JP3091944B2 - Method for producing carbon particles for negative electrode of lithium ion secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lithium ion secondary battery.
The present invention relates to a method for producing carbon particles for a negative electrode of a pond.

[0002]

2. Description of the Related Art In recent years, a lithium ion secondary battery is a high energy storage battery which can be reduced in size and weight.
It is attracting attention as a power source for portable electronic devices. And
In this lithium ion secondary battery, the positive electrode active material includes LixMyOz (M is one or more metal elements mainly composed of a transition metal element, 0.5 ≦ x ≦ 2, 1 ≦ y ≦
2, 2 ≦ z ≦ 4) lithium metal composite oxide particles are used, and a carbonaceous material such as petroleum pitch coke or coal pitch coke particles is used for the negative electrode.

The energy density indicating the battery performance depends on the degree of lithium ion doping (occluding) of a carbonaceous material as an active material of a negative electrode. The positive electrode active material emits lithium ions during charging, is doped (charged) into the carbonaceous material of the negative electrode, and is dedoped (discharged) from the carbonaceous material during discharge. Since filling the limited internal volume of the battery can with more active material leads to an increase in the capacity of the battery, it is preferable that the carbonaceous material has a higher specific gravity. Further, it is desirable that the higher the current efficiency, that is, the higher the percentage of the amount of dedoping electricity with respect to the amount of doping electricity, the less lithium in the lithium-metal composite oxide of the positive electrode is consumed except for charging and discharging.

[0004] As a power source for various electronic and electric devices, the appearance of batteries with higher capacity is expected. Natural graphite and artificial graphite have high specific gravities of 2.23 to 2.25, and high capacity can be achieved by selecting an aprotic organic solvent as the electrolytic solution. And, as the particle size of these graphites decreases, the surface area per unit weight increases and the capacity increases, but the graphite surface becomes more active and lithium is easily precipitated, which causes a problem in battery safety such as dendrite short-circuit. There is a possibility that this may occur, and the electrolyte solution is easily decomposed, which limits the choice of the solvent. Therefore, various modifications of the graphite surface have been proposed.

[0005] That is, JP-A-4-368778 discloses a method in which hydrocarbons and the like are thermally decomposed in a heating furnace, deposited on a graphite surface, and covered with amorphous carbon having a turbostratic structure.
No. 121066, binder pitch is dissolved in quinoline or the like, graphite particles are immersed, quinoline is evaporated and calcined by heating to reduce the carbon interlayer distance (d002) to 0.33.
Coating with carbonaceous material of 7 nm or more
209, a method of providing a carbon layer that is more disordered than graphite by mixing a dimethylformamide solution of polyacrylonitrile and powdered graphite and evaporating the solvent to form a polyacrylonitrile deposition layer.
No. 370662, perylene-3,4,9,10
- the Tetorakaru Bonn dianhydride was heat treated to 2800 ° C., true density 2.20 g / cm ^3, an average particle diameter of 5 [mu] m, the carbon interlayer distance (d002) is 3.39A, the thickness Lc in the C-axis direction of crystallites Is 250 °, and perylene-3,
4, 9, 10 - mixing the Tetorakaru Bonn tribasic anhydride,
There is a method of raising the temperature to 900 ° C. to form a multiphase structure. Further, in JP-A-5-94838, d002 is 3.36 °.
Above 3.45 ° and in JP-A-5-159771,
d002 is greater than or equal to 3.35 ° and less than 3.45 °;
No. 307959 proposes a method of coating particles having a d002 of less than 3.40 ° with a high molecular substance such as a phenol resin and subjecting them to thermal decomposition.

However, in the method of carbonizing a polymer substance by thermal decomposition, it tends to be porous and easily decomposed by contact of an organic solvent to a graphite surface through pores, so that a relatively large amount is used to prevent this. A polymer coating is required. On the other hand, in the firing of a coating such as a binder pitch, graphite particles are fused by sintering of the pitch, and it is necessary to re-pulverize the particles. At that time, the surface of the graphite particles was exposed again by the pulverization, and there was a risk that a defect of graphite might appear.

[0007]

An object of the present invention is to provide a rapid
Excellent charging property, industrially useful excellent lithium ion secondary battery negative electrode carbon particles in safety have capacitance have high
It is an object of the present invention to provide a method of manufacturing with high economic efficiency .

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that tar pitch (A)
And a heat curable phenolic resin (B) are fused, condensed, and cross-linked to the particle surface of the specific carbonaceous material (C), and then heat-treated, or tar pitch (A)
And a curable phenolic resin (B) at least one selected from a specific carbonaceous material (C) , green mesophase pitch small spheres, and green mesophase pitch ground particles.
The present inventors have found that a method for producing carbon particles that is subjected to heat treatment after fusion, condensation, and cross-linking to the surface of the mixture (D) with the seed is extremely effective in solving the above-described problems, and has completed the present invention. That is, the present invention is hard and tar pitch (A)
A resistance phenolic resin (B), an average particle diameter of from 1 to 20
μm, distance between carbon layers (d002) is 0.336 to 0.3
40 nm, the crystallite thickness (Lc) in the C-axis direction is 8 to 70
fusion to the particle surface of the carbonaceous material (C) in the range of nm,
After condensation and cross-linking, heat treatment (C) 10
(A + B) is 30 to 100 parts by weight relative to 0 parts by weight,
(A) / ratio of (B) is 5/1 to 0.5 / 1 lithium
A method for producing carbon particles for a negative electrode of a secondary battery , or a method in which a tar pitch (A) and a curable phenol resin (B) are mixed with an average particle diameter of 1 to 20 μm and a carbon interlayer distance (d00
2) particles of carbonaceous material (C) having a crystallite thickness in the range of 0.336 to 0.340 nm and a crystallite in the C-axis direction (Lc) of 8 to 70 nm , toluene-insoluble content of 85 to 98% by weight, quinoline At least one selected from green mesophase pitch small spheres and green mesophase pitch ground particles having a soluble content of 15 to 5% by weight and a volatile content of 6 to 14% by weight.
After being fused, condensed, and cross-linked to the surface of the mixture (D) with the seed , upon heat treatment, (A) + (B) is 30 to 100 parts by weight with respect to 100 parts by weight of (C) + (D). (A) / (B) ratio of 5/1 to 0.5 / 1 and (C) /
Lithium ion having a ratio of (D) of from 95/5 to 5/95
Is a manufacturing how the secondary battery negative electrode carbon particles.

Hereinafter, the present invention will be described in detail. Examples of the tar pitch (A) used in the present invention include petroleum tar pitch, coal tar pitch and the like by naphtha cracking, crude oil cracking, thermal cracking of coal, asphalt cracking and the like.

The curable phenolic resin (B) used in the present invention is not particularly limited as long as it has a property of condensing and crosslinking at room temperature or under heating in the presence of a curing agent or a curing accelerator, that is, a curability. Examples thereof include phenolic resins of novolak type, resol type or benzylic ether type, and resins obtained by modifying these with furan resin, furfuryl alcohol, melamine resin, xylene resin and the like.

Since the specific carbonaceous material (C) is required to have a quick chargeability within 2 hours, an average particle diameter of 1-2
0 μm, preferably 3 to 10 μm, a carbon interlayer distance (d002) of 0.336 to 0.340 nm, and a crystallite thickness (Lc) in the C-axis direction of 8 to 70 nm are used. When the average particle diameter is less than 1 μm, the amount of the tar pitch (A) and the curable phenol resin (B) fused to the particle surface becomes too large, and the electric capacity of the carbonized particles becomes small. If it exceeds, the quick chargeability is impaired, which is not preferable. Preferred particle size is 3 to
10 μm. Further, a carbonaceous material (C) having a carbon interlayer distance (d002) of 0.336 to 0.340 nm and a crystallite thickness (Lc) in the C-axis direction of 8 to 70 nm.
Is made by, for example, impact-crushing natural graphite or artificial graphite or intercalating the stage 1 with concentrated sulfuric acid or the like, followed by washing with water. The distance between carbon layers (d002) is less than 0.336 nm, or the thickness of crystallite (L
If c) exceeds 70 nm, the rapid charging property is impaired, and the carbon interlayer distance (d002) exceeds 0.340 nm, or
When the thickness (Lc) of the crystallite in the C-axis direction is less than 8 nm, the electric capacity is small, so that the above range is preferable.

[0012] Green mesophase pitch globules or green mesophase pitch milled grain child used in the present invention
Is obtained by centrifuging the mesophase pitch microspheres generated when the tar pitch is heated to 300 to 500 ° C., or further, by isolating the mesophase pitch microspheres into a lump and then pulverizing them. Min 85
98% by weight, a quinoline-soluble content of 15 to 5% by weight, and a volatile content (weight ratio reduced in 800 ° C. for 7 minutes) of 6 to 14% by weight.
It is 15 μm, preferably 3 to 10 μm.

The total amount of the tar pitch (A) and the curable phenolic resin (B) used is the same as that of the carbonaceous material (C).
Or carbonaceous material and (C) from the green mesophase pitch globules and Green mesophase pitch milled particles
Total amount of the mixture (D) with at least one selected one is 1
30 to 100 parts by weight in terms of solid content with respect to 00 parts by weight,
Preferably it is 45 to 90 parts by weight. If the amount is less than 30 parts by weight, the electric capacity deteriorated at high temperature (60 ° C.) becomes large.
On the other hand, when the amount exceeds 90 parts by weight, the electric capacity becomes small and the object cannot be achieved.

In order to obtain the highest electric capacity, either the green mesophase pitch small spheres or the green mesophase pitch ground particles or the mixture (D) is used in combination with the specific carbonaceous material (C) described above. At that time, (C) /
The ratio of (D) can be adjusted in the range of 95/5 to 5/95. When the ratio of (C) is high, the discharge voltage is more flattened to increase the capacity, and when the ratio of (D) is high,
Higher capacity and quick chargeability can be obtained, and flattening of the discharge voltage, which cannot be obtained by (D) alone, becomes possible.

[0015] The carbon particles of the present invention are obtained by mixing the tar pitch and the curable phenol resin with a carbonaceous material or the carbonaceous material .
At least selected from quality material and green mesophase pitch globules and Green <br/> down mesophase pitch milled particles
After putting into a kneader capable of stirring and mixing with the mixture with one kind , for example, a heating kneader or the like, for example, 120 to 180
The mixture which has been stirred and mixed to a temperature of ° C. is transferred to a heat treatment furnace, and is subjected to a heat treatment at an appropriate heating rate from a normal temperature to a predetermined temperature in an atmosphere in which oxidation is unlikely to occur, for example, an atmosphere of nitrogen, argon, or the like. It can be obtained by:

The negative electrode for a lithium ion secondary battery according to the present invention is characterized in that the carbon particles and a binder such as carboxymethyl cellulose, fluoro rubber, polyvinylidene fluoride, polyvinyl pyridine, polyvinyl alcohol, polyacrylate, EPDM rubber, diene-based A dispersion liquid of rubber or the like is obtained by applying, for example, a copper, stainless steel or nickel metal foil having a thickness of 1 to 50 μm on a current collector such as a net or a porous body, followed by drying and pressing.

In the non-aqueous secondary battery according to the present invention,
The positive electrode is made of lithium cobalt oxide, for example, Lix
CoyMzO2 (where M is Al, In, Sn, M
represents at least one metal selected from n, Fe, Ti, Zr, and Ce, where x, y, and z are each 0 <x ≦ 1.
1, representing 0.5 <y ≦ 1, z ≦ 0.15), Li
xCoO2 (0 <x ≦ 1), LixCoyNizO2
(0 <x ≦ 1, y + z = 1), for example, LixNiO 2 (0 <x ≦ 1), Lix
NiyMzO2 (where M represents at least one metal selected from Mn, Ti, and Fe, and x and z represent the numbers 0 <x ≦ 1, 0.1 <z ≦ 0.3, respectively) , As lithium manganese oxide, for example, LiMnO3, Lix
MnO2 (0 <x ≦ 1), LixMn2O4 (0 <x <
2), LiCoxMn2-xO4 (0 <x ≦ 0.5),
LixMn2-yMyO4 (where M is Ni, Co,
Represents at least one metal selected from Ti and Fe, and x and y are 0.5 ≦ x ≦ 2 and 0.1 <y ≦ 0.2, respectively.
The electrolyte is, for example, LiClO.
4, LiAsF6, LiPF6, LiBF4, CH3S
O3Li, CF3SO3Li, (CF3SO2) 2NL
a mixture of any one or two or more lithium salts such as i, and a solvent such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, γ -Butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolan, sulfolane, methylsulfolane, acetonitrile, propionitrile, methyl formate, ethyl formate, methyl acetate, ethyl acetate, butyl acetate, hexyl acetate, methyl propionate, propionate Ethyl acid, butyl propionate, hexyl propionate, triethyl phosphate, triethylhexyl phosphate, a mixture of two or more of trilaurel phosphate and the like, separator,
It refers to a single film of a polyolefin microporous film such as polyethylene or polypropylene, a single film or a bonded film of one or more of them, and a film using a carbonaceous material as an active material as a negative electrode.

The negative electrode for a lithium ion secondary battery containing carbon particles according to the present invention may be doped with lithium ions from the positive electrode during the initial charge using the above-described positive electrode, electrolyte and separator as it is, Lithium ions may be contacted with lithium metal, a lithium alloy, or lithium iodide for doping.

[0019]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. (Measurement method) The current efficiency (%) is the amount of discharged electricity / the amount of charged electricity × 100.
Expressed by The discharge capacity (mAh / g) of the negative electrode active material is determined as the amount of discharge electricity per weight of the active material. The lamination thickness Lc (nm) of the carbon mesh plane in the C-axis direction and the spacing d002 (nm) of the carbon mesh plane are X in accordance with the “Japan Society for the Promotion of Science”.
It is calculated by the line diffraction method. Preparation of negative electrode for lithium ion secondary battery 0.8 parts by weight of carboxymethyl cellulose as a binder and 100 parts by weight of carbon particles obtained in Examples and Comparative Examples, and crosslinked rubber latex particles of styrene-butadiene 2.0 100 parts by weight of an aqueous solution consisting of parts by weight is added to form a dispersion, which is coated on one surface of an electrolytic copper foil having a thickness of 18 μm, dried, and pressed by compression. Using this as a working electrode, a lithium sheet pressed against a stainless steel net via a polyethylene microporous membrane was used as a counter electrode, and the volume fraction of 1.0 mol of LiBF4 propylene carbonate 25%, ethylene carbonate 25%, and γ-butyrolactone 50% In the mixed solvent of (1), charging is started at a maximum current density of 1.0 mA / cm2, and charging is performed for 8 hours. Doping (charging) is performed up to a Li / Li + potential of 10 mV. The discharge is
The discharge capacity is determined by performing the process up to an i / Li + potential of 1.0 V, and expressed as mAh / g as the amount of discharge electricity per weight of the active material. Quick chargeability Charge at a current density of 3.0 mA / cm 2 for 2 hours,
The ratio of the amount of discharged electricity to the case where the battery was charged at a current density of mA / cm 2 for 2 hours is expressed as a percentage.

(Example 1) A coal-based binder pitch (softening point: 89 ° C) of 45 parts by weight as a tar pitch (A) and a resole type phenol resin aqueous solution of 50 parts by weight (solid content) as a curable phenol resin (B) 30 parts by weight) and a concentrated sulfuric acid-treated product of artificial graphite as a carbonaceous material (C) (average particle diameter: 5 μm, distance between carbon layers (d002): 0.336 nm, crystallite thickness in the C-axis direction (Lc): 55 nm) 90 parts by weight and green
10 parts by weight of sophase pitch microspheres (D) (toluene-insoluble matter 91% by weight, quinoline-soluble matter 11% by weight, volatile matter 9% by weight, average particle diameter 4 μm) are put into a heating kneader and heated to 160 Gradually increase to 2 ° C over 2 hours,
Condensate, crosslink and dehydrate. After maintaining the temperature at 160 ° C. for another 30 minutes, it is cooled, taken out and transferred to an electric furnace. Then, under a nitrogen atmosphere, the temperature is raised from room temperature to 900 ° C. at a rate of 0.2 ° C./min.
C. and carbonized. This was taken out of the electric furnace, unraveled, and passed through a 200-mesh sieve to determine the ratio of pass products. Table 1 shows the results of the implementation, including the results of the negative electrode evaluation using a 200 mesh pass product.

(Example 2) The same tar pitch (A) and curable phenolic resin (B) as those in Example 1 were used, and these were used as the carbonaceous material (C) in a jet-milled product of natural graphite (C). Average particle diameter 3 μm, distance between carbon layers (d002) 0.336 nm,
45 parts by weight of the thickness of the crystallite in the C-axis direction (Lc) of 38 nm) and the same green mesophase pitch sphere as in Example 1.
55 parts by weight of the body (D) is placed in a heating kneader, gradually raised from room temperature to 150 ° C. over 1.5 hours, condensed, crosslinked, and dehydrated. After keeping the temperature at 150 ° C. for another hour, it is cooled, taken out, and transferred to an electric furnace. Then, the temperature was increased from room temperature to 200 ° C. at a rate of 2 ° C./min in a nitrogen atmosphere, and then heat-treated to 900 ° C. at a rate of 0.2 ° C./min. Table 1 shows the evaluation results.

[0022] and Example 3 Example 1 the same tar pitch and (A) 40 parts by weight, hardness
Of novolak type phenolic resin 20 parts by weight with a curable phenol resin (B) (including 2 parts by weight of hexamethylenetetramine as a curing agent), a carbonaceous material (C) as artificial graphite jet milling products (average Particle diameter 7 μm, carbon interlayer distance (d002) 0.337 nm,
100 parts by weight of the crystallite thickness (Lc) in the C-axis direction (Lc) of 48 nm) is placed in a heating kneader, and the temperature is raised from room temperature to 160 ° C. over 2 hours to effect crosslinking. 160 ° C for another 30 minutes
, And then transferred to an electric furnace at 5 ° C /
Then, the temperature was raised from room temperature to 200 ° C. per minute, and then heat-treated to 1000 ° C. at a rate of 0.2 ° C./min.
Table 1 shows the evaluation results.

(Example 4) The same tar pitch (A) and curable phenol resin (B) as in Example 1 were combined with the same carbonaceous material (C) as in Example 1.
And the same green mesophase pitch globules as in Example 1.
Using the body (D) , first, the carbonaceous material (C) and the green mesophase pitch small sphere (D) are heated by a heating kneader.
20 parts by weight of tar pitch and 10 parts by weight of a curable phenol resin (solid content) are heated from room temperature to 160 ° C. over 2 hours, condensed, crosslinked and dehydrated based on 0 part by weight. , 6
After cooling to 0 ° C., 45 parts by weight of tar pitch and 10 parts by weight of a curable phenol resin (solid content) were added, and 150 parts by weight were added.
The temperature was raised again to 2 ° C. over 2 hours, followed by condensation, crosslinking and dehydration.
Then, the temperature was raised from room temperature to 1000 ° C. at a rate of 0.2 ° C./min in an electric furnace, and heat treatment was performed. Table 1 shows the evaluation results.

Example 5 The same tar pitch (A) as in Example 1 and 60 parts by weight were cured.
Put sex phenolic resin (B) 15 parts by weight and (solids) in the heating kneader, green mesophase pitch milled grain
Child (toluene insoluble content 93 wt%, a quinoline-soluble component 10 weight%, a volatile content 8% by weight, average particle diameter 5 [mu] m) and 20 parts by weight, artificial graphite shock pulverized product (average particle size 5 [mu] m, the carbon interlayer distance (d002 ) 0.336 nm, the thickness of the crystallite in the C-axis direction (Lc) 46 nm) and 80 parts by weight are placed in a heating kneader, and the temperature is raised from room temperature to 160 ° C. over 2 hours, followed by condensation, crosslinking and dehydration. . After further maintaining the temperature at 160 ° C. for 30 minutes, it was transferred to an electric furnace and heat-treated from room temperature to 900 ° C. at a rate of 0.2 ° C./min in a nitrogen atmosphere. Table 1 shows the evaluation results.

Comparative Example 1 The same curable phenol resin as in Example 1 (45 parts by weight (solid content)) and natural graphite (average particle diameter 15 μm, carbon interlayer distance (d002) 0.335 nm, crystal in the C-axis direction) 100 parts by weight (thickness (Lc) of 100 nm or more) is placed in a heating kneader, and the temperature is raised from room temperature to 160 ° C. over 2 hours to condense, crosslink, and dehydrate. After maintaining the temperature at 160 ° C. for another 30 minutes, it is cooled, taken out and transferred to an electric furnace. Then, under a nitrogen atmosphere, the temperature is raised from room temperature to 120 ° C. at a rate of 2 ° C./min.
The temperature is raised to 0 ° C. and carbonized. This was taken out of the electric furnace, unraveled, and passed through a 200-mesh sieve to determine the ratio of pass products. Table 1 shows the results of the evaluation, including the evaluation of the negative electrode using a 200 mesh pass product.

Comparative Example 2 Coal binder pitch 45 as tar pitch (A)
Parts by weight and 100 parts by weight of the same natural graphite as in Comparative Example 1 are put into a heating kneader and gradually raised from room temperature to 150 ° C. over 2 hours. After holding at 160 ° C. for another 30 minutes, cool, take out, and transfer to an electric furnace. Then, in a nitrogen atmosphere, the temperature is raised from room temperature to 1200 ° C. at a rate of 2 ° C./min to carbonize. This was taken out of the electric furnace, unraveled, and passed through a 200-mesh sieve to determine the ratio of pass products. Table 1 shows the evaluation results including the evaluation of the negative electrode using a 200 mesh pass product.

Comparative Example 3 The same tar pitch of 10 parts by weight as in Example 1 and curing
10 parts by weight (solid content) of a water- soluble phenol resin and 100 parts by weight of the same natural graphite as in Comparative Example 1 were gradually heated from room temperature to 150 ° C. over 1.5 hours, and then condensed and crosslinked. And dehydrate. After keeping the temperature at 150 ° C. for another hour, it is cooled, taken out, and transferred to an electric furnace. Then, in a nitrogen atmosphere, the temperature is raised from room temperature to 1200 ° C. at a rate of 2 ° C./min to carbonize. This was taken out of the electric furnace, unraveled, and passed through a 200-mesh sieve to determine the ratio of pass products. Table 1 shows the evaluation results including the evaluation of the negative electrode using a 200 mesh pass product.

(Comparative Example 4) A petroleum-based needle coke pulverized product which is a conventional technique (average particle diameter: 10 μm, carbon layer distance (d002): 0.347 n)
The negative electrode was evaluated based on the crystallite thickness (Lc) of 5.2 m in the m and C axis directions. The results are shown in Table 1.

As shown in Table 1, in Examples 1 to 5 according to the present invention, the quick chargeability was 100% less than that in Comparative Examples 1 to 3.
%, And has an extremely large initial discharge capacity as compared with the petroleum-based needle coke of Comparative Example 4 which is a conventional technique.

[0030]

[Table 1]

[0031]

According to the present invention, the tar pitch and the curable phenol resin are mixed with each other at an average particle diameter of 1 to 20 μm, a carbon interlayer distance (d002) of 0.336 to 0.340 nm,
After being fused, condensed and cross-linked to the particle surface of the carbonaceous material having a crystallite thickness (Lc) in the range of 8 to 70 nm in the C-axis direction, heat treatment is performed, or tar pitch and curability are obtained. A phenolic resin having an average particle diameter of 1 to 20 μm, a carbon interlayer distance (d002) of 0.336 to 0.340 nm,
Carbonaceous material and green mesophase pitch small spheres having a crystallite thickness (Lc) in the C-axis direction in the range of 8 to 70 nm
Small selected from a green mesophase pitch milled particles
At least one type is fused, condensed and cross-linked to the surface of the mixture , and then heat-treated to have excellent rapid chargeability and high electric capacity, and to have excellent safety by deactivating the surface. In addition, carbon particles suitable for a negative electrode for a lithium ion secondary battery can be produced at low cost.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-307959 (JP, A) JP-A-48-94709 (JP, A) JP-A-2-26818 (JP, A) JP-A-4- 188559 (JP, A) JP-A-4-280068 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 4/58 H01M 4/02 C04B 41/85 C04B 35/52

Claims (2)

(57) [Claims] 1. A crystallite having a tar pitch (A) and a curable phenol resin (B) having an average particle diameter of 1 to 20 μm, a carbon interlayer distance (d002) of 0.336 to 0.340 nm, and a C-axis direction. Is fused, condensed and cross-linked to the particle surface of the carbonaceous material (C) having a thickness (Lc) in the range of 8 to 70 nm, and then subjected to a heat treatment, where (A + B) is 30 per 100 parts by weight of (C). ~ 100 parts by weight and (A) /
A method for producing carbon particles for a negative electrode of a lithium ion secondary battery , wherein the ratio of (B) is from 5/1 to 0.5 / 1. 2. Tar tar (A)CurabilityPhenol
Resin (B) having an average particle size of 1 to 20 μm,
Distance (d002) is 0.336 to 0.340 nm, C axis
The crystallite thickness (Lc) in the direction is in the range of 8 to 70 nm.
Of carbonaceous material (C)WhenToluene insolubles 85-98
Wt%, quinoline soluble content 15-5 wt%, volatile content 6-1
Green mesophase pitch globules in the range of 4% by weight
bodyas well asGreen mesophase pitch ground particlesChosen from
Mixtures with at least oneFused and shrunk to the surface of (D)
In the case of heat treatment after crosslinking,(C + D)1
To 00 parts by weight(A + B)But 30 to 100 parts by weight
Yes, the ratio of (A) / (B) is 5/1 to 0.5 / 1as well as
That the ratio of (C) / (D) is 95/5 to 5/95
FeatureFor negative electrode of lithium ion secondary batteryCarbon particles
Manufacturing method.