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CN-122025439-A - Porous carbon material for super capacitor, preparation method of porous carbon material and super capacitor

CN122025439ACN 122025439 ACN122025439 ACN 122025439ACN-122025439-A

Abstract

The invention discloses a porous carbon material for a supercapacitor, a preparation method of the porous carbon material and the supercapacitor, wherein the porous carbon material comprises a plurality of porous channels, the pore size of a first porous channel is 1.0-2.0 nm, and the pore size of a second porous channel is 0.4-0.9 nm. The preparation method comprises the steps of (1) uniformly mixing petroleum coke and an activating agent, performing first activation treatment, (2) treating a first activation product under the condition of a first atmosphere, (3) performing second activation treatment on the material treated in the step (2), and (4) treating a second activation product under the condition of a second atmosphere to obtain the porous carbon material. The super-capacitor carbon with high tap density and good cycle performance is obtained by a method combining composite carbonization, two-stage activation and pore canal fine regulation.

Inventors

  • ZHAO LIPING
  • SONG YONGYI
  • ZHANG SHUDONG
  • LI YUYING
  • MA RUI

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 for the super capacitor is characterized by comprising a plurality of porous channels, wherein the pore size of a first-stage porous channel is 1.0-2.0 nm, the pore size of a second-stage porous channel is 0.4-0.9 nm, and the pore volume of the first-stage porous channel accounts for 25% -70%, preferably 25% -55% of the total pore volume.
  2. 2. The porous carbon material for a supercapacitor according to claim 1, wherein the ratio of pore volume of 1.5 to 2.0nm pores in the primary pore canal to the total pore volume is 7 to 23%, preferably 12 to 20%.
  3. 3. The porous carbon material for a supercapacitor according to claim 1, wherein the porous carbon material for a supercapacitor has a specific surface area of 1400 to 2200 m 2 /g, preferably 1550 to 2000 m 2 /g, and a total pore volume of 0.7 to 1.1cm 3 /g, preferably 0.75 to 1.05 cm 3 /g.
  4. 4. The porous carbon material for a supercapacitor according to claim 1, wherein the tap density of the porous carbon material for a supercapacitor is 0.35 to 0.51g/cm 3 , preferably 0.38 to 0.40 g/cm 3 .
  5. 5. The porous carbon material for a supercapacitor according to claim 1, wherein the carbon surface density P of the porous carbon material for a supercapacitor is 0.38 to 0.71, preferably 0.39 to 0.65, p= (carbon element content: 1000)/the specific surface area of the porous carbon material.
  6. 6. The porous carbon material for a supercapacitor according to claim 1, wherein the pH value of the porous carbon material for a supercapacitor is 6 to 9, preferably 6 to 8.
  7. 7. A method for preparing a porous carbon material for a supercapacitor, the method comprising the steps of: (1) Under the first activation condition, uniformly mixing petroleum coke and an activating agent, and performing first activation treatment to obtain a first activation product; (2) Treating the first activated product 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) Under the second activation condition, carrying out second activation treatment on the material treated in the step (2), and then washing and drying to obtain a second activation product; (4) And treating the second activated product in the presence of a second atmosphere to obtain a porous carbon material, wherein the second atmosphere comprises atmosphere A, atmosphere B and an optional inert atmosphere, the atmosphere A is one or two of carbon dioxide and water vapor, the atmosphere B is one or more of hydrogen and hydrocarbon, and the hydrocarbon is at least one of alkane, alkene and alkyne with the carbon number of 1-10, preferably 1-4.
  8. 8. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the volatile content in the petroleum coke in step (1) is 1 to 15wt%, preferably 5 to wt to 10wt%.
  9. 9. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the activator in the step (1) is an alkali activator selected from at least one of an alkali metal hydroxide, an alkali metal salt compound, an alkaline earth metal hydroxide, and an alkaline earth metal salt compound, the alkali metal being selected from sodium and/or potassium, and the alkaline earth metal being selected from magnesium and/or calcium.
  10. 10. The method for producing a porous carbon material for a supercapacitor according to claim 9, wherein the alkali activator is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium bicarbonate, sodium bicarbonate, calcium hydroxide, magnesium hydroxide, preferably one or more of sodium hydroxide, potassium hydroxide, and potassium carbonate.
  11. 11. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the first activation condition in the step (1) is such that the first activation temperature is 700 to 1000 ℃, preferably 780 to 950 ℃, and the first activation is performed in the presence of an inert atmosphere, which is nitrogen and/or an inert gas.
  12. 12. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the water vapor-containing atmosphere in the step (2) comprises water vapor and an optional inert atmosphere, the volume content of the water vapor in the water vapor-containing atmosphere is 20% -100%, the alcohol vapor-containing atmosphere comprises alcohol vapor and an optional inert atmosphere, the volume content of the alcohol vapor in the alcohol vapor-containing atmosphere is 10% -100%, the alcohol vapor is produced by gasifying an alcohol compound, and the alcohol compound is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, ethylene glycol and n-hexanol.
  13. 13. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the treatment temperature in step (2) is 100 to 300 ℃, preferably 150 to 250 ℃.
  14. 14. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the second activation condition in the step (3) is such that the second activation temperature is 700 to 1000 ℃, preferably 700 to 900 ℃.
  15. 15. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the washing in step (3) comprises acid washing and water washing, the acid washing is carried out with an acid solution, the acid is one or more of hydrochloric acid, nitric acid, sulfuric acid and acetic acid, and the mass fraction of the acid solution is 0.5% -20%, preferably 1% -10%.
  16. 16. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the hydrocarbon is at least one of methane, ethane, ethylene, propylene, propane, n-butane, isobutane, 1-butene, 2-butene, isobutene, acetylene, propyne, and butyne.
  17. 17. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein when the atmosphere a contains both carbon dioxide gas and water vapor, the carbon dioxide gas content in the atmosphere a is 10% to 60%, preferably 20% to 50%.
  18. 18. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein in the second atmosphere, the ratio of atmosphere a to atmosphere B is 10 to 70:0.1 to 40, preferably 20 to 60:0.5 to 30.
  19. 19. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the volume ratio of atmosphere a and atmosphere B in the second atmosphere is 10% to 100%, preferably 20% to 80%.
  20. 20. The method for producing a porous carbon material for a supercapacitor according to claim 7, wherein the treatment temperature in step (4) is 700 to 1000 ℃, preferably 800 to 900 ℃.

Description

Porous carbon material for super capacitor, preparation method of porous carbon material and super capacitor Technical Field The invention relates to a porous carbon material for a supercapacitor and a preparation method thereof, and belongs to the field of carbon material preparation. Background Supercapacitors are a new type of energy storage device between traditional capacitors and batteries. The device has the remarkable advantages of high charging speed, long cycle life, high power density and the like, can complete the charging and discharging process in a very short time, and meets the requirement of instantaneous high power output. In practical application, the super capacitor is widely used in the fields of electric automobiles, wind power generation, smart grids and the like, provides instantaneous heavy current support for equipment, and ensures stable operation of the system. Meanwhile, in the fields of consumer electronics, wearable equipment and the like, the super capacitor plays an important role, and longer standby time and smoother use experience are provided for users. However, the super-capacitor carbon is used as a core electrode material of the super-capacitor, research hotspots often concentrate on the aspects of pore structure regulation and specific capacitance improvement, and the defect that the large-specific-surface-area capacitor carbon has obvious tap density is ignored. The lower tap density limits the exertion of volumetric energy density and power performance, resulting in limited energy storage capacity in compact space and a significant compromise in rapid charge and discharge efficiency. In addition, low tap density can also lead to reduced stability of the material during recycling, thereby affecting the overall life of the supercapacitor. Therefore, future research is required to greatly improve the tap density of the supercapacitor carbon by means of regulating and controlling the preparation process and the like, so that the comprehensive performance of the supercapacitor carbon is comprehensively enhanced, and the supercapacitor technology is promoted to realize wider application in the field of energy storage. The patent CN103723720A uses traditional coconut shell activated carbon as a raw material, and graphene matched with specific parameters is subjected to high-temperature activation to obtain graphene modified activated carbon suitable for the super capacitor, wherein the tap density is 0.28-0.31 g/mL. However, the two-dimensional material is expensive, and the addition amount is small, so that the improvement range of the tap density of the material is limited. The tap density of the material can be improved to a certain extent by adopting an ultrahigh pressure technology, and patent CN 115196630A discloses a preparation method for improving the tap density of a carbon electrode material for an energy storage device, and the tap density of the carbon material is improved by pressurizing at 20-630 MPa for 5-20 min by adopting the ultrahigh pressure technology, but a huge pressure environment brings more severe requirements to the electrode material device. The shaping and fusing modes can reduce the stacking gaps among particles to a certain extent and improve the tap density. The patent CN112079356A takes 5-200 mu m active carbon as a raw material, the rotating speed is 500-6000 r/min under the anaerobic condition, the treatment is carried out for 8-24 hours, and the blind porosity of the active carbon material is reduced after long-time mechanical densification treatment, so that the tap density is further improved. 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. In summary, the current methods for increasing the tap density of the porous carbon material have certain limitations and have limited effects on increasing the tap density. Therefore, a new method is urgently needed to be explored to realize balanced optimization of specific capacity and tap density in the process of preparing the porous carbon material, and further the rate capability and long-period cycle stability of the material are remarkably improved. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide the porous carbon material for the supercapacitor and the preparation method thereof by taking petroleum coke and an organic carbon source as raw materials, and the supercapacitor carbon with higher tap density and good cycle performance is obtained by combining the methods of composite carbonization, two-stage activation and fine pore channel regulation. The porous carbon material for the super capacitor is characterized by comprising a plurality of porous channels, wherein the pore size of the first porous channel is 1.0-2.0 nm, the pore size of the second porous channel is 0.