JPH05121066A - Negative electrode for nonaqueous battery - Google Patents

Abstract

PURPOSE:To provide a high battery capacity by using a composite carbonaceous material as active material of a negative electrode containing an electrolyte, which is an organic solvent, and arranging the active material at a certain plane spacing. CONSTITUTION:Graphite whose carbon net plane spacing is d002<0.337nm is prepared from petroleum pitch etc. through a processing at a temp. over 3000 deg.C, wherein the thickness shall be no less than 50nm. The surface area is made below 50m<2>/g to preclude occurrence of side reaction. On the other hand, a carbonaceous material of plane spacing d002>0.337nm is prepared from petroleum pitch, etc., through a baking process at 1000-2000 deg.C. The ratio of graphite to carbonaceous as covering is selected to 1/2 thru 1/0.5. One example of the organic solvent for electrolytic solution is tetrahydraflane while that of the electrolyte is LiBF4, etc. The positive electrode is made for example from MnO2, etc. As separator is used a fine porous film, etc., of polyolefin solely, and this is accommodated in a can made of stainless steel. By this constitution a high capacity secondary battery of nonaqueous type is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high capacity non-aqueous battery containing an organic solvent as an electrolytic solution, and more particularly to a non-aqueous secondary battery negative electrode.

[0002]

2. Description of the Related Art It is known to use a carbonaceous material as a negative electrode of a non-aqueous secondary battery using an organic solvent as an electrolytic solution. The carbonaceous materials used as electrodes are roughly classified into the following three types based on their electrochemical properties.

The first is that the distance between carbon mesh planes represented by graphite is narrow (d ₀₀₂ <0.337 nm), and crystallites grow in the stacking direction of the carbon mesh planes and mesh planes. It is known that such a carbon material is doped with both cations and anions between the carbon network planes to form a layered compound, and is considered to be applied as a conductive material, an organic synthesis reaction catalyst or a battery. There is.

The use of graphite as the negative electrode of a battery is disclosed in JP-A-57-208079 and JP-A-58-1.
92266, JP-A-59-143280,
JP-A-60-54181, JP-A-60-1826
70, JP 60-221973 A, JP 61-7567 A, JP 1-311565 A, and the like.

In these patents, propylene carbonate (hereinafter abbreviated as PC), tetrahydrofuran (hereinafter abbreviated as THF), gammabutyrolactone (hereinafter abbreviated as γ-BL), 1,2-dimethoxy as organic solvents that can be used. Ethane (hereinafter abbreviated as DME), sulfolane and the like are described. As an example, LiClO ₄ or LiBF ₄ is used, and PC or T is used as a typical solvent.
HF is used. As an example using a mixed solvent, PC / DME is disclosed in JP-A-57-208079.

However, when LiClO ₄ or LiBF ₄ was used as the electrolyte and PC was used as the solvent, an attempt was made to charge and discharge with graphite, but the PC continued to react and was not charged or discharged. Also, using LiBF ₄ as an electrolyte,
When using PC / DEM as a mixed solvent and attempting charge / discharge using graphite as an electrode, it was found that charge / discharge is possible, but the current efficiency is extremely low and not practical.

When graphite is doped with lithium as a cation, the doping amount (lithium storage amount per carbon) is as large as 16.7%, but when it is intended to be used as a negative electrode of a battery, it is electrochemically charged as described above. It cannot effectively absorb and release lithium. This is the first issue of the Journal of Electrochemical Society (J. Electrochem. Soc.).
Volume 17, page 222 (1970) and JP-A-63-255.
As described in Comparative Example 1 of Japanese Patent Laid-Open No. 5 publication, the layered compound in which lithium ions are occluded in graphite has a high reactivity with an organic solvent, and the reaction with the electrolytic solution takes precedence over the function as the electrode, and the layered compound as the electrode The utility value is low.

The second group is a group having a very large surface area (S _A > 100 m ² / g) represented by activated carbon and a large spacing between carbon mesh planes (d ₀₀₂ > 0.337 nm). Since this type has a large surface adsorption amount, the doping amount is large, but the current efficiency is low and the cycleability is low.

In the third group, the carbon network planes have grown to some extent, but the spacing between the carbon network planes is wider (d ₀₀₂ > 0.337 nm) than in the first group. This group shows various electrochemical characteristics depending on its structure, but unlike the first group, it can occlude lithium with almost no reaction with the electrolytic solution. However, the doping amount (lithium storage amount per carbon) is smaller than that of the first group.

On the other hand, examples in which graphite is used as a negative electrode are US Pat. No. 4,423,125 and Journal of Electrochemical Society (J. Electrochem. Soc.) 137.
Vol. 2009 (1990), U.S. Pat. No. 4,423,125 uses dioxolane as an electrolyte. Dioxolane is chemically unstable, and also electrochemically at 3.5 V or higher, polymerization of the electrolytic solution occurs, and it is not possible to use a high-voltage active material for the positive electrode, which is disadvantageous.

Journal of Electrochemicals
Society (J. Electrochem. So
c. ) Vol. 137, 2009 (1990) describes electrochemical lithium intercalation using graphite or petroleum coke as an electrode and PC / EC (ethylene carbonate) as an electrolyte.

In petroleum coke, the side reaction that occurs during the initial charge depends on the surface area, whereas in graphite, the side reaction that does not depend on the surface area occurs in addition to the side reaction that depends on the surface area during the initial charge. Is stated to be low. When a battery is assembled in such a system, a large number of positive electrodes are needed because the initial current efficiency is low, and it is difficult to increase the capacity because the utilization rate of the positive electrode as an active material per battery cannot be increased. Is.

Therefore, in order to increase the capacity, both the positive electrode and the negative electrode are in a charged state (a state in which the negative electrode carbon absorbs lithium and the positive electrode has an empty site for receiving lithium).
However, it is necessary to take complicated steps such as assembling a battery under an inert gas because a charged electrode has extremely high reactivity and a safety problem occurs. It's out of the ordinary and not practical.

Furthermore, in the system described in this paper, side reactions continue to occur even after 2 cycles, and the current efficiency is 100%.
It states that it does not become. High current efficiency is especially important for battery cycleability. In order to discharge a certain capacity when the current efficiency of the negative electrode is low, the positive electrode always needs to have a charge amount equal to or greater than the discharge capacity, and the positive electrode is gradually overloaded, and eventually the positive electrode becomes overcharged and the capacity decreases. Bring Further, if constant-capacity charging is performed on the positive electrode so that the positive electrode does not become overcharged, the current efficiency is low, so that the capacity is reduced by repeating the cycle.

A method of mixing two kinds of carbonaceous substances belonging to the third group to form a negative electrode is also disclosed in Japanese Patent Laid-Open No. 1-311565. d ₀₀₂ is 0.3354 to 0.3400
carbonaceous and d ₀₀₂ of nm has proposed using a mixture of carbonaceous 0.343~0.355nm as the negative electrode. As seen in the examples, these carbonaceous materials were synthesized by a gas phase pyrolysis method, and had a mixture of d ₀₀₂ of 0.339 nm and 0.356 nm, and had a capacity of d ₀₀₂ of less than 0.337 nm. It is smaller than the capacity obtained from the lithium doping amount of certain artificial graphite.

On the other hand, d ₀₀₂ is 0.3355 nm in the same electrolyte as used in JP-A 1-311565.
When a charge / discharge experiment was tried with a battery in which the artificial graphite and the needle coke having a d ₀₀₂ of 0.345 nm were mixed and used as a negative electrode, the reaction of the solvent continued to occur for the first time, and almost no charge / discharge was possible.

In Japanese Patent Laid-Open No. 3-129664, d _{002 is used.}
Is disclosed a fine fibrous graphite having a half-value width of the peak of 1 ° or less or a negative electrode containing the fine fibrous graphite and a carbon material. The d ₀₀₂ of these fine fibrous graphites is 0.339 nm from the examples. For example, the capacity is 0.340 nm, and the capacity is smaller than that of artificial graphite having d ₀₀₂ of less than 0.337 nm. It is also described that when artificial graphite is used as the negative electrode, almost no charge / discharge can be performed at the first time.

In any case, in order to obtain a secondary battery having a high capacity and good cycle characteristics, what is required for the negative electrode is that the electrode is stable during assembly, the current efficiency is high, and the doping amount is large. In the conventional electrolyte system, the first group of carbonaceous materials reacts with the electrolyte solution, the second group has low current efficiency, so the utility value is low, and the third group has partially good current efficiency. However, this also has a utilization rate (amount of lithium absorbed per carbon atom) of about 10%, and in order to increase the capacity of the battery, a negative electrode material having a larger doping amount and good current efficiency has been desired. ..

[0019]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a negative electrode using a specific carbonaceous material having a large doping amount and a high current efficiency in order to increase the capacity of a non-aqueous battery, particularly a non-aqueous secondary battery. It is intended to provide.

[0020]

In order to solve the above problems, the inventors of the present invention have diligently studied a combination of a carbonaceous material used for a negative electrode and an organic solvent electrolyte solution, and found that a large amount of lithium ion Although it doping spacing of use as a negative electrode and graphite hexagonal carbon the reaction has been considered not be effectively charged and discharged with priority with the electrolyte of the battery d ₀₀₂
It was found that, when graphite is coated with a carbonaceous material having a size larger than d ₀₀₂ , it can be charged / discharged even with an electrolytic solution such as PC, and has a large chargeable / dischargeable capacity and high current efficiency, and has completed the present invention.

That is, the present invention is a negative electrode of a non-aqueous battery containing an organic solvent as an electrolytic solution, wherein the active material in the negative electrode is
It is a composite carbonaceous material obtained by coating a graphite-like carbonaceous material having a carbon mesh surface spacing d ₀₀₂ of less than 0.337 nm with a carbonaceous material having a carbon mesh surface spacing d ₀₀₂ of 0.337 nm or more. , A non-aqueous battery negative electrode is provided. In particular, the present invention is a non-aqueous battery comprising a chargeable / dischargeable positive electrode, an organic solvent-based electrolytic solution containing an electrolyte, and a negative electrode mainly containing a carbonaceous material as an active material, and a negative electrode constituting the non-aqueous battery,
The present invention also provides a non-aqueous battery, preferably a non-aqueous secondary battery, which is characterized by using the above specific novel composite carbonaceous material.

The present invention will be described in detail below. In the present invention, the graphite having a carbon network plane spacing d ₀₀₂ of less than 0.337 nm refers to a carbonaceous material in which carbon network planes are regularly laminated, such as graphite. The carbonaceous material has various structures depending on its starting material and its treatment (manufacturing) method. However, in any material, the interplanar spacing d ₀₀₂ of the carbon mesh plane becomes small due to the high temperature treatment, and the laminated thickness Lc of the carbon mesh plane Graphite tends to be large, and graphite has the smallest interplanar spacing d ₀₀₂ = 0.3354 nm.

The decrease of d ₀₀₂ and the increase of Lc greatly differ depending on the carbonaceous material, and high temperature treatment (up to 3,000 ° C.)
It is classified into easily graphitized carbon that is easily graphitized by the method and difficultly graphitized carbon (d ₀₀₂ does not easily become small). During graphitization of this carbonaceous material, the density, surface area, electric resistance, and the like, in addition to the above-mentioned d ₀₀₂ and Lc, change greatly, but the interplanar spacing is particularly important for the formation of the intercalation compound.

D ₀₀₂ used in the present invention is 0.337n
The starting material of the graphite having a size of less than m is not particularly limited, but petroleum pitch, coal tar pitch, pyrolytic carbon, needle coke, condensed polycyclic hydrocarbon and the like are generally 2,500 ° C. or higher, more preferably 3,000 ° C. or higher. It is obtained by heat treatment in. Also, naturally occurring graphite can be used in the present invention.

The lamination thickness Lc of the graphitic carbon mesh surface used in the present invention is not particularly limited, but Lc is also an important parameter for graphitization, and preferably 3
The thickness is preferably 0 nm or more, more preferably 50 nm or more. Thirty
When it is less than nm, the utilization factor tends to be low. The surface area is also not particularly limited, but if the surface area is large, side reactions are likely to occur more often, so it is preferably 50 m ² / g.
The following is good.

The spacing d ₀₀₂ of the carbon mesh surface of the present invention is 0.3.
Carbonaceous material of 37 nm or more does not particularly limit the starting material,
Petroleum pitch, coal tar pitch, condensed polycyclic hydrocarbons and the like are 800 to 2,400 ° C., more preferably 1,000.
Obtained by firing at ˜2,000 ° C.

In the present invention, the composite carbonaceous material obtained by coating the above-mentioned graphite with such a carbonaceous material is used, and by making it composite, the volume of the graphiteaceous material is utilized, and d ₀₀₂ formed on the surface layer of the graphite is used. The carbonaceous material having a particle size of 0.337 nm or more prevents the reaction between the graphite material and the electrolytic solution, can be charged and discharged even with a typical electrolytic solution such as PC, and has a high current efficiency. In order to obtain a high current efficiency, it is more preferable that the carbonaceous material used for the coating layer has d ₀₀₂ of 0.339 nm or more.

There is no particular limitation on the formation of the coating layer on the graphite, but one method is to mix the graphite with a petroleum pitch, coal tar pitch, condensed polycyclic hydrocarbon, etc., which has been heated to a liquid state, to form 300 Pre-fired at ~ 700 ° C, then 2,800 ° C or less, preferably 1,000-2,500
It is obtained by firing at ℃. In another method, petroleum pitch, coal tar pitch, condensed polycyclic hydrocarbon, etc. are dissolved in an organic solvent such as aromatic hydrocarbon, quinoline, nitrogen-containing aromatic compound such as pyridine, and graphite is mixed with this. Then, after removing the organic solvent by evaporation, pre-baking and baking can be performed.

The ratio of the graphite constituting the composite carbonaceous material of the present invention to the carbonaceous material of the coating layer is preferably 1: 3 to 1: 0.2, more preferably 1 in view of the capacity and the current efficiency. : 2 to 1: 0.5.

As the organic solvent of the electrolytic solution used in the present invention, for example, ethers, ketones, lactones, nitriles, amines, amides, sulfone compounds, carbonates, esters and the like can be used. Of these, ethers, ketones, lactones, esters, carbonates and the like are preferable. As typical examples of these, tetrahydrofuran, 2-methyl-tetrahydrofuran, 1,4-dioxane, 4-methyl-2-
Pentanone, cyclohexanone, γ-butyrolactone,
Acetonitrile, propionitrile, butyronitrile,
Examples thereof include dimethoxyethane, propylene carbonate, ethylene carbonate, dimethylformamide, dimethylsulfoxide, anisole, sulfolane, 3-methyl-sulfolane, ethyl acetate, ethyl propionate, and mixed solvents thereof, but not necessarily limited to these. It is not something that will be done.

The electrolyte used in the present invention is not particularly limited, but LiBF ₄ , LiAsF ₆ and LiPF ₄ are used.
₆ , LiClO ₄ , CF ₃ SO ₃ Li, LiI, LiA
_{lCl 4, NaClO 4, NaBF 4} , NaI, (n-
Bu) ₄ NClO ₄ , (n-Bu) ₄ NBF ₄ , KPF
₆ or the like is used, LiBF from the viewpoint of safety and toxicity on cell performance and handling Among these ₄ are preferred.

The positive electrode to be combined with the negative electrode of the present invention is not particularly limited, but MnO ₂ , M
_o O ₃ , V ₂ O ₆ , V ₆ O ₁₃ , Fe ₂ O ₃ , Fe ₃ O ₄
Lithium-containing transition metal chalcogen compound, Li _(1-x) C
_{oO 2, Li (1-x} ) · NiO 2, TiS 2, MoS 3,
Inorganic compounds such as FeS ₂ , CuF ₂ , and NiF ₂ , carbon fluoride, graphite, vapor grown carbon fibers and / or pulverized products thereof, carbon materials such as pitch-based carbon fibers and / or pulverized products thereof, polyacetylene, poly- Examples thereof include conductive polymers such as p-phenylene.

For a positive electrode not containing lithium, a battery can be assembled by using the negative electrode of the present invention by occluding lithium, or by using the negative electrode of the present invention in combination with a required amount of metallic lithium. .. However, such a battery complicates the assembling process such that it is necessary to assemble under an inert gas at the time of assembling.

When a transition metal chalcogen compound containing lithium is used, a battery can be assembled in a stable discharge state in the positive electrode and negative electrode in the air, there are few restrictions on processing and assembly, and heat generation due to short circuit of the battery is caused. There is no danger of explosion, etc., which is preferable from the viewpoint of safety. Examples of such lithium-containing transition metal chalcogen compounds include Li _(1-x) CoO ₂ , Li _(1-X) NiO ₂ , Li _(1-X)
Co _(1-y) Ni _y O ₂ , LiMn ₂ O ₄ , Li _(1-X) C
_{o (1-y) M y} O 2 (M is Co, transition metal other than Ni, A
l, In, Sn and the like).

Further, when forming an electrode using the composite carbonaceous material of the present invention, a current collector, a mixture (binder), etc. may be used. The current collector is not particularly limited, but Cu, N
i, a metal foil or net having a thickness of about 50 to 1 μm such as stainless steel is used.

The mixture used to attach the electrode material to the current collector is not particularly limited, and examples thereof include polytetrafluoroethylene, polyethylene, nitrile rubber, polybutadiene, butyl rubber, polystyrene, styrene / butadiene rubber, polysulfide rubber, Polymers such as nitrocellulose, cyanoethyl cellulose, acrylonitrile, vinyl fluoride, vinylidene fluoride, and chlorobrene are used. The amount of the mixture is not particularly limited, but is 0.1 to 20 parts by weight, preferably 0.5 to 100 parts by weight with respect to 100 parts by weight of the active material.
10 parts by weight.

As a method of forming this electrode, a method of mixing an electrode active material and an organic polymer and compression-molding; a method of dispersing the electrode active material in a solvent solution of the organic polymer, followed by coating and drying; A method is known in which an electrode active material is dispersed in an aqueous or oily dispersion of an organic polymer, and then the coating is dried. Although it is not particularly limited, it is not preferable if the distribution of the binder becomes non-uniform. Therefore, a method of dispersing the electrode active material in an aqueous or oily dispersion of an organic polymer and then coating and drying it; more preferably organic It is preferable to use a non-fluorine-containing organic polymer containing particles of 0.5 μm or less as the polymer.

If necessary, components such as a separator, a terminal and an insulating plate are used as the constituent elements of the battery. The separator is not particularly limited, but for example, a single microporous film of polyolefin such as polyethylene or polypropylene, or a laminated film or polyolefin thereof,
Nonwoven fabrics such as polyester, polyamide, and cellulose can be used alone or in a laminated film with the microporous film.

When the present invention is used as a battery can as shown in FIG. 2, stainless steel or nickel-plated steel is used as the material, and its shape is generally cylindrical or oval.

[0040]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited thereto. In addition, in Examples 1 to 4 and Comparative Examples 1 to 3, in order to see the performance of the negative electrode alone, metallic lithium was used as the counter electrode. In this case, the carbonaceous negative electrode is conventionally the positive electrode,
Since lithium ions are received and reduced at the time of discharging, the term “negative electrode” is used here, and the direction of reduction is called charging.

The current efficiency represents discharge electricity quantity / charge electricity quantity. The utilization factor represents the capacity of the negative electrode, and the utilization factor is defined as the discharge electricity amount / (the electricity amount per negative electrode active material weight when 72 kg of the negative electrode active material is 96485 coulomb). The utilization rate represents the capacity of the negative electrode. The capacity is the discharge electricity quantity / (total weight of positive electrode and negative electrode). The capacity retention rate is a percentage of the discharge capacity ratio of a certain cycle with respect to the first discharge capacity. The X-ray diffraction was performed according to the "Japan Society for the Promotion of Science".

[0042]

[Composite carbonaceous material A] Binder pitch (Mitsubishi Kasei Co., Ltd.)
3 parts by weight was dissolved in 15 parts by weight of quinoline, and graphite (made by Lonza, KS-6, average particle size 3 μ,
(d ₀₀₂ = 0.3355 nm, Lc> 100 nm) 1 part by weight was immersed, and most of the quinoline was evaporated under reduced pressure, followed by firing in N ₂ gas at 400 ° C. for 3 hours. Further, after firing for 1 hour at 1,200 ° C. in an argon stream, it was cooled and pulverized to obtain 2.5 parts by weight of composite carbonaceous material.
From the X-ray diffraction peak, the carbonaceous material A is a sharp diffraction peak at d ₀₀₂ = 0.336 nm and d
_It also had a broad diffraction peak near ₀₀₂ = 0.355 nm.

[0043]

[Composite carbonaceous B] were mixed binder pitch 2 parts by weight of graphite, 1 part by weight of the 400 under N ₂ gas stream
℃ calcination for 3 hours, then in argon flow 1,50
After firing at 0 ° C. for 1 hour, it was cooled and pulverized to obtain 2.0 parts by weight of composite carbonaceous material. This product has d ₀₀₂ of 0.336n
m and 0.347 nm.

[0044]

[Composite carbonaceous material C] In the production example of the composite carbonaceous material A, 1 part by weight of the binder pitch was used and the temperature when firing in an argon stream was set to 1,700 ° C. Otherwise in the same manner as the method for the composite carbonaceous material A, d ₀₀₂ was 0.336 nm and 0.34 nm.
1.5 parts by weight of 5 nm complex carbonaceous material was obtained.

[0045]

Example 1 A styrene / butadiene latex (L15, manufactured by Asahi Kasei Corporation) was added to 100 parts by weight of the composite carbonaceous material A.
71) (48% by weight of solid content) 4.17 parts by weight, carboxymethyl cellulose as a thickener (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
BSH12) aqueous solution (solid content 1% by weight) 130 parts by weight,
30 parts by weight of water was added and mixed to obtain a coating liquid. This coating liquid is applied and dried using a Cu foil with a thickness of 10 μm as a base material to obtain a thickness of 1
An electrode of 00 μ, 93 g / m ² was obtained. 1 cm above the electrode
Cut to width and leave a 1 cm x 1 cm coating, peel off,
The working electrode shown in FIG. 1 was used.

On the other hand, a SUS net was used as the counter electrode and metallic lithium was pressure bonded thereto, and metallic lithium was used as the reference electrode. A battery of FIG. 1 was assembled by using a PC in which 1 M of LiClO ₄ was dissolved in an electrolyte of the above electrodes under an argon gas atmosphere. When this battery was charged with a constant current of 1 mA to 10 mV and repeatedly discharged with a constant current of 1 mA to 1 V, the initial current efficiency was 70% and the utilization rate was 67.
8%, current efficiency becomes 98% from the second cycle, 10
It became almost 100% at the cycle. The capacity retention rate after 30 cycles was almost 100%.

[0047]

Example 2 A carbonaceous B electrode was prepared in the same manner as in Example 1, and charging and discharging were repeated under the same conditions as in Example 1. The initial current efficiency was 68%, the utilization rate was 75%, and the cycle was 30 cycles. The subsequent capacity retention was almost 100%.

[0048]

Example 3 A carbonaceous C electrode was prepared in the same manner as in Example 1, and charging / discharging was repeated under the same conditions as in Example 1. The initial current efficiency was 66%, the utilization rate was 80.4%, and the capacity retention rate after 30 cycles was almost 100%.

[0049]

Comparative Example 1 Graphite (KS-6, manufactured by Lonza)
Was used in place of the carbonaceous material A, an electrode was prepared in the same manner as in Example 1, and charged under the same conditions as in Example 1. About 0.
The voltage became constant at 8 V, and charging was possible, but discharging was not possible.

[0050]

[Comparative Example 2] Needle coke (d ₀₀₂ = 0.344n)
m, average particle diameter 10 μ) and graphite (KS-6) were mixed at a ratio of 9: 1, and an experiment was conducted in the same manner as in Comparative Example 1, but the same charging as in Comparative Example 1 was possible.
It couldn't be discharged.

[0051]

Comparative Example 3 An electrode was prepared in the same manner as in Example 1 except that the needle coke of Comparative Example 2 was used instead of the carbonaceous material A.
Charge and discharge were performed under the same conditions as in Example 1. The initial current efficiency was 75%, the utilization rate was 60%, and the capacity retention rate after 30 cycles was 96%.

[0052]

Example 4 The LiClO ₄ of Example 1 was replaced with LiBF ₄ ,
Charge and discharge were repeated in the same manner as in Example 1 except that PC was changed to γ-BL. The initial current efficiency was 84%, the utilization rate was 67%, and the capacity retention rate after 30 cycles was 92%.

[0053]

Example 5 LiCo _0.95 Sn _0.05 O having an average particle size of 5 μm
_{2 To} 100 parts by weight, 20 parts by weight of graphite (KS-6) as a conductive filler and 100 parts by weight of a polyvinylidene fluoride 5% solution as a binder were added and mixed to obtain a coating liquid. This coating solution was applied and dried using a 15 μ thick Al foil as a base material to obtain a positive electrode having a thickness of 120 μ and 270 g / m ² .

The above positive electrode and the negative electrode obtained in Example 1 were 1 cm ×
It cut into 5 cm and assembled the battery shown in FIG. The electrolyte used was 1M LiClO ₄ / PC. This battery 1
Constant current charge up to 4.2V at 0mA, 2.7mA at 10mA.
The cycle of discharging with a constant current to V was repeated. The initial current efficiency of this battery is 73%, and the capacity is 66 AH / kg (2
30 WH / kg), capacity retention after 30 cycles is 96
%Met.

[0055]

Example 6 The charging was carried out in the same manner as in Example 5 except that the electrolytic solution was a mixture of γ-BL and ethylene carbonate 3: 1, the electrolyte was LiBF _4, and the coating amount of the positive electrode was 245 g / m ^2. The discharge was repeated. The initial current efficiency was 80% and the capacity was 72 AH / kg (252 WH / kg). Also,
The current efficiency of the second time is 98%, the current efficiency of the tenth time is almost 100%, and the capacity retention ratio after 100 cycles is 8%.
It was 5%.

[0056]

[Effects of the Invention] The carbon mesh surface spacing d ₀₀₂ is 0.337n.
When a composite carbonaceous material obtained by coating a graphite-like carbonaceous material having a m of less than m with a carbonaceous material having a d ₀₀₂ of 0.337 nm or more is used as a negative electrode, a nonaqueous battery having high current efficiency and a large capacity, particularly a nonaqueous secondary battery can be obtained. Be done.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a structural example of a battery of the present invention.

FIG. 2 is a cross-sectional view of a structural example of a battery of the present invention.

[Explanation of symbols]

 1 Working Electrode (Carbon Negative Electrode) 2 Counter Electrode (Metallic Lithium) 3 Reference Electrode (Metallic Lithium) 4 Electrolyte 5 Glass Container 6 Inert (Argon) Gas 7 Positive Electrode 8 Negative Electrode 9, 10 Current Collector 11, 12 SUS Net 13, 14 External Electrode Terminal 15 Battery Case 16 Separator 17 Electrolyte

Claims (1)

[Claims] 1. A negative electrode of a non-aqueous battery containing an organic solvent as an electrolytic solution, wherein the active material in the negative electrode has a carbon mesh plane spacing d.
_A non-aqueous battery negative electrode, which is a composite carbonaceous material in which ₀₀₂ is less than 0.337 nm and graphitic carbonaceous material is covered with carbonaceous material having a carbon mesh surface spacing d ₀₀₂ of 0.337 nm or more.