JP2006096781A - Phenolic resin composition for carbon material, carbon material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic resin composition which can be applied to the negative electrode material of a lithium ion secondary cell and can obtain a carbon material to be used in the negative electrode of a highly efficient and large-capacity secondary cell, a carbon material obtained by the carbonization of this composition, and its manufacturing method. <P>SOLUTION: The phenolic resin composition for a carbon material comprises a phenolic resin (A) and a compound (B) having reactivity with the phenolic hydroxy group of the phenolic resin, and the carbon material is obtained by subjecting this phenolic resin composition for a carbon material to heat treatment, and the method for manufacturing a carbon material comprises a step of subjecting this phenolic resin composition for a carbon material to heat treatment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a phenol resin composition for a carbon material, a carbon material, and a method for producing the same.

Currently, materials used for the negative electrode of lithium ion secondary batteries mainly include natural graphite and artificial graphite. The characteristics of this material include a theoretical charge / discharge capacity of 372 mAh / g, a charge / discharge efficiency as high as 90% or higher, and a higher density than a non-graphitizable carbon material.
With respect to graphite, various studies have been made to improve the electrode density, and studies have been made to give various shapes such as flakes, milleds, and spheres. Further studies have been made to increase the charge / discharge efficiency (for example, see Patent Document 1 and Non-Patent Document 1), and further studies are required.

As described above, in order to solve the problem that the theoretical charge / discharge capacity of graphite is 372 mAh / g and a charge / discharge capacity higher than that is not obtained, studies on materials other than graphite have been conducted. Specifically, non-graphitizable carbon materials, metal nitrides, and the like have been studied. These materials are known for their very high discharge capacity.
However, it is difficult that the charge / discharge efficiency is low and the cycle deterioration is large when the charge / discharge is repeated, and further improvement in characteristics is desired (for example, see Patent Document 2 and Patent Document 3). ).

  Moreover, since the carbon material derived from a phenol resin is a non-graphitizable carbon material, it has the same problem as described above. Further, as a technique for improving the characteristics, a composite of a non-graphitizable carbon material and an easily graphitizable carbon material has been tried, but the actual situation has not yet been put to practical use.

Japanese Patent Laid-Open No. 10-284061 Japanese Patent Laid-Open No. 9-293507 JP-A-11-204105 J. et al. Electrochem. Soc. , Vol. 142, no. 8, 1995

  The present invention can be applied to a lithium ion secondary battery negative electrode material, and can provide a carbon material used for a secondary battery negative electrode material having high efficiency and high capacity. A carbon material obtained by carbonizing and a method for producing the same is provided.

Such an object is achieved by the following present inventions (1) to (8).
(1) A phenol resin composition for a carbon material comprising a phenol resin (A) and a compound (B) having reactivity with a phenolic hydroxyl group of the phenol resin.
(2) The phenol resin composition for carbon materials according to (1), wherein the weight blending ratio (A: B) of the phenol resin (A) and the compound (B) is 95: 5 to 50:50.
(3) The compound (B) has one or more types selected from a hydroxyl group, a carboxyl group, an amide group, a sulfone group, and an epoxy group, for the carbon material according to the above (1) or (2) Phenolic resin composition.
(4) A carbon material obtained by heat-treating the phenol resin composition for carbon material according to any one of (1) to (3).
(5) A method for producing a carbon material, comprising a step of heat-treating the phenol resin composition for a carbon material according to any one of (1) to (3).
(6) The heat treatment step includes
(A) A step of performing a first heat treatment on the phenolic resin composition for carbon material to react the phenolic resin (A) and the compound (B) in at least a part thereof to obtain a reaction composition;
(B) performing a second heat treatment on the reaction composition to form a carbon material;
The manufacturing method of the carbon material as described in said (5) containing.
(7) The carbon material manufacturing method according to (6), wherein the first heat treatment is performed at 100 to 300 ° C.
(8) The method for producing a carbon material according to (6) or (7), wherein the second heat treatment is performed at 600 to 1400 ° C.

  According to the present invention, in particular, when used as a secondary battery negative electrode material, a carbon material having a high charge / discharge capacity and excellent charge / discharge efficiency can be obtained.

Below, the phenol resin composition for carbon materials of this invention, a carbon material, and its manufacturing method are demonstrated.
The phenol resin composition for carbon materials of the present invention (hereinafter sometimes simply referred to as “composition”) comprises a phenol resin (A) and a compound (B) having reactivity with the phenolic hydroxyl group of the phenol resin. It is characterized by containing.
In addition, the carbon material of the present invention is obtained by heat-treating the composition of the present invention.
And the manufacturing method of the carbon material of this invention includes the process of heat-processing the said composition of this invention, and obtaining the carbon material.
First, the composition of the present invention will be described in detail.

  The phenol resin (A) used in the composition of the present invention is obtained by reacting phenols and aldehydes by a known method, for example, a novolak type obtained by reacting in the presence of an acidic catalyst. Examples thereof include a phenol resin and a resol type phenol resin obtained by reacting in the presence of a basic catalyst, and these can be used alone or in combination.

  Although it does not specifically limit as phenols used for the synthesis | combination of the said phenol resin, For example, cresol, such as a phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2, 5-xylenol, 2,6-xylenol, 3,4-xylenol, xylenol such as 3,5-xylenol, ethylphenol such as o-ethylphenol, m-ethylphenol, p-ethylphenol, isopropylphenol, butylphenol, p -Butylphenol such as tert-butylphenol, p-tert-amylphenol, p-octylphenol, p-nonylphenol, alkylphenols such as p-cumylphenol, fluorophenol, chlorophenol, bromophenol, iodine Halogenated phenols such as dephenol, monovalent phenol substitutes such as p-phenylphenol, aminophenol, nitrophenol, dinitrophenol and trinitrophenol, and monovalent phenols such as 1-naphthol and 2-naphthol, resorcin And polyhydric phenols such as alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, phloroglucin, bisphenol A, bisphenol F, bisphenol S, dihydroxynaphthalene, and isomers thereof. These can be used alone or in combination of two or more.

  The aldehydes used for the synthesis of the phenol resin are not particularly limited. For example, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyl. Examples include aldehyde, caproaldehyde, allyl aldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. These can be used alone or in combination of two or more.

When a novolac type phenol resin is used, a curing agent can be used together with the resin. Although it does not specifically limit as a hardening | curing agent, For example, aldehyde sources, such as a hexamethylenetetramine, a trioxane, and paraformaldehyde, an amine type hardening | curing agent, an acid catalyst, a resole resin etc. are mentioned.
Although the usage-amount of a hardening | curing agent is not specifically limited, Usually, 0.1-20 weight part can be used with respect to 100 weight part of phenol resins.

  The composition of the present invention is characterized in that it contains a compound (B) having reactivity with the phenolic hydroxyl group of the phenol resin (hereinafter, sometimes simply referred to as “compound (B)”).

  Although it does not specifically limit as such a compound (B), The thing which has 1 or more types chosen from a hydroxyl group, a carboxyl group, an amide group, a sulfone group, and an epoxy group in a molecule | numerator can be used suitably.

  Examples of the compound having a hydroxyl group in the molecule include polycyclic aromatic alcohols such as α-naphthol and β-naphthol, ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, decanediol, pinacol, glycerin and the like. Examples thereof include polyhydric alcohols and isomers thereof, and high-boiling chain alcohols such as hexyl alcohol, cyclohexanol, octyl alcohol, decyl alcohol, lauryl alcohol, cetyl alcohol, and stearic alcohol.

  Examples of the compound having a carboxyl group in the molecule include carboxylic acids such as succinic acid, adipic acid, terephthalate acid, isophthalic acid and pyromellitic acid, and anhydrides thereof.

  Examples of compounds having an amide group in the molecule include amides such as acetamide, dimethylformamide, aniline, melamine, aminophenol, salicylamide, benzenesulfonamide, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, etc. The polyamides can be mentioned.

  Examples of the compound having a sulfone group in the molecule include p-toluenesulfonic acid, o-toluenesulfonic acid, naphthalene-β-sulfonic acid, benzenesulfonic acid, and styrenesulfonic acid.

  Examples of the compound having an epoxy group in the molecule include epichlorohydrin, various epoxy resins synthesized from epichlorohydrin and bisphenol A or F, halogenated bisphenol epoxy resin, tetrahydroxyphenylmethane epoxy resin, polyolefin Type epoxy resin.

Among the above compounds (B), those having good compatibility with the phenol resin and good reactivity with the hydroxyl group of the phenol resin can be particularly preferably used. Examples of such a compound (B) include succinic acid, adipic acid, pyromellitic anhydride, terephthalate acid, p-toluenesulfonic acid, aminophenol, β-naphthol, and benzenesulfonamide.

In the composition of this invention, it is thought that the following effects can be expressed by using the said compound (B) with a phenol resin (A).
First, the compound (B) has reactivity with the phenolic hydroxyl group of the phenol resin (A). Thereby, in the process of heat-treating the composition of the present invention, the phenolic hydroxyl group of the phenol resin (A) reacts with at least a part of the compound (B) to obtain a more stable and highly uniform reaction composition. It is considered possible.
And the said reaction composition can form many pores in the carbon material surface which makes the condensate of a phenol resin (A) a basic structure by the further heat processing. The pores formed here are considered to be formed by decomposition and volatilization of a part of the structure derived from the compound (B) reacted with the phenol resin (A). The pore diameter of the pores thus formed is governed by the molecular diameter of the volatile substance generated by the decomposition of the compound (B), and the pore volume depends on the compounding amount of the compound (B). Conceivable. And it is thought that many pores with a more uniform pore diameter can be produced | generated by disperse | distributing a compound (B) uniformly with respect to a phenol resin (A).
The uniform and selectively formed pores should be suitable for insertion and desorption of lithium ions when the obtained carbon material is used as a negative electrode material for a secondary battery. Thus, it is considered that good charge / discharge characteristics can be imparted.
On the other hand, when an additive having no reactivity with the phenolic hydroxyl group of the phenol resin (A) is used instead of the compound (B), the uniform dispersibility of the additive in the composition may decrease. Furthermore, since this additive volatilizes in the molecular unit or molecular aggregation unit by the heat treatment, it is considered that the pore diameter formed on the surface of the obtained carbon material and inside thereof is not uniform. Such a carbon material is not suitable for insertion / extraction of lithium ions, and when used as a negative electrode material for a secondary battery, it is considered difficult to become a preferable carbon material.

In the composition of the present invention, the weight ratio (A: B) of the phenol resin (A) and the compound (B) is not particularly limited, but is preferably 95: 5 to 50:50, more preferably 95: 5 to 70:30. The mixing ratio can be appropriately selected within the optimum range depending on the types of the phenol resin (A) and the compound (B), but the reaction equivalent ratio is less than the phenolic hydroxyl group possessed by the phenol resin (A) ( B) is preferably blended.
Thereby, in the process of heat-treating the composition, a suitable amount of pores suitable for the carbon material surface can be formed. When the compounding ratio of the compound (B) is less than the lower limit, pore formation may not be sufficiently promoted. On the other hand, when the amount is larger than the above upper limit value, pore formation can be promoted, but the ratio of volatile components in the composition increases, and the yield of carbon material (carbonization yield) decreases. It may not be economical.

Although it does not specifically limit as a preparation method of the composition of this invention, For example,
(1) A method in which both the phenol resin (A) and the compound (B) are in solid form, and these are separately or simultaneously pulverized and mixed.
(2) A method in which the phenol resin (A) and the compound (B) are dissolved and mixed in a solvent that dissolves both,
(3) A method in which the phenol resin (A) and the compound (B) are heated and melt-mixed at a temperature higher than any melting point,
(4) A method of adding the compound (B) during or after the synthesis of the phenol resin (A),
And so on.

Next, the carbon material of the present invention and the manufacturing method thereof will be described in detail.
The carbon material of the present invention is obtained by heat-treating the composition of the present invention.
The method for producing a carbon material of the present invention includes a step of heat-treating the composition of the present invention.
And the heat-treating step includes
(A) performing the first heat treatment on the composition, and reacting the phenol resin (A) and the compound (B) in at least a part thereof to obtain a reaction composition;
(B) performing a second heat treatment on the reaction composition to form a carbon material;
It is preferable to contain.

First, in the method for producing a carbon material of the present invention,
(A) The composition is subjected to a first heat treatment, and the phenol resin (A) and the compound (B) are reacted at least in part to obtain a reaction composition.

Although it does not specifically limit as conditions of the 1st heat processing in the said (a) process, It is preferable to carry out temperature at 100-300 degreeC. More preferably, it is 150-200 degreeC. Thereby, while being able to react the phenolic hydroxyl group of a phenol resin (A) and a compound (B), the uniformity as a composition can be improved.
If this temperature is less than the said lower limit, reaction rate may become slow or the uniformity as a composition may become insufficient. On the other hand, when the above upper limit is exceeded, both the phenol resin (A) and the compound (B) are likely to be decomposed.
Although it does not specifically limit as time to perform this 1st heat processing, Usually, it can carry out in 1 to 15 hours.
In addition, the atmosphere in which the first heat treatment is performed can be performed under any conditions such as in the air, in an inert gas atmosphere, and in a vacuum.

In addition, it is preferable to implement hardening of a phenol resin (A) after reaction with a compound (B), or to implement substantially simultaneously with reaction with a compound (B).
Specifically, when a novolak type phenol resin is used as the phenol resin (A), first, a mixture of the novolak type phenol resin and the compound (B) is prepared, and the reaction composition is obtained by the first heat treatment. It is preferable to mix hexamethylenetetramine as a curing agent. And hardening of a novolak-type phenol resin may be implemented by heat-processing further after this, and can also be implemented in a (b) process.
When using a self-hardening resol type phenol resin, a mixture of the resol type phenol resin and the compound (B) is prepared, and the reaction between the resol type phenol resin and the compound (B) is performed by the first heat treatment. It is preferable to simultaneously cure the resol type phenolic resin.

Next, in the production method of the present invention,
(B) The reaction composition is subjected to a second heat treatment to obtain a carbon material.

Although it does not specifically limit as conditions which perform 2nd heat processing to the reaction composition obtained at the said (a) process, It is preferable to carry out temperature at 600-1400 degreeC. More preferably, it is 1100-1300 degreeC.
Thereby, the carbon material which has a favorable characteristic when it uses for a negative electrode material can be obtained. If the temperature is less than the above lower limit value, a large number of heteroatoms, oxygen-containing functional groups, and the like are present in the carbon material, which may increase the irreversible capacity and lower the charge / discharge characteristics. On the other hand, when the upper limit is exceeded, the irreversible capacity decreases, but the reversible capacity also decreases, and the energy density may decrease when the negative electrode material is used as a secondary battery.

  Moreover, although the rate of temperature increase is not particularly limited, the temperature can be normally increased at 50 to 200 ° C./hour. Although it does not specifically limit about a cooling rate, Usually, it can cool at 50-400 degreeC / hour.

Although it does not specifically limit as time to perform this 2nd heat processing, It can carry out for 0.1 to 15 hours.
In addition, the atmosphere for performing the second heat treatment is preferably performed in an inert atmosphere in which carbon monoxide, nitrogen, or helium, and a minute amount of hydrogen or oxygen is mixed. In addition, the temperature which open | releases an inert atmosphere can be made into room temperature-100 degreeC.

  In the method for producing a carbon material of the present invention, in addition to the steps (a) and (b), for example, after the step (a) or after the step (b), the obtained product is pulverized and atomized. Can have.

  As described above, by using the composition of the present invention, it is possible to obtain a carbon material that is suitably used for a secondary battery negative electrode material having high efficiency and high capacity.

Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to the examples. Further, “parts” and “%” shown in the examples and comparative examples are all “parts by weight” and “% by weight” except for the calculation of the initial charge / discharge efficiency.

Example 1
950 parts of a commercially available resol type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50087”) and 50 parts of adipic acid as compound (B) were dissolved and mixed in 1000 parts of methanol to obtain a composition.
The obtained composition was subjected to a first heat treatment in an oven at 150 ° C. for 3 hours to volatilize and remove methanol, then cooled to room temperature, and an average particle size of about 10 μm using a table grinder. To obtain a powdery reaction composition.
The obtained reaction composition was heated at 100 ° C./hour in a nitrogen atmosphere, reached 1200 ° C., and maintained for 3 hours to perform a second heat treatment to obtain a carbon material.

(Example 2)
850 parts of a commercially available resol type phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50087”) and 150 parts of adipic acid as compound (B) were dissolved and mixed in 1000 parts of methanol to obtain a composition.
Thereafter, a carbon material was obtained in the same manner as in Example 1.

(Example 3)
700 parts of a commercially available resol type phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50087”) and 300 parts of adipic acid as the compound (B) were dissolved and mixed in 1000 parts of methanol to obtain a composition.
Thereafter, a carbon material was obtained in the same manner as in Example 1.

Example 4
950 parts of a commercially available novolac-type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50731”) and 50 parts of β-naphthol as a compound (B) were placed in a 3 L sealed pressure-resistant heating apparatus (autoclave), 300 The first heat treatment was performed while being melted and mixed at 3 ° C. for 3 hours.
The obtained product and 100 parts of hexamethylenetetramine were pulverized and mixed, then heat-treated in an oven at 150 ° C. for 3 hours, cooled to room temperature, and an average particle size of about 10 μm using a desktop pulverizer. This was pulverized until a powdery reaction composition was obtained.
Thereafter, a carbon material was obtained in the same manner as in Example 1.

(Example 5)
850 parts of a commercially available novolac type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50731”) and 150 parts of diethylaminopropylamine (manufactured by Kanto Chemical Co., Ltd.) as a compound (B) are dissolved and mixed in 1000 parts of ethanol. I got a thing.
The obtained composition was subjected to a first heat treatment in an oven at 150 ° C. for 3 hours to volatilize and remove ethanol, then cooled to room temperature, and an average particle size of about 10 μm using a table grinder. To obtain a powdery reaction composition.
The obtained reaction composition was heated at 100 ° C./hour in a nitrogen atmosphere, reached 1200 ° C., and maintained for 3 hours to perform a second heat treatment to obtain a carbon material.

(Example 6)
Composition by dissolving 700 parts of a commercially available novolac-type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50731”) and 300 parts of diethylaminopropylamine (manufactured by Kanto Chemical Co., Ltd.) as a compound (B) in 1000 parts of ethanol. I got a thing.
Thereafter, a carbon material was obtained in the same manner as in Example 5.

(Example 7)
850 parts of a commercially available novolac type phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50731”) and 150 parts of pyromellitic anhydride (manufactured by Kanto Chemical Co., Ltd.) as a compound (B) are sealed in a 3 L sealed pressure heating apparatus ( The first heat treatment was performed while being melted and mixed at 300 ° C. in an autoclave.
The obtained product and 100 parts of hexamethylenetetramine were pulverized and mixed, then heat-treated in an oven at 150 ° C. for 3 hours, cooled to room temperature, and an average particle size of about 10 μm using a desktop pulverizer. This was pulverized until a powdery reaction composition was obtained.
Thereafter, a carbon material was obtained in the same manner as in Example 1.

(Comparative Example 1)
Without compounding the compound (B), 1000 parts of a commercially available resol type phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50087”) was used and heat-treated in an oven at 150 ° C. for 3 hours. Then, it grind | pulverized until the average particle diameter became 10 micrometers using the desktop grinder.
The obtained pulverized product was heated at 100 ° C./hour in a nitrogen atmosphere, and after reaching 1200 ° C., maintained for 3 hours for carbonization to obtain a carbon material.

(Comparative Example 2)
Except for using 1000 parts of hexamethylenetetramine crushed and mixed with 1000 parts of a commercially available novolak type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., “PR-50731”) without compounding the compound (B), A carbon material was obtained in the same manner as in Comparative Example 1.

(Evaluation of carbon materials)
1. Carbonization yield About the reaction composition in an Example, it computed with the following formula from the weight before and behind 2nd heat processing.
Carbonization yield (%) = (weight after second heat treatment / weight before second heat treatment) × 100
Moreover, in the comparative example, it computed with the following formula from the completion | finish before and behind carbonization.
Carbonization yield (%) = (weight after carbonization / weight before carbonization) × 100

2. Evaluation of battery characteristics (1) Preparation of positive electrode Lithium cobaltate (LiCoO ₂ ) was used as a positive electrode active material, and acetylene black and polyvinylidene fluoride (PVDf) were blended at a ratio of 5%, respectively, and further diluted. An appropriate amount of N-methyl-2-pyrrolidone as a solvent was added and mixed to prepare a slurry-like positive electrode mixture.
This positive electrode slurry-like mixture was applied to both sides of a 25 μm aluminum foil, and then vacuum dried at 110 ° C. for 1 hour. After vacuum drying, the electrode was pressure-formed by a roll press. This was cut into a size of 40 mm in width and 280 mm in length to produce a positive electrode. Aluminum foil was exposed at the 10 mm both ends of the positive electrode, and a positive electrode tab was pressure-bonded to one side.

(2) Production of Negative Electrode The carbon material obtained above was used and blended in a proportion of 10% polyvinylidene fluoride and 3% acetylene black as a binder, and N-methyl-2 as a diluent solvent. -An appropriate amount of pyrrolidone was added and mixed to prepare a slurry-like negative electrode mixture.
This negative electrode slurry mixture was applied to both sides of a 10 μm copper foil, and then vacuum dried at 110 ° C. for 1 hour. After vacuum drying, the electrode was pressure-formed by a roll press. This was cut into a size of 40 mm in width and 290 mm in length to produce a negative electrode. The copper foil was exposed at the 10 mm both ends of the negative electrode, and a negative electrode tab was pressure-bonded to this one.

(3) Production of secondary battery The positive electrode, the separator (polypropylene porous film: width 45 mm, thickness 25 μm), the negative electrode, the separator, the positive electrode, and so on are wound in a spiral shape so that the negative electrode is on the outside. Thus, an electrode was produced. The produced electrode was inserted into an AA type battery can, and the negative electrode tab was welded to the bottom of the can. Further, an electrolytic solution prepared by dissolving lithium perchlorate at a concentration of 1 [mol / liter] in a mixed solution of ethylene carbonate and diethylene carbonate (volume ratio is 1: 1) is prepared. Then, the positive electrode tab was welded to the positive electrode cover, and the positive electrode cover was attached to produce a secondary battery.

(4) Evaluation Regarding the charging capacity, constant current charging is performed with the current density at the time of charging being 25 mA / g. When the potential reaches 0 V, constant voltage charging is performed at 0 V, and the current density is 1.25 mA / g. The amount of electricity charged up to is the charge capacity.
On the other hand, with respect to the discharge capacity, constant current discharge was performed with a current density at the time of discharge of 25 mA / g, and constant voltage discharge was performed at 2.5 V from the time when the potential reached 2.5 V, and the current density was 1.25 mA. The amount of electricity discharged up to / g was taken as the discharge capacity.
Each of the first cycle charge capacities is referred to as an initial charge capacity, a discharge capacity is referred to as an initial discharge capacity, and a ratio between the two (initial discharge capacity / initial charge capacity) is defined as initial charge / discharge efficiency.

  The above evaluation results are shown in Table 1.

  From the results of Table 1, Examples 1 to 7 are all carbon materials of the present invention obtained by heat-treating the composition of the present invention characterized in that it contains a phenol resin and a compound (B). Compared with Comparative Examples 1 and 2 not containing (B), the charge / discharge characteristics were high. Moreover, as a result of secondary battery evaluation using these carbon materials, the initial charge and discharge efficiency was higher than that of the comparative example, and the discharge capacity was excellent.

The present invention comprises a phenol resin composition for a carbon material containing a phenol resin (A) and a compound (B) having reactivity with the phenolic hydroxyl group of the phenol resin (A), and heat treatment of the phenol resin composition. When used as a negative electrode material for a lithium ion secondary battery, it is excellent in charge / discharge characteristics. Therefore, the carbon material of the present invention is suitable as a material for a negative electrode material for a lithium ion secondary battery.

Claims (8)

A phenol resin composition for a carbon material, comprising a phenol resin (A) and a compound (B) having reactivity with a phenolic hydroxyl group of the phenol resin. 2. The phenol resin composition for a carbon material according to claim 1, wherein a weight ratio (A: B) of the phenol resin (A) to the compound (B) is 95: 5 to 50:50. The phenolic resin composition for a carbon material according to claim 1 or 2, wherein the compound (B) has one or more selected from a hydroxyl group, a carboxyl group, an amide group, a sulfone group, and an epoxy group. A carbon material obtained by heat-treating the phenol resin composition for a carbon material according to any one of claims 1 to 3. A method for producing a carbon material, comprising a step of heat-treating the phenol resin composition for carbon material according to any one of claims 1 to 3. The heat treatment step includes
(A) performing a first heat treatment on the phenol resin composition for carbon material, and reacting the phenol resin (A) and the compound (B) in at least a part thereof to obtain a reaction composition;
(B) performing a second heat treatment on the reaction composition to obtain a carbon material;
The manufacturing method of the carbon material of Claim 5 containing this. The method for producing a carbon material according to claim 6, wherein the first heat treatment is performed at 100 to 300 ° C. 8. The method for producing a carbon material according to claim 6 or 7, wherein the second heat treatment is performed at 600 to 1400 ° C.