JPH0878010A - Negative electrode for nonaqueous electrolyte secondary battery and its manufacture - Google Patents

Abstract

PURPOSE: To provide a negative electrode for a nonaqueous electrolyte secondary battery with high energy density, excellent quick charge/discharge performance, and low capacity deterioration attendant on charge/discharge cycles by constituting with a molding containing a specified carbon material and having a specified plane peak intensity ratio. CONSTITUTION: A negative electrode is constituted with a molding containing a carbon material (example: artificial graphite) with a spacing of (002) planes as determined by Cu-Kα source X-ray wide angle diffraction of 3.40Å or less and a crystal size in the direction of (c) axis of 100Å or more, and in which the ratio of peak intensity in (100) planes as determined by Cu-Kαsource X-ray wide angle diffraction to peak intensity in (002) planes is 0.5/100-2.5/100. The negative electrode is manufactured by forming a pasty mixture containing the carbon material and 10-50wt.% water on the surface of a negative current collector, then heating them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative electrode for a non-aqueous electrolyte secondary battery using a carbon material and an improvement in its manufacturing method.

[0002]

2. Description of the Related Art Non-aqueous electrolyte secondary batteries using lithium as a negative electrode have high electromotive force and are expected to have higher energy density than conventional nickel-cadmium storage batteries and lead storage batteries, and many studies have been conducted. However, when metallic lithium is used for the negative electrode, a dendrite is generated during charging, a short circuit is likely to occur, and the battery has low reliability. In order to solve this problem, the use of an alloy negative electrode of Li, aluminum, and lead was studied. When these alloy negative electrodes are used, Li is occluded in the negative electrode alloy by charging, and dendrite is not generated, so that the battery has high reliability. However, since the discharge potential of the alloy negative electrode is about 0.5 V more noble than that of metallic Li, the voltage of the battery also drops by 0.5 V, which also reduces the energy density of the battery.

[0003] On the other hand, researches using an intercalation compound of a carbon material such as graphite and Li as a negative electrode active material have been actively conducted. Also in this compound negative electrode, Li enters the interlayer of the carbon material due to charging, and dendrite is not generated. The discharge potential is only about 0.1 to 0.3 V more noble than that of metallic Li, so the decrease in battery voltage is small. This can be said to be a more preferable negative electrode. Usually, carbonaceous materials decompose organic matter by heating at about 400 to 3000 ° C. in an inert atmosphere,
It can be obtained by carbonization and then graphitization. The starting material for carbonaceous materials is almost always organic,
By heating up to around 1500 ° C. which is a carbonization step, almost only carbon atoms remain and heating up to a high temperature near 3000 ° C. develops a graphite structure. As the organic raw material, in the liquid phase, pitch, coulter or a mixture of coke and pitch is used, and in the solid phase, a wood raw material,
Furan resin, Cellulose, Polyacrylonitrile, Ray
Yeon is used. In the gas phase, hydrocarbon gas such as methane and propane is used.

[0004] So far, a so-called easily graphitizable carbon material having a developed graphite structure, which is generally burned at a high temperature of 2000 ° C or more, using petroleum pitch as a starting material, or a heat such as a furan resin is used. Using a curable resin as a starting material, a so-called non-graphitizable carbon material having a turbostratic structure that is fired at a relatively low temperature of 2000 ° C. or less is used as a negative electrode material for a non-aqueous electrolyte secondary battery that occludes and releases lithium. Attempts are being made. The inventors of the present invention have studied in detail to find out a better carbon material as a negative electrode for a lithium secondary battery, and as a result, (002)
A carbon material having crystallinity in which the interplanar spacing is 3.40 angstroms or less and the crystallite size (Lc) in the c-axis direction is 100 angstroms or more has high charge / discharge capacity, high density, and excellent cycle characteristics. Also found it to be excellent. That is, it has been clarified that a carbon material or a graphite material that is relatively close to a graphite crystal is more desirable as a negative electrode for a lithium secondary battery.

[0005]

However, there has been a serious problem when the carbon material such as graphite and the intercalation compound of Li are used as the negative electrode active material. Theoretically, the maximum amount of Li that can enter between layers during charging is C ₆ Li, and although the electric capacity in that case is 372 Ah / kg, the electric capacity of the negative electrode is 230 Ah during normal battery charging / discharging. At present, the value is only as small as about / kg.

The carbon material having the above crystal structure has a relatively regular carbon hexagonal net plane lamination due to its high crystallinity, and the hexagonal net plane is easily orientated selectively at the time of molding the negative electrode. In this case, there is a peculiar directionality in the invasion and desorption of lithium during charging / discharging, and even though it has a crystal structure with a large charging / discharging capacity, its high orientation causes the charging / discharging. It becomes a negative electrode that is difficult to discharge. That is, for example, Li approaches from the opposite side by charging,
When penetrating between the hexagonal plane layers of carbon, the a-axis of the carbon crystal is oriented so as to be nearly perpendicular to the traveling direction of Li.
Li hardly penetrates into the layers, and as a result, the battery has a small charge / discharge capacity, low rapid charge / discharge performance, and a large capacity reduction due to charge / discharge cycles.

[0007]

The negative electrode for a non-aqueous electrolyte secondary battery of the present invention has a (002) plane spacing of 3.40 angstroms or less in the X-ray wide-angle diffraction method using a Cu-Kα radiation source and a c-axis. The crystallite size in the direction (Lc) is 100 angstroms or more
The ratio of the (100) plane peak intensity to the (002) plane peak intensity in the X-ray wide-angle diffraction pattern by the Cu-Kα radiation source of the molded body was in the range of 0.5 / 100 to 2.5 / 100. is there.

The negative electrode for a non-aqueous electrolyte secondary battery of the present invention is (0) in the X-ray wide-angle diffraction method using a Cu-Kα radiation source.
02) surface spacing is 3.40 angstroms or less c
A carbon material having a crystallite size (Lc) in the axial direction of 100 angstroms or more and a (002) plane spacing of 3.43 to 3.
The size of the crystallite in the c-axis direction at 90 Å (L
c) contains a carbon material having a thickness of 1 to 50 angstroms.

Furthermore, the negative electrode for a non-aqueous electrolyte secondary battery of the present invention has a (002) plane spacing of 3.40 angstroms or less in the X-ray wide-angle diffraction method using a Cu-Kα radiation source and a crystallite in the c-axis direction. Of a carbon material having a size (Lc) of 100 angstroms or more and a (002) plane in an X-ray wide-angle diffraction method using a Cu-Kα radiation source has a surface spacing of 3.43 to
A molded body containing a carbon material having a crystallite size (Lc) in the c-axis direction of 3.90 angstroms of 1 to 50 angstroms, and the molded body in an X-ray wide-angle diffraction pattern by a Cu-Kα radiation source. The ratio of the (100) plane peak strength to the (002) plane peak strength is 0.5 / 100.
To 2.5 / 100. Here, Cu-Kα
In the X-ray wide-angle diffraction method using a radiation source, the content of the carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more is W _A , Cu. -The (002) plane spacing in the X-ray wide-angle diffraction method using a Kα radiation source is 3.43 to 3.9.
The crystallite size in the c-axis direction at 0 angstrom (L
c) is 1 to 50 Å, and W _B is the content of the carbon material, W _B / (W _A + W _B ) is 20/100 to 5
It is preferably 0/100.

The method for producing a negative electrode for a non-aqueous electrolyte secondary battery of the present invention is a crystal in the c-axis direction when the (002) plane spacing in the X-ray wide-angle diffraction method using a Cu-Kα radiation source is 3.40 angstroms or less. Carbon material having a child size (Lc) of 100 angstroms or more and 10 to 50% by weight of the carbon material
Forming a paste-like mixture containing water on the surface of the negative electrode current collector, and heating the mixture. The method for producing the negative electrode for a non-aqueous electrolyte secondary battery of the present invention is Cu-K.
10 to 30 of the carbon material and the carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using an α-ray source. Forming a paste-like mixture containing a weight% of an organic solvent on the negative electrode current collector surface;
And heating this.

[0011]

The negative electrode according to the present invention has a large discharge capacity,
The capacity decrease due to charge / discharge cycles is suppressed. The mechanism is considered as follows. The ratio of the (100) plane peak intensity to the (002) plane peak intensity in the X-ray wide-angle diffraction pattern of the molded product is an index of the selective orientation of the carbon hexagonal net plane. That is, it can be considered to represent the degree of strength of the c-axis orientation with respect to the a-axis orientation of the carbon material. When the ratio of the (100) plane peak strength to the (002) plane peak strength is in the range of 0.5 / 100 to 2.5 / 100, when lithium invades or desorbs during charge / discharge, It has been found that the orientation is not a peculiar orientation that causes a substantial adverse effect. As a result, the negative electrode has a high capacity that is closer to the theoretical electric capacity.

[0012]

Embodiments of the present invention will be described below. Example 1 First, the crystal structure of the negative electrode material used will be described. The carbonaceous material is (00
2) Artificial graphite having a surface spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 100 angstroms.

In order to study the characteristics of this carbonaceous material as an electrode, a test cell shown in FIG. 1 was made. Carbonaceous material 1
1 g of polyethylene powder as a binder was mixed with 0 g, and as a means for obtaining molded products having various orientations, petroleum coke was added to each predetermined amount shown in Table 1 to obtain a mixture. The amount of petroleum coke added to the sum of the weight of petroleum coke in the electrode and the weight of artificial graphite was expressed as a percentage, and the amount of petroleum coke added (wt%) was used. Each mixture 0.1
g was pressure-molded into a disk shape having a diameter of 17.5 mm to obtain a carbon electrode. As shown in Table 1, the ratio of the (100) plane peak intensity to the (002) plane peak intensity in the X-ray wide-angle diffraction pattern of these molded products was from 0.1 / 100 to 3.
The range was 0/100.

The structure of the test cell shown in FIG. 1 is as follows. The carbon electrode 1 is arranged in the center of the battery case 2, and the separator 3 made of microporous polypropylene is arranged on the carbon electrode 1. As a non-aqueous electrolyte, a solution prepared by dissolving 1 mol / l of lithium perchlorate (LiClO ₄ ) in a mixed solvent of ethylene carbonate and dimethoxyethane in a volume ratio of 1: 1 was used. To diameter 1
A disk-shaped metallic lithium 4 of 7.5 mm is attached and sealed with a sealing plate 6 having a polypropylene gasket 5 on the outer peripheral portion. For the above test cell, first 0.5
At a constant current of mA, cathode polarization (corresponding to charging when the carbon electrode is viewed as a negative electrode) is performed until the carbon electrode becomes 0 V with respect to the Li counter electrode, and then anodic polarization (discharge is performed until the electrode becomes 1.0 V). Equivalent to). This cathodic polarization and anodic polarization were repeated 10 times, and the capacity at the 10th cycle was taken as the initial capacity. The capacity was evaluated based on the weight of carbon. Further, the following rapid charge / discharge test was conducted. The rapid charge / discharge test conditions were a constant current of 4.0 mA, and similarly to the above, the cathode polarization until the carbon electrode became 0 V against the Li counter electrode and the anode polarization until it became 1.0 V,
The capacity was measured. The capacity at this time was defined as the rapid charge / discharge capacity. The capacity was evaluated based on the weight of carbon. further,
A charge / discharge cycle test was conducted. The condition is a constant current of 0.5 mA, and the carbon electrode is cathode-polarized until it becomes 0 V against the Li counter electrode, and then the electrode is anode-polarized (corresponding to discharge) until it becomes 1.0 V, which is 100 cycles. I repeated. The results are shown in Table 1 and FIG.

[0015]

[Table 1]

A negative electrode molded body having a ratio of (100) plane peak strength to (002) plane peak strength of 0.5 / 100 or more and a large initial capacity and excellent rapid charge / discharge characteristics was obtained. You can see that In the conventional example and the peak intensity ratio of 0.1 / 100, the initial capacity was large, but the rapid charge / discharge characteristics were very poor. This is a negative electrode molded body having a considerably strong selective orientation on the hexagonal mesh plane of carbon, and thus is in a state in which charging / discharging is difficult, and it is considered that this tendency is particularly remarkable in the rapid charging / discharging test. The discharge capacity after 100 cycles is (100)
The ratio of the surface peak strength to the (002) surface peak strength was high in the range of 0.5 / 100 to 2.5 / 100. When the peak intensity ratio exceeded 2.5 / 100, the discharge capacity after 100 cycles drastically decreased. The reason for this is considered as follows. That is, when the peak ratio increases, the state becomes closer to the state where there is almost no selective orientation of the carbon hexagonal net plane or the state where the hexagonal net plane is oriented in the direction perpendicular to the current collector. Therefore, when charging / discharging is repeated, carbon expansion / contraction with charging / discharging occurs in a direction nearly horizontal to the current collector surface. As a result, it is considered that current collection failure occurs at the contact interface between the electrode mixture and the current collector as the charge / discharge cycle progresses. Therefore, when the initial capacity, the rapid charge / discharge performance, and the charge / discharge cycle property are comprehensively considered, the ratio of the (100) plane peak strength to the (002) plane peak strength is 0.5 / 100 to 2.5. / 10
The range of 0 is desirable. Above all, the peak strength ratio is more preferably in the range of 1.0 / 100 to 2.0 / 100 because it exhibits particularly excellent performance.

[Example 2] As a means for obtaining molded products having various orientations, an example in which calcium oxide is added at various ratios will be described. The carbonaceous material has a (002) plane spacing of 3.40 angstroms by the X-ray wide-angle diffraction method, and c
Artificial graphite having a crystallite size (Lc) in the axial direction of 100 angstrom. As a means of mixing 10 g of this carbonaceous material with 1 g of polyethylene powder as a binder, and further adding calcium oxide at various ratios as shown in Table 2 to obtain molded bodies having various orientations. I used it as an agent. The amount of calcium oxide added (wt%) was expressed as a percentage of the weight of calcium oxide with respect to the sum of the weight of calcium oxide in the electrode and the weight of artificial graphite. 0.1 g of these mixture materials was pressure-molded into a disk shape having a diameter of 17.5 mm to form a carbon electrode, and a test cell having the configuration shown in FIG. 1 was assembled in the same manner as in Example 1. In the X-ray wide-angle diffraction pattern of these carbon electrode molded bodies, the (100) plane peak intensity of (00
2) As shown in Table 2, the ratio to the surface peak strength is 0.
The range was 1/100 to 3.0 / 100. The results of the tests conducted under exactly the same conditions as in Example 1 are shown in Table 2 and FIG.

[0018]

[Table 2]

As in Example 1, the ratio of the (100) plane peak strength to the (002) plane peak strength was 0.5 / 100.
As described above, it was found that a molded negative electrode having a large initial capacity and excellent rapid charge / discharge characteristics can be obtained. Incidentally, the conventional example and the peak strength of 0.1 / 100 had a large initial capacity, but had very poor rapid charge / discharge characteristics. This is a negative electrode molded body having a considerably strong selective orientation on the hexagonal mesh plane of carbon, and thus is in a state in which charging / discharging is difficult, and it is considered that this tendency is particularly remarkable in the rapid charging / discharging test. The discharge capacity after 100 cycles showed a high value in the range of 0.5 / 100 to 2.5 / 100 in the ratio of the (100) plane peak intensity to the (002) plane peak intensity. The peak intensity ratio is 2.5 / 100
When it exceeded, the discharge capacity after 100 cycles dropped sharply. It is considered that this is because, as described in Example 1, the hexagonal mesh plane of carbon has almost no selective orientation or the hexagonal mesh plane is oriented in the direction perpendicular to the current collector. Therefore, when the initial capacity, the rapid charge / discharge performance, and the charge / discharge cycle property are comprehensively considered, the ratio of the (100) plane peak strength to the (002) plane peak strength is 0.5 / 100 to 2.5. A range of / 100 is desirable. Above all, the peak intensity ratio is 1.0
In the range of / 100 to 2.0 / 100, particularly excellent performance is exhibited, which is more preferable.

[Embodiment 3] Here, carbon having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more according to the X-ray wide angle diffraction method. The negative electrode molded body containing the material and the carbon material having various crystal structure parameters was examined in detail. First, by X-ray wide angle diffraction method (002)
An artificial graphite having a surface spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 100 angstroms was used. To this, 30% by weight of carbon materials having various crystal structure parameters shown in Table 3 were added to prepare a molded negative electrode. Example 1 using each of these negative electrode molded bodies
A test cell was prepared in the same manner as in, and evaluated under the same conditions as in Example 1. Table 3 shows the results.

[0021]

[Table 3]

From this result, the X-ray wide angle diffraction method (0
02) face spacing is 3.40 angstroms or less,
2. A carbon material having a crystallite size (Lc) in the c-axis direction of 100 angstroms or more and a (002) plane spacing of 3.
A negative electrode containing a carbon material having a crystallite size (Lc) in the c-axis direction of 43 to 3.90 angstroms in the c-axis direction of 1 to 50 angstroms has a large initial capacity and is also excellent in rapid rapid charge / discharge performance. I understand.

[Embodiment 4] X-ray wide angle diffraction method (00
2) The interplanar spacing is 3.40 angstroms or less, and c
A detailed study on the weight of water in the paste-like mixture when a paste-like mixture containing a carbon material having an axial crystallite size (Lc) of 100 Å or more and water is formed on the surface of the negative electrode current collector. did. First, in this embodiment, as the carbon material, artificial graphite having a (002) plane spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 300 angstroms according to the X-ray wide-angle diffraction method is used. I was there. In this example, the cylindrical battery shown in FIG. 2 was constructed and the characteristics were examined.

A battery was manufactured by the following procedure. LiMn _1.8 Co _0.2 O ₄ , which is the positive electrode active material, contains Li ₂ CO ₃ and M
n ₃ O ₄ and CoCO ₃ are mixed at a predetermined molar ratio to obtain 900
It was synthesized by heating at ℃. In addition, 1
The positive electrode active material was classified to a size of 00 mesh or less.
One carbon powder as a conductive agent for 100 g of the positive electrode active material
A positive electrode was obtained by adding 0 g of an aqueous dispersion of polytetrafluoroethylene as a binder, 8 g of a resin component, and pure water to form a paste, coating it on a titanium core material, and drying and rolling it. The weight of the positive electrode active material per one electrode plate was 5 g.

The negative electrode was prepared by mixing a 1% by weight aqueous solution of sodium salt of carboxymethyl cellulose and the above-mentioned artificial graphite powder as the negative electrode active material in various weight ratios as shown in Table 4, and then forming a paste. After applying the shaped material to a copper core material, 10
It was prepared by drying at 0 ° C. In addition, styrene-butadiene rubber was added to the carbon material as a binder.
The mixing ratio of the carbon material and the binder was 100: 5 by weight. The weight of carbon material per sheet is 2 for each negative plate.
It was set to g.

The electrode body is wider than the positive electrode plate 11 having the positive electrode lead 14 of the same material as the core material attached by spot welding, the negative electrode plate 12 having the negative electrode lead 15, and the both electrode plates interposed between the both electrode plates. And a separator 13 made of porous polypropylene having a wide band shape. Further, polypropylene insulating plates 16 and 17 are arranged on the upper and lower sides of the electrode body, respectively, and inserted into a battery case 18 to form a step on the upper part of the battery case 18. Then, ethylene carbonate is added as a non-aqueous electrolyte. A solution in which lithium perchlorate was dissolved at a ratio of 1 mol / l was injected into a mixed solvent having a volume ratio of 1: 1 with dimethoxyethane, and sealed with a sealing plate 19 provided with a positive electrode terminal 20 to obtain a battery. The initial capacity and the rapid charging / discharging performance of the battery constructed by using seven different kinds of negative electrode plates were examined. After repeating charge and discharge for 10 cycles at a charge and discharge current of 100 mA and a charge and discharge voltage range of 4.3 V to 3.0 V, a rapid charge and discharge test was performed at a charge and discharge current of 500 mA. Table 4 shows the initial capacity and the rapid charge / discharge capacity.

[0027]

[Table 4]

It was found that the initial capacity was large and the rapid charge / discharge capacity was also large when the water content in the paste-like mixture was 10% to 50% of the weight of the carbon material. In addition,
If the water content exceeds the above range, (0
02) The surface peak intensity is increased. Further, if the water content is small, it becomes difficult to mold the electrode. The carbon material used in this example is (002) according to the X-ray wide angle diffraction method.
Artificial graphite having a surface spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 300 angstroms was used. As a result of further detailed study, as a preferable carbon material, X-rays were used. Wide-angle diffraction method (00
2) The interplanar spacing is 3.40 angstroms or less, and c
It was confirmed that the carbon material had a crystallite size (Lc) in the axial direction of 100 angstroms or more.

[Embodiment 5] X-ray wide angle diffraction method (00
2) The interplanar spacing is 3.40 angstroms or less, and c
Details of the weight of the organic solution in the paste-like mixture when a paste-like mixture containing a carbon material having an axial crystallite size (Lc) of 100 angstroms or more and water is formed on the surface of the negative electrode current collector Study was carried out. First, in the present embodiment, as the carbon material, X-ray wide angle diffraction method (0
Artificial graphite having a 02) plane spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 300 angstroms was used. This artificial graphite and organic solvent n, n-
Dimethylformamide was mixed in various weight ratios shown in Table 5, and polyvinylidene fluoride was further added as a binder. The mixing ratio of the carbon material and the binder is 100: by weight.
It was set to 10. The paste-like mixture thus obtained was applied to a copper core material and dried at 100 ° C. to obtain a negative electrode plate. The weight of the carbon material per one negative electrode plate was 2 g. The cylindrical battery shown in FIG. 2 was constructed in the same manner as in Example 4 except that the above negative electrode was used, and the characteristics were examined under the same conditions as in Example 4. Table 5 shows the initial capacity and the rapid charge / discharge capacity. The amount of organic solvent in the paste mixture is 10% of the weight of the carbon material.
It was found that the initial capacity was large and the rapid charge / discharge capacity was also large when the content was ˜30%. When the amount of organic solvent exceeds the above range, the (002)
The surface peak intensity increases. Moreover, when the amount of the organic solvent is small, it becomes difficult to mold the electrode.

[0030]

[Table 5]

The carbon material used in this example has a (002) plane spacing of 3.40 angstroms and a crystallite size (Lc) in the c-axis direction of 3 according to the X-ray wide-angle diffraction method.
Artificial graphite of 00 Å was used, but as a result of further detailed examination, as a preferable carbon material, X
The spacing between (002) planes measured by the wide-angle diffraction method is 3.40 angstroms or less, and the crystallite size (L
It was confirmed that c) is a carbon material having a thickness of 100 Å or more. Regarding the shape of the carbon material, the same effect can be obtained with carbon or graphite having various shapes such as fibrous, phosphorus-like, scaly, earth-like, and spherical. Further, although the coin type and cylindrical type batteries have been described in the present embodiment, the technical ideas such as the excellent rapid charging / discharging performance shown in the present invention are the same, and thus the structure is limited to this structure. Instead, the same effect can be obtained with a secondary battery having a prismatic shape, a flat shape, or the like. Furthermore, as carbon or graphite, natural graphite, artificial graphite,
It goes without saying that the same effect can be obtained when using a negative electrode carbon material having reversibility for charging and discharging, such as carbon fiber and graphite whiskers.

[0032]

Industrial Applicability As described above, according to the present invention, a negative electrode providing a highly reliable non-aqueous electrolyte secondary battery which has a high energy density and is also excellent in rapid charge / discharge characteristics and is free from short circuit due to dendrite. Obtainable.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a test cell for electrode evaluation used in an example of the present invention.

FIG. 2 is a schematic vertical sectional view of a cylindrical battery used in an example of the present invention.

FIG. 3 shows the carbon material (100) used for the negative electrode of Example 1.
The ratio of the surface peak strength to the (002) surface peak strength;
It is a figure which shows the relationship with a rapid charge / discharge capacity and the discharge capacity of the 100th cycle.

4 is a graph of the carbon material (100) used for the negative electrode of Example 2. FIG.
The ratio of the surface peak strength to the (002) surface peak strength;
It is a figure which shows the relationship with a rapid charge / discharge capacity and the discharge capacity of the 100th cycle.

[Explanation of symbols]

 1 Test Electrode (Negative Electrode) 2 Case 3 Separator 4 Metal Li 5 Gasket 6 Sealing Plate 11 Positive Electrode 12 Negative Electrode 13 Separator 14 Positive Electrode Lead Plate 15 Negative Electrode Lead Plate 16 Upper Insulating Plate 17 Lower Insulating Plate 18 Battery Case 19 Sealing Plate 20 Positive Electrode Terminal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Ito 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. In the company

Claims (6)

[Claims] 1. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. Consisting of a molded body containing
The ratio of the (100) plane peak intensity to the (002) plane peak intensity in the X-ray wide-angle diffraction pattern by the Cu-Kα radiation source of the molded body was in the range of 0.5 / 100 to 2.5 / 100. A negative electrode for a non-aqueous electrolyte secondary battery, which is characterized by being present. 2. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. And the (002) plane spacing in the X-ray wide-angle diffraction method using a Cu-Kα radiation source is 3.
A negative electrode for a non-aqueous electrolyte secondary battery, comprising a carbon material having a crystallite size (Lc) in the c-axis direction of 43 to 3.90 angstroms and 1 to 50 angstroms. 3. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. And the (002) plane spacing in the X-ray wide-angle diffraction method using a Cu-Kα radiation source is 3.
A Cu-Kα of a molded body containing a carbon material having a crystallite size (Lc) in the c-axis direction of 43 to 3.90 angstroms in the c-axis direction of 1 to 50 angstroms.
(100) plane peak in the X-ray wide-angle diffraction pattern by the radiation source
The ratio of the peak intensity to the (002) plane peak intensity is 0.5 /
A negative electrode for a non-aqueous electrolyte secondary battery, which is in the range of 100 to 2.5 / 100. 4. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. Content of W _A , Cu-
Content of carbon material having a (002) plane spacing of 3.43 to 3.90 angstroms and a crystallite size (Lc) in the c-axis direction of 1 to 50 angstroms in the X-ray wide-angle diffraction method using a Kα-ray source when was the _{W B, W B / (W} a +
W _B) is 20 / 100-50 / 100 at which claim 2 or 3 negative electrode for a non-aqueous electrolyte secondary battery according. 5. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. And carbon material 10-50
A method for producing a negative electrode for a non-aqueous electrolyte secondary battery, comprising: a step of forming a paste-like mixture containing water by weight on a surface of a negative electrode current collector; and a step of heating the same. 6. A carbon material having a (002) plane spacing of 3.40 angstroms or less and a crystallite size (Lc) in the c-axis direction of 100 angstroms or more in an X-ray wide-angle diffraction method using a Cu-Kα radiation source. And carbon material 10-30
A method for producing a negative electrode for a non-aqueous electrolyte secondary battery, comprising the steps of forming a paste-like mixture containing a weight% of an organic solvent on the surface of a negative electrode current collector and heating the same.