Method for producing a graphite crystal-containing carbon material

Abstract

One of the problems addressed by the present invention is to obtain a graphite crystal-containing carbon material by using biomass as a material and performing a uniform baking treatment on the biomass at a low-temperature condition.　The present invention involves: preparing a second carbon material in which one or more metal ions selected from the group consisting of iron ion, nickel ion, chromium ion, and cobalt ion are supported on a first carbon material containing a cellulose-based polysaccharide that has an anionic functional group; and heating the second carbon material in an inert gas atmosphere at a temperature condition of not lower than 600°C but lower than 1400°C.

Description

[Technical Field]

[0001] The present disclosure relates to the production of a graphite crystal-containing carbon material, and more particularly to a method for producing a graphite crystal-containing carbon material using a carbon raw material containing a cellulose-based polysaccharide, and materials such as precursors related thereto. [Background technology]

[0002] Graphite is a carbon material with excellent properties such as lubricity, electrical conductivity, heat resistance, and chemical resistance. Because of these excellent characteristics, graphite is used in a wide range of applications, including battery components, circuit paints, brake pads, oil seals, fireproofing materials, and heat dissipation materials.

[0003] In recent years, there has been a global consensus that promoting sustainable development is being emphasized, and from this perspective, there is a demand in the field of carbon material development for the production and development of carbon materials made from biomass. Biomass originally meant the amount (mass) of biological resources (bio), but it is now also used as a comprehensive term to refer broadly to resources derived from living organisms (excluding fossil resources).

[0004] When considering a method for obtaining a carbon material containing graphite using biomass as a raw material, a calcination process and the setting of its conditions are necessary. However, the calcination temperature in devices commonly used for biomass calcination, such as rotary kilns and continuous calcination furnaces, is generally 1400°C or lower, and graphitization does not usually proceed sufficiently at this temperature. It is said that temperatures of 2500°C or higher, particularly 2800°C or higher, are required to obtain a carbon material containing graphite crystals (e.g., Patent Document 1).

[0005] Development is also underway to develop methods for obtaining graphite more efficiently. For example, it has been reported that a thermosetting resin is pre-baked at a low temperature of 800 to 1700°C, and then calcined under pressure in the presence of fine metal particles and hydrogen atoms as a graphitization catalyst (e.g., Patent Document 2), and that petroleum-based resins, microcrystalline cellulose, etc. are graphitized at low temperatures using iron, nickel, cobalt, etc. as catalysts (e.g., Non-Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-203973 [Patent Document 2] Japanese Patent Application Publication No. 6-206716 [Non-patent literature]

[0007] [Non-Patent Document 1] Catalytic Graphitization of Carbon Aerogels by Transition metals, FJ Maldonado-Hodar et. Al., Langmuir 2000, 16, 4367-4373 [Non-patent document 2] Base Metal Catalyzed Graphitization of Cellulose: A Combined Raman Spectroscopy, Temperature-Dependent X-Ray Diffraction and High-Resolution Transmission Electron Microscopy Study, J. Hoekstra et.al., J. Phys. Chem. C, 2015, 119, 10653-10661 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, obtaining a carbon material containing graphite crystals (hereinafter also referred to as a "graphite crystal-containing carbon material" in the present disclosure) generally requires calcination at a high temperature of 2500°C or higher, which places a strain on equipment capable of such high-temperature calcination. Furthermore, calcination at high temperatures consumes a large amount of energy, and it is desirable to suppress the calcination temperature as much as possible from the viewpoint of reducing energy consumption. Therefore, the use of a metal-based catalyst may be considered to achieve sufficient graphitization by calcination at a low temperature. However, simply mixing a metal-based catalyst with, for example, wood-based biomass containing cellulose polysaccharides makes it difficult to uniformly disperse the catalyst, and therefore, it has not been easy to obtain a uniform calcined product.

[0009] In view of the above circumstances, one of the problems to be solved is to obtain a graphite crystal-containing carbon material by using biomass as a raw material and subjecting it to a uniform calcination treatment under low-temperature conditions. [Means for solving the problem]

[0010] The invention presented in this disclosure can be understood from multiple perspectives as several aspects, and includes aspects that can be embodied as means for solving problems, for example, as follows. In this disclosure, the invention presented in this disclosure is also referred to as "the present invention."

[0011] [1] A method for producing a second carbon material in which one or more metal ions selected from the group consisting of iron ions, nickel ions, chromium ions, and cobalt ions are supported on a first carbon material containing a cellulose-based polysaccharide having an anionic functional group; heat-treating the second carbon material under an inert gas atmosphere at a temperature of 600°C or higher and lower than 1400°C; A method for producing a graphite crystal-containing carbon material, comprising: [2] The manufacturing method according to [1] above, wherein the first carbon raw material is one or more selected from the group consisting of paper pulp, regenerated cellulose fiber, and chemically modified paper pulp or regenerated cellulose fiber. [3] The production method according to the above [1] or [2], wherein the content of the anionic functional group in the first carbon raw material is 0.01 to 2.00 mmol / g. [4] The method according to any one of [1] to [3] above, wherein the anionic functional group is a carboxyl group. [5] The method according to any one of [1] to [4] above, wherein the metal ion is an iron ion. [6] The production method according to any one of [1] to [5] above, further comprising supporting the iron ions on the cellulose polysaccharide using one or more salts selected from the group consisting of iron hydrochloride, iron sulfate, and iron nitrate. [7] A precursor of a graphite crystal-containing carbon material, in which one or more metal ions selected from the group consisting of iron ions, nickel ions, chromium ions, and cobalt ions are supported on a first carbon raw material containing a cellulose-based polysaccharide having an anionic functional group. [Effects of the Invention]

[0012] According to one aspect of the invention disclosed in the present disclosure, a graphite crystal-containing carbon material can be obtained by using biomass as a raw material and subjecting it to a uniform calcination treatment under low-temperature conditions. As a more specific result, according to one aspect of the invention disclosed in the present disclosure, a graphite crystal-containing carbon material can be obtained by using a cellulose-based polysaccharide composite as a raw material and calcining it under low-temperature conditions below 2500°C. DETAILED DESCRIPTION OF THE INVENTION

[0013] This disclosure has been filed as an international application under the Patent Cooperation Treaty, and the original language of the application is Japanese. It is intended that this disclosure will be translated into the languages ​​required by each designated and elected state upon entry into those states. In this disclosure, unless otherwise specified, Japanese nouns may be singular or plural, depending on the context or the full text of this disclosure. Furthermore, when translated into a language such as English that distinguishes between countable and uncountable nouns, and between singular and plural countable nouns, unless otherwise specified, the singular designation includes the plural, and the plural designation includes the singular, depending on the context or the full text of this disclosure.

[0014] Hereinafter, embodiments of the present invention will be described. In this disclosure, unless otherwise specified, the term "one embodiment of the present invention" refers to any one embodiment among multiple embodiments included in the scope of the present invention, and does not deny or limit the existence of other or multiple embodiments, and therefore the present invention is not limited to that one embodiment. Furthermore, in this disclosure, when simply describing an "embodiment," it may include one or multiple embodiments unless otherwise specified.

[0015] In this disclosure, unless otherwise specified, the expression "AA to BB" regarding a numerical range means "greater than or equal to AA and less than or equal to BB" (where "AA" and "BB" represent arbitrary numerical values). Furthermore, unless otherwise specified, the units of the lower and upper limits are the same as the units immediately following the latter (i.e., "BB" in this case). Furthermore, the expression "X and / or Y" means both X and Y, or either one of them.

[0016] One embodiment of the present invention provides a method for producing a graphite crystal-containing carbon material. In this disclosure, a carbon raw material containing a cellulose-based polysaccharide having an anionic functional group is referred to as a "first carbon raw material." The first carbon raw material supported with metal ions capable of catalyzing the graphitization of carbon is referred to as a "second carbon raw material." The second carbon raw material may be prepared from the first carbon raw material, or may be obtained and prepared in the form of a second carbon raw material. The prepared second carbon raw material is subjected to a heat treatment under a predetermined temperature condition in an inert gas atmosphere to graphitize it, thereby obtaining a graphite crystal-containing carbon material. Here, the second carbon raw material may also be referred to as a precursor of the graphite crystal-containing carbon material.

[0017] Graphite crystals are elemental minerals composed of carbon, and their crystalline form is hexagonal, hexagonal plate-like. The graphite crystal structure is a layered substance resembling a turtle shell. Within each layer, carbon atoms are connected by strong covalent bonds (sp2-like), while between layers (inter-plane), weak van der Waals forces bind them. Their electronic structure is semimetallic. Applications include bearings, sliding parts such as carbon brushes, heat diffusion sheets, internal parts of high-temperature furnaces, crucibles, electric furnace electrodes (artificial graphite electrodes), electrolytic electrodes, insoluble anodes, conductive materials for batteries, negative electrodes for secondary batteries, and friction materials such as brake pads. Conventional artificial graphite is made by crushing, separating, and blending the primary raw material, coal coke, and then kneading it with pitch coke or coal tar pitch, which acts as an adhesive. The mixture is then repeatedly fired at approximately 1000°C and soaked in coal tar pitch. The material is then heat treated at around 2700 to 3000 degrees Celsius to be graphitized. This conventional method has the problem of high manufacturing costs in terms of energy consumption, as it requires high-temperature firing during production.

[0018] In the present disclosure, the term "cellulosic polysaccharide" refers to a fibrous polymer containing a structure in which D-glucopyranose units are linked via β1,4 bonds, and includes cellulose and modified products thereof. Modified cellulose is also included in the category of cellulosic polysaccharides as long as the structure in which D-glucopyranose units are linked via β1,4 bonds is maintained in the molecule. While cellulose is usually linked in a linear chain, "cellulosic polysaccharides" may have side chains or may be branched.

[0019] Examples of carbonaceous materials containing cellulose polysaccharides include cotton, paper pulp, and regenerated cellulose fibers such as rayon, as well as chemically modified versions of these. Materials containing cellulose polysaccharides may be used singly or in combination of two or more. Cotton, paper pulp, regenerated cellulose fibers, etc., may contain trace amounts of carboxyl groups introduced during a purification process such as bleaching, or may already contain anionic functional groups due to the coexistence of hemicellulose.

[0020] The cellulose polysaccharide having anionic functional groups may be used as is, or the anionic functional groups may be added by chemical modification. The chemical modification may be performed using known methods for imparting anionic functional groups. Examples of chemical modification methods include carboxyl methylation, TEMPO oxidation, phosphate esterification, and sulfonation. Other examples include mild oxidation methods such as ozone treatment, hydrogen peroxide treatment, and Fenton reaction. In this manner, cellulose polysaccharides having anionic functional groups such as carboxyl groups, phosphate groups, and sulfonate groups can be prepared. The cellulose polysaccharide having anionic functional groups may have other substituents, characteristic groups, or functional groups in addition to the anionic functional groups.

[0021] A preferred example of a chemical modification technique is TEMPO oxidation. Cellulosic polysaccharides can be efficiently treated with a catalytic amount of 2,2,6,6-tetramethyl-1-piperidine-N-oxy radical (TEMPO) in the presence of sodium hypochlorite, an inexpensive oxidizing agent, to introduce carboxyl groups onto the surface of the cellulose polysaccharides. The carboxyl groups can be used as starting points for free modification of the cellulose polysaccharides. Carboxyl groups are suitable for supporting metal ions through the ion exchange treatment described below. From this perspective, materials containing cellulose polysaccharides chemically modified by TEMPO oxidation can be suitable.

[0022] The cellulose polysaccharide or the material containing the cellulose polysaccharide may be used alone or in combination. Paper pulp, regenerated cellulose fiber, and chemically modified products thereof may be suitable as the material containing the cellulose polysaccharide, because of their availability and the ease of the process of washing and removing excess metal ions after supporting metal ions such as iron ions.

[0023] Carbon material precursors other than cellulose-based polysaccharides may be used in combination with the carbon raw material that supplies the carbon source. Precursors that can be used in combination include biomass-based materials and non-biomass-based materials. Examples of biomass-based materials include polysaccharides such as hemicellulose, chitin, and chitosan, and lignin. Examples of non-biomass-based materials include synthetic polymers such as phenolic resins and polyacrylonitrile. When used in combination, the amount of biomass-based material is not particularly limited, but is preferably 200 parts by weight or less, more preferably 100 parts by weight or less, per 100 parts by weight of the carbon raw material containing cellulose-based polysaccharides. From the perspective of sustainability, the amount of the non-biomass-based material used in combination is preferably 50 parts by weight or less, and more preferably 25 parts by weight or less, per 100 parts by weight of the carbon raw material containing cellulose-derived polysaccharides.

[0024] In one embodiment of the present invention, examples of the anionic functional group include a carboxyl group, a sulfonic acid group, and a phosphate group. The cellulose-based polysaccharide may have one or more types of anionic functional groups. A preferred example of the anionic functional group is a carboxyl group. By binding a specific metal ion to the anionic functional group, the metal can be uniformly supported on the cellulose-based polysaccharide, and the quality of the graphite crystal-containing carbon material obtained after heat treatment can be stabilized.

[0025] In one embodiment of the present invention, the content of the anionic functional group in the first carbon raw material may be preferably 0.01 to 2.00 mmol / g. When the first carbon raw material contains the anionic functional group in such a range, metal ions are sufficiently supported, which contributes to smooth graphitization.

[0026] Although it depends on the type of carbon raw material and the type of metal ion, from the viewpoint of sufficiently supporting the metal ions and smoothly proceeding with graphitization, the lower limit of the content of the anionic functional group in the first carbon raw material may be more preferably 0.02 mmol / g or more, even more preferably 0.03 mmol / g or more, and even more preferably 0.05 mmol / g or more. On the other hand, the upper limit of the content of the anionic functional group in the first carbon raw material is not particularly limited and can be any amount from the viewpoint of sufficiently supporting metal ions and smoothly proceeding with graphitization, but even if the content is 2.00 mmol / g or more, the effect does not improve as much as it increases in amount. When it is desired to reduce the content of the anionic functional group in the first carbon raw material as much as possible, the content of the anionic functional group may be, for example, 1.90, 1.80, or 1.70 mmol / g or less.

[0027] In one embodiment of the present invention, a specific transition metal is supported on a cellulose-based polysaccharide and then heat-treated, whereby the transition metal acts as a catalyst to produce a carbon material containing graphite crystals. Examples of transition metals that have this type of catalytic activity include iron, nickel, chromium, and cobalt, and iron is preferred from the viewpoint of low toxicity.

[0028] Examples of iron ion sources include iron(II) chloride, iron(III) chloride, iron(II) sulfate, iron(III) sulfate, iron(II) phosphate, iron(III) phosphate, iron(II) nitrate, iron(III) nitrate, and hydrates thereof, as well as organic complex iron salts such as Prussian blue. From the viewpoint of ease of solution preparation when supporting iron ions on the first carbon material containing cellulose polysaccharides, preferred examples include iron(II) chloride, iron(III) chloride, iron(II) sulfate, iron(III) sulfate, iron(II) nitrate, iron(III) nitrate, and hydrates thereof, as well as soluble Prussian blue partially containing potassium ions, ammonium ions, or the like in its composition.

[0029] The metal ions supported on the carbon raw material containing cellulosic polysaccharides may be of one type or two or more types.

[0030] A carbon raw material in which metal ions are supported on a carbon raw material containing cellulose-based polysaccharides (i.e., a second carbon raw material (also called a precursor of a graphite crystal-containing carbon material)) is prepared, and then heat treatment is performed under an inert gas atmosphere.

[0031] The heat treatment is preferably carried out in an inert gas atmosphere. Examples of the inert gas include helium, argon, and nitrogen. Among these, nitrogen is more preferable from the viewpoint of industrial costs.

[0032] The heat treatment device is not particularly limited as long as it is a device that can heat to a predetermined temperature, for example, 600 to 1400° C., but a gas exchange furnace is preferred. The gas exchange furnace is preferably a batch or continuous gas exchange furnace, and more preferably a continuous gas exchange furnace.

[0033] The heat treatment temperature may be preferably 600°C or higher and lower than 1400°C. The lower limit of the heat treatment temperature may more preferably be 700°C or higher, and even more preferably be 800°C or higher. From the viewpoint of graphitizing the carbon material, the upper limit of the heat treatment temperature need not be particularly limited. However, from the viewpoint of constraints of general heat treatment devices and energy conservation, the upper limit of the heat treatment temperature may be preferably lower than 1400°C, more preferably 1200°C or lower, and even more preferably 1100°C or 1000°C or lower. According to some embodiments of the present invention, metal ions that act as a catalyst can be uniformly dispersed, so that graphitization can be carried out under low-temperature conditions for the heat treatment for graphitization as described above, and the obtained graphite crystal-containing carbon material can be homogeneous.

[0034] The heat treatment time is preferably 0.1 to 4 hours, and more preferably 0.5 to 3 hours.

[0035] The heat treatment can produce a graphite crystal-containing carbon material in the form of black carbide. The residual ratio (weight ratio) of the black carbide after the heat treatment can be preferably 1 to 40%, more preferably 10 to 30%, of the dry weight of the raw material before the heat treatment, i.e., the dry weight of the second carbon raw material.

[0036] The obtained black carbide can be evaluated using X-ray diffraction (hereinafter referred to as XRD), Raman spectroscopy, etc. In XRD, X-rays are incident on a crystal in which atoms are regularly arranged, and strong X-rays are observed in a specific direction, resulting in a diffraction phenomenon. The interlayer distance d002 is commonly used as an index of graphitization. The interlayer distance (d002) is preferably in the range of 3.3 Å to 4.0 Å, and more preferably in the range of 3.3937 Å to 3.4635 Å. The thickness of the network plane group (Lc) is preferably in the range of 10 nm to 200 nm, and more preferably in the range of 30 nm to 187 nm. [Example]

[0037] The present invention will be described in more detail below with reference to examples, but the technical scope of the present invention in this disclosure is not limited to the following examples.

[0038] Example 1 TEMPO-oxidized pulp (anionic functional group content: 1.6 mmol / g, cation: sodium ion) was used as a raw material containing cellulosic polysaccharides (first carbon raw material). 100 ml of 0.1 mol / L hydrochloric acid was added to 3 g of TEMPO-oxidized pulp (dry weight). The mixture was then held for 30 minutes, filtered, and thoroughly washed with ion-exchanged water to exchange the cations for protons. Subsequently, 100 ml of a 2% aqueous solution of iron(II) chloride tetrahydrate was added as an iron ion source. The mixture was then held for 30 minutes, filtered, and thoroughly washed with ion-exchanged water to exchange the cations for iron(II). The resulting pulp was light brown, and some of the iron(II) ions had been oxidized to iron(III) ions. This pulp was used as a second carbon raw material loaded with iron ions.

[0039] The resulting pulp (i.e., the second carbon raw material) was dried at 105°C for 1 hour and then heat-treated in a batch-type gas exchange furnace under a nitrogen atmosphere at 900°C for 2 hours to obtain a black charcoal. The residual ratio of the black charcoal to the dry weight of the pulp was 24%. When the resulting black charcoal was analyzed by X-ray diffraction, a clear graphitization peak (2θ = 25.5-26.6°) was observed.

[0040] <Example 2> A black charcoal was obtained by the same procedure as in Example 1, except that iron (III) nitrate nonahydrate was used as the iron ion source and a continuous gas displacement furnace was used in the heat treatment process. The residual ratio of the black charcoal to the dry weight of the pulp was 23%. When the obtained black charcoal was analyzed by X-ray diffraction, a clear graphitization peak (2θ = 25.5-26.6°) was observed.

[0041] Example 3 A black charcoal was obtained in the same manner as in Example 1, except that bleached paper pulp (NBKP, anionic functional group content 0.04 mmol / g) derived from coniferous trees was used as the raw material containing cellulosic polysaccharides (first carbon raw material) and iron (III) chloride hexahydrate was used as the iron ion source. The residual ratio of the black charcoal to the dry weight of the pulp was 20%. When the obtained black charcoal was analyzed by X-ray diffraction, a clear graphitization peak (2θ = 25.5-26.6°) was observed.

[0042] Example 4 A black charcoal was obtained in the same manner as in Example 1, except that a rayon nonwoven fabric (fiber diameter 3.3 dtex, anionic functional group content 0.015 mmol / g) was used as the raw material containing cellulosic polysaccharides (first carbon raw material) and iron (II) sulfate heptahydrate was used as the iron ion source. The residual ratio of the black charcoal to the dry weight of the rayon nonwoven fabric was 20%. When the obtained black charcoal was analyzed by X-ray diffraction, a clear graphitization peak (2θ = 25.5-26.6°) was observed.

[0043] <Example 5> A dry weight of 3 g of rayon nonwoven fabric (fiber diameter 3.3 dtex, anionic functional group content 0.015 mmol / g) was added to 100 ml of 5% hydrogen peroxide solution and immersed at room temperature for 15 minutes. After thoroughly wringing, the fabric was immersed in 100 ml of 2% iron(II) sulfate heptahydrate solution for 30 minutes to induce the Fenton reaction. After thorough rinsing, an oxidized rayon nonwoven fabric (anionic functional group content 0.12 mmol / g) was obtained.

[0044] The obtained oxidized rayon nonwoven fabric was used as a raw material containing cellulosic polysaccharides (first carbon raw material). 100 ml of a 5% aqueous solution of iron (II) sulfate heptahydrate was added, and the mixture was left for 30 minutes. The mixture was then filtered and thoroughly washed with ion-exchanged water, thereby exchanging the cations for iron (II). The obtained rayon nonwoven fabric was light brown, and some of the iron (II) ions had been oxidized to iron (III). The obtained rayon nonwoven fabric was used as a second carbon raw material carrying iron ions.

[0045] Thereafter, heat treatment was carried out in the same manner as in Example 1 to obtain a black charcoal. The residual ratio of the black charcoal to the dry weight of the rayon nonwoven fabric was 18%. When the obtained black charcoal was analyzed by X-ray diffraction, a clear graphitization peak (2θ = 25.5-26.6°) was observed.

[0046] <Comparative Example 1> TEMPO-oxidized pulp (anionic functional group content 1.6 mmol / g, sodium cation) was used as the raw material containing cellulosic polysaccharides. 3 g of TEMPO-oxidized pulp (dry weight) was dried at 105°C for 1 hour and then heat-treated in a batch-type gas exchange furnace under a nitrogen atmosphere at 900°C for 2 hours to obtain a black char. The residual ratio of the black char to the dry weight of the pulp was 21%. When the obtained black char was analyzed by X-ray diffraction, no graphitization peak (2θ = 25.5-26.6°) was observed.

[0047] <Comparative Example 2> TEMPO-oxidized pulp (anionic functional group content 1.6 mmol / g, cation: sodium ion) was used as a raw material containing cellulosic polysaccharides. 100 ml of 0.1 mol / L hydrochloric acid was added to 3 g of TEMPO-oxidized pulp (dry weight), and the mixture was left for 30 minutes. After filtration and thorough washing with ion-exchanged water, the cations were exchanged for protons.

[0048] The resulting pulp was dried at 105°C for 1 hour, then heat-treated in a batch-type gas exchange furnace under a nitrogen atmosphere at 900°C for 2 hours to obtain black charcoal. The residual ratio of black charcoal to the dry weight of pulp was 23%. When the resulting black charcoal was analyzed by X-ray diffraction, no graphitization peak (2θ = 25.5-26.6°) was observed.

[0049] <Comparative Example 3> TEMPO-oxidized pulp (anionic functional group content 1.6 mmol / g, cation: sodium ion) was used as a raw material containing cellulosic polysaccharides. 100 ml of 0.1 mol / L hydrochloric acid was added to 3 g of TEMPO-oxidized pulp (dry weight) and held for 30 minutes. After filtration, the mixture was thoroughly washed with ion-exchanged water to exchange the cations for protons. Next, 100 ml of a 2% aqueous solution of copper(II) sulfate pentahydrate was added and held for 30 minutes. After filtration, the mixture was thoroughly washed with ion-exchanged water to exchange the cations for copper(II) ions.

[0050] The resulting pulp was dried at 105°C for 1 hour, then heat-treated in a batch-type gas exchange furnace under a nitrogen atmosphere at 900°C for 2 hours to obtain a black char. The residual ratio of the black char to the dry weight of the pulp was 20%. When the resulting black char was analyzed by X-ray diffraction, no graphitization peak (2θ = 25.5-26.6°) was observed.

[0051] The results of the above analysis are summarized in Table 1.

[0052] [Table 1]

Claims

1. A method for producing a carbon material comprising: preparing paper pulp and / or regenerated cellulose fiber as a first carbon raw material, the paper pulp and / or regenerated cellulose fiber being chemically modified so that the content of anionic functional groups is 0.05 to 2.00 mmol / g; preparing a second carbon raw material in which one or more metal ions selected from the group consisting of iron ions, nickel ions, chromium ions, and cobalt ions are supported on the first carbon raw material; heat-treating the second carbon raw material under an inert gas atmosphere at a temperature of 600°C or higher and lower than 1400°C; A method for producing a graphite crystal-containing carbon material, comprising:

2. The manufacturing method described in claim 1, wherein the chemical modification is TEMPO oxidation.

3. The manufacturing method described in claim 1, wherein the graphite crystal-containing carbon material is a carbon material in which a peak is detected at 2θ = 25.5° to 26.6° by X-ray diffraction.

4. The method according to claim 1 , wherein the anionic functional group is a carboxyl group.

5. The method according to claim 1 , wherein the metal ions are iron ions.

6. The manufacturing method described in claim 1, wherein the chemical modification is TEMPO oxidation and the metal ion is an iron ion.

7. 6. The production method according to claim 5, comprising supporting the iron ions on the first carbon raw material using one or more salts selected from the group consisting of iron hydrochloride, iron sulfate, and iron nitrate.

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