polar plate for the electric deintercalation lithium extraction needs to be provided, and has higher flushing capability and can improve the lithium extraction performance. Disclosure of Invention The invention aims to provide an electrodeletric lithium-extracting polar plate, a preparation method and application thereof, wherein the electrodeletric lithium-extracting polar plate is embedded into a current collector through a slurry coating containing a structural agent, so that a very firm polar plate with a three-dimensional conductive net structure and line contact is formed, and the scouring resistance of the polar plate and the conductivity and lithium-extracting capability of the polar plate can be improved. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the invention provides an electrode plate for extracting lithium by electrodialyzing, which comprises a porous current collector and slurry coatings on two sides of the porous current collector, wherein the slurry coatings on two sides of the porous current collector are connected through holes of the porous current collector, and the slurry coatings comprise a structural agent. According to the invention, the structural agent capable of enhancing mechanical properties is added into the slurry coating, the slurry coating is coated on two sides of the porous current collector, the slurry coating is connected with each other through the structural agent and the porous structure of the current collector, and the slurry coating penetr