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EP-4741339-A1 - POROUS CARBON MATERIAL, STORAGE BATTERY USING POROUS CARBON MATERIAL, POWER-GENERATING DEVICE USING POROUS CARBON MATERIAL, AND METHOD FOR PRODUCING POROUS CARBON MATERIAL

EP4741339A1EP 4741339 A1EP4741339 A1EP 4741339A1EP-4741339-A1

Abstract

A porous carbon material includes a calcined body, wherein the calcined body has a specific surface area of 500 to 3000 m 2 /g, and the calcined body includes pores having a pore diameter of 100 nm or less, and the calcined body has a nitrogen content rate of 1 to 15 atomic%, with a remainder of the calcined body being carbon, and the calcined body has a biomass degree in a range of 5 to 100 pMC, the biomass degree being expressed as a ratio of a 14 C concentration ( 14 C/ 12 C) of the calcined body when measured using accelerator mass spectrometry (AMS) method to the 14 C concentration ( 14 C/ 12 C) of a standard sample not derived from fossil fuels.

Inventors

  • KUWABARA, RYOU
  • OIKAWA, KAZUMA
  • TANIGUCHI, Nao
  • SAKAGUCHI, SHIGEKI
  • TANAKA, SHUNSUKE
  • KOBARI, KOICHI
  • HORINO, Toki
  • KADOBAYASHI, Kenta

Assignees

  • Panasonic Holdings Corporation

Dates

Publication Date
20260513
Application Date
20240614

Claims (12)

  1. A porous carbon material comprising a calcined body, wherein the calcined body has a specific surface area of 500 to 3000 m 2 /g, and the calcined body includes pores having a pore diameter of 100 nm or less, and the calcined body has a nitrogen content rate of 1 to 15 atomic%, with a remainder of the calcined body being carbon, and the calcined body has a biomass degree in a range of 5 to 100 pMC, the biomass degree being expressed as a ratio of a 14 C concentration ( 14 C/ 12 C) of the calcined body when measured using accelerator mass spectrometry (AMS) method to the 14 C concentration ( 14 C/ 12 C) of a standard sample not derived from fossil fuels.
  2. The porous carbon material according to claim 1, wherein the pores comprise micropores having a pore diameter of 2 nm or less and mesopores having a pore diameter of 2 nm or more to 50 nm or less.
  3. The porous carbon material according to claim 2, wherein the pores further comprise macropores having a pore diameter of 100 nm or more.
  4. An electrode comprising the porous carbon material according to claim 1.
  5. A device for storing or generating electricity comprising the electrode according to claim 4.
  6. A method for producing a porous carbon material comprising: (1) preparing a precursor starting material by mixing, foaming, and dispersing a dispersion medium, a nitrogen-containing biomass starting material, and metal oxide nanoparticles as template particles with a number average particle size of 100 nm or less; (2) calcining and graphitizing the precursor starting material to obtain a calcined body; and (3) removing the metal oxide nanoparticles from the calcined body to obtain the porous carbon material.
  7. The method for producing a porous carbon material according to claim 6, wherein the metal oxide nanoparticles as the template particles are ZnO particles.
  8. The method for producing a porous carbon material according to claim 6, wherein the nitrogen-containing biomass starting material is at least one or more selected from a group consisting of natural sugars, proteins, and nucleic acids.
  9. The method for producing a porous carbon material according to claim 6, wherein the nitrogen-containing biomass starting material is at least one or more selected from a group consisting of gelatin, chitin, chitosan, glucosamine, deoxyribonucleic acid (DNA), ribonucleic acid (RNA).
  10. The method for producing a porous carbon material according to claim 6, wherein produced porous carbon material has a biomass degree of the nitrogen-containing biomass starting material is in a range of 5 to 100 pMC, the biomass degree being expressed as a ratio of a 14 C concentration ( 14 C/ 12 C) of the nitrogen-containing biomass starting material as measured using accelerator mass spectrometry (AMS) method to the 14 C concentration ( 14 C/ 12 C) of a standard sample not derived from fossil fuels.
  11. The method for producing a porous carbon material according to claim 6, wherein metal compound particles other than metal oxides are added as the precursor starting materials.
  12. The method for producing a porous carbon material according to claim 11, wherein the metal compound particles are ZnCl 2 particles.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a porous carbon material, a power storage and generation device using the same, and a method for producing the porous carbon material. 2. Description of the Related Art Toward achieving carbon neutrality, there is a strong demand for improved performance and spread of power storage devices, such as secondary batteries and capacitors, and power generation devices, such as fuel cells and solar cells. In many cases, the performance of these energy devices is specified by that of electrode materials. Carbon materials are promising as electrodes, but are required to reconcile a control technology for such as crystallinity, electrical conductivity, porosity, and an amount of surface functional groups with its economic efficiency. In particular, the porosity, that is, the size of a specific surface area, is an important factor for carbon materials applied to electrochemical devices. As methods for producing a porous carbon material, mainly two methods are known, which are a method using a template and one not using a template. A representative example of the porous carbon material not using a template is activated carbon. For example, activated carbon derived from coconut shells is obtained by calcining and carbonizing a part with relatively large amounts of pores, which is called as a shell (endocarp), to be activated with chemicals or steam as shown in JP-5168585B as Patent Document 1. However, there is a problem in that many functional groups including hydrogen and oxygen atoms, etc., present on a surface of the activated carbon cause side reactions during the operation of the energy devices, resulting in affecting long-term reliability of the devices. As a porous carbon material using a template, a plant-based starting material such as rice and wheat straw is calcined to remove inorganic template components such as silica as shown in JP-2021-38103A as Patent Document 2. However, since natural inorganic components are used as templates, a porous carbon material with a desired pore diameter distribution was hard to obtain. There is a problem in that large amounts of waste liquids are generated by alkali/acid treatment for removing the silica remaining after calcination. In addition, there is a porous carbon material that is obtained by calcining and carbonizing a mixture of a synthetic polymer serving as a carbon source and a template material, for template removal. The examples of the template include a soft template, such as surfactants, and a hard template using metal oxide nanoparticles such as silica, alumina, and magnesia as shown in JP-2019-102711A as Patent Documents 3 and JP-2021-084819A as Patent Document 4. In a method using a surfactant as the template, due to thermolability of micelles formed by the surfactant, micellar structures are destroyed in a process of heating, resulting in difficulty for controlling the pore diameter uniformly. On the other hand, thermal stability of the metal oxide nanoparticles makes control on uniform pore diameter relatively easy, but they have a problem of requiring alkaline or acid washing, just like natural silica. Since the synthetic polymer is used as the carbon source, there is an issue of promoting use of starting materials not derived from fossil fuels, in terms of carbon footprint and life cycle assessment (LCA). PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: JP-5168585BPatent Document 2: JP-2021-38103APatent Document 3: JP-2019-102711APatent Document 4: JP-2021-084819A SUMMARY In one general aspect, the techniques disclosed here feature: a porous carbon material includes a calcined body, wherein the calcined body has a specific surface area of 500 to 3000 m2/g, andthe calcined body includes pores having a pore diameter of 100 nm or less, andthe calcined body has a nitrogen content rate of 1 to 15 atomic%, with a remainder of the calcined body being carbon, andthe calcined body has a biomass degree in a range of 5 to 100 pMC, the biomass degree being expressed as a ratio of a 14C concentration (14C/12C) of the calcined body when measured using accelerator mass spectrometry (AMS) method to the 14C concentration (14C/12C) of a standard sample not derived from fossil fuels. In another general aspect, the techniques disclosed here feature: a method for producing a porous carbon material includes: (1) preparing a precursor starting material by mixing, foaming, and dispersing a dispersion medium, a nitrogen-containing biomass starting material, and metal oxide nanoparticles as template particles with a number average particle size of 100 nm or less;(2) calcining and graphitizing the precursor starting material to obtain a calcined body; and(3) removing the metal oxide nanoparticles from the calcined body to obtain the porous carbon material. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will become readily understood from the following description of non-limiti