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CN-117735521-B - Hard carbon anode material, preparation method and application thereof, and sodium ion battery

CN117735521BCN 117735521 BCN117735521 BCN 117735521BCN-117735521-B

Abstract

The invention discloses a hard carbon anode material, a preparation method and application thereof, and a sodium ion battery. The preparation method of the hard carbon anode material comprises the following steps of (1) carrying out heat treatment on a mixture of phenolic compounds, aldehyde compounds and amine compounds to obtain a resin solution, wherein the amine compounds are aliphatic amines, the molar ratio of the phenolic compounds to the aldehyde compounds is 1 (1-3), the molar ratio of the phenolic compounds to the amine compounds is 1 (0.2-3), and (2) carrying out spray drying and carbonization on the resin solution to obtain the hard carbon anode material, wherein carbonization comprises first carbonization and second carbonization. The hard carbon anode material prepared by the method has a regular microstructure, is rich in nitrogen elements, is suitable in pore size distribution and specific surface area, has excellent electrochemical performance when being applied to batteries, can realize in-situ doping of the nitrogen elements, is simple in preparation process, can realize large-scale production, and has good industrial application prospect.

Inventors

  • REN ZHANXIN
  • FAN ZHENGHUA
  • ZHANG XIUYUN
  • ZHANG ZILU
  • REN BOYANG

Assignees

  • 上海杉杉新材料有限公司

Dates

Publication Date
20260508
Application Date
20231226

Claims (19)

  1. 1. The preparation method of the hard carbon anode material is characterized by comprising the following steps of: (1) Carrying out heat treatment on a mixture of a phenolic compound, an aldehyde compound and an amine compound to obtain a resin solution, wherein the amine compound is one or more of 1, 6-hexamethylenediamine, 1, 8-octanediamine, melamine and N-methylimidazole, the molar ratio of the phenolic compound to the aldehyde compound is 1 (1-3), and the molar ratio of the phenolic compound to the amine compound is 1 (0.2-3); The water-soluble high molecular polymer is one or more of polyvinyl alcohol, polyethylene glycol and polyvinyl butyral; (2) Spray drying and carbonizing the resin solution to obtain a hard carbon anode material, wherein the carbonization comprises first carbonization and second carbonization; The temperature of the first carbonization is 400-700 ℃; the temperature of the second carbonization is 1200-1500 ℃.
  2. 2. The method for producing a hard carbon negative electrode material according to claim 1, wherein in the step (1), the phenolic compound is selected from one or more of phenol, bisphenol a, resorcinol and xylenol; and/or, in the step (1), the aldehyde compound is selected from one or more of formaldehyde, furfural, glutaraldehyde, paraldehyde and benzaldehyde; And/or, in the step (1), the molar ratio of the phenolic compound to the aldehyde compound is 1 (1-2); And/or, in the step (1), the amine compound is 1, 6-hexamethylenediamine, 1, 8-octanediamine, melamine or N-methylimidazole; and/or, in the step (1), the molar ratio of the phenolic compound to the amine compound is 1 (0.2-2); In the step (1), the solid content of the resin solution is 2-40wt%.
  3. 3. The method for producing a hard carbon negative electrode material according to claim 1, wherein in the step (1), the phenolic compound is resorcinol, phenol or xylenol; and/or in the step (1), the aldehyde compound is formaldehyde, furfural or glutaraldehyde, wherein the formaldehyde or the furfural is prepared into a 37wt% solution for use, and the glutaraldehyde is prepared into a 25wt% solution for use; And/or, in the step (1), the solid content of the resin solution is 3-15wt%.
  4. 4. The method for producing a hard carbon negative electrode material according to claim 1, wherein the aldehyde compound is a 37wt% formaldehyde solution, a 37wt% furfural solution or a 25wt% glutaraldehyde solution.
  5. 5. The method for producing a hard carbon negative electrode material according to claim 1, wherein in the step (1), a phosphorus-containing compound is further included in the mixture; And/or, in the step (1), the mixture is prepared by dissolving the phenolic compound in a solvent to prepare a solution A, adding the aldehyde compound and the amine compound into the solution A, stirring and heating.
  6. 6. The method for producing a hard carbon negative electrode material according to claim 5, wherein in the step (1), a phosphorus-containing compound selected from one or more of phosphorus pentoxide, phosphoric acid, sodium dihydrogen phosphate, sodium phosphate, potassium phosphate, ammonium phosphate and ammonium dihydrogen phosphate is further included in the mixture; and/or, in the step (1), a phosphorus-containing compound is further included in the mixture, and the addition amount of the phosphorus-containing compound is 0.5-8wt% of the mass of the resin solution.
  7. 7. The method for producing a hard carbon negative electrode material according to claim 6, wherein the phosphorus-containing compound is sodium phosphate or ammonium phosphate; and/or the addition amount of the phosphorus-containing compound is 0.5 to 4wt% of the mass of the resin solution.
  8. 8. The method for producing a hard carbon negative electrode material according to claim 5, wherein the solvent is one or more selected from the group consisting of water, ethanol and toluene; and/or the mass ratio of the phenolic compound to the solvent is 1 (10-100); and/or the temperature of the solution A is 30-50 ℃; and/or the stirring speeds are 20-150rpm; And/or, the stirring time is 1-4h; and/or, the temperature of the heating is 30-90 ℃; and/or the constant temperature time of the heating is 2-24 hours; And/or adding the phosphorus-containing compound to the solution A.
  9. 9. The method for producing a hard carbon negative electrode material according to claim 8, wherein the solvent is water; and/or the stirring speeds are all 30-140rpm; and/or, the temperature of the heating is 70-90 ℃; and/or the constant temperature time of the heating is 4-10h.
  10. 10. The method for producing a hard carbon negative electrode material according to claim 1, wherein in the step (2), the inlet temperature of the spray drying is 110 to 350 ℃; And/or the spray-dried outlet temperature is 70-150 ℃; and/or the feed flow rate of the spray drying is 500-1500mL/h; and/or the compressed air inlet pressure of the spray drying is 0.1-1.0MPa; And/or, when centrifugal spray drying is adopted for the spray drying, the rotating speed of the atomizer is 5000-25000rpm.
  11. 11. The method for producing a hard carbon negative electrode material according to claim 10, wherein in the step (2), the inlet temperature of the spray drying is 120 to 250 ℃; and/or the spray-dried outlet temperature is 80-150 ℃; And/or the feed flow rate of the spray drying is 800-1200mL/h; And/or the compressed air inlet pressure of the spray drying is 0.3-0.8MPa; and/or, when centrifugal spray drying is adopted for spray drying, the rotating speed of the atomizer is 10000-20000rpm.
  12. 12. The method for producing a hard carbon negative electrode material according to claim 1, wherein in the step (2), the constant temperature time for the first carbonization is 1 to 5 hours; And/or, in the step (2), the constant temperature time of the second carbonization is 1-4h; And/or, in the step (2), the temperature rising rate of carbonization is 1-10 ℃ per minute; and/or, in the step (2), the carbonization is carried out under an inert atmosphere, wherein the inert atmosphere is argon or nitrogen; and/or in the step (2), the carbonization adopts a vacuum carbonization or normal pressure carbonization mode, and the vacuum degree of the vacuum carbonization is 1-1000Pa.
  13. 13. The method for producing a hard carbon negative electrode material according to claim 12, wherein in the step (2), the carbonization is performed under an inert atmosphere, the inert atmosphere being nitrogen gas; And/or in the step (2), the carbonization adopts a vacuum carbonization or normal pressure carbonization mode, and the vacuum degree of the vacuum carbonization is 10-100Pa.
  14. 14. A hard carbon negative electrode material, characterized in that it is produced by the production method according to any one of claims 1 to 13.
  15. 15. The hard carbon negative electrode material according to claim 14, wherein the microstructure of the hard carbon negative electrode material is a spherical structure having a diameter of 1 to 50 μm; and/or the specific surface area of the hard carbon anode material is 1-40m 2 /g; And/or the micropore diameter of the hard carbon anode material is 0.3-1.5nm; And/or, the median particle diameter D50 of the hard carbon anode material is 3-15 mu m; And/or the tap density of the hard carbon anode material is 0.5-0.9g/cm 3 .
  16. 16. The hard carbon negative electrode material according to claim 15, wherein the microstructure of the hard carbon negative electrode material is a spherical structure having a diameter of 1 to 10 μm; And/or the specific surface area of the hard carbon anode material is 2-10m 2 /g; and/or the micropore diameter of the hard carbon anode material is 0.4-1.0nm; And/or, the hard carbon anode material has a median particle diameter D50 of 3-8 μm; And/or the tap density of the hard carbon anode material is 0.70-0.85g/cm 3 .
  17. 17. Use of a hard carbon anode material according to any one of claims 14-16 in a battery.
  18. 18. Use of a hard carbon negative electrode material according to claim 17 in a battery, said battery being a sodium ion battery.
  19. 19. A sodium ion battery comprising a hard carbon negative electrode material according to any one of claims 14 to 16.

Description

Hard carbon anode material, preparation method and application thereof, and sodium ion battery Technical Field The invention relates to a hard carbon anode material, a preparation method and application thereof, and a sodium ion battery. Background In recent years, with the large-scale application of lithium ion batteries in related fields such as consumption, power and energy storage, the demand for lithium resources is increased, and the problems of lithium resource shortage and uneven reserve distribution become important factors for restricting the development of the lithium ion batteries. The sodium ion battery as a novel secondary battery has the advantages of abundant sodium resource reserves, wide distribution, low cost, high safety and the like, and has good application prospect in the fields of low-end power markets of two-wheelers, large-scale energy storage and the like. It is well known that graphite is the most commonly used negative electrode material in lithium ion batteries due to its abundant resources, excellent conductivity, low average potential and excellent cycling stability. However, since the ionic radius (0.102 nm) of sodium ions is larger than that of lithium ions (0.076 nm), sodium ions are hardly entered into the graphite layer due to the restriction of the smaller graphite layer spacing (0.34 nm), and the thermodynamic instability of intercalation compounds formed by sodium ions and graphite determines that graphite is not suitable for use as a negative electrode material of sodium ion batteries. Thus, a suitable negative electrode material is a key point in the widespread use of sodium ion batteries. Hard carbon is a carbon material which is difficult to graphitize, the microstructure composition of the hard carbon is highly disordered, the inside of the hard carbon is intertwined with each other to form a relatively rich defect and nano-pore structure, the hard carbon is different from graphite, the hard carbon structure is mainly divided into short-range graphite domains and long-range amorphous characteristic compositions, and the structure comprises a plurality of active sites, such as edges, defects, functional groups and the like. Meanwhile, the precursor raw materials of the hard carbon material are relatively wide in sources, including biomass, polysaccharides, resin polymers, coal-based materials, asphalt and the like, and in combination, the hard carbon is considered as one of the most promising negative electrode materials of sodium ion batteries. Among them, the resin polymer has the advantages of high purity of raw materials, low production difficulty, good product consistency, high carbon residue value, controllable structure and the like, and is favored by researchers. Chinese patent CN106450320B discloses a method for preparing phenolic resin hard carbon, which uses phenol and aldehyde monomers to perform polycondensation and coprecipitation to obtain phenolic resin precursor, and then uses hydrothermal reaction, centrifugal washing, freeze drying and carbonization to prepare spherical hard carbon. Chinese patent CN113321202B discloses a preparation method of phenolic resin based hard carbon microsphere material, which comprises adding phenol and aldehyde monomers into aqueous solution of alkaline catalyst and water-soluble high molecular polymer, reacting to obtain phenolic resin oligomer, adding water to obtain emulsion, spray drying, pre-oxidizing, carbonizing, etc. to obtain hard carbon material, wherein various reagents are used in the process, which involves strong alkali catalyst, and the preparation period is long. Chinese patent CN109742383B discloses a method for preparing hard carbon negative electrode material of phenolic resin based sodium ion battery, which mixes phenolic resin and ethanol according to different proportions, and obtains phenolic resin based hard carbon material through water heat curing treatment, mechanical crushing and carbonization, but the preparation process needs water heat curing, and the microscopic morphology of finished product is irregular structure, and the phenolic resin based hard carbon material tends to show lower bulk density and energy density in practical application. In addition, for hard carbon materials, nitrogen doping helps to increase electrochemical activity, conductivity and surface wettability, and enlarges interlayer spacing, while nitrogen doping can also create external defects, which is beneficial for increasing sodium cell capacity (j. Mater. Chem. A,2018, 6.27:12932-12944.). Based on the method, the preparation process of the hard carbon material is optimized, and the hard carbon material with controllable micro morphology and nitrogen element doping is obtained, so that the electrochemical performance of the hard carbon material in sodium ion battery application is particularly important. Disclosure of Invention The invention aims to overcome the defects of complex and tedious preparation process