WO2024164415A1 - Modified positive electrode material, electrochemical lithium extraction electrode sheet, and preparation method therefor and use thereof - Google Patents

Modified positive electrode material, electrochemical lithium extraction electrode sheet, and preparation method therefor and use thereof Download PDF

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WO2024164415A1
WO2024164415A1 PCT/CN2023/085289 CN2023085289W WO2024164415A1 WO 2024164415 A1 WO2024164415 A1 WO 2024164415A1 CN 2023085289 W CN2023085289 W CN 2023085289W WO 2024164415 A1 WO2024164415 A1 WO 2024164415A1
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positive electrode
lithium
graphene oxide
weak acid
mmol
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PCT/CN2023/085289
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French (fr)
Chinese (zh)
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李爱霞
余海军
谢英豪
李长东
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广东邦普循环科技有限公司
湖南邦普循环科技有限公司
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Publication of WO2024164415A1 publication Critical patent/WO2024164415A1/en

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/02—Electrodes; Connections thereof
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/45—Phosphates containing plural metal, or metal and ammonium
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C25C1/02—Electrolytic production, recovery or refining of metals by electrolysis of solutions of light metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer

Definitions

  • the present application relates to the technical field of lithium extraction from salt lakes, and more specifically, to modified positive electrode materials, electrochemical lithium extraction electrodes, and preparation methods and applications thereof.
  • Lithium-ion batteries are widely used in optoelectronics, information, transportation and other fields due to their excellent performance. With the promotion of lithium-ion batteries, the demand for lithium resources is also increasing.
  • Lithium resources in salt lakes account for more than 70% of lithium reserves. How to develop lithium resources in salt lakes at low cost, pollution-free and high efficiency is of great significance to the continuous supply of lithium products.
  • the main technologies for extracting lithium from salt lakes include precipitation, adsorption, solvent extraction, electrochemical and membrane separation. Among them, precipitation refers to the process of evaporating and concentrating the lithium-containing brine in the salt lake, adding lime to remove alkaline metal impurities such as calcium and magnesium remaining in the brine, and then adding sodium carbonate precipitant to prepare lithium carbonate products.
  • Adsorption refers to the process of using a special resin to adsorb lithium ions in the salt lake, and then eluting and refining.
  • Solvent extraction refers to the method of extracting lithium ions into an organic phase by means of an extractant, thereby separating lithium ions from impurity ions.
  • Electrochemical method refers to the electrochemical deintercalation method, which uses the reverse working principle of lithium batteries to enrich lithium on the cathode material of a specific material, and then further separates it.
  • Membrane separation refers to the method of separating and filtering lithium ions and other impurity ions by using the properties of the membrane.
  • the electrochemical method has good selectivity and enrichment ability for lithium, but in practical applications, the brine contains a large amount of magnesium impurities, which hinders the extraction of lithium ions.
  • the lithium ions in the brine chamber are embedded in the lithium ion sieve to form a lithium-intercalated electrode.
  • the lithium ion sieve such as iron phosphate
  • the weakly alkaline brine water electrolysis reaction occurs on the electrode, and the reaction produces hydrogen.
  • the production of hydrogen will cause the alkalinity of the solution around the electrode to increase.
  • the Mg2+ ion content in the brine is relatively high.
  • magnesium ions can easily react with hydroxide to form magnesium hydroxide precipitation, causing electrode oxidation, and lithium ions will co-precipitate with it, resulting in lithium loss.
  • the purpose of this application is to provide a modified positive electrode material, an electrochemical lithium extraction electrode sheet, and a preparation method and application thereof, in order to improve the lithium adsorption capacity and cycle performance.
  • the present application provides a modified positive electrode material, wherein the modified positive electrode material contains a positive electrode active material, graphene oxide, a weak acid modifier and a polymer;
  • the weak acid modifier is an organic salt containing a weak acid radical
  • the polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
  • the weak acid modifier is selected from at least one of sodium aminobenzoate, sodium hydroxybenzoate, sodium 2-hydroxy-5-aminobenzoate and sodium aminosalicylate;
  • the positive electrode active material is selected from at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide and lithium manganese oxide.
  • the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the content of the weak acid modifier corresponding to each 40 mg-100 mg of graphene oxide is 0.05 mmol-0.1 mmol;
  • the amount of the corresponding polymer monomer used is 1 mmol to 3 mmol for every 40 mg to 100 mg of graphene oxide.
  • the present application provides a method for preparing a modified positive electrode material according to any one of the aforementioned embodiments, comprising: using a positive electrode active material, graphene oxide, a weak acid modifier and a polymer monomer
  • the modified positive electrode material is prepared using the body as raw material.
  • graphene oxide, a weak acid modifier and a positive electrode active material are mixed in a solution system to obtain a blended solution, and the blended solution is mixed with a polymer monomer to perform a polymerization reaction;
  • the amount of the corresponding polymer monomer is 1 mmol to 3 mmol per 40 mg to 100 mg of graphene oxide;
  • the polymerization temperature is 160°C to 200°C, and the polymerization time is 8h to 12h;
  • the obtained polymer solution is dried and ground into powder, and D50 is controlled to be 0.5 ⁇ m to 15 ⁇ m;
  • the drying of the polymer solution is freeze drying for 24 h to 48 h.
  • the preparation process of the blended solution includes: mixing the graphene oxide solution with a weak acid modifier, and then mixing with a positive electrode active material;
  • the mixing ratio of the weak acid modifier and graphene oxide is 0.05 mmol to 0.1 mmol: 40 mg to 100 mg; the mass ratio of the positive electrode active material to graphene oxide is 100: 2 to 10;
  • the concentration of the graphene oxide solution is 3 mg/mL to 5 mg/mL.
  • the present application provides a method for preparing an electrochemical lithium extraction electrode sheet, which is prepared using any of the modified positive electrode materials in the aforementioned embodiments or a modified positive electrode material prepared by any of the preparation methods in the aforementioned embodiments.
  • the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant are mixed to form a slurry, the slurry is coated on the electrode substrate, and the coated electrode substrate is dried;
  • the mass ratio of the modified positive electrode material, the binder, the conductive agent, the pore former and the dispersant is 100:1-1.5:0.2-1:10-30:150-250;
  • the binder is polyvinylidene fluoride
  • the conductive agent is selected from at least one of acetylene black, Ketjen black, conductive graphite powder and carbon nanotubes;
  • the pore former is selected from at least one of bicarbonate, sodium carbonate and potassium carbonate;
  • the dispersant is N-methylpyrrolidone
  • the pole piece substrate is selected from at least one of aluminum foil, carbon fiber cloth, carbon fiber felt, porous carbon-based material, titanium plate, and titanium mesh;
  • the coating density of the slurry is 0.3 g/cm 2 to 0.5 g/cm 2 ;
  • the coated electrode substrate is first dried at 50° C. to 60° C. for 3 h to 5 h, and then dried at 100° C. to 120° C. for 2 h to 10 h.
  • the present application provides an electrochemical lithium extraction electrode sheet prepared by the preparation method of the aforementioned embodiment.
  • the present application provides an electrochemical lithium extraction device, comprising the electrochemical lithium extraction electrode of the aforementioned embodiment.
  • the positive electrode active material is modified by using graphene oxide, weak acid modifier and polymer.
  • the H 2 O in the weak acid replacement solution is ionized to avoid the generation of hydroxide and prevent the local pH from being too high, thereby inhibiting the formation of magnesium hydroxide precipitation; when desorbing lithium ions, weak acid groups can be generated again to continuously inhibit the generation of magnesium hydroxide precipitation.
  • the use of polymers can better fix the positive electrode active material and increase the service life of the pole piece;
  • the oxygen-containing groups in the weak acid modifier and the six-membered rings on the graphene oxide sheet have ⁇ - ⁇ conjugation and multiple hydrogen bonding effects, and can form a combination of modified substances and graphene oxide, which can well fix the modified groups, and graphene can increase the conductivity of the pole piece.
  • the pole piece prepared by the modified positive electrode material provided in the present application can improve the adsorption capacity of lithium during the electrochemical lithium extraction process, and has better cycle performance.
  • ⁇ - ⁇ conjugation refers to the electron delocalization effect that occurs when two or more double bonds (or triple bonds) are connected by a single bond.
  • multiple hydrogen bonding effect refers to the synergistic or multiple effects of multiple intermolecular hydrogen bonds.
  • cycling performance it is characterized by the ratio between the adsorption capacity after multiple lithium extraction cycles and the initial adsorption capacity. The larger the ratio, the better the cycling performance of the electrode.
  • the embodiment of the present application provides a method for preparing a modified positive electrode material, which uses positive electrode active material, graphene oxide, weak acid modifier and polymer monomer as raw materials to prepare the modified positive electrode material, and uses graphene oxide, weak acid modifier and polymer obtained by the reaction to modify the positive electrode active material, so that the prepared positive electrode material can improve the adsorption capacity of lithium when used for lithium extraction from salt lakes, and has better cycle performance.
  • the preparation process of the modified positive electrode material includes the following steps:
  • the graphene oxide, the weak acid modifier and the positive electrode active material are mixed in a solution system to obtain a blended solution.
  • the mixing method is not limited, and conventional mechanical stirring or ultrasonic mixing can be used.
  • the preparation process of the blended solution includes: mixing the graphene oxide solution and the weak acid modifier evenly, then ultrasonicating for 30 minutes to 60 minutes, and then mixing and stirring with the positive electrode active material, and then ultrasonicating for 30 minutes to 60 minutes to make the components evenly dispersed.
  • the weak acid modifier is an organic salt containing a weak acid radical.
  • the oxygen-containing groups in the modified substance and the six-membered rings on the graphene oxide sheet have ⁇ - ⁇ conjugation and multiple hydrogen bonding effects, which can form a combination of the modified substance and graphene oxide, can well fix the modified groups, and graphene can increase the conductivity of the electrode.
  • At least one selected from sodium aminobenzoate, sodium hydroxybenzoate, sodium 2-hydroxy-5-aminobenzoate and sodium aminosalicylate can be any one or more of the above raw materials.
  • the positive electrode active material is selected from at least one selected from lithium iron phosphate, lithium iron manganese phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide and lithium manganese oxide, and can be any one or more of the above active materials.
  • the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the mixing ratio of the weak acid modifier and graphene oxide is 0.05mmol-0.1mmol:40mg-100mg.
  • the mass ratio of the positive electrode active material to graphene oxide may be 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, or the like.
  • the amount of the weak acid modifier is 0.05 mmol to 0.1 mmol
  • the corresponding amount of graphene oxide is 40 mg to 100 mg.
  • the mixing ratio of the weak acid modifier and graphene oxide can be 0.05 mmol: 40 mg, 0.06 mmol: 50 mg, 0.06 mmol: 60 mg, 0.07 mmol: 70 mg, 0.08 mmol: 80 mg, 0.09 mmol: 90 mg, 0.10 mmol: 100 mg, etc., or any value between the above adjacent values.
  • the concentration of the graphene oxide solution is 3 mg/mL to 5 mg/mL, such as 3 mg/mL, 4 mg/mL, 5 mg/mL, etc.
  • the blended solution is mixed with a polymer monomer for polymerization reaction, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene, and can be any one or more.
  • the oxygen-containing group can induce the polymer to polymerize into an ordered molecular chain, so that the molecular chains can be more easily and tightly combined, so that the positive electrode material can be better fixed between the molecular chains to ensure the service life of the electrode.
  • the amount of polymer monomer corresponding to each 40 mg to 100 mg of graphene oxide is The amount of the polymer monomer is 1mmol to 3mmol, the blended solution and the polymer monomer are ultrasonically stirred for 30min to 60min, and then transferred to a reactor for polymerization. It is appropriate to control the amount of the polymer monomer within the above range, so that the positive electrode material can be better fixed between the molecular chains to ensure the service life of the electrode.
  • the amount of graphene oxide is 40 mg to 100 mg
  • the amount of the corresponding polymer monomer is 1 mmol to 3 mmol.
  • the mixing ratio of graphene oxide and polymer monomer can be 40 mg: 1 mmol, 50 mg: 1 mmol, 60 mg: 2 mmol, 70 mg: 2 mmol, 80 mg: 3 mmol, 90 mg: 3 mmol, 100 mg: 3 mmol, etc., or any value between the above adjacent values.
  • the polymerization temperature is 160°C to 200°C
  • the polymerization time is 8h to 12h to allow the reaction to be sufficient.
  • the polymerization temperature can be 160°C, 170°C, 180°C, 190°C, 200°C, etc.
  • the polymerization time can be 8h, 9h, 10h, 11h, 12h, etc.
  • the obtained polymer solution is dried and ground into powder for subsequent use.
  • the drying method is not limited, and may be, but is not limited to, freeze drying.
  • the freeze drying time may be 24 to 48 hours, such as 24 hours, 30 hours, 35 hours, 40 hours, 45 hours, 48 hours, and the like.
  • the particle size D50 of the ground powder can be 0.5 ⁇ m to 15 ⁇ m, such as 0.5 ⁇ m, 1 ⁇ m, 3 ⁇ m, 5 ⁇ m, 7 ⁇ m, 10 ⁇ m, 15 ⁇ m, etc.
  • the embodiment of the present application also provides a modified positive electrode material, which contains a positive electrode active material, graphene oxide, a weak acid modifier and a polymer; wherein the weak acid modifier is an organic salt containing a weak acid radical; the polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
  • the weak acid modifier is an organic salt containing a weak acid radical
  • the polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
  • modified positive electrode material can be prepared by the preparation method provided in the examples of the present application.
  • the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the content of the weak acid modifier corresponding to each 40 mg to 100 mg of graphene oxide is 0.05 mmol to 0.1 mmol.
  • the content of the weak acid modifier corresponding to each 40 mg to 100 mg of graphene oxide is 0.05 mmol to 0.1 mmol.
  • the amount of the polymer monomer is 1 mmol to 3 mmol.
  • the embodiment of the present application also provides a method for preparing an electrochemical lithium extraction electrode sheet, which is prepared using the above-mentioned modified positive electrode material.
  • the preparation method is not limited, and the electrode sheet can be prepared using existing methods, which is not limited here.
  • the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant are mixed to form a slurry, the slurry is coated on the electrode substrate, and the coated electrode substrate is dried to obtain an electrode sheet.
  • the mass ratio of the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant is 100:1-1.5:0.2-1:10-30:150-250, such as 100:1:0.2:10:150, 100:1.2:0.5:15:180, 100:1.3:0.7:20:200, 100:1.5:1.0:30:250, etc.
  • the binder can be but not limited to polyvinylidene fluoride;
  • the conductive agent is selected from at least one of acetylene black, Ketjen black, conductive graphite powder and carbon nanotubes;
  • the pore former is selected from at least one of bicarbonate, sodium carbonate and potassium carbonate;
  • the dispersant can be but not limited to N-methylpyrrolidone.
  • the binder, conductive agent, pore former and dispersant can be any one or more of the above.
  • the electrode substrate is selected from at least one of aluminum foil, carbon fiber cloth, carbon fiber felt and porous carbon-based material, titanium plate, and titanium mesh. It can be any one or more of the above, and can also be adjusted as needed.
  • the coating density of the slurry is 0.3 g/cm 2 to 0.5 g/cm 2 so that the coating thickness meets the process requirements.
  • the coating density can be 0.3 g/cm 2 , 0.4 g/cm 2 , 0.5 g/cm 2 and the like.
  • the coated electrode substrate is first dried at 50°C to 60°C for 3h to 5h, and then dried at 100°C to 120°C for 2h to 10h. It is first dried at low temperature and then at high temperature to prevent the slurry from affecting the uniformity of the coating due to excessively high temperature in the initial stage.
  • the initial drying temperature may be 50°C, 52°C, 55°C, 57°C, 60°C, etc.
  • the drying time can be 3h, 4h, 5h, etc.; the temperature of the later drying can be 100°C, 110°C, 120°C, etc., and the drying time can be 2h, 5h, 7h, 10h, etc.
  • the embodiment of the present application also provides an electrochemical lithium extraction electrode sheet, which is prepared by the above-mentioned preparation method of the electrochemical lithium extraction electrode sheet.
  • the electrochemical lithium extraction process the adsorption capacity of lithium can be improved and the cycle performance is better.
  • the embodiment of the present application also provides an electrochemical lithium extraction device, including the above-mentioned electrochemical lithium extraction electrode sheet, which may include a negative electrode, a power supply, etc., to form a complete electrochemical lithium extraction device that can perform electrochemical lithium extraction more efficiently.
  • This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
  • a polymer solution D 2 mmol of pyrrole monomer was added to the mixed solution C, ultrasonically stirred for 30 min, and then transferred to a reactor and reacted at 180° C. for 8 h to obtain a polymer solution D.
  • the polymer solution D was freeze-dried for 48 h and then ground into powder, with D50 controlled to be 1-3 ⁇ m.
  • the obtained modified positive electrode material powder, PVDF (binder), acetylene black (conductive agent), pore former (ammonium carbonate) and N-methylpyrrolidone (dispersant) were mixed evenly in a mass ratio of 100:1:0.5:10:200, and stirred into a uniform slurry using a stirrer under vacuum conditions.
  • the slurry was then coated on aluminum foil with a coating density of 0.5 g/cm 2 .
  • the coated electrode was dried at 60°C for 3 hours and then at 120°C for 8 hours to obtain an electrode sheet.
  • Performance test Using simulated brine as the source liquid (the composition is shown in Table 1), the Lithium iron phosphate is used as the positive electrode, carbon rod is used as the negative electrode, the voltage between the two electrodes ranges from 0.5-2.5mV/cm -2 , a constant current of 0.5mA/cm -2 is applied for desorption, and then -0.5mA/cm -2 is applied for adsorption, one adsorption and desorption is one cycle, and 50 cycles of lithium extraction experiments are performed.
  • the lithium ion adsorption capacity can be obtained through ICP testing.
  • the test showed that the adsorption capacity was 38.31 mg ⁇ g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve was 37.74 mg ⁇ g -1 , and the capacity retention rate was 98.52%.
  • This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
  • LiMn 0.3 Fe 0.7 PO 4 1 g of lithium manganese iron phosphate, whose chemical formula is LiMn 0.3 Fe 0.7 PO 4 , is added to the mixed solution B. After mixing and stirring, ultrasonic treatment is performed for 30 minutes to make the mixture dispersed evenly, thereby obtaining a mixed solution C.
  • a polymer solution D 0.5 mmol of pyrrole monomer was added to the mixed solution C, ultrasonically stirred for 30 min, and then transferred to a reactor and reacted at 180° C. for 8 h to obtain a polymer solution D.
  • the polymer solution D was freeze-dried for 48 h and then ground into powder, with D50 controlled to be 1-3 ⁇ m.
  • the positive electrode material powder prepared in this embodiment is used for preparation, and the specific steps are the same as those in embodiment 1.
  • the adsorption capacity is 38.28 mg ⁇ g -1 .
  • the lithium adsorption capacity of the lithium ion sieve is 37.70 mg ⁇ g -1 , and the capacity retention rate is 98.48%.
  • This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
  • the positive electrode material powder prepared in this embodiment is used for preparation, and the specific steps are the same as those in Embodiment 1.
  • the adsorption capacity is 40.16 mg ⁇ g -1 .
  • the lithium adsorption capacity of the lithium ion sieve is 37.76 mg ⁇ g -1 , and the capacity retention rate is 94.02%.
  • Example 1 The only difference from Example 1 is that sodium aminobenzoate is not added.
  • the adsorption capacity was 37.54 mg ⁇ g -1 .
  • the lithium adsorption capacity of the lithium ion sieve was 34.02 mg ⁇ g -1 , and the capacity retention rate was 90.62%.
  • magnesium hydroxide precipitates formed on the electrode to block the pores, resulting in a decrease in capacity after multiple cycles.
  • Example 1 The only difference from Example 1 is that no pyrrole monomer was added and no polymerization reaction was performed.
  • the ICP test showed that the adsorption capacity was 35.81 mg ⁇ g -1 . After 50 cycles, the lithium ion The lithium adsorption capacity of the sieve was 33.05 mg ⁇ g -1 , and the capacity retention rate was 92.30%. Without adding pyrrole monomer, the graphene oxide with modified groups on the electrode was not well fixed, and the capacity after multiple cycles was lower than that of Example 1.
  • Example 1 The only difference from Example 1 is that no graphene oxide is added.
  • Example 1 The difference from Example 1 is that the amount of sodium aminobenzoate is 0.01 mmol.
  • the adsorption capacity was 37.65 mg ⁇ g -1 .
  • the lithium adsorption capacity of the lithium ion sieve was 34.40 mg ⁇ g-1 , and the capacity retention rate was 91.36%.
  • magnesium hydroxide precipitates would still form on the electrode to block the pores, resulting in a decrease in capacity after multiple cycles.
  • Example 1 The difference from Example 1 is only that the amount of sodium aminobenzoate is 5 mmol.
  • the adsorption capacity is 38.18 mg ⁇ g -1
  • the lithium adsorption capacity of the lithium ion sieve is 36.86 mg ⁇ g -1
  • the capacity retention rate is 96.53%. Adding more sodium aminobenzoate will cause waste and increase costs.

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Abstract

The present application relates to the technical field of lithium extraction from salt lakes. Disclosed are a modified positive electrode material, an electrochemical lithium extraction electrode sheet, and a preparation method therefor and the use thereof. Graphene oxide, a weak acid modifier and a polymer are used for modifying a positive electrode active material, and during the lithium extraction process, a weak acid is ionized instead of H2O in a solution, such that hydroxide is prevented from being generated, and overhigh local pH is prevented, such that the formation of magnesium hydroxide precipitate is inhibited; and when lithium ions are desorbed, a weak acid group can be generated again, such that the generation of magnesium hydroxide precipitate is continuously inhibited. The positive electrode active material can be better fixed by using the polymer, such that the service life of an electrode sheet is prolonged. When an electrode sheet prepared from the modified positive electrode material provided in the present application is subjected to an electrochemical lithium extraction process, the lithium adsorption capacity can be improved, and the cycling performance is better.

Description

改性正极材料、电化学提锂极片及其制备方法和应用Modified positive electrode material, electrochemical lithium extraction electrode sheet and preparation method and application thereof 技术领域Technical Field
本申请涉及盐湖提锂技术领域，具体而言，涉及改性正极材料、电化学提锂极片及其制备方法和应用。The present application relates to the technical field of lithium extraction from salt lakes, and more specifically, to modified positive electrode materials, electrochemical lithium extraction electrodes, and preparation methods and applications thereof.
背景技术Background Art
近年来，随着资源危机愈发严重，新能源的开发利用已经成为人们关注的焦点。锂离子电池由于其优异的性能被广泛应用于光电、信息、交通等领域，随着锂离子电池的推广，锂资源的需求也越来越高。In recent years, as the resource crisis has become more serious, the development and utilization of new energy has become the focus of people's attention. Lithium-ion batteries are widely used in optoelectronics, information, transportation and other fields due to their excellent performance. With the promotion of lithium-ion batteries, the demand for lithium resources is also increasing.
由于含锂矿石储量较低，难以大量地持续供应锂盐产品。盐湖中的锂资源占锂储量的70％以上，如何低成本无污染且高效率地开发盐湖中的锂资源，对持续保障锂产品的供应有重要意义。目前盐湖提锂的技术主要有沉淀法、吸附法、溶剂萃取法、电化学法和膜分离法等。其中，沉淀法是指将盐湖含锂卤水蒸发、浓缩后，加入石灰去除卤水中残留的钙镁等碱性金属杂质，再加入碳酸钠沉淀剂制备碳酸锂产品的过程。吸附法是指利用一种特殊的树脂，将盐湖中的锂离子吸附住，之后再洗脱进而提炼的过程。溶剂萃取法是指用萃取剂的方式将锂离子萃取至有机相，从而使得锂离子和杂质离子分离的方法。电化学法是指电化学脱嵌法，其运用锂电池的反向工作原理，把锂富集在特定材料的阴极材料上，再进一步进行分离。膜分离法是指利用膜的性质，将锂离子和其他杂质离子分离过滤的方法。Due to the low reserves of lithium-containing ores, it is difficult to continuously supply lithium salt products in large quantities. Lithium resources in salt lakes account for more than 70% of lithium reserves. How to develop lithium resources in salt lakes at low cost, pollution-free and high efficiency is of great significance to the continuous supply of lithium products. At present, the main technologies for extracting lithium from salt lakes include precipitation, adsorption, solvent extraction, electrochemical and membrane separation. Among them, precipitation refers to the process of evaporating and concentrating the lithium-containing brine in the salt lake, adding lime to remove alkaline metal impurities such as calcium and magnesium remaining in the brine, and then adding sodium carbonate precipitant to prepare lithium carbonate products. Adsorption refers to the process of using a special resin to adsorb lithium ions in the salt lake, and then eluting and refining. Solvent extraction refers to the method of extracting lithium ions into an organic phase by means of an extractant, thereby separating lithium ions from impurity ions. Electrochemical method refers to the electrochemical deintercalation method, which uses the reverse working principle of lithium batteries to enrich lithium on the cathode material of a specific material, and then further separates it. Membrane separation refers to the method of separating and filtering lithium ions and other impurity ions by using the properties of the membrane.
电化学法对锂具有很好的选择性和富集能力，但是在实际应用中，卤水中含有大量的镁杂质，对锂离子的提取造成了一定阻碍。在电化学提锂过程中，卤水室中的锂离子嵌入到锂离子筛中，形成嵌锂态的电极。在反应末期，极片上锂离子筛(例如磷酸铁)全部转化完成。在弱碱性的卤水 中，极片上出现电解水反应，反应产生氢气，氢气产生的同时会导致极片周围溶液碱性升高。卤水中Mg2+离子含量较高，在极片周围碱性升高时，镁离子很容易与氢氧根发生反应生成氢氧化镁沉淀，造成电极发生，且会使得锂离子与其发生共沉淀，造成锂的损失。The electrochemical method has good selectivity and enrichment ability for lithium, but in practical applications, the brine contains a large amount of magnesium impurities, which hinders the extraction of lithium ions. In the process of electrochemical lithium extraction, the lithium ions in the brine chamber are embedded in the lithium ion sieve to form a lithium-intercalated electrode. At the end of the reaction, the lithium ion sieve (such as iron phosphate) on the electrode is completely converted. In the weakly alkaline brine In the process, water electrolysis reaction occurs on the electrode, and the reaction produces hydrogen. The production of hydrogen will cause the alkalinity of the solution around the electrode to increase. The Mg2+ ion content in the brine is relatively high. When the alkalinity around the electrode increases, magnesium ions can easily react with hydroxide to form magnesium hydroxide precipitation, causing electrode oxidation, and lithium ions will co-precipitate with it, resulting in lithium loss.
鉴于此，特提出本申请。In view of this, this application is hereby filed.
发明内容Summary of the invention
本申请的目的在于提供改性正极材料、电化学提锂极片及其制备方法和应用，旨在提升锂吸附容量和循环性能。The purpose of this application is to provide a modified positive electrode material, an electrochemical lithium extraction electrode sheet, and a preparation method and application thereof, in order to improve the lithium adsorption capacity and cycle performance.
本申请是这样实现的：This application is implemented as follows:
第一方面，本申请提供一种改性正极材料，改性正极材料中含有正极活性材料、氧化石墨烯、弱酸改性物和聚合物；In a first aspect, the present application provides a modified positive electrode material, wherein the modified positive electrode material contains a positive electrode active material, graphene oxide, a weak acid modifier and a polymer;
其中，弱酸改性物为含有弱酸根的有机盐；Among them, the weak acid modifier is an organic salt containing a weak acid radical;
聚合物是由聚合物单体聚合而得，聚合物单体选自吡咯、苯胺和噻吩中的至少一种。The polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
在可选的实施方式中，弱酸改性物选自氨基苯甲酸钠、羟基苯甲酸钠、2-羟基-5-氨基苯甲酸钠和氨基水杨酸钠中的至少一种；In an optional embodiment, the weak acid modifier is selected from at least one of sodium aminobenzoate, sodium hydroxybenzoate, sodium 2-hydroxy-5-aminobenzoate and sodium aminosalicylate;
优选地，正极活性材料选自磷酸铁锂、磷酸锰铁锂、镍钴锰酸锂、钴酸锂和锰酸锂中的至少一种。Preferably, the positive electrode active material is selected from at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide and lithium manganese oxide.
在可选的实施方式中，正极活性材料和氧化石墨烯的质量比为100:2～10，每40mg～100mg的氧化石墨烯对应弱酸改性物的含量为0.05mmol～0.1mmol；In an optional embodiment, the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the content of the weak acid modifier corresponding to each 40 mg-100 mg of graphene oxide is 0.05 mmol-0.1 mmol;
优选地，在改性正极材料制备过程中，每40mg～100mg的氧化石墨烯对应聚合物单体的用量为1mmol～3mmol。Preferably, in the process of preparing the modified positive electrode material, the amount of the corresponding polymer monomer used is 1 mmol to 3 mmol for every 40 mg to 100 mg of graphene oxide.
第二方面，本申请提供一种前述实施方式中任一项改性正极材料的制备方法，包括：利用正极活性材料、氧化石墨烯、弱酸改性物和聚合物单 体为原料制备改性正极材料。In a second aspect, the present application provides a method for preparing a modified positive electrode material according to any one of the aforementioned embodiments, comprising: using a positive electrode active material, graphene oxide, a weak acid modifier and a polymer monomer The modified positive electrode material is prepared using the body as raw material.
在可选的实施方式中，将氧化石墨烯、弱酸改性物和正极活性材料在溶液体系中混合得到共混溶液，将共混溶液与聚合物单体混合进行聚合反应；In an optional embodiment, graphene oxide, a weak acid modifier and a positive electrode active material are mixed in a solution system to obtain a blended solution, and the blended solution is mixed with a polymer monomer to perform a polymerization reaction;
优选地，每40mg～100mg的氧化石墨烯对应聚合物单体的用量为1mmol～3mmol；Preferably, the amount of the corresponding polymer monomer is 1 mmol to 3 mmol per 40 mg to 100 mg of graphene oxide;
优选地，聚合温度为160℃～200℃，聚合时间为8h～12h；Preferably, the polymerization temperature is 160°C to 200°C, and the polymerization time is 8h to 12h;
优选地，在聚合反应之后将得到的聚合物溶液干燥并研磨成粉，控制D50＝0.5μm～15μm；Preferably, after the polymerization reaction, the obtained polymer solution is dried and ground into powder, and D50 is controlled to be 0.5 μm to 15 μm;
更优选地，将聚合物溶液干燥是进行冷冻干燥24h～48h。More preferably, the drying of the polymer solution is freeze drying for 24 h to 48 h.
在可选的实施方式中，共混溶液的制备过程包括：将氧化石墨烯溶液与弱酸改性物混合，再与正极活性材料混合；In an optional embodiment, the preparation process of the blended solution includes: mixing the graphene oxide solution with a weak acid modifier, and then mixing with a positive electrode active material;
优选地，弱酸改性物和氧化石墨烯的混合比例为0.05mmol～0.1mmol：40mg～100mg；正极活性材料与氧化石墨烯的质量比为100：2～10；Preferably, the mixing ratio of the weak acid modifier and graphene oxide is 0.05 mmol to 0.1 mmol: 40 mg to 100 mg; the mass ratio of the positive electrode active material to graphene oxide is 100: 2 to 10;
优选地，氧化石墨烯溶液的浓度为3mg/mL～5mg/mL。Preferably, the concentration of the graphene oxide solution is 3 mg/mL to 5 mg/mL.
第三方面，本申请提供一种电化学提锂极片的制备方法，利用前述实施方式中任一项改性正极材料或前述实施方式中任一项制备方法制备得到的改性正极材料进行制备。In a third aspect, the present application provides a method for preparing an electrochemical lithium extraction electrode sheet, which is prepared using any of the modified positive electrode materials in the aforementioned embodiments or a modified positive electrode material prepared by any of the preparation methods in the aforementioned embodiments.
在可选的实施方式中，将改性正极材料、粘结剂、导电剂、造孔剂和分散剂混合形成浆料，将浆料涂覆于极片基材上，将涂覆后的极片基材进行干燥；In an optional embodiment, the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant are mixed to form a slurry, the slurry is coated on the electrode substrate, and the coated electrode substrate is dried;
优选地，改性正极材料、粘结剂、导电剂、造孔剂和分散剂的质量比为100：1～1.5：0.2～1：10～30：150～250；Preferably, the mass ratio of the modified positive electrode material, the binder, the conductive agent, the pore former and the dispersant is 100:1-1.5:0.2-1:10-30:150-250;
优选地，粘结剂为聚偏氟乙烯；Preferably, the binder is polyvinylidene fluoride;
优选地，导电剂选自乙炔黑、科琴黑、导电石墨粉和碳纳米管中的至少一种； Preferably, the conductive agent is selected from at least one of acetylene black, Ketjen black, conductive graphite powder and carbon nanotubes;
优选地，造孔剂选自碳酸氨盐、碳酸钠和碳酸钾中的至少一种；Preferably, the pore former is selected from at least one of bicarbonate, sodium carbonate and potassium carbonate;
优选地，分散剂为N-甲基吡咯烷酮；Preferably, the dispersant is N-methylpyrrolidone;
优选地，极片基材选自铝箔、碳纤维布、碳纤维毡和多孔炭基材料、钛板、钛网中的至少一种；Preferably, the pole piece substrate is selected from at least one of aluminum foil, carbon fiber cloth, carbon fiber felt, porous carbon-based material, titanium plate, and titanium mesh;
优选地，浆料的涂覆密度为0.3g/cm2～0.5g/cm2；Preferably, the coating density of the slurry is 0.3 g/cm 2 to 0.5 g/cm 2 ;
优选地，将涂覆后的极片基材先在50℃～60℃的条件下干燥3h～5h，然后在100℃～120℃下干燥2h～10h。Preferably, the coated electrode substrate is first dried at 50° C. to 60° C. for 3 h to 5 h, and then dried at 100° C. to 120° C. for 2 h to 10 h.
第四方面，本申请提供一种电化学提锂极片，通过前述实施方式的制备方法制备而得。In a fourth aspect, the present application provides an electrochemical lithium extraction electrode sheet prepared by the preparation method of the aforementioned embodiment.
第五方面，本申请提供一种电化学提锂装置，包括前述实施方式的电化学提锂极片。In a fifth aspect, the present application provides an electrochemical lithium extraction device, comprising the electrochemical lithium extraction electrode of the aforementioned embodiment.
本申请具有以下有益效果：利用氧化石墨烯、弱酸改性物和聚合物对正极活性材料进行改性，在提取锂过程中，弱酸替代溶液中的H2O被电离，避免产生氢氧根，防止局部pH过高，从而抑制氢氧化镁沉淀的形成；在脱附锂离子时，能够再次生成弱酸基团，持续地抑制氢氧化镁沉淀的产生。利用聚合物能够更好地固定正极活性材料，提高极片的使用寿命；弱酸改性物中的含氧基团与氧化石墨烯片层上的六元环存在π-π共轭和多重氢键效应，能够形成改性物质和氧化石墨烯的组合体，可以很好地固定改性基团，且石墨烯能够增加极片的导电性。本申请提供的改性正极材料制备得到的极片在进行电化学提锂过程时，能够提升对锂的吸附容量，且循环性能更好。The present application has the following beneficial effects: the positive electrode active material is modified by using graphene oxide, weak acid modifier and polymer. During the lithium extraction process, the H 2 O in the weak acid replacement solution is ionized to avoid the generation of hydroxide and prevent the local pH from being too high, thereby inhibiting the formation of magnesium hydroxide precipitation; when desorbing lithium ions, weak acid groups can be generated again to continuously inhibit the generation of magnesium hydroxide precipitation. The use of polymers can better fix the positive electrode active material and increase the service life of the pole piece; the oxygen-containing groups in the weak acid modifier and the six-membered rings on the graphene oxide sheet have π-π conjugation and multiple hydrogen bonding effects, and can form a combination of modified substances and graphene oxide, which can well fix the modified groups, and graphene can increase the conductivity of the pole piece. The pole piece prepared by the modified positive electrode material provided in the present application can improve the adsorption capacity of lithium during the electrochemical lithium extraction process, and has better cycle performance.
具体实施方式DETAILED DESCRIPTION
为使本申请实施例的目的、技术方案和优点更加清楚，下面将对本申请实施例中的技术方案进行清楚、完整地描述。实施例中未注明具体条件者，按照常规条件或制造商建议的条件进行。所用试剂或仪器未注明生产 厂商者，均为可以通过市售购买获得的常规产品。In order to make the purpose, technical scheme and advantages of the examples of the present application clearer, the technical scheme in the examples of the present application will be described clearly and completely below. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. Manufacturers are all conventional products that can be purchased on the market.
在本申请中，术语“π-π共轭”是指两个及以上双键(或三键)以单键相联结时所发生的电子的离位作用。术语“多重氢键效应”是指多种分子间氢键的协同或多重作用。关于术语“循环性能”，通过多次提取锂循环后的吸附容量与初始吸附容量之间的比值表征，比值越大表明极片的循环性能越好。In the present application, the term "π-π conjugation" refers to the electron delocalization effect that occurs when two or more double bonds (or triple bonds) are connected by a single bond. The term "multiple hydrogen bonding effect" refers to the synergistic or multiple effects of multiple intermolecular hydrogen bonds. Regarding the term "cycling performance", it is characterized by the ratio between the adsorption capacity after multiple lithium extraction cycles and the initial adsorption capacity. The larger the ratio, the better the cycling performance of the electrode.
本申请实施例提供一种改性正极材料的制备方法，其利用正极活性材料、氧化石墨烯、弱酸改性物和聚合物单体为原料制备改性正极材料，利用氧化石墨烯、弱酸改性物和反应得到的聚合物对正极活性材料进行改性，使制备得到的正极材料在应用于盐湖提锂时，能够提升对锂的吸附容量，且循环性能更好。The embodiment of the present application provides a method for preparing a modified positive electrode material, which uses positive electrode active material, graphene oxide, weak acid modifier and polymer monomer as raw materials to prepare the modified positive electrode material, and uses graphene oxide, weak acid modifier and polymer obtained by the reaction to modify the positive electrode active material, so that the prepared positive electrode material can improve the adsorption capacity of lithium when used for lithium extraction from salt lakes, and has better cycle performance.
具体而言，改性正极材料的制备过程包括以下步骤：Specifically, the preparation process of the modified positive electrode material includes the following steps:
S1、制备含有正极活性材料、氧化石墨烯和弱酸改性物的混合溶液S1. Preparing a mixed solution containing a positive electrode active material, graphene oxide and a weak acid modifier
将氧化石墨烯、弱酸改性物和正极活性材料在溶液体系中混合得到共混溶液，混合的手段不限，可以采用常规的机械搅拌或超声混合的方式。The graphene oxide, the weak acid modifier and the positive electrode active material are mixed in a solution system to obtain a blended solution. The mixing method is not limited, and conventional mechanical stirring or ultrasonic mixing can be used.
在一些实施例中，共混溶液的制备过程包括：将氧化石墨烯溶液与弱酸改性物混合均匀后超声30min～60min，再与正极活性材料混合搅拌后超声30min～60min，使各组分分散均匀。In some embodiments, the preparation process of the blended solution includes: mixing the graphene oxide solution and the weak acid modifier evenly, then ultrasonicating for 30 minutes to 60 minutes, and then mixing and stirring with the positive electrode active material, and then ultrasonicating for 30 minutes to 60 minutes to make the components evenly dispersed.
其中，弱酸改性物为含有弱酸根的有机盐。改性物质中的含氧基团与氧化石墨烯片层上的六元环存在π-π共轭和多重氢键效应，能够形成改性物质和氧化石墨烯的组合体，可以很好的固定改性基团，且石墨烯能够增加极片的导电性。Among them, the weak acid modifier is an organic salt containing a weak acid radical. The oxygen-containing groups in the modified substance and the six-membered rings on the graphene oxide sheet have π-π conjugation and multiple hydrogen bonding effects, which can form a combination of the modified substance and graphene oxide, can well fix the modified groups, and graphene can increase the conductivity of the electrode.
需要说明的是，在制备贫锂态电极时，磺酸盐转化为磺酸基团。在提锂过程中，弱酸替代溶液中的H2O被电离，避免产生氢氧根，防止局部pH过高，从而抑制氢氧化镁沉淀的形成。在脱附锂离子时，能够再次生成弱酸基团，持续地抑制氢氧化镁沉淀的产生。反应方程式如下： It should be noted that when preparing lithium-deficient electrodes, sulfonates are converted into sulfonic acid groups. During the lithium extraction process, the H 2 O in the weak acid replacement solution is ionized to avoid the generation of hydroxide and prevent the local pH from being too high, thereby inhibiting the formation of magnesium hydroxide precipitation. When desorbing lithium ions, weak acid groups can be generated again, continuously inhibiting the generation of magnesium hydroxide precipitation. The reaction equation is as follows:
锂脱附时：4RCOONa-4e-+2H2O→4RCOOH+O2+4Na+；When lithium is desorbed: 4RCOONa-4e - +2H 2 O→4RCOOH+O 2 +4Na + ;
锂吸附时：2RCOOH+2e-+2Na+→2RCOONa+H2。When lithium is adsorbed: 2RCOOH+2e - +2Na + →2RCOONa+H 2 .
在一些实施例中，选自氨基苯甲酸钠、羟基苯甲酸钠、2-羟基-5-氨基苯甲酸钠和氨基水杨酸钠中的至少一种，可以为以上原料中的任意一种或几种。正极活性材料选自磷酸铁锂、磷酸锰铁锂、镍钴锰酸锂、钴酸锂和锰酸锂中的至少一种，可以为以上活性材料中的任意一种或几种。In some embodiments, at least one selected from sodium aminobenzoate, sodium hydroxybenzoate, sodium 2-hydroxy-5-aminobenzoate and sodium aminosalicylate can be any one or more of the above raw materials. The positive electrode active material is selected from at least one selected from lithium iron phosphate, lithium iron manganese phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide and lithium manganese oxide, and can be any one or more of the above active materials.
在一些实施例中，正极活性材料与氧化石墨烯的质量比为100：2～10，弱酸改性物和氧化石墨烯的混合比例为0.05mmol～0.1mmol：40mg～100mg。通过精确控制正极活性材料、氧化石墨烯和弱酸改性物的用量，能够使制备得到的正极材料的使用寿命更长，应用于电化学提锂时能够提升对锂的吸附容量。In some embodiments, the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the mixing ratio of the weak acid modifier and graphene oxide is 0.05mmol-0.1mmol:40mg-100mg. By precisely controlling the amount of the positive electrode active material, graphene oxide and weak acid modifier, the service life of the prepared positive electrode material can be extended, and the adsorption capacity of lithium can be increased when applied to electrochemical lithium extraction.
具体地，正极活性材料与氧化石墨烯的质量比可以为100:2、100:3、100:4、100:5、100:6、100:7、100:8、100:9、100:10等。Specifically, the mass ratio of the positive electrode active material to graphene oxide may be 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, or the like.
具体地，当弱酸改性物用量为0.05mmol～0.1mmol时，对应氧化石墨烯的用量为40mg～100mg。弱酸改性物和氧化石墨烯的混合比例可以为0.05mmol：40mg、0.06mmol：50mg、0.06mmol：60mg、0.07mmol：70mg、0.08mmol：80mg、0.09mmol：90mg、0.10mmol：100mg等，也可以为以上相邻取值之间的任意值。Specifically, when the amount of the weak acid modifier is 0.05 mmol to 0.1 mmol, the corresponding amount of graphene oxide is 40 mg to 100 mg. The mixing ratio of the weak acid modifier and graphene oxide can be 0.05 mmol: 40 mg, 0.06 mmol: 50 mg, 0.06 mmol: 60 mg, 0.07 mmol: 70 mg, 0.08 mmol: 80 mg, 0.09 mmol: 90 mg, 0.10 mmol: 100 mg, etc., or any value between the above adjacent values.
在一些实施例中，氧化石墨烯溶液的浓度为3mg/mL～5mg/mL，如可以为3mg/mL、4mg/mL、5mg/mL等。In some embodiments, the concentration of the graphene oxide solution is 3 mg/mL to 5 mg/mL, such as 3 mg/mL, 4 mg/mL, 5 mg/mL, etc.
S2、聚合S2, Aggregation
将共混溶液与聚合物单体混合进行聚合反应，聚合物单体选自吡咯、苯胺和噻吩中的至少一种，可以为任意一种或几种。含氧基团能够诱导聚合物聚合为有序分子链，使得分子链间能够更容易且更紧密的结合，因此能够更好地将正极材料固定在分子链之间，保证极片的使用寿命。The blended solution is mixed with a polymer monomer for polymerization reaction, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene, and can be any one or more. The oxygen-containing group can induce the polymer to polymerize into an ordered molecular chain, so that the molecular chains can be more easily and tightly combined, so that the positive electrode material can be better fixed between the molecular chains to ensure the service life of the electrode.
在一些实施例中，每40mg～100mg的氧化石墨烯对应聚合物单体的用 量为1mmol～3mmol，将共混溶液和聚合物单体超声搅拌30min～60min，随后转移至反应釜中进行聚合。聚合物单体的用量控制在上述范围内为宜，能够使正极材料更好地固定在分子链之间，保证极片的使用寿命。In some embodiments, the amount of polymer monomer corresponding to each 40 mg to 100 mg of graphene oxide is The amount of the polymer monomer is 1mmol to 3mmol, the blended solution and the polymer monomer are ultrasonically stirred for 30min to 60min, and then transferred to a reactor for polymerization. It is appropriate to control the amount of the polymer monomer within the above range, so that the positive electrode material can be better fixed between the molecular chains to ensure the service life of the electrode.
具体地，当氧化石墨烯用量为40mg～100mg时，对应聚合物单体的用量为1mmol～3mmol。氧化石墨烯和聚合物单体的混合比例可以为40mg：1mmol、50mg：1mmol、60mg：2mmol、70mg：2mmol、80mg：3mmol、90mg：3mmol、100mg：3mmol等，也可以为以上相邻取值之间的任意值。Specifically, when the amount of graphene oxide is 40 mg to 100 mg, the amount of the corresponding polymer monomer is 1 mmol to 3 mmol. The mixing ratio of graphene oxide and polymer monomer can be 40 mg: 1 mmol, 50 mg: 1 mmol, 60 mg: 2 mmol, 70 mg: 2 mmol, 80 mg: 3 mmol, 90 mg: 3 mmol, 100 mg: 3 mmol, etc., or any value between the above adjacent values.
在一些实施例中，聚合温度为160℃～200℃，聚合时间为8h～12h，以使反应充分。聚合温度可以为160℃、170℃、180℃、190℃、200℃等，聚合时间可以为8h、9h、10h、11h、12h等。In some embodiments, the polymerization temperature is 160°C to 200°C, and the polymerization time is 8h to 12h to allow the reaction to be sufficient. The polymerization temperature can be 160°C, 170°C, 180°C, 190°C, 200°C, etc., and the polymerization time can be 8h, 9h, 10h, 11h, 12h, etc.
S3、后处理S3, post-processing
在聚合反应之后将得到的聚合物溶液干燥并研磨成粉，以便于后续应用。After the polymerization reaction, the obtained polymer solution is dried and ground into powder for subsequent use.
在一些实施例中，干燥的方式不限，可以但不限于冷冻干燥，冷冻干燥的时间可以为24h～48h，如24h、30h、35h、40h、45h、48h等。In some embodiments, the drying method is not limited, and may be, but is not limited to, freeze drying. The freeze drying time may be 24 to 48 hours, such as 24 hours, 30 hours, 35 hours, 40 hours, 45 hours, 48 hours, and the like.
在一些实施例中，研磨成粉的粒径D50可以为0.5μm～15μm，如0.5μm、1μm、3μm、5μm、7μm、10μm、15μm等。In some embodiments, the particle size D50 of the ground powder can be 0.5 μm to 15 μm, such as 0.5 μm, 1 μm, 3 μm, 5 μm, 7 μm, 10 μm, 15 μm, etc.
本申请实施例还提供一种改性正极材料，改性正极材料中含有正极活性材料、氧化石墨烯、弱酸改性物和聚合物；其中，弱酸改性物为含有弱酸根的有机盐；聚合物是由聚合物单体聚合而得，聚合物单体选自吡咯、苯胺和噻吩中的至少一种。The embodiment of the present application also provides a modified positive electrode material, which contains a positive electrode active material, graphene oxide, a weak acid modifier and a polymer; wherein the weak acid modifier is an organic salt containing a weak acid radical; the polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
需要指出的是，该改性正极材料可以通过本申请实施例提供的制备方法制备而得。It should be pointed out that the modified positive electrode material can be prepared by the preparation method provided in the examples of the present application.
在一些实施例中，正极活性材料和氧化石墨烯的质量比为100:2～10，每40mg～100mg的氧化石墨烯对应弱酸改性物的含量为0.05mmol～0.1mmol。优选地，在改性正极材料制备过程中，每40mg～100mg的氧化石墨烯对应 聚合物单体的用量为1mmol～3mmol。通过精确控制正极活性材料、氧化石墨烯和弱酸改性物的用量，能够使制备得到的正极材料的使用寿命更长，应用于电化学提锂时能够提升对锂的吸附容量。In some embodiments, the mass ratio of the positive electrode active material to graphene oxide is 100:2-10, and the content of the weak acid modifier corresponding to each 40 mg to 100 mg of graphene oxide is 0.05 mmol to 0.1 mmol. Preferably, in the preparation process of the modified positive electrode material, the content of the weak acid modifier corresponding to each 40 mg to 100 mg of graphene oxide is 0.05 mmol to 0.1 mmol. The amount of the polymer monomer is 1 mmol to 3 mmol. By precisely controlling the amount of the positive electrode active material, graphene oxide and weak acid modifier, the service life of the prepared positive electrode material can be extended, and the adsorption capacity of lithium can be increased when applied to electrochemical lithium extraction.
本申请实施例还提供一种电化学提锂极片的制备方法，利用上述改性正极材料进行制备，制备方法不限，可以采用现有的方法制备极片，在此不做限定。The embodiment of the present application also provides a method for preparing an electrochemical lithium extraction electrode sheet, which is prepared using the above-mentioned modified positive electrode material. The preparation method is not limited, and the electrode sheet can be prepared using existing methods, which is not limited here.
在一些实施例中，将改性正极材料、粘结剂、导电剂、造孔剂和分散剂混合形成浆料，将浆料涂覆于极片基材上，将涂覆后的极片基材进行干燥，得到电极片。改性正极材料、粘结剂、导电剂、造孔剂和分散剂的质量比为100：1～1.5：0.2～1：10～30：150～250，如可以为100:1:0.2:10:150、100:1.2:0.5:15:180、100:1.3:0.7:20:200、100:1.5:1.0:30:250等。In some embodiments, the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant are mixed to form a slurry, the slurry is coated on the electrode substrate, and the coated electrode substrate is dried to obtain an electrode sheet. The mass ratio of the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant is 100:1-1.5:0.2-1:10-30:150-250, such as 100:1:0.2:10:150, 100:1.2:0.5:15:180, 100:1.3:0.7:20:200, 100:1.5:1.0:30:250, etc.
粘结剂、导电剂、造孔剂和分散剂的具体种类不限，可以采用制备极片的常用原料。在一些实施例中，粘结剂可以但不限于聚偏氟乙烯；导电剂选自乙炔黑、科琴黑、导电石墨粉和碳纳米管中的至少一种；造孔剂选自碳酸氨盐、碳酸钠和碳酸钾中的至少一种；分散剂可以但不限于N-甲基吡咯烷酮。粘结剂、导电剂、造孔剂和分散剂可以为以上任意一种或几种。The specific types of binders, conductive agents, pore formers and dispersants are not limited, and common raw materials for preparing pole pieces can be used. In some embodiments, the binder can be but not limited to polyvinylidene fluoride; the conductive agent is selected from at least one of acetylene black, Ketjen black, conductive graphite powder and carbon nanotubes; the pore former is selected from at least one of bicarbonate, sodium carbonate and potassium carbonate; the dispersant can be but not limited to N-methylpyrrolidone. The binder, conductive agent, pore former and dispersant can be any one or more of the above.
在一些实施例中，极片基材选自铝箔、碳纤维布、碳纤维毡和多孔炭基材料、钛板、钛网中的至少一种，可以为以上任意一种或几种，也可以根据需要进行针对性调整。In some embodiments, the electrode substrate is selected from at least one of aluminum foil, carbon fiber cloth, carbon fiber felt and porous carbon-based material, titanium plate, and titanium mesh. It can be any one or more of the above, and can also be adjusted as needed.
在一些实施例中，浆料的涂覆密度为0.3g/cm2～0.5g/cm2，以使涂层厚度满足工艺要求。具体地，涂覆密度可以为0.3g/cm2、0.4g/cm2、0.5g/cm2等。In some embodiments, the coating density of the slurry is 0.3 g/cm 2 to 0.5 g/cm 2 so that the coating thickness meets the process requirements. Specifically, the coating density can be 0.3 g/cm 2 , 0.4 g/cm 2 , 0.5 g/cm 2 and the like.
在一些实施例中，将涂覆后的极片基材先在50℃～60℃的条件下干燥3h～5h，然后在100℃～120℃下干燥2h～10h，先在低温条件下干燥然后在高温条件下干燥，防止浆料在初期由于温度过高影响涂层的均匀性。In some embodiments, the coated electrode substrate is first dried at 50°C to 60°C for 3h to 5h, and then dried at 100°C to 120°C for 2h to 10h. It is first dried at low temperature and then at high temperature to prevent the slurry from affecting the uniformity of the coating due to excessively high temperature in the initial stage.
具体地，初期干燥的温度可以为50℃、52℃、55℃、57℃、60℃等， 干燥时间可以为3h、4h、5h等；后期干燥的温度可以为100℃、110℃、120℃等，干燥时间可以为2h、5h、7h、10h等。Specifically, the initial drying temperature may be 50°C, 52°C, 55°C, 57°C, 60°C, etc. The drying time can be 3h, 4h, 5h, etc.; the temperature of the later drying can be 100°C, 110°C, 120°C, etc., and the drying time can be 2h, 5h, 7h, 10h, etc.
本申请实施例还提供一种电化学提锂极片，通过上述电化学提锂极片的制备方法制备而得，在进行电化学提锂过程时，能够提升对锂的吸附容量，且循环性能更好。The embodiment of the present application also provides an electrochemical lithium extraction electrode sheet, which is prepared by the above-mentioned preparation method of the electrochemical lithium extraction electrode sheet. During the electrochemical lithium extraction process, the adsorption capacity of lithium can be improved and the cycle performance is better.
本申请实施例还提供一种电化学提锂装置，包括上述电化学提锂极片，可以包括负极、电源等，形成一套完整的电化学提锂装置，能够更高效地进行电化学提锂。The embodiment of the present application also provides an electrochemical lithium extraction device, including the above-mentioned electrochemical lithium extraction electrode sheet, which may include a negative electrode, a power supply, etc., to form a complete electrochemical lithium extraction device that can perform electrochemical lithium extraction more efficiently.
以下结合实施例对本申请的特征和性能作进一步的详细描述。The features and performance of the present application are further described in detail below in conjunction with the embodiments.
实施例1Example 1
本实施例提供一种电化学提锂极片的制备方法，包括如下步骤：This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
(1)改性正极材料制备(1) Preparation of modified positive electrode materials
将15ml，3mg/ml的氧化石墨烯水溶液与0.1mmol氨基苯甲酸钠混合均匀后超声30min，得到混合物溶液B。15 ml of 3 mg/ml graphene oxide aqueous solution was mixed evenly with 0.1 mmol of sodium aminobenzoate and then ultrasonicated for 30 min to obtain a mixture solution B.
向混合物溶液B中加入1g磷酸铁锂。混合搅拌后，超声30min使其分散均匀，得到混合溶液C。1 g of lithium iron phosphate was added to the mixed solution B. After mixing and stirring, ultrasonic treatment was performed for 30 min to make the mixture dispersed evenly, thereby obtaining a mixed solution C.
向混合溶液C中加入2mmol的吡咯单体，超声搅拌30，随后转移至反应釜中，180℃下反应8h得到聚合物溶液D。将聚合物溶液D冷冻干燥48h后研磨成粉，控制D50＝1～3μm。2 mmol of pyrrole monomer was added to the mixed solution C, ultrasonically stirred for 30 min, and then transferred to a reactor and reacted at 180° C. for 8 h to obtain a polymer solution D. The polymer solution D was freeze-dried for 48 h and then ground into powder, with D50 controlled to be 1-3 μm.
(2)极片制备(2) Electrode preparation
将得到的改性正极材料粉末、PVDF(粘结剂)、乙炔黑(导电剂)、造孔剂(碳酸氨盐)和N-甲基吡咯烷酮(分散剂)按照质量比100：1：0.5：10：200混合均匀，在真空条件下利用搅拌机搅拌成均一的浆料。随后将浆料涂覆在铝箔上，涂覆密度为0.5g/cm2。将涂覆后的电极在60℃干燥3h后再在120℃下干燥8h得到电极片。The obtained modified positive electrode material powder, PVDF (binder), acetylene black (conductive agent), pore former (ammonium carbonate) and N-methylpyrrolidone (dispersant) were mixed evenly in a mass ratio of 100:1:0.5:10:200, and stirred into a uniform slurry using a stirrer under vacuum conditions. The slurry was then coated on aluminum foil with a coating density of 0.5 g/cm 2 . The coated electrode was dried at 60°C for 3 hours and then at 120°C for 8 hours to obtain an electrode sheet.
性能测试：采用模拟卤水为源液(成分如表1所示)，以实施例制备的 磷酸铁锂正极采用为正极，碳棒为负电极，两电极间的电压范围为0.5-2.5mV/cm-2，施加恒定电流0.5mA/cm-2进行一次脱附，随后施加-0.5mA/cm-2恒电流进行一次吸附，一次吸脱附为一个循环，进行50圈循环的锂提取实验。经过ICP测试可得锂离子吸附容量。Performance test: Using simulated brine as the source liquid (the composition is shown in Table 1), the Lithium iron phosphate is used as the positive electrode, carbon rod is used as the negative electrode, the voltage between the two electrodes ranges from 0.5-2.5mV/cm -2 , a constant current of 0.5mA/cm -2 is applied for desorption, and then -0.5mA/cm -2 is applied for adsorption, one adsorption and desorption is one cycle, and 50 cycles of lithium extraction experiments are performed. The lithium ion adsorption capacity can be obtained through ICP testing.
表1模拟卤水的离子种类和含量
Table 1 Ion types and contents of simulated brine
经测试：吸附容量为38.31mg·g-1，循环50次后，锂离子筛的锂吸附容量为37.74mg·g-1，容量保持率为98.52％。The test showed that the adsorption capacity was 38.31 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve was 37.74 mg·g -1 , and the capacity retention rate was 98.52%.
实施例2Example 2
本实施例提供一种电化学提锂极片的制备方法，包括如下步骤：This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
(1)改性正极材料制备(1) Preparation of modified positive electrode materials
将6.7ml，3mg/ml的氧化石墨烯水溶液与0.025mmol羟基苯甲酸钠混合均匀后超声30min，得到混合物溶液B。6.7 ml of 3 mg/ml graphene oxide aqueous solution and 0.025 mmol sodium hydroxybenzoate were mixed evenly and then ultrasonicated for 30 min to obtain a mixture solution B.
向混合物溶液B中加入1g磷酸锰铁锂，化学式为LiMn0.3Fe0.7PO4。混合搅拌后，超声30min使其分散均匀，得到混合溶液C。1 g of lithium manganese iron phosphate, whose chemical formula is LiMn 0.3 Fe 0.7 PO 4 , is added to the mixed solution B. After mixing and stirring, ultrasonic treatment is performed for 30 minutes to make the mixture dispersed evenly, thereby obtaining a mixed solution C.
向混合溶液C中加入0.5mmol的吡咯单体，超声搅拌30，随后转移至反应釜中，180℃下反应8h得到聚合物溶液D。将聚合物溶液D冷冻干燥48h后研磨成粉，控制D50＝1～3μm。0.5 mmol of pyrrole monomer was added to the mixed solution C, ultrasonically stirred for 30 min, and then transferred to a reactor and reacted at 180° C. for 8 h to obtain a polymer solution D. The polymer solution D was freeze-dried for 48 h and then ground into powder, with D50 controlled to be 1-3 μm.
(2)极片制备(2) Electrode preparation
采用本实施例制备的正极材料粉末进行制备，具体步骤与实施例1相同。 The positive electrode material powder prepared in this embodiment is used for preparation, and the specific steps are the same as those in embodiment 1.
经测试(测试方法同实施例1)：吸附容量为38.28mg·g-1，循环50次后，锂离子筛的锂吸附容量为37.70mg·g-1，容量保持率为98.48％。After testing (testing method is the same as that of Example 1), the adsorption capacity is 38.28 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve is 37.70 mg·g -1 , and the capacity retention rate is 98.48%.
实施例3Example 3
本实施例提供一种电化学提锂极片的制备方法，包括如下步骤：This embodiment provides a method for preparing an electrochemical lithium extraction electrode sheet, comprising the following steps:
(1)改性正极材料制备(1) Preparation of modified positive electrode materials
将33ml，3mg/ml的氧化石墨烯水溶液与0.1mmol 2-羟基-5-氨基苯甲酸钠混合均匀后超声30min，得到混合物溶液B。Mix 33 ml of 3 mg/ml graphene oxide aqueous solution and 0.1 mmol sodium 2-hydroxy-5-aminobenzoate evenly and ultrasonicate for 30 minutes to obtain a mixture solution B.
向混合物溶液B中加入1g镍钴锰酸锂，化学式为LiNi0.5Co0.2Mn0.3O2。混合搅拌后，超声30min使其分散均匀，得到混合溶液C。1 g of lithium nickel cobalt manganese oxide, whose chemical formula is LiNi 0.5 Co 0.2 Mn 0.3 O 2 , is added to the mixed solution B. After mixing and stirring, ultrasonic treatment is performed for 30 minutes to make the mixture dispersed evenly, thereby obtaining a mixed solution C.
向混合溶液C中加入3mmol的吡咯单体，超声搅拌30，随后转移至反应釜中，180℃下反应8h得到聚合物溶液D。将聚合物溶液D冷冻干燥48h后研磨成粉，控制D50＝5～15μm。3 mmol of pyrrole monomer was added to the mixed solution C, ultrasonically stirred for 30 min, and then transferred to a reactor and reacted at 180° C. for 8 h to obtain a polymer solution D. The polymer solution D was freeze-dried for 48 h and then ground into powder, with D50 controlled to be 5-15 μm.
(2)极片制备(2) Electrode preparation
采用本实施例制备的正极材料粉末进行制备，具体步骤与实施例1相同。The positive electrode material powder prepared in this embodiment is used for preparation, and the specific steps are the same as those in Embodiment 1.
经测试(测试方法同实施例1)：吸附容量为40.16mg·g-1，循环50次后，锂离子筛的锂吸附容量为37.76mg·g-1，容量保持率为94.02％。After testing (testing method is the same as that of Example 1), the adsorption capacity is 40.16 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve is 37.76 mg·g -1 , and the capacity retention rate is 94.02%.
对比例1Comparative Example 1
与实施例1的区别仅在于：未加入氨基苯甲酸钠。The only difference from Example 1 is that sodium aminobenzoate is not added.
经过ICP测试可得，吸附容量为37.54mg·g-1，循环50次后，锂离子筛的锂吸附容量为34.02mg·g-1，容量保持率为90.62％。未加入氨基苯甲酸钠，极片上产生氢氧化镁沉淀堵塞孔洞，导致多次循环后容量降低。After ICP testing, the adsorption capacity was 37.54 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve was 34.02 mg·g -1 , and the capacity retention rate was 90.62%. Without the addition of sodium aminobenzoate, magnesium hydroxide precipitates formed on the electrode to block the pores, resulting in a decrease in capacity after multiple cycles.
对比例2Comparative Example 2
与实施例1的区别仅在于：未加入吡咯单体，且未进行聚合反应。The only difference from Example 1 is that no pyrrole monomer was added and no polymerization reaction was performed.
经过ICP测试可得，吸附容量为35.81mg·g-1，循环50次后，锂离子 筛的锂吸附容量为33.05mg·g-1，容量保持率为92.30％。未加入吡咯单体，极片上带有改性基团的氧化石墨烯没有被很好的固定，多次循环后容量相比实施例1有所降低。The ICP test showed that the adsorption capacity was 35.81 mg·g -1 . After 50 cycles, the lithium ion The lithium adsorption capacity of the sieve was 33.05 mg·g -1 , and the capacity retention rate was 92.30%. Without adding pyrrole monomer, the graphene oxide with modified groups on the electrode was not well fixed, and the capacity after multiple cycles was lower than that of Example 1.
对比例3Comparative Example 3
与实施例1的区别仅在于：未加入氧化石墨烯。The only difference from Example 1 is that no graphene oxide is added.
经过ICP测试可得，吸附容量为36.42mg·g-1，循环50次后，锂离子筛的锂吸附容量为33.22mg·g-1，容量保持率为91.21％。未加入氧化石墨烯，没有物质很好的去与改性基团结合，多次循环后容量相比实施例1有所降低。ICP test showed that the adsorption capacity was 36.42 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve was 33.22 mg·g -1 , and the capacity retention rate was 91.21%. Without adding graphene oxide, there was no substance to combine well with the modified group, and the capacity after multiple cycles was lower than that of Example 1.
对比例4Comparative Example 4
与实施例1的区别仅在于：氨基苯甲酸钠用量为0.01mmol。The difference from Example 1 is that the amount of sodium aminobenzoate is 0.01 mmol.
经过ICP测试可得，吸附容量为37.65mg·g-1，循环50次后，锂离子筛的锂吸附容量为34.40mg·g-1，容量保持率为91.36％。加入较少的氨基苯甲酸钠，极片上仍会产生氢氧化镁沉淀堵塞孔洞，导致多次循环后容量降低。After ICP testing, the adsorption capacity was 37.65 mg·g -1 . After 50 cycles, the lithium adsorption capacity of the lithium ion sieve was 34.40 mg·g-1 , and the capacity retention rate was 91.36%. When less sodium aminobenzoate was added, magnesium hydroxide precipitates would still form on the electrode to block the pores, resulting in a decrease in capacity after multiple cycles.
对比例5Comparative Example 5
与实施例1的区别仅在于：氨基苯甲酸钠用量为5mmol。The difference from Example 1 is only that the amount of sodium aminobenzoate is 5 mmol.
经过ICP测试可得，吸附容量为38.18mg·g-1，循环50次后，锂离子筛的锂吸附容量为36.86mg·g-1，容量保持率为96.53％。加入较多的氨基苯甲酸钠，会造成浪费，增大成本。According to ICP test, the adsorption capacity is 38.18 mg·g -1 , and after 50 cycles, the lithium adsorption capacity of the lithium ion sieve is 36.86 mg·g -1 , and the capacity retention rate is 96.53%. Adding more sodium aminobenzoate will cause waste and increase costs.
为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。 The preferred embodiments of the present application are only for reference only and are not intended to limit the present application. For those skilled in the art, the present application may be subject to various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims (10)

  1. 一种改性正极材料，其特征在于，所述改性正极材料中含有正极活性材料、氧化石墨烯、弱酸改性物和聚合物；A modified positive electrode material, characterized in that the modified positive electrode material contains a positive electrode active material, graphene oxide, a weak acid modifier and a polymer;
    其中，所述弱酸改性物为含有弱酸根的有机盐；Wherein, the weak acid modifier is an organic salt containing a weak acid radical;
    所述聚合物是由聚合物单体聚合而得，所述聚合物单体选自吡咯、苯胺和噻吩中的至少一种。The polymer is obtained by polymerizing a polymer monomer, and the polymer monomer is selected from at least one of pyrrole, aniline and thiophene.
  2. 根据权利要求1所述的改性正极材料，其特征在于，所述弱酸改性物选自氨基苯甲酸钠、羟基苯甲酸钠、2-羟基-5-氨基苯甲酸钠和氨基水杨酸钠中的至少一种；The modified positive electrode material according to claim 1, characterized in that the weak acid modifier is at least one selected from the group consisting of sodium aminobenzoate, sodium hydroxybenzoate, sodium 2-hydroxy-5-aminobenzoate and sodium aminosalicylate;
    优选地，所述正极活性材料选自磷酸铁锂、磷酸锰铁锂、镍钴锰酸锂、钴酸锂和锰酸锂中的至少一种。Preferably, the positive electrode active material is selected from at least one of lithium iron phosphate, lithium iron manganese phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide and lithium manganese oxide.
  3. 根据权利要求2所述的改性正极材料，其特征在于，所述正极活性材料和所述氧化石墨烯的质量比为100:2～10，每40mg～100mg的所述氧化石墨烯对应所述弱酸改性物的含量为0.05mmol～0.1mmol；The modified positive electrode material according to claim 2, characterized in that the mass ratio of the positive electrode active material to the graphene oxide is 100:2-10, and the content of the weak acid modifier corresponding to each 40 mg-100 mg of the graphene oxide is 0.05 mmol-0.1 mmol;
    优选地，在所述改性正极材料制备过程中，每40mg～100mg的所述氧化石墨烯对应所述聚合物单体的用量为1mmol～3mmol。Preferably, in the process of preparing the modified positive electrode material, the amount of the polymer monomer used is 1 mmol to 3 mmol for every 40 mg to 100 mg of the graphene oxide.
  4. 一种权利要求1～3中任一项所述改性正极材料的制备方法，其特征在于，包括：利用所述正极活性材料、所述氧化石墨烯、所述弱酸改性物和所述聚合物单体为原料制备所述改性正极材料。A method for preparing the modified positive electrode material according to any one of claims 1 to 3, characterized in that it comprises: using the positive electrode active material, the graphene oxide, the weak acid modifier and the polymer monomer as raw materials to prepare the modified positive electrode material.
  5. 根据权利要求4所述的制备方法，其特征在于，将所述氧化石墨烯、所述弱酸改性物和所述正极活性材料在溶液体系中混合得到共混溶液，将所述共混溶液与所述聚合物单体混合进行聚合反应；The preparation method according to claim 4, characterized in that the graphene oxide, the weak acid modifier and the positive electrode active material are mixed in a solution system to obtain a blended solution, and the blended solution is mixed with the polymer monomer to perform a polymerization reaction;
    优选地，每40mg～100mg的所述氧化石墨烯对应所述聚合物单体的用量为1mmol～3mmol；Preferably, the amount of the polymer monomer used for every 40 mg to 100 mg of the graphene oxide is 1 mmol to 3 mmol;
    优选地，聚合温度为160℃～200℃，聚合时间为8h～12h； Preferably, the polymerization temperature is 160°C to 200°C, and the polymerization time is 8h to 12h;
    优选地，在聚合反应之后将得到的聚合物溶液干燥并研磨成粉，控制D50＝0.5μm～15μm；Preferably, after the polymerization reaction, the obtained polymer solution is dried and ground into powder, and D50 is controlled to be 0.5 μm to 15 μm;
    更优选地，将所述聚合物溶液干燥是进行冷冻干燥24h～48h。More preferably, drying the polymer solution is freeze-drying for 24 h to 48 h.
  6. 根据权利要求5所述的制备方法，其特征在于，所述共混溶液的制备过程包括：将氧化石墨烯溶液与所述弱酸改性物混合，再与所述正极活性材料混合；The preparation method according to claim 5 is characterized in that the preparation process of the blended solution comprises: mixing the graphene oxide solution with the weak acid modifier, and then mixing with the positive electrode active material;
    优选地，所述弱酸改性物和所述氧化石墨烯的混合比例为0.05mmol～0.1mmol：40mg～100mg；所述正极活性材料与氧化石墨烯的质量比为100：2～10；Preferably, the mixing ratio of the weak acid modifier and the graphene oxide is 0.05 mmol to 0.1 mmol: 40 mg to 100 mg; the mass ratio of the positive electrode active material to the graphene oxide is 100: 2 to 10;
    优选地，所述氧化石墨烯溶液的浓度为3mg/mL～5mg/mL。Preferably, the concentration of the graphene oxide solution is 3 mg/mL to 5 mg/mL.
  7. 一种电化学提锂极片的制备方法，其特征在于，利用权利要求1～3中任一项所述改性正极材料或权利要求4～6中任一项所述制备方法制备得到的改性正极材料进行制备。A method for preparing an electrochemical lithium extraction electrode sheet, characterized in that it is prepared using the modified positive electrode material described in any one of claims 1 to 3 or the modified positive electrode material prepared by the preparation method described in any one of claims 4 to 6.
  8. 根据权利要求7所述的制备方法，其特征在于，将所述改性正极材料、粘结剂、导电剂、造孔剂和分散剂混合形成浆料，将所述浆料涂覆于极片基材上，将涂覆后的极片基材进行干燥；The preparation method according to claim 7, characterized in that the modified positive electrode material, the binder, the conductive agent, the pore-forming agent and the dispersant are mixed to form a slurry, the slurry is coated on the electrode substrate, and the coated electrode substrate is dried;
    优选地，所述改性正极材料、所述粘结剂、所述导电剂、所述造孔剂和所述分散剂的质量比为100：1～1.5：0.2～1：10～30：150～250；Preferably, the mass ratio of the modified positive electrode material, the binder, the conductive agent, the pore former and the dispersant is 100:1-1.5:0.2-1:10-30:150-250;
    优选地，所述粘结剂为聚偏氟乙烯；Preferably, the binder is polyvinylidene fluoride;
    优选地，所述导电剂选自乙炔黑、科琴黑、导电石墨粉和碳纳米管中的至少一种；Preferably, the conductive agent is selected from at least one of acetylene black, Ketjen black, conductive graphite powder and carbon nanotubes;
    优选地，所述造孔剂选自碳酸氨盐、碳酸钠和碳酸钾中的至少一种；Preferably, the pore-forming agent is selected from at least one of bicarbonate, sodium carbonate and potassium carbonate;
    优选地，所述分散剂为N-甲基吡咯烷酮；Preferably, the dispersant is N-methylpyrrolidone;
    优选地，所述极片基材选自铝箔、碳纤维布、碳纤维毡和多孔炭基材料、钛板、钛网中的至少一种；Preferably, the pole piece substrate is selected from at least one of aluminum foil, carbon fiber cloth, carbon fiber felt, porous carbon-based material, titanium plate, and titanium mesh;
    优选地，所述浆料的涂覆密度为0.3g/cm2～0.5g/cm2； Preferably, the coating density of the slurry is 0.3 g/cm 2 to 0.5 g/cm 2 ;
    优选地，将涂覆后的极片基材先在50℃～60℃的条件下干燥3h～5h，然后在100℃～120℃下干燥2h～10h。Preferably, the coated electrode substrate is first dried at 50° C. to 60° C. for 3 h to 5 h, and then dried at 100° C. to 120° C. for 2 h to 10 h.
  9. 一种电化学提锂极片，其特征在于，通过权利要求7或8所述的制备方法制备而得。An electrochemical lithium extraction electrode, characterized in that it is prepared by the preparation method described in claim 7 or 8.
  10. 一种电化学提锂装置，其特征在于，包括权利要求9所述的电化学提锂极片。 An electrochemical lithium extraction device, characterized in that it comprises the electrochemical lithium extraction electrode sheet according to claim 9.
PCT/CN2023/085289 2023-02-09 2023-03-31 Modified positive electrode material, electrochemical lithium extraction electrode sheet, and preparation method therefor and use thereof WO2024164415A1 (en)

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Families Citing this family (1)

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Publication number Priority date Publication date Assignee Title
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108232139A (en) * 2017-12-20 2018-06-29 中国科学院福建物质结构研究所 A kind of graphene composite material and preparation method thereof
WO2021160239A1 (en) * 2020-02-10 2021-08-19 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Method and apparatus for the extraction of lithium from aqueous lithium sources
CN113278820A (en) * 2021-05-21 2021-08-20 中南大学 Electrode material for lithium extraction in salt lake and preparation method and application thereof
CN113293312A (en) * 2021-05-21 2021-08-24 中南大学 Preparation method of composite porous electrode material for lithium extraction
CN113293289A (en) * 2021-05-21 2021-08-24 江苏中南锂业有限公司 Preparation method of hydrophilic lithium extraction electrode
CN113293291A (en) * 2021-05-21 2021-08-24 江苏中南锂业有限公司 Preparation method of high-conductivity lithium extraction electrode
CN113842878A (en) * 2021-09-24 2021-12-28 中国科学院青海盐湖研究所 Preparation method of carbon-based lithium adsorption electrode for extracting liquid lithium resource

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108232139A (en) * 2017-12-20 2018-06-29 中国科学院福建物质结构研究所 A kind of graphene composite material and preparation method thereof
WO2021160239A1 (en) * 2020-02-10 2021-08-19 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Method and apparatus for the extraction of lithium from aqueous lithium sources
CN113278820A (en) * 2021-05-21 2021-08-20 中南大学 Electrode material for lithium extraction in salt lake and preparation method and application thereof
CN113293312A (en) * 2021-05-21 2021-08-24 中南大学 Preparation method of composite porous electrode material for lithium extraction
CN113293289A (en) * 2021-05-21 2021-08-24 江苏中南锂业有限公司 Preparation method of hydrophilic lithium extraction electrode
CN113293291A (en) * 2021-05-21 2021-08-24 江苏中南锂业有限公司 Preparation method of high-conductivity lithium extraction electrode
CN113842878A (en) * 2021-09-24 2021-12-28 中国科学院青海盐湖研究所 Preparation method of carbon-based lithium adsorption electrode for extracting liquid lithium resource

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ZHANG, FAN; JI, ZHIYONG; WANG, JING; GUO, ZHIYUAN; FANG, JIAWEI: "Study on the Preparation of GO/LiMn2 O4 Film Electrode and Its Lithium Extraction Property", MATERIALS REVIEW, vol. 36, no. 11, 31 December 2022 (2022-12-31), CN , pages 16 - 222, XP009556782, ISSN: 1005-023X, DOI: 10.11896/cldb.21040052 *

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