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CN-115461305-B - Carbonaceous material, method for producing same, and electrochemical device

CN115461305BCN 115461305 BCN115461305 BCN 115461305BCN-115461305-B

Abstract

The present invention relates to a carbonaceous material having a pore volume of 0.05cm 3 /g or more and 0.20cm 3 /g or less, which is obtained by performing a giant standard ensemble Monte Carlo simulation on an adsorption/desorption isotherm of carbon dioxide, wherein a ratio of a desorption amount to an adsorption amount (desorption amount/adsorption amount) at a relative pressure of 0.01 in the adsorption/desorption isotherm is 1.05 or more.

Inventors

  • ARIMA JUNICHI
  • YAMABATA AKINORI
  • OKUNO TAKETOSHI
  • TAGO SHINYA

Assignees

  • 株式会社可乐丽

Dates

Publication Date
20260505
Application Date
20210419
Priority Date
20200420

Claims (20)

  1. 1. A carbonaceous material wherein, in an adsorption/desorption isotherm of carbon dioxide obtained by measuring adsorption/desorption of carbon dioxide at 273K at a relative pressure p/p 0 of 0.00075 to 0.030, a ratio of a desorption amount to an adsorption amount, that is, a desorption amount/adsorption amount, at a relative pressure of 0.01 is 1.05 or more, an average surface spacing d 002 of (002) planes calculated using a Bragg formula based on a wide angle X-ray diffraction method is 0.36nm or more and 0.42nm or less, The carbonaceous material is produced by a production method comprising a temperature increasing step and a heat treatment step subsequent to the temperature increasing step, The temperature raising step is a step of raising the temperature of a carbon precursor having a BET specific surface area of 500m 2 /g or less by a nitrogen adsorption method to 900 ℃ in the presence of a volatile organic compound, the temperature raising rate in the temperature raising step being 60 ℃ per minute or less between 600 ℃ and 900 ℃, The heat treatment step is a step of raising the temperature to 900 ℃ or higher and 1180 ℃ or lower and holding the temperature.
  2. 2. The carbonaceous material according to claim 1, wherein the oxygen element content is 0.5% by mass or more.
  3. 3. The carbonaceous material according to claim 1 or 2, wherein a BET specific surface area by nitrogen adsorption is 1m 2 /g or more and 20m 2 /g or less.
  4. 4. The carbonaceous material according to claim 1, wherein the mesoporous volume obtained by the BJH method is 3.7mm 3 /g or more and 41mm 3 /g or less.
  5. 5. The carbonaceous material according to claim 4, wherein the average particle diameter D 50 is 1.3 μm or more and 9.5 μm or less.
  6. 6. The carbonaceous material according to claim 4 or 5, wherein a BET specific surface area by nitrogen adsorption is 3m 2 /g or more and 60m 2 /g or less.
  7. 7. The carbonaceous material according to claim 1 or 2, wherein an average surface pitch d 002 of (002) planes calculated using Bragg formula based on a wide angle X-ray diffraction method is 0.38nm or more and 0.40nm or less.
  8. 8. The carbonaceous material according to claim 1 or 2, for use in an electrochemical device.
  9. 9. The carbonaceous material according to claim 8, which is pre-doped with metal ions for use.
  10. 10. A carbonaceous material wherein, in an adsorption/desorption isotherm of carbon dioxide obtained by measuring adsorption/desorption of carbon dioxide at 273K at a relative pressure p/p 0 of 0.00075 to 0.030, a ratio of a desorption amount to an adsorption amount, that is, a desorption amount/adsorption amount, at a relative pressure of 0.01 is 1.05 or more, an average surface spacing d 002 of (002) planes calculated using a Bragg formula based on a wide angle X-ray diffraction method is 0.36nm or more and 0.42nm or less, The carbonaceous material is produced by a production method comprising a temperature increasing step and a heat treatment step subsequent to the temperature increasing step, The temperature raising step is a step of raising the temperature of a carbon precursor having a BET specific surface area of 500m 2 /g or less by a nitrogen adsorption method to 900 ℃ in the absence of volatile organic compounds, the temperature raising rate in the temperature raising step being 60 ℃ per minute or less between 600 ℃ and 900 ℃, The heat treatment step is a step of raising the temperature to a value exceeding 1100 ℃ and 1180 ℃ or lower and holding the temperature.
  11. 11. The carbonaceous material according to claim 10, wherein the oxygen element content is 0.5% by mass or more.
  12. 12. The carbonaceous material according to claim 10 or 11, wherein a BET specific surface area by nitrogen adsorption is 1m 2 /g or more and 20m 2 /g or less.
  13. 13. The carbonaceous material according to claim 10, wherein the mesoporous volume obtained by the BJH method is 3.7mm 3 /g or more and 41mm 3 /g or less.
  14. 14. The carbonaceous material according to claim 13, having an average particle diameter D 50 of 1.3 μm or more and 9.5 μm or less.
  15. 15. The carbonaceous material according to claim 13 or 14, wherein a BET specific surface area by nitrogen adsorption is 3m 2 /g or more and 60m 2 /g or less.
  16. 16. The carbonaceous material according to claim 10 or 11, wherein an average surface pitch d 002 of (002) planes calculated using Bragg formula based on a wide angle X-ray diffraction method is 0.38nm or more and 0.40nm or less.
  17. 17. The carbonaceous material according to claim 10 or 11, for use in an electrochemical device.
  18. 18. The carbonaceous material according to claim 17, which is pre-doped with metal ions for use.
  19. 19. A carbonaceous material wherein, in an adsorption/desorption isotherm of carbon dioxide obtained by measuring adsorption/desorption of carbon dioxide at 273K at a relative pressure p/p 0 of 0.00075 to 0.030, a ratio of a desorption amount to an adsorption amount, that is, a desorption amount/adsorption amount, at a relative pressure of 0.01 is 1.05 or more, an average surface spacing d 002 of (002) planes calculated using a Bragg formula based on a wide angle X-ray diffraction method is 0.36nm or more and 0.42nm or less, The carbonaceous material is produced by a production method comprising a heat treatment step and an additional heat treatment step, The heat treatment step is a step of heat treating a carbon precursor having a BET specific surface area of 500m 2 /g or less by a nitrogen adsorption method for more than 5 minutes in the presence of a volatile substance derived from a volatile organic compound at a temperature of 600 ℃ or more and less than 900 ℃, The additional heat treatment step is a step of raising the temperature to 900 ℃ or higher and 1180 ℃ or lower and holding the temperature.
  20. 20. The carbonaceous material according to claim 19, wherein the oxygen element content is 0.5% by mass or more.

Description

Carbonaceous material, method for producing same, and electrochemical device Technical Field The present patent application claims priority from the paris convention for japanese patent application No. 2020-074737 (filing date: 20 th month of 2020) and japanese patent application No. 2020-217813 (filing date: 25 th month of 2020), which are incorporated herein by reference in their entirety. The present invention relates to carbonaceous materials, methods of manufacturing the same, and electrochemical devices. Background Carbonaceous materials are used in nonaqueous electrolyte batteries such as lithium ion secondary batteries and sodium ion batteries, electrochemical devices such as lithium ion capacitors, and the like, and carbonaceous materials having characteristics suitable for the application are demanded. For example, in small-sized portable devices such as mobile phones and notebook computers, the battery capacity per unit volume is important, and thus, improvement in discharge capacity is demanded. Further, since the lithium ion secondary battery for vehicle use is large in size and expensive, and is difficult to replace during use, it is required to have at least the same durability as that of an automobile, and high cycle durability in which the discharge capacity is not lowered even when charge and discharge are repeated is required. In response to such a demand, for example, patent document 1 describes a carbonaceous material for a nonaqueous electrolyte secondary battery having a good discharge capacity and a good resistance to oxidative degradation. Patent document 2 describes a carbonaceous material that realizes suppressed hygroscopicity and good battery characteristics. Prior art literature Patent literature Japanese patent application laid-open No. 2016-152226 Patent document 2, japanese patent application No. 6237781. Disclosure of Invention Problems to be solved by the invention However, the carbonaceous material described in patent document 1 is fired at a relatively high temperature, and the discharge capacity of the nonaqueous electrolyte secondary battery including the carbonaceous material is not necessarily sufficiently high. In addition, if the heat treatment temperature is lowered for the purpose of increasing the discharge capacity, durability tends to be poor. Further, the carbonaceous material described in patent document 2 has a skin portion containing a carbonaceous material derived from a volatile component of an organic material, and thus it is considered that the pores thereof are covered, thereby achieving suppression of moisture absorption and a high discharge capacity. However, carbonaceous materials having higher discharge capacities and high durability while maintaining the discharge capacities are demanded. Accordingly, an object of the present invention is to provide a carbonaceous material having excellent discharge capacity and cycle durability and high initial efficiency, and a method for producing the carbonaceous material. Means for solving the problems The present inventors have made intensive studies to solve the above problems, and as a result, have found that a carbonaceous material having high durability while maintaining discharge capacity is obtained by having pores such that the adsorption curve and the desorption curve do not coincide (lag) in the adsorption/desorption isotherm of carbon dioxide even when the heat treatment temperature is lowered, thereby completing the present invention. That is, the present invention includes the following suitable modes. [1] And a carbonaceous material having a pore volume of 0.05cm 3/g or more and 0.20cm 3/g or less, which is obtained by subjecting a carbon dioxide adsorption/desorption isotherm to a meganormal ensemble Monte Carlo simulation, wherein the ratio of the desorption amount to the adsorption amount (desorption amount/adsorption amount) at a relative pressure of 0.01 in the adsorption/desorption isotherm is 1.05 or more. [2] The carbonaceous material according to [1], wherein the oxygen element content is 0.5% by mass or more. [3] The carbonaceous material according to [1] or [2], wherein the BET specific surface area by nitrogen adsorption is 1m 2/g or more and 20m 2/g or less. [4] The carbonaceous material according to [1], wherein the mesoporous volume obtained by the BJH method is 3.7mm 3/g or more and 41mm 3/g or less. [5] The carbonaceous material according to [4], wherein the average particle diameter (D 50) is 1.3 μm or more and 9.5 μm or less. [6] The carbonaceous material according to [4] or [5], wherein the BET specific surface area by nitrogen adsorption is 3m 2/g or more and 60m 2/g or less. [7] The carbonaceous material according to any one of [1] to [6], wherein an average surface distance d 002 of (002) planes calculated by using Bragg method based on wide-angle X-ray diffraction method is 0.36nm to 0.42 nm. [8] The carbonaceous material according to any one of [1] to [7], which is used