An electrode plate for lithium extraction and intercalation and a preparation method and application thereof

Abstract

This invention provides an electrode plate for electro-deintercalation and extraction of lithium, its preparation method, and its application. The electrode plate comprises a porous current collector and slurry coatings on both sides of the porous current collector. The slurry coatings on both sides of the porous current collector are connected through the pores of the current collector, and the slurry coatings include a structural agent. The electrode plate of this invention, by embedding the slurry coating containing the structural agent into the current collector, forms an extremely robust three-dimensional conductive mesh structure electrode plate with line contact, which improves both the electrode plate's erosion resistance and its conductivity and lithium extraction capability.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical lithium extraction technology, and relates to an electrode plate for electro-deintercalation and extraction of lithium, its preparation method and application. Background Technology

[0002] With the rapid development of the new energy industry, the significance of lithium resources is becoming increasingly important. For lithium extraction from salt lakes, there are already mature industrialized technologies such as adsorbent adsorption, solvent extraction, ion-exchange membrane electrodialysis, calcination, and solar pond methods. Although each has its own characteristics, they all suffer from low lithium extraction efficiency, severe environmental pollution, and high costs. Currently, new lithium extraction processes such as electrochemical deintercalation, novel extraction and adsorption methods, and coupled membrane methods have emerged.

[0003] Among them, the electrochemical deintercalation and insertion method for lithium extraction is an improvement on traditional lithium extraction methods. It is suitable for low-grade and complex salt lake brine systems and has advantages such as strong adaptability to raw materials, modular lithium extraction equipment, high lithium extraction efficiency, and low cost.

[0004] Specifically, the electrochemical deintercalation and extraction lithium extraction technology requires the use of electrode systems such as LiFePO4 / FePO4 to achieve selective extraction of lithium from salt lake brines. For example, CN 116964233A discloses an application of lithium ferrocyanide, an anode electrolyte, and a method for electrochemical deintercalation and extraction of lithium from salt lake brines. This method includes using a salt lake brine electrochemical deintercalation and extraction lithium device to perform electrochemical deintercalation and extraction of lithium from salt lake brines. The salt lake brine electrochemical deintercalation and extraction lithium device includes an electrolytic cell, an anion exchange membrane, an anode, and a cathode. The anion exchange membrane is placed in the electrolytic cell, which is vertically divided into a cathode chamber and an anode chamber. The anode is placed in the anode chamber, and the cathode is placed in the cathode chamber. A voltage is applied to the cathode and anode to perform electrochemical deintercalation and extraction of lithium. During the electrochemical deintercalation and extraction process, an anode electrolyte is added to the anode chamber.

[0005] Therefore, taking the LiFePO4 / FePO4 electrode system as an example, the electrolyzer is divided into two compartments using an anion selective exchange membrane. LiFePO4 is placed in the recovery compartment as the lithium-rich electrode, and FePO4 is placed in the raw material brine as the lithium-poor electrode. A positive electric field is applied in the electrolyzer, and the lithium-rich electrode undergoes oxidation (delithiation) reaction, while the lithium-poor electrode undergoes reduction (lithiation) reaction. However, the electrode plates will be continuously eroded in the electrolyzer, and the integrity and lifespan of the electrode plates seriously affect the lithium extraction efficiency. Moreover, the current electro-deintercalation lithium extraction technology has a low lithium extraction density.

[0006] Based on the above research, although electro-deintercalation and lithium extraction has obvious advantages, the resistance of the electrode plate to water erosion still needs to be improved and optimized. Therefore, it is necessary to provide an electrode plate for electro-deintercalation and lithium extraction that has high erosion resistance and can improve lithium extraction performance. Summary of the Invention

[0007] The purpose of this invention is to provide an electrode plate for electro-deintercalation and extraction of lithium, its preparation method and application. The electrode plate for electro-deintercalation and extraction of lithium is embedded in the current collector by a slurry coating containing a structural agent, forming an extremely strong three-dimensional conductive mesh structure electrode plate with line contact. This can improve the electrode plate's erosion resistance, conductivity and lithium extraction capability.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides an electrode plate for electrolytic lithium extraction, the electrode plate comprising a porous current collector and slurry coatings on both sides of the porous current collector, the slurry coatings on both sides of the porous current collector being connected through the pores of the porous current collector, and the slurry coatings comprising a structural agent.

[0010] This invention adds a structural agent that enhances mechanical properties to a slurry coating and applies the slurry coating to both sides of a porous current collector. The slurry coating is interconnected through the structural agent and the porous structure of the current collector. The slurry coating passes through the porous structure of the current collector, strengthening the connection between the slurry coating and the current collector. This results in a strong bond between the current collector, the slurry coating, and the structural agent, forming a conductive three-dimensional network structure internally and a robust whole externally. This enhances the cohesion of the electrode plate, improves its erosion resistance, extends its service life, and ultimately improves lithium extraction performance.

[0011] Preferably, the structural agent includes a conductive polymer structural agent and / or a conductive fiber structural agent.

[0012] The structural agent of this invention not only enhances the strength of the electrode plate but also possesses strong conductivity, enabling the formation of a line-contact conductive network within the electrode plate. Furthermore, this invention preferably utilizes both conductive polymer structural agent and conductive fiber structural agent simultaneously. This not only strengthens the physical strength of the electrode plate, allowing for internal bonding within the slurry coating and enhancing the plate's cohesion, but also improves its erosion resistance, extends its service life, and forms a three-dimensional network structure with line-contact conductivity. Additionally, it reduces the amount of conductive agent required, increases the proportion of the active material, and significantly reduces electron conduction and Li... + Migration resistance, thereby increasing lithium extraction efficiency.

[0013] Preferably, the conductive polymeric structural agent includes any one or a combination of at least two of polyacetylene, polyaniline, polypyrrole, polyaromatic hydrocarbons, polyhexane hydrocarbons, or phthalocyanine chelates.

[0014] The conductive polymer structural agent of the present invention is an electronically conductive polymer and a redox conductive polymer. Compared with traditional structural agents, it enhances the connection of the slurry coating, improves the erosion resistance of the slurry coating, and has a curved contact conductive network, which enhances the conductivity of the electrode plate, reduces the amount of conductive agent added, increases the active main material, and improves the lithium extraction capability of the electrode plate.

[0015] Preferably, the conductive fiber structural agent comprises carbon fiber.

[0016] Preferably, in the raw materials for preparing the slurry coating, the content of the structural agent is 1.5-5.5 wt% based on a solid mass fraction of 100%, for example, it can be 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] The content of the structural agent in the slurry coating of this invention will affect the erosion resistance of the electrode plate. If the content is too low, the mechanical strength and erosion resistance of the electrode plate will decrease. If the content is too high, the proportion of the main material will be reduced, and the lithium extraction efficiency and other properties will be reduced.

[0018] Preferably, in the raw materials for preparing the slurry coating, the content of the conductive fiber structural agent is 20-80% of the conductive polymer structural agent, based on a solid mass fraction of 100%. For example, it can be 30%, 40%, 50%, 60%, 70%, or 80%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] The present invention uses conductive fiber structural agent and conductive polymer structural agent in combination. When their contents are within a specific range, they can further improve the performance of the electrode plate. If the content of conductive polymer structural agent is too high compared to conductive fiber structural agent, it is easy to cause uneven dispersion of the slurry coating and excessive polarization of the electrode plate. If the content of conductive polymer structural agent is too low compared to conductive fiber structural agent, it will lead to poor conductivity of the electrode plate.

[0020] Preferably, the porous current collector includes a porous current collector that has undergone surface treatment, and more preferably a porous current collector that has undergone frosted surface treatment.

[0021] The surface-treated current collector of this invention greatly increases the contact area between the slurry coating and the current collector, reduces the contact resistance, enhances the shear force of the electrode plate, strengthens the physical strength of the electrode plate, improves the erosion resistance, and greatly improves the electrochemical performance of the electrode plate, thus promoting the industrial application of the electro-deintercalation and extraction lithium technology.

[0022] Preferably, the thickness of the porous current collector is 0.6-1.3 mm, for example, it can be 0.8 mm, 1 mm, 1.2 mm or 1.3 mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, the porous current collector has a rhomboid or triangular pore shape and a pore diameter of 1*3mm or 2*4mm.

[0024] Preferably, the porous current collector includes any one or a combination of at least two of the following: ruthenium-iridium-plated titanium mesh, titanium mesh, porous graphite plate, carbon-plated copper mesh, or carbon-plated aluminum mesh.

[0025] The porous current collector of the present invention is preferably a porous rigid current collector.

[0026] Preferably, the slurry coating further includes a conductive agent, a binder, a hydrophilic agent, and a delithiated active material.

[0027] The active material after delithiation of the present invention includes LFP / FP (lithium iron phosphate and iron phosphate), which is obtained by delithiation of the active material lithium iron phosphate.

[0028] Preferably, in the raw materials for preparing the slurry coating, based on a solid mass fraction of 100%, the content of the active material is 65-90 wt%, for example, 65 wt%, 75 wt%, 85 wt%, or 90 wt%; the content of the conductive agent is 4-10 wt%, for example, 4 wt%, 6 wt%, 8 wt%, or 10 wt%; the content of the binder is 4-15 wt%, for example, 4 wt%, 8 wt%, 10 wt%, or 15 wt%; and the content of the hydrophilic agent is 2-10 wt%, for example, 2 wt%, 4 wt%, 8 wt%, or 10 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the active material includes lithium iron phosphate.

[0030] Preferably, the conductive agent includes any one or a combination of at least two of SP, KS-6, or Ketjen Black.

[0031] Preferably, the adhesive comprises any one or a combination of at least two of PVDF, VW770, or HSV900.

[0032] Preferably, the hydrophilic agent includes any one or a combination of at least two of PEG, polydopamine, chitosan, and polyvinyl alcohol.

[0033] In a second aspect, the present invention provides a method for preparing an electrode plate for electro-deintercalation and extraction of lithium as described in the first aspect, the method comprising the following steps:

[0034] The coating slurry is coated on both sides of the porous current collector, and after drying and delithiation, the electrode plate for electro-deintercalation and extraction of lithium is obtained.

[0035] Preferably, the porous current collector is subjected to a frosted surface treatment before being coated on both sides.

[0036] Preferably, the abrasive surface treatment includes any one or a combination of at least two of sandblasting, shot peening, or quenching.

[0037] Preferably, the coating thickness is 1-2 mm, for example, 1 mm, 1.5 mm or 2 mm, and the coating mass is 1.5-3 g, for example, 1.5 g, 2 g, 2.5 g or 3 g, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the method for preparing the coating slurry includes mixing the hydrophilic agent and solvent according to the formula amount, then adding the binder, then adding the conductive agent and active material and stirring and mixing, and finally adding the structural agent and mixing.

[0039] Thirdly, the present invention provides an electrolytic lithium extraction apparatus, the electrolytic lithium extraction apparatus comprising the electrode plate for electrolytic lithium extraction as described in the first aspect.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] This invention adds a structural agent to a traditional slurry coating and uses a porous rigid current collector. The slurry coating is applied to both sides of the current collector. The slurry coating is interconnected inside and outside the electrode plate through the porous structure of the structural agent and the porous rigid current collector, forming an extremely strong three-dimensional conductive mesh structure electrode plate with line contact. This not only improves the electrode plate's erosion resistance and conductivity, but also increases the proportion of active main material and enhances lithium extraction capability. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the electrode plate for electro-deintercalation and extraction of lithium as described in Embodiment 1 of the present invention;

[0043] Figure 2 This is a schematic diagram of the porous rigid current collector described in Embodiment 1 of the present invention;

[0044] Among them, 1-porous rigid current collector, 2-slurry coating. Detailed Implementation

[0045] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0046] Example 1

[0047] This embodiment provides a method such as Figure 1 The electrode plate for lithium extraction and intercalation shown includes a porous rigid current collector 1 and slurry coatings 2 on both sides of the porous rigid current collector 1. A schematic diagram of the porous rigid current collector 1 is shown below. Figure 2 As shown, the slurry coating 2 on both sides of the porous rigid current collector 1 is embedded in the pores of the porous rigid current collector 1 and connected through the pores of the porous rigid current collector 1.

[0048] The raw materials for preparing the slurry coating 2, based on a solid mass fraction of 100%, include 73.5 wt% LFP, 8 wt% SP, 10 wt% PVDF, 4 wt% PEG, 3% polyacetylene, and 1.5 wt% carbon fiber, with the carbon fiber comprising 50% of the mass of the polyacetylene.

[0049] The porous rigid current collector 1 is a porous rigid current collector 1 with a frosted surface treatment. The porous rigid current collector 1 is a titanium mesh with a thickness of 1 mm and a rhomboid hole shape.

[0050] The method for preparing the electrode plate for electro-deintercalation and extraction of lithium includes the following steps:

[0051] (1) According to the formula, PEG and NMP are mixed evenly at a mass ratio of 4:120 and stirred at 800 r / min to dissolve. Then PVDF is added and stirred at 800 r / min to dissolve to make a glue solution. At the same speed, conductive agent SP is added to the glue solution and stirred for 20 min. Then LFP is added and stirred for 20 min. Finally, polyacetylene and carbon fiber are added and stirred at 800 r / min for 2.5 h to make slurry coating 2.

[0052] (2) Place the sandblasted current collector titanium mesh in the middle of the two molds and fix them together as a whole with bolts to ensure that the coating thickness of the electrode plate is consistent with the thickness of the mold. Then, apply the slurry coating 2 described in step (1) to the current collector titanium mesh using a weighing spoon. The edge size of the mold is 4*4mm and the thickness is 1mm. When coating, first coat one side of the titanium mesh. First coat the entire side of the titanium mesh with slurry and squeeze the slurry through the holes of the titanium mesh to the other side. Then, flatten the slurry on both sides of the titanium mesh. It is necessary to ensure that the contact part between the current collector and the mold is filled with slurry. Use a 1mm scraper to repair the edge of the slurry coating 2 and then scrape off the excess slurry from top to bottom to make the surface of the slurry coating 2 smooth and flat.

[0053] (3) Fix the coated electrode plate obtained in step (2) and hang it vertically in the oven. Use the vertical drying method to bake it at 80°C for 12 hours.

[0054] (4) The dried electrode plate was placed in 0.5wt%, 100mL sodium persulfate solution and stirred to remove lithium for 4h. After the lithium removal was completed, it was taken out, rinsed under running water for 10min, and then placed in water to soak for 24h. The electrode plate after the lithium removal was placed in an oven at 65℃ and baked for 12h to obtain the electrode plate for electro-deintercalation and extraction of lithium.

[0055] Example 2

[0056] This embodiment provides an electrode plate for electrolytic lithium extraction, the electrode plate for electrolytic lithium extraction includes a porous rigid current collector and slurry coatings on both sides of the porous rigid current collector, the slurry coatings on both sides of the porous rigid current collector are embedded in the pores of the porous rigid current collector and are connected through the pores of the porous rigid current collector;

[0057] The raw materials for preparing the slurry coating, based on a solid mass fraction of 100%, include 72.6 wt% LFP, 8 wt% SP, 10 wt% PVDF, 4 wt% PEG, 3% polyacetylene, and 2.4 wt% carbon fiber, with the carbon fiber comprising 80% of the mass of the polyacetylene.

[0058] The porous rigid current collector is a porous rigid current collector with a frosted surface treatment. The porous rigid current collector is a titanium mesh with a thickness of 1 mm and a rhomboid hole shape.

[0059] The method for preparing the electrode plate for electro-deintercalation and extraction of lithium includes the following steps:

[0060] (1) According to the formula, PEG and NMP are mixed evenly at a mass ratio of 4:120 and stirred at 800 r / min to dissolve. Then PVDF is added and stirred at 800 r / min to dissolve to make a glue solution. At the same speed, conductive agent SP is added to the glue solution and stirred for 20 min. Then LFP is added and stirred for 20 min. Finally, polyacetylene and carbon fiber are added and stirred at 800 r / min for 2.5 h to make a coating slurry.

[0061] (2) Place the sandblasted current collector titanium mesh in the middle of the two molds and fix them together as a whole with bolts or reverse tail clips to ensure that the coating thickness of the electrode plate is consistent with the thickness of the mold. Then, apply the coating slurry described in step (1) to the current collector titanium mesh using a weighing spoon. The edge size of the mold is 4*4mm and the thickness is 1mm. When coating, first coat one side of the titanium mesh. First coat the entire side of the titanium mesh with the slurry and squeeze the slurry through the titanium mesh holes to the other side. Then, flatten the slurry on both sides of the titanium mesh. It is necessary to ensure that the contact part between the current collector and the mold is filled with slurry. Use a 1mm scraper to repair the edge of the coating and then scrape off the excess slurry from top to bottom to make the slurry coating surface smooth and flat.

[0062] (3) Fix the coated electrode plate obtained in step (2) and hang it vertically in the oven. Use the vertical drying method to bake it at 80°C for 12 hours.

[0063] (4) The dried electrode plate was placed in 0.5wt%, 100mL sodium persulfate solution and stirred to remove lithium for 4h. After the lithium removal was completed, it was taken out, rinsed under running water for 10min, and then placed in water to soak for 24h. The electrode plate after the lithium removal was placed in an oven at 65℃ and baked for 12h to obtain the electrode plate for electro-deintercalation and extraction of lithium.

[0064] Example 3

[0065] This embodiment provides an electrode plate for electrolytic lithium extraction, the electrode plate for electrolytic lithium extraction includes a porous rigid current collector and slurry coatings on both sides of the porous rigid current collector, the slurry coatings on both sides of the porous rigid current collector are embedded in the pores of the porous rigid current collector and are connected through the pores of the porous rigid current collector;

[0066] The raw materials for preparing the slurry coating, based on a solid mass fraction of 100%, include 75 wt% LFP, 9.08 wt% SP, 8 wt% PVDF, 6 wt% PEG, 1.6% polyacetylene, and 0.32 wt% carbon fiber, with the carbon fiber comprising 20% ​​of the mass of polyacetylene.

[0067] The porous rigid current collector is a porous rigid current collector with a frosted surface treatment. The porous rigid current collector is a titanium mesh with a thickness of 1 mm and a rhomboid hole shape.

[0068] The method for preparing the electrode plate for electro-deintercalation and extraction of lithium includes the following steps:

[0069] (1) According to the formula, PEG and NMP are mixed evenly at a mass ratio of 6:120 and stirred at 800 r / min to dissolve. Then PVDF is added and stirred at 800 r / min to dissolve to make a glue solution. At the same speed, conductive agent SP is added to the glue solution and stirred for 20 min. Then LFP is added and stirred for 20 min. Finally, polyacetylene and carbon fiber are added and stirred at 800 r / min for 2.5 h to make a coating slurry.

[0070] (2) Place the sandblasted current collector titanium mesh in the middle of the two molds and fix them together as a whole with bolts or reverse tail clips to ensure that the coating thickness of the electrode plate is consistent with the thickness of the mold. Then, apply the slurry coating material described in step (1) to the current collector titanium mesh using a weighing spoon. The edge size of the mold is 4*4mm and the thickness is 1mm. When coating, first coat one side of the titanium mesh. First coat the entire side of the titanium mesh with the slurry and squeeze the slurry through the titanium mesh holes to the other side. Then, flatten the slurry on both sides of the titanium mesh. It is necessary to ensure that the contact part between the current collector and the mold is filled with slurry. Use a 1mm scraper to repair the edge of the coating and then scrape off the excess slurry from top to bottom to make the coating surface smooth and flat.

[0071] (3) Fix the coated electrode plate obtained in step (2) and hang it vertically in the oven. Use the vertical drying method to bake it at 80°C for 12 hours.

[0072] (4) The dried electrode plate was placed in 0.5wt%, 100mL sodium persulfate solution and stirred to remove lithium for 4h. After the lithium removal was completed, it was taken out, rinsed under running water for 10min, and then placed in water to soak for 24h. The electrode plate after the lithium removal was placed in an oven at 65℃ and baked for 12h to obtain the electrode plate for electro-deintercalation and extraction of lithium.

[0073] Example 4

[0074] This embodiment provides an electrode plate for electro-deintercalation and extraction of lithium. Except for replacing polyacetylene by mass with polyaniline, the electrode plate for electro-deintercalation and extraction of lithium is the same as that in Embodiment 1.

[0075] Example 5

[0076] This embodiment provides an electrode plate for electro-deintercalation and extraction of lithium. Except for the polyacetylene content being 1.5 wt%, the carbon fiber content being 100% of the polyacetylene content, and the LFP content being adaptably varied, the electrode plate is otherwise the same as in Example 1.

[0077] Example 6

[0078] This embodiment provides an electrode plate for electro-deintercalation and extraction of lithium. Except for the carbon fiber content being 0.3 wt%, making the carbon fiber content 10% of the polyacetylene content, and the LFP content being adaptably varied, the electrode plate is the same as in Embodiment 1.

[0079] Example 7

[0080] This embodiment provides an electrode plate for electro-deintercalation and extraction of lithium. Except that the raw materials for preparing the slurry coating do not contain carbon fiber, the content of conductive agent SP is adapted to 4 wt%, and the content of LFP is 79 wt%, the electrode plate is the same as that in Example 1.

[0081] Example 8

[0082] This embodiment provides an electrode plate for electro-deintercalation and extraction of lithium. Except for replacing the polyacetylene by mass with carbon fiber and the absence of polyacetylene in the slurry coating, the electrode plate is otherwise identical to that in Embodiment 1.

[0083] Example 9

[0084] This embodiment provides an electrode plate for electrolytic lithium extraction. Except for the porous rigid current collector which has not undergone sandblasting and grinding surface treatment, the electrode plate for electrolytic lithium extraction is the same as that in Embodiment 1.

[0085] Comparative Example 1

[0086] This comparative example provides an electrode plate for electro-deintercalation and extraction of lithium, which is the same as that in Example 1 except that the porous rigid current collector is replaced with a non-porous titanium plate.

[0087] Comparative Example 2

[0088] This comparative example provides an electrode plate for electro-deintercalation and extraction of lithium. Except for the fact that the slurry coating does not contain polyacetylene and carbon fiber, and the LFP content is adapted to 78 wt%, the electrode plate is the same as that in Example 1.

[0089] The electrode plates obtained in the above embodiments and comparative examples were tested for shear force and cohesive force. The test methods included measuring shear force through tensile testing and measuring cohesive force through peel testing. The test results are shown in Table 1. The electrode plate resistance was measured using a diaphragm resistance meter, and then the rate performance and cycle performance were tested using a Blue Electric charge / discharge cabinet. The test results are shown in Table 2.

[0090] Table 1

[0091]

[0092]

[0093] Table 2

[0094]

[0095] As can be seen from Tables 1 and 2:

[0096] The electrode plate for lithium extraction by electro-deintercalation of the present invention possesses excellent physical strength and erosion resistance, as well as excellent lithium extraction capability. As shown in Example 1 and Comparative Examples 1-2, when the slurry coating of the present invention is interlocked on both sides of the porous rigid current collector and contains a structural agent, it can improve the erosion resistance and lithium extraction performance of the electrode plate. As shown in Example 1 and Examples 5-8, the structural agent of the present invention is preferably a conductive polymer structural agent and a conductive fiber structural agent used simultaneously. When the contents of the two are matched, it can further improve the physical strength of the electrode plate, improve the erosion resistance and electrochemical performance, etc. The addition of structural conductive polymer to the electrode plate has a significant improvement effect on electrochemical performance and lithium extraction amount. As shown in Example 1 and Example 9, the porous current collector with surface treatment of the present invention greatly enhances the physical stability of the electrode plate, thereby further improving the lithium extraction capability of the electrode plate.

[0097] In summary, the present invention provides an electrode plate for electro-deintercalation and extraction of lithium, its preparation method and application. The electrode plate for electro-deintercalation and extraction of lithium is embedded in the current collector by a slurry coating containing a structural agent, forming an extremely strong three-dimensional conductive mesh structure electrode plate with line contact. This can improve the electrode plate's erosion resistance, conductivity and lithium extraction capability.

[0098] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An electrode plate for electro-deintercalation and extraction of lithium, characterized in that, The electrode plate for electro-deintercalation and extraction of lithium includes a porous current collector and slurry coatings on both sides of the porous current collector. The slurry coatings on both sides of the porous current collector are connected through the pores of the porous current collector, and the slurry coatings include a structural agent. The slurry coating also includes conductive agents, binders, hydrophilic agents, and delithiated active materials; The structural agent includes conductive polymer structural agents and conductive fiber structural agents; The conductive polymer structural agent includes any one or a combination of at least two of polyacetylene, polyaniline, polypyrrole, polyaromatic hydrocarbon, polyhexane, or phthalocyanine chelate. The conductive fiber structural agent includes carbon fiber; In the raw materials for preparing the slurry coating, the content of the structural agent is 1.5-5.5 wt% based on a solid mass fraction of 100%, and the content of the conductive fiber structural agent is 20-80% of the conductive polymer structural agent.

2. The electrode plate for electro-deintercalation and extraction of lithium according to claim 1, characterized in that, The porous current collector includes a porous current collector that has undergone surface treatment.

3. The electrode plate for electro-deintercalation and extraction of lithium according to claim 2, characterized in that, The porous current collector is a porous current collector with a frosted surface treatment.

4. The electrode plate for electro-deintercalation and extraction of lithium according to claim 1, characterized in that, The thickness of the porous current collector is 0.6-1.3 mm.

5. The electrode plate for electro-deintercalation and extraction of lithium according to claim 1, characterized in that, The porous current collector has rhomboid or triangular pores.

6. The electrode plate for electro-deintercalation and extraction of lithium according to claim 1, characterized in that, The porous current collector includes any one or a combination of at least two of the following: ruthenium-iridium-plated titanium mesh, titanium mesh, porous graphite plate, carbon-plated copper mesh, or carbon-plated aluminum mesh.

7. The electrode plate for electro-deintercalation and extraction of lithium according to claim 1, characterized in that, In the raw materials for preparing the slurry coating, based on a solid mass fraction of 100%, the content of active material is 65-90 wt%, the content of conductive agent is 4-10 wt%, the content of binder is 4-15 wt%, and the content of hydrophilic agent is 2-10 wt%.

8. The electrode plate for electro-deintercalation and extraction of lithium according to claim 7, characterized in that, The active material includes lithium iron phosphate.

9. The electrode plate for electro-deintercalation and extraction of lithium according to claim 7, characterized in that, The conductive agent includes any one or a combination of at least two of SP, KS-6, or Ketjen Black.

10. The electrode plate for electro-deintercalation and extraction of lithium according to claim 7, characterized in that, The adhesive includes any one or a combination of at least two of PVDF, VW770, or HSV900.

11. The electrode plate for electro-deintercalation and extraction of lithium according to claim 7, characterized in that, The hydrophilic agent includes any one or a combination of at least two of PEG, polydopamine, chitosan, and polyvinyl alcohol.

12. A method for preparing an electrode plate for electro-deintercalation and extraction of lithium as described in any one of claims 1-11, characterized in that, The preparation method includes the following steps: The coating slurry is coated on both sides of the porous current collector, and after drying and delithiation, the electrode plate for electro-deintercalation and extraction of lithium is obtained.

13. The preparation method according to claim 12, characterized in that, Before coating both sides of the porous current collector, the porous current collector is first subjected to a frosted surface treatment.

14. The preparation method according to claim 13, characterized in that, The abrasive surface treatment includes sandblasting and / or shot peening.

15. The preparation method according to claim 12, characterized in that, The coating slurry has a thickness of 1-2 mm and a mass of 1.5-3 g.

16. The preparation method according to claim 12, characterized in that, The method for preparing the coating slurry includes mixing a hydrophilic agent and a solvent according to the formula amount, then adding a binder, then adding a conductive agent and an active material and stirring and mixing, and finally adding a structural agent and mixing.

17. An electro-deintercalation and extraction device for lithium, characterized in that, The electrode for lithium extraction and intercalation includes the electrode plate for lithium extraction and intercalation as described in any one of claims 1-11.

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