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CN-122025437-A - Porous carbon material, manufacturing method thereof and application of porous carbon material in super capacitor

CN122025437ACN 122025437 ACN122025437 ACN 122025437ACN-122025437-A

Abstract

The invention provides a porous carbon material, a manufacturing method thereof and application thereof in a supercapacitor, wherein the porous carbon material comprises a plurality of porous channels, the total pore volume is 0.7-1.2 cm 3 /g, and the specific surface area is 1400-2500 m 2 /g. The preparation method of the porous carbon material comprises the steps of uniformly mixing a carbon precursor A, an auxiliary agent, an activating agent and a transition metal compound, carrying out activation treatment, treating a material obtained after the activation treatment under a certain atmosphere, carrying out heat treatment on the material obtained after the activation treatment under the existence of an inert atmosphere, washing the material after the heat treatment, carrying out heat treatment, and washing and drying. According to the invention, the super capacitor carbon with excellent overall capacitance performance is obtained by introducing the auxiliary agent and combining means such as secondary activation and high-temperature treatment.

Inventors

  • ZHAO LIPING
  • SONG YONGYI
  • ZHANG SHUDONG
  • YAN DONG
  • LI YUYING

Assignees

  • 中国石油化工股份有限公司
  • 中石化（大连）石油化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (20)

  1. 1. The porous carbon material is characterized in that the porous carbon material comprises a plurality of porous channels, wherein the pore size of a first porous channel is 1.0-3.0 nm, the pore size of a second porous channel is 0.6-0.8 nm, and the pore volume of 0.6-0.8 nm accounts for 15% -35% of the total pore volume, preferably 18% -30%.
  2. 2. The porous carbon material according to claim 1, wherein the porous carbon material has a total pore volume of 0.7-1.2 cm 3 /g, preferably 0.8-1.1 cm 3 /g, and a specific surface area of 1400-2500 m 2 /g, preferably 1500-2200 m 2 /g.
  3. 3. The porous carbon material of claim 1, wherein the tap density of the porous carbon material is 0.35-0.51 g/cm 3 , preferably 0.38-0.40 g/cm 3 .
  4. 4. The porous carbon material of claim 1, wherein the porous carbon material has a carbon surface concentration P of 0.38-0.71, preferably 0.39-0.65, p= (carbon element content 1000)/specific surface area of the porous carbon material.
  5. 5. The porous carbon material of claim 1, wherein the organic system of the porous carbon material has a first discharge specific capacitance of not less than 26F/g.
  6. 6. The porous carbon material according to claim 1, wherein a specific capacitance retention rate after one hundred thousand charge and discharge cycles of the porous carbon material is not less than 90%.
  7. 7. The porous carbon material according to claim 1, wherein the specific capacitance of the porous carbon material at a current density of 15A/g is not less than 83% in terms of specific capacitance retention as compared with a current density of 1A/g.
  8. 8. A method for manufacturing a porous carbon material comprises the following steps: (1) Uniformly mixing a carbon precursor A, an auxiliary agent, an activating agent and a transition metal compound for activation treatment, wherein the auxiliary agent is polyethylene glycol and/or polyvinyl alcohol; (2) Treating the material obtained after the first activation treatment in the presence of a first atmosphere, wherein the first atmosphere is a water vapor-containing atmosphere and/or an alcohol vapor-containing atmosphere; (3) Carrying out heat treatment on the material obtained after the treatment in the step (2) in the presence of inert atmosphere; (4) Washing the material subjected to the heat treatment in the step (3); (5) And (3) carrying out heat treatment on the material obtained in the step (4), and washing and drying after the heat treatment.
  9. 9. The method for manufacturing a porous carbon material according to claim 8, wherein the carbon precursor a in the step (1) is petroleum coke, and the type of petroleum coke includes but is not limited to needle coke, sponge coke, shot coke, preferably needle coke and/or shot coke, and the volatile content in the petroleum coke is 1-15 wt%, preferably 5-wt-10 wt%.
  10. 10. The method for producing a porous carbon material according to claim 8, wherein the polyethylene glycol in step (1) is one or more selected from the group consisting of PEG-100, PEG-200, PEG-400, PEG-800, PEG-1000, PEG-2000, PEG-4000, PEG-6000, PEG-8000 and PEG-10000, preferably one of PEG-4000, PEG-6000 and PEG-10000.
  11. 11. The method according to claim 8, wherein the polyvinyl alcohol in the step (1) has a molecular weight of 1000 to 10000.
  12. 12. The method for producing a porous carbon material according to claim 8, wherein the activator in step (1) is an alkali activator, and the alkali activator is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium bicarbonate, sodium bicarbonate, calcium hydroxide, and magnesium hydroxide, preferably one or more of sodium hydroxide, potassium hydroxide, and potassium carbonate.
  13. 13. The method for producing a porous carbon material according to claim 8, wherein the transition metal compound in the step (1) is at least one of a transition metal oxide and/or a transition metal salt, wherein the transition metal is at least one of manganese, iron, cobalt, nickel, and copper, and the transition metal salt is at least one selected from a transition metal nitrate, a transition metal acetate, and a transition metal carbonate.
  14. 14. The method for producing a porous carbon material according to claim 8 or 13, wherein the transition metal compound is at least one selected from the group consisting of manganese nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, manganese acetate, iron acetate, cobalt acetate, nickel acetate, copper acetate, manganese carbonate, iron carbonate, cobalt carbonate, nickel carbonate, and copper carbonate.
  15. 15. The method for producing a porous carbon material according to claim 8, wherein the activation treatment in step (1) is performed under an inert atmosphere, and the activation treatment temperature is 700 to 1000 ℃, preferably 780 to 950 ℃.
  16. 16. The method for producing a porous carbon material according to claim 8, wherein the treatment temperature in step (2) is 100 to 300 ℃, preferably 150 to 250 ℃.
  17. 17. The method for producing a porous carbon material according to claim 8, wherein the steam-containing atmosphere in the step (2) is a mixed gas of steam and an optional inert atmosphere, the volume content of steam in the steam-containing atmosphere is 10% to 100%, the steam-containing atmosphere is a mixed gas of steam and an optional inert atmosphere, the volume content of steam in the steam-containing atmosphere is 5% to 100%, the steam-containing atmosphere is produced by gasifying an alcohol compound having not more than 6 carbon atoms, preferably at least one of methanol, ethanol, propanol, butanol and n-hexanol.
  18. 18. The method for producing a porous carbon material according to claim 8, wherein the material obtained after the first activation treatment in step (2) is treated in the presence of a first atmosphere, and when the first atmosphere is selected to include both a water vapor-containing atmosphere and an alcohol vapor-containing atmosphere, the volume ratio of the water vapor-containing atmosphere to the alcohol vapor-containing atmosphere is 10 to 90:5 to 50.
  19. 19. The method for producing a porous carbon material according to claim 8, wherein the heat treatment temperature in step (3) is 700 to 1000 ℃, preferably 700 to 900 ℃.
  20. 20. The method for producing a porous carbon material according to claim 8, wherein the washing with water in the step (4) comprises a step of drying the washed product at a drying temperature of 60 to 150 ℃, preferably 60 to 120 ℃.

Description

Porous carbon material, manufacturing method thereof and application of porous carbon material in super capacitor Technical Field The invention mainly relates to a carbon material and a preparation method thereof, and belongs to the technical field of carbon materials. Background Super capacitor has been successfully applied in the fields of electric power storage, electric automobile, subway, high-speed railway and the like due to the characteristics of rapid charge and discharge performance, super high power density, excellent cycle stability and the like. At present, the electrode materials are various in variety and have various advantages in performance, and the porous carbon electrode material becomes an important research and development direction of industry due to the advantages of unique chemical stability, rich specific surface area, relatively low production cost and the like. The activation process of the porous carbon material is carried out through the mass transfer of the porous carbon material in contact with an activator from inside to outside, the porous carbon internal pore canal is zigzag, the porous carbon internal pore canal is in a deeper dendritic slit-shaped pore canal structure, a large number of blind holes and closed pore structures exist, the full infiltration of electrolyte is not facilitated, the diffusion resistance of electrolyte ions is large, and the conductivity of the amorphous carbon structure is poor, so that the whole capacitance performance of the porous carbon material serving as an electrode material of the supercapacitor is limited, and the requirements of practical application cannot be met. Under the condition of the same carbon electrode material, the balance of the capacitance characteristic and basic physical property of the electrode material is an important direction as an energy storage device, so that the improvement of the tap density and the volume specific capacity of the carbon electrode material is very important while the energy density of the super capacitor is ensured. Patent CN112079356a discloses a modified activated carbon material, a preparation method and application of super capacitor thereof. The modified activated carbon material is obtained by taking activated carbon with the particle size of 5-200 microns as a starting raw material and carrying out mechanical densification treatment under the anaerobic condition, wherein the blind hole rate is lower than 5%, the tap density is higher than 0.6g/cm 3, and the conductivity is higher than 130S/m. The modified active carbon material shows good electrochemical performance when being used as an electrode material of a super capacitor, and has excellent multiplying power performance and cycle stability. In addition, the time for the voltage to drop to half the initial voltage due to the self-discharge process can be prolonged by 300% at the highest, and the voltage decay can be reduced by 20% at the highest after 48 hours. This process increases tap density but the loss of specific surface area of porous carbon is severe, leading to a sharp drop in specific capacitance and a huge energy consumption for long-time high-speed grinding. The bulk tap density of the material can be improved to a certain extent by doping a certain amount of two-dimensional carbon material with good conductivity into the traditional activated carbon material. However, the two-dimensional material is expensive, and the improvement range of the tap density of the material is very limited under the condition of small addition amount. In summary, the method for improving the tap density of the porous carbon material by performing the subsequent treatment has certain limitations, and the improvement range of the tap density is limited. The novel method is needed to be capable of improving the tap density of the capacitor carbon in the preparation process of the porous carbon material without complicated process steps. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a porous carbon material, a manufacturing method thereof and application thereof in a supercapacitor, and the supercapacitor carbon with excellent overall capacitance performance is obtained under the synergistic effect of polyethylene glycol and means such as secondary activation, high-temperature treatment and the like. In order to solve the problems and the defects existing in the prior art, the technical scheme of the invention mainly comprises the following aspects: The porous carbon material is characterized in that the porous carbon material comprises a plurality of porous channels, wherein the pore size of the first porous channel is 1.0-3.0 nm, the pore size of the second porous channel is 0.6-0.8 nm, and the pore volume of pores with the size of 0.6-0.8 nm accounts for 15% -35%, preferably 18% -30% of the total pore volume. Further, in the porous carbon material, the total pore volume of the porou