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CN-122025438-A - Capacitor carbon and preparation method and application thereof

CN122025438ACN 122025438 ACN122025438 ACN 122025438ACN-122025438-A

Abstract

The invention discloses a capacitor carbon which is characterized in that the specific surface area of the capacitor carbon is 1400-2500 m 2 /g, and the tap density of the capacitor carbon is 0.35-0.51 g/cm 3 . The preparation method of the capacitor carbon comprises the following steps of (1) uniformly mixing a first carbon source, a polyhydroxy compound and a transition metal compound for activation treatment, (2) removing an activating agent from the activated material, and (3) carrying out heat treatment on the material obtained in the step (2), washing and drying to obtain the capacitor carbon. The invention provides high tap density capacitor carbon and a preparation method thereof, and super capacitor carbon with high tap density and excellent cycle performance is obtained. The problem that the tap density of a carbon electrode material for an energy storage device in the prior art is not large is solved.

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 capacitor carbon is characterized in that the specific surface area of the capacitor carbon is 1400-2500 m 2 /g, preferably 1500-2200 m 2 /g, and the tap density of the capacitor carbon is 0.35-0.51 g/cm 3 , preferably 0.38-0.40 g/cm 3 .
  2. 2. The capacitive carbon of claim 1, wherein the capacitive carbon has a carbon surface concentration P of 0.38 to 0.71, preferably 0.45 to 0.65, p= (carbon element content 1000)/specific surface area of the capacitive carbon.
  3. 3. The capacitive charcoal according to claim 1, wherein the capacitive charcoal has a particle size distribution D50 of 4-10 μm, preferably 5-9 μm.
  4. 4. The capacitive carbon of claim 1, wherein the capacitive carbon has a particle size distribution D10 of not less than 2 μm and a particle size distribution D90 of not more than 20 μm, preferably not more than 18 μm, more preferably not more than 15 μm.
  5. 5. The capacitive charcoal according to claim 1, wherein the total pore volume of the capacitive charcoal is 0.7-1.2 cm 3 /g, preferably 0.8-1.1 cm 3 /g.
  6. 6. The capacitive charcoal according to claim 1, wherein the organic system of the capacitive charcoal has a specific capacitance of not less than 26F/g for the first time and a specific capacitance retention of not less than 90% after one hundred thousand charge-discharge cycles.
  7. 7. A preparation method of capacitance carbon comprises the following steps: (1) Uniformly mixing a first carbon source, a polyhydroxy compound and a transition metal compound in the presence of an activating agent, and performing activation treatment; (2) Removing an activator from the material subjected to the activation treatment in the step (1); (3) And (3) carrying out heat treatment on the material obtained in the step (2), and washing and drying to obtain the capacitance carbon.
  8. 8. The method for producing a capacitor charcoal according to claim 7, wherein the first carbon source in step (1) is petroleum coke selected from at least one of needle coke, sponge coke, shot coke, preferably needle coke and/or shot coke.
  9. 9. The method for preparing the capacitor carbon according to claim 8, wherein the volatile content in the petroleum coke is 1-15 wt%, and preferably the volatile content is 5-wt-10 wt%.
  10. 10. The method for producing a capacitor charcoal according to claim 7, 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.
  11. 11. The method for producing a capacitive carbon according to claim 7, wherein a second carbon source is added during the activation treatment in the step (1), wherein the second carbon source is an organic carbon source selected from at least one of pitch, residual oil, ethylene tar, styrene tar, preferably pitch.
  12. 12. The method for producing a capacitor charcoal according to claim 11, wherein the asphalt has a softening point of 80 to 350 ℃, preferably 100 to 300 ℃, and the asphalt is one or more of petroleum asphalt and coal asphalt, preferably petroleum asphalt.
  13. 13. The method for producing a capacitor carbon according to claim 11, wherein the second carbon source is carbonized, preferably the first carbon source and the second carbon source are mixed and then carbonized, and the carbonized material obtained is mixed with an alkali activator, a polyhydroxy compound and a transition metal compound and then activated.
  14. 14. The method for preparing the capacitor carbon according to claim 13, wherein the carbonization process is performed under an anaerobic condition, preferably under an inert atmosphere, the carbonization temperature is 200-650 ℃, preferably 300-600 ℃, and the carbonization time is 40-500 minutes.
  15. 15. The method for producing a capacitor carbon according to claim 11, wherein when the second carbon source is introduced during the activation treatment in step (1), the weight ratio of the first carbon source to the second carbon source is 10:1 to 1:5, preferably 6:1 to 1:3.
  16. 16. The method for producing a capacitor charcoal according to claim 7, wherein the polyol in the step (1) is a hydrocarbon compound having at least 2 hydroxyl groups, and the polyol is a sugar selected from at least one of monosaccharides, disaccharides and polysaccharides.
  17. 17. The method for producing a capacitor charcoal according to claim 7 or 16, wherein the polyhydroxy compound is at least one selected from glucose, lactose, maltose, sucrose, fructose, hemicellulose, and starch.
  18. 18. The method for producing a capacitive carbon according to claim 7, wherein the transition metal compound in the step (1) is at least one of a transition metal oxide and a transition metal salt, wherein the transition metal is preferably at least one of manganese, iron, cobalt, nickel, copper, and the transition metal salt is selected from at least one of a transition metal nitrate, a transition metal acetate, and a transition metal carbonate.
  19. 19. The method for producing a capacitor carbon as claimed in claim 7 or 18, 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.
  20. 20. The method for preparing capacitive carbon according to claim 13, wherein the weight ratio of polyhydroxy compound to carbonized material is 0.01:1-0.5:1, preferably 0.05:1-0.3:1, the weight ratio of transition metal compound to carbonized material is 0.1:1-1.2:1, preferably 0.2:1-0.8:1, and the weight ratio of carbonized material to activator is 1:0.2-1:10, preferably 1:1.5-1:4.

Description

Capacitor carbon and preparation method and application thereof Technical Field The invention belongs to the technical field of carbon materials, relates to capacitor carbon and a preparation method thereof, and particularly relates to high-tap-density capacitor carbon and a preparation method thereof. Background Super capacitor is an energy storage device with performance between that of a traditional capacitor and a secondary battery, has the characteristics of excellent cycling stability, rapid charge and discharge performance, super large power density and the like, and is widely applied to the fields of high-speed rails, subways, power storage, electric automobiles and the like. Among the numerous electrode materials, carbon electrode materials have been attracting attention due to their unique chemical stability, abundant specific surface area, and relatively low production cost. The current research focus is mainly focused on the improvement of the carbon specific capacitance of the super capacitor, but in the practical application process, as the volume of the super capacitor is fixed, under the condition of the same carbon electrode material, the improvement of the tap density and the volume specific capacity of the carbon electrode material is an important research and development direction of the energy storage device industry. The tap density of the material can be improved to a certain extent by adopting an ultrahigh pressure technology, and patent CN115196630A 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. 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. 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. The patent CN103723721A uses traditional shell, wood or straw active carbon as raw materials, and graphene with specific parameters is matched, and the graphene modified active carbon is obtained through high-temperature activation, wherein the tap density is 0.30-0.33 g/mL. But the two-dimensional material is high in price, the addition amount is small, and the improvement range of the tap density of the material is limited. The patent CN108178141A uses amino acid and phenolic resin as carbon source, and then mixes them with copper salt, and makes them undergo the process of heat treatment so as to obtain microporous carbon with high specific surface area, and uses the residual partial copper in the carbon material to raise conductivity and tap density of the material. Although the residual metal ions can improve the tap density to a certain extent, the long-period cycle performance of the electrode material can be adversely affected in the practical application process. Disclosure of Invention As described above, in order to overcome the defects existing in the existing super-capacitor carbon and the preparation method thereof, the invention aims to provide the high tap density capacitor carbon with low cost and petroleum coke as a carbon source and the preparation method thereof, thereby obtaining the super-capacitor carbon with high tap density and excellent cycle performance. The problem that the tap density of a carbon electrode material for an energy storage device in the prior art is not large is solved. The tap density is taken as an important parameter for measuring the packing tightness degree of particles in the volume of the material, and is directly related to the volume utilization rate and electrochemical performance of the super-capacitor carbon. The specific surface area and porosity are key factors affecting the electrochemical performance of the supercapacitor carbon, and they determine th