JPH08273702A - Lithium secondary battery - Google Patents

Abstract

PURPOSE: To provide a lithium secondary battery with high discharge capacity, high output density, and excellent cycle characteristics by constituting a negative electrode of a unit cell by holding carbon particles on which a metal forming an alloy with lithium is carried in a current collector. CONSTITUTION: A lithium secondary battery having a capacity of 0.5wh-50kwh is obtained by winding a negative electrode 17 and a positive electrode 15 using LiCoO2 or the like as an active material around a positive terminal 16 through a separator 19. The negative electrode 17 is formed by applying carbon particles such as artificial graphite on which a metal capable of alloying with lithium, such as silver is carried to a current collector such as a copper foil. The carbon particles are preferable to have a spacing of planes (d002) as determined by X-ray diffraction of 3.354-3.369Å, a crystalline size in the direction of c axis (Lc) of 300Å or more, and a specific surface area of 0.1-30m<2> /g or more. Particle size of the metal is preferable to be 1000Å or less, and the metal is fixed on the carbon particle for carrying. Energy density of 350w/kg of more and energy density of 30w/l at a charge/discharge rate of 1C or more can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery, and more particularly to a negative electrode for a lithium secondary battery which has a large discharge capacity and output density and is excellent in cycle characteristics. Lithium secondary batteries are used for electric vehicles, memory backup,
It is used as a power source for driving portable equipment.

[0002]

2. Description of the Related Art Conventionally, lithium (Li) metal and alloys such as Li-Al and Li-Pb have been used as the negative electrode of a lithium secondary battery. However, these batteries are positive and negative due to precipitation of resinous lithium. Short circuit of both poles and short cycle life,
It had the drawback of low energy density. Recently, in order to solve these problems, research using a carbon material for the negative electrode is active. This type of negative electrode is disclosed, for example, in JP-A-5-29.
No. 9073 and Japanese Patent Application Laid-Open No. 2-121258. The structure disclosed in JP-A-5-299073 is such that the surface of the highly crystalline carbon particles forming the core is coated with a film containing a Group VIII metal element, and the carbon is further coated on the surface of the carbon composite electrode. As a material, it is said that the carbon material having a disordered layer structure on the surface assists the intercalation of lithium and, at the same time, the charge and discharge capacity and the charge and discharge rate are remarkably improved due to the large surface area of the electrode. On the other hand, in Japanese Unexamined Patent Publication (Kokai) No. 2-121258, a carbon material and a Li having a hexagonal crystal structure with H / c <0.15, a plane spacing> 3.37Å, and a crystallite size Lc <150Å in the C-axis direction
By using a mixture of a metal that can be alloyed with, the charge and discharge cycle life is long, and the charge and discharge characteristics at large currents are also good. However, in each case, the difficulty of the alloy of the negative electrode carbon material and the theoretical capacity of carbon were not taken out, and the output density was not sufficient yet. Therefore, the energy density and output density were insufficient for mounting on electric vehicles and motorcycles.

[0003]

As described above, when a carbon material and a composite material are used as the negative electrode, there are problems that the theoretical capacity of carbon cannot be derived and that electrode manufacturing is difficult.

The present invention solves the above-mentioned problems by
By using a negative electrode in which carbon particles supporting fine particles of a metal capable of alloying with lithium are held by a current collector,
Aiming to provide a lithium secondary battery with high capacity and excellent charge / discharge cycle characteristics

[0005]

As a result of various studies to solve the above problems, the inventors of the present invention have completed the present invention based on the following knowledge.

FIG. 1 shows the measurement results of the cycle characteristics of the conventional negative electrode and the improved negative electrode. The carbon used is highly purified natural graphite and has a particle size of about 11 μm. A solution prepared by dissolving ethylene propylene terpolymer (hereinafter abbreviated as EPDM) in diethylbenzene as a binder to carbon and using carbon and EPDM in a weight ratio of 94: 6 as a current collector was prepared. A 20 μm thick copper foil was applied, and separately from this, the paste was filled in a copper foam metal having a three-dimensional network structure with a thickness of 0.9 mm and a porosity of 93% as a current collector. The former is called the conventional type and the latter is called the improved type. Both were air dried, then vacuum dried at 80 ° C for 3 hours and molded at a pressure of 0.5 ton / cm ² and then for another 15
It was vacuum dried at 0 ° C. for 2 hours and used as a negative electrode. One of these negative electrodes is sandwiched by a polypropylene microporous membrane that is a separator, and is combined with a lithium metal counter electrode, and 1 M LiPF ₆ / ethylene carbonate-dimethoxyethane (hereinafter abbreviated as EC-DME) as an electrolytic solution, A test cell using lithium metal as a reference electrode was assembled. Using this test cell, a conventional negative electrode and an improved negative electrode were each subjected to a cycle test at a charge / discharge rate of 120 mA / g of carbon and a charge / discharge potential width of 0.01 to 1.0 V.

As is apparent from FIG. 1, the results of the test show that when the conventional negative electrode 1 is used, the discharge capacity decreases with each cycle, and after about 500 cycles, the discharge capacity drops to about 60% of the initial capacity. did. On the other hand, when the improved negative electrode 2 is used, it is 5
Even after 00 cycles, the reduction rate was very small at 4.5%, and the effect of improving the current collector was confirmed. This experimental fact is considered to be because the improved electrode having a three-dimensional network structure was able to suppress the reduction of the current collecting effect between carbon particles due to the swelling of the electrode due to the volume change due to repeated charging and discharging. To be Then, the following experiment was conducted to verify the above. That is, it was examined whether the same effect can be obtained by adding metal fibers to the negative electrode mixture. The result is shown in Figure 2.
Shown in The experiment of FIG. 2 is almost the same as that of FIG. 1, but the outline of the measurement conditions is shown below. The carbon used has a particle size of about 3μ.
m artificial graphite to which 9 μm diameter copper fiber
Mixed in a weight ratio of 0:10. Polyvinylidene fluoride (hereinafter abbreviated as PVDF) as a binder in this mixture
N-methylpyrrolidone solution of
The paste containing DF in a weight ratio of 90:10 was applied to a copper foil having a thickness of 20 μm as a current collector, air-dried, and then 80
After vacuum drying at 3 ° C. for 3 hours and molding at a pressure of 0.5 t / cm ² , vacuum drying was further performed at 120 ° C. for 2 hours to obtain a negative electrode. This negative electrode is combined with a counter electrode of lithium metal with a polypropylene microporous film interposed, and 1 M LiP is added to the electrolytic solution.
A test cell using F ₆ / ethylene carbonate + dimethyl carbonate (hereinafter abbreviated as EC + DMC) and lithium metal as a reference electrode was assembled. Charge / discharge speed is carbon 1
120 mA per gram, and the upper and lower limit potentials of charge and discharge were 1.0 V and 0.01 V, respectively. The obtained results are shown in FIG. Incidentally, FIG. 2 also shows the characteristics of the negative electrode to which no copper powder was added. As is clear from the results of FIG. 2, it was found that the negative electrode 3 with the copper powder added had a large discharge capacity and the decrease with each cycle was extremely small as compared with the negative electrode 4 without the copper powder. Similar results were obtained for the negative electrode using copper powder instead of copper fiber. From the above results, increasing the current collecting property of the negative electrode mixture layer is an important factor for improving the discharge capacity and cycle characteristics, and as a result of further detailed study,
Compared to a mixed system of carbon and conductive material, by adding fine particles of metal that forms an alloy with lithium on carbon, rather than simply mixing carbon with conductive fiber or conductive powder, Even if the amount of (supported) is small, the same effect can be obtained, and at the same time, the alloying capacity with lithium can be utilized, and the electrical conductivity and thermal conductivity can be expected to be improved by interposing a metal between carbon particles. I found that it brings a new function.

The gist of the present invention will be described below. That is, the first invention is a lithium secondary battery having a capacity of 0.5 wh to 50 kwh, wherein carbon particles carrying a metal forming an alloy with lithium are used as a negative electrode of a single battery constituting the secondary battery. This secondary battery is capable of discharging for 15 minutes or more at an output of energy density of 350 w or more per 1 kg of battery weight by using a current collector holding

A second aspect of the present invention is, in the same manner as described above, a positive electrode, a negative electrode,
A lithium secondary battery comprising a separator and an electrolytic solution, the negative electrode of the battery comprising a current collector holding carbon particles carrying a metal forming an alloy with lithium, and the carbon particles having an X-ray diffraction pattern. The interplanar spacing (d002) by the method is 3.354 to 3.369Å, and the crystal size (Lc) in the C-axis direction is 300Å or more.

A third aspect of the present invention is to provide a positive electrode, a negative electrode, and
A lithium secondary battery comprising a separator and an electrolyte, wherein the negative electrode of the battery comprises a current collector holding carbon particles carrying carbon particles carrying a metal forming an alloy with lithium, and carbon particles Has a specific surface area of 0.1 to
It is characterized by being 30 m ² / g or more.

A fourth aspect of the present invention is similar to the above, in which a positive electrode, a negative electrode,
A lithium secondary battery provided with a separator and an electrolytic solution, wherein the negative electrode of the battery is composed of a current collector holding carbon particles carrying carbon particles carrying a metal forming an alloy with lithium, and the carbon particles are , The interplanar spacing (d002) by X-ray diffraction method is 3.354 to 3.369Å, the crystal size (Lc) in the C-axis direction is 300Å or more, and the specific surface area is 0.1 to 30 m ² / g or more. In addition, the metal that forms an alloy with lithium is characterized by having a particle size of 1000 Å or less.

A fifth invention is an electric vehicle in which the lithium secondary battery according to any one of the second to fourth inventions is driven by a motor as a power source. This lithium secondary battery is assumed to have a charge / discharge rate of 1 coulomb (C) or more and an energy density of 300 wh or more per liter of battery volume.

A sixth invention is a motorcycle in which the lithium secondary battery according to any of the second to fourth inventions is driven by a motor as a power source. This lithium secondary battery is assumed to have a charge / discharge rate of 1 C or more in charge and an energy density of 300 wh or more per liter of battery volume.

That is, the present invention provides a high-performance lithium secondary battery by using carbon particles carrying fine particles of a metal forming an alloy with lithium as described above in a negative electrode for a lithium secondary battery. It is in.

The carbon particles of the present invention can be obtained by heat-treating highly crystalline carbon particles such as natural graphite, petroleum coke or coal pitch coke at a high temperature of 2500 ° C. or higher. The average particle size is 50μ
m or less, preferably 1 to 20 μm. The shape may be spherical, lumpy, scale-like, fibrous or a crushed product thereof.

Next, as the supported metal, Al, Sb, B,
Ba, Bi, Cd, Ca, Ga, In, Ir, Pb, H
At least one of g, Si, Ag, Sr, Te, Tl, and Sn is selected, but elements satisfying the following conditions are preferable.

(1) Alloy composition having a high lithium content,
(2) The atomic weight is relatively small and the density is relatively large,
(3) Easy reduction, (4) low oxidation-reduction potential of lithium alloy, (5) few problems in disposal, (6) relatively inexpensive.

As a method of supporting the metal, there are methods such as a vapor deposition method, a sputtering method, a wet reduction method, an electrochemical reduction method, a plating method and a vapor phase reducing gas treatment method, which are most suitable for the metal species used. Any supporting method may be applied. The amount of metal supported is 30 wt% or less, preferably 1 to 1
0 wt% is suitable. Further, the particle size of the supported metal is
Considering the precipitation / dissolution rate of the lithium alloy during charging / discharging, it is preferably 1000 Å or less.

A negative electrode is prepared using the metal-supported carbon particles obtained above, and in this case, a binder is used. The binder is not particularly limited as long as it does not react with the electrolytic solution such as EPDM, PVDF, and polytetrafluoroethylene. The binder content is 1 to carbon.
30 wt%, preferably 5 to 15 wt% is suitable. As the negative electrode shape using the above mixture, a sheet shape,
It is possible to adapt to the shape of the battery by filling it with a film, a film on a metal foil or a foam metal. The mixture layer thickness is preferably in the range of 10 to 200 μm.

The thus obtained negative electrode can be used as an optimum lithium secondary battery by combining it with a commonly used positive electrode, separator and electrolytic solution. As the active material used for the positive electrode, LiCoO ₂ , LiNiO ₂
A composite oxide containing lithium such as LiMn ₂ O ₄ or LiMn ₂ O ₄ may be used, and a mixture of carbon black as a conductive agent or carbon and an adhesive agent is applied to a current collector such as an Al foil to form a positive electrode. To do.

As the separator, a polypropylene, polyethylene or polyolefin type porous film is used. Further, as the electrolytic solution, propylene carbonate (PC), ethylene carbonate (EC), 1,2-dimethoxyethane (DME), dimethyl carbonate (D)
Two or more kinds of mixed solvents such as MC), diethyl carbonate (DEC) and methyl ethyl carbonate (MEC) are used. Further, as the electrolyte, LiPF ₆ , Li
There are BF ₄ , LiClO _4, etc., and those dissolved in the above solvent are used.

In order to improve the carbon negative electrode for a lithium secondary battery and to improve the discharge capacity, power density and cycle characteristics, by using carbon particles carrying fine metal particles forming an alloy with lithium, (1) increase of discharge capacity, (2) improvement of electric conductivity, (3) improvement of output density,
(4) Improvement of cycle characteristics, (5) Improvement of heat dissipation in assembled battery, and (6) High-speed charge / discharge are possible.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] Natural graphite (particle size 1
1 μm) is suspended in 450 ml of water containing 25 ml of ethyl alcohol. This is heated to about 60 ° C., and 1.73 of silver nitrate (AgNO ₃ ) is added and dissolved with vigorous stirring. A 0.5 wt% sodium tetrahydridoborate (NaBH ₄ ) aqueous solution is added dropwise to this with a microtube pump, and the reduction reaction is completed in about 3 hours. Then, it was filtered, washed with water, and vacuum dried at 300 ° C. for 6 hours. According to a chemical analysis, the carried amount of the obtained powder A was 9.9 wt% with respect to 10.0 wt% of the composition of the charged amount, which was a good carried amount. In addition, by X-ray diffraction, Ag
As a result of examining the existence state of, only the diffraction line of silver in the metallic state was detected. Next, when the dispersed state of Ag was observed by energy dispersive electron probe microanalysis,
The Ag particles were distributed over the entire surface of the graphite particles, and were slightly concentrated on the end faces of the graphite particles. Furthermore, when the size of the Ag particles was observed with a transmission electron microscope, particles of several 100 Å were dispersed almost uniformly.

[Embodiment 2] Artificial graphite (particle size: 3 μm)
9.0g of a commercially available tin plating solution (manufactured by Kojundo Chemical Co., GL
S-500B) was suspended in 500 ml and stirred while being heated to about 65 ° C. to electrolessly plate tin on carbon powder. It was filtered, washed with water, and vacuum dried at 300 ° C. for 6 hours to obtain powder B. As a result of chemical analysis, the supported amount of Sn was 4.6% by weight.

[Embodiment 3] 9.0 g of highly purified natural graphite (particle size: 11 μm) is suspended in 450 ml of water containing 25 ml of ethyl alcohol. About 6
The mixture is heated to 0 ° C., and 2.32 g of bismuth nitrate (Bi (NO ₃ ) ₃ .xH ₂ O) is added and dissolved with vigorous stirring.
Ammonia water (1: 4) is added dropwise thereto by a microtube pump until the liquid becomes alkaline. Then, it was filtered, washed with water, and vacuum dried at 300 ° C. for 6 hours. This powder was heated at 600 ° C. for 3 hours in a helium gas stream containing 4% by volume of hydrogen for reduction treatment to obtain powder C. The powder C was chemically analyzed, and an analysis result of 9.6% by weight was obtained with respect to 10.0% by weight of the composition of the charged amount.

[Embodiment 4] An N-methylpyrrolidone solution of PVDF is used as a binder in the powder A, the powder B, and the powder C obtained in the first to third embodiments, and each powder and PVDF are mixed with 90: The paste having a weight ratio of 10 was applied to a copper foil having a thickness of 20 μm, which is a current collector, air-dried, and then 3 at 80 ° C.
After vacuum drying for a period of time and molding at a pressure of 0.5 t / cm ² ,
Furthermore, it vacuum-dried at 120 degreeC for 2 hours, and obtained the negative electrode A, the negative electrode B, and the negative electrode C. These negative electrodes were combined with a lithium metal counter electrode through a polyester film, and 1 M LiPF ₆ was added to the electrolytic solution.
/ EC + DMC, and a test cell using lithium metal as a reference electrode was assembled. Charge / discharge rate is 80mA / g carbon,
The upper and lower limit potentials of charge and discharge were set to 1.0 V and 0.01 V, respectively. The results obtained are summarized in Table 1 in comparison with carbon that does not carry metal. Here, the powder of Comparative Example 1 is a highly purified natural graphite (particle size 11 μm), and the powder of Comparative Example 2 is artificial graphite (particle size 3 μm).

[0027]

[Table 1]

The powders A, B, and C express values exceeding the theoretical capacity density of graphite of 372 mAh / g, which is because the alloying capacity of metal and lithium is added. Further, the result of the cycle test of the negative electrode of powder A is shown in FIG.
The discharge capacity of h / g is maintained.

[Fifth Embodiment] The negative electrode of the powder A obtained in the fourth embodiment, a positive electrode using lithium cobalt oxide (LiCoO ₂ ) as a positive electrode material, a separator made of a polyester film, and 1M LiPF ₆ / EC + DMC are used. An AA battery was constructed using the electrolytic solution and evaluated. This battery is
From the first cycle, it shows a discharge capacity of 350 Wh / 1, 1
The value did not decrease even after 30 cycles.

[Embodiment 6] Almost the same as in Embodiment 1, a highly purified natural graphite (particle size: 11 μm)
The silver nitrate (AgNO _3), tetra-hydride sodium borate (NaBH ₄₎ treatment was carried out in the like. However, before adding the reducing agent (NaBH ₄ ), 0.02 mol / l potassium hydrogen phthalate was added to control the pH, and powder D was obtained. When the particle size of Ag metal and the dispersion state were examined, it was found that the powder D had a Ag particle size (100
~ 200Å) is small and the dispersion state has been improved significantly.

[Embodiment 7] Artificial graphite (plane spacing (d0
02) = 3.359Å, the crystal size in the c-axis direction Le = 5
The same preparation as in Embodiment 1 was carried out using 46Å and specific surface area = 10.5 m ² / g) to obtain a powder E carrying Ag particles.

[Embodiment 8] Artificial graphite (plane spacing (d0
02) = 3.359Å, the crystal size in the c-axis direction Le = 5
46Å, specific surface area = 10.5 m ² / g) and the same operation as in Embodiment 6 was carried out to obtain a powder F carrying Ag particles having a smaller particle diameter.

[Embodiment 9] Artificial graphite (plane spacing (d00
2) = 3.359Å, crystal size in the c-axis direction Le = 54
6Å, specific surface area = 10.5m ² / g) 9.0g 25ml
Suspended in 200 ml of water containing C ₂ H ₅₆ H. Add 1.9 g of S to 50 ml of water containing 0.5 ml of HCl.
What dissolved ncl ₂ .2H ₂ O and water were added to make a total volume of 450 ml. While heating and stirring this at 50 to 60 ° C., a 0.5% NaBH ₄ aqueous solution is dropped using a microtube pump, and the reduction reaction is carried out for about 3 hours. After that, filtration and washing are performed, and heating is performed in vacuum at 350 ° C. for 6 hours or more to dry. Regarding the powder G obtained here, Sn was subjected to ICP analysis, and the charged amount was 10.0.
It showed a good value of 9.76 wt% with respect to wt%. In addition, when the Sn morphology was examined by X-ray diffraction, Sn
Was confirmed to be completely metallic.

[Embodiment 10] Powders D, E, F and G
To each of these, PVDF dissolved in N.methylpyrrolidone was added as a binder, and PVDF was added to the powder in an amount of 10 wt% and kneaded to prepare various pastes. This paste was applied on a copper foil having a thickness of 20 μm as a current collector, air-dried, and then dried in vacuum at 80 ° C. for 3 hours.
Then, after molding at a pressure of 0.5 ton / cm ² , it was dried in vacuum at 120 ° C. for 2 hours to prepare negative electrodes D, E, F and G. These negative electrodes are combined with a Li metal counter electrode and a polyethylene-based porous membrane as a separator, and the electrolyte is 1M.
A cycle test was performed using LiPF ₆ / EC-DMC, Li metal as a reference electrode, a charge / discharge rate of 80 mA / g of carbon, and a potential width of 0.01 V to 1.0 V. The results are shown in Table 1 above using carbon that does not carry a metal as a comparative example.
Are summarized in.

The powders D, E and F develop a value exceeding the theoretical capacity of carbon because the capacity for alloying metal and lithium is added.

By the way, the cycle test result of the negative electrode of the powder D shows the same tendency as shown in FIG. 3, and the discharge capacity of 370 mAh / g is maintained even after 300 cycles.

[Embodiment 11] An aluminum foil having a thickness of 20 μm is coated with a mixture of LiCoO ₂ active material, artificial graphite and PVDF at a weight ratio of 87: 9: 4 on both sides so as to have a thickness of 90 μm on one side. Dried and rolled positive electrode 15 and thickness 2
The powder D obtained in Embodiment 6 was applied to a copper foil of 0 μm on one side 5
Negative electrode 1 coated on both sides to a thickness of 8 μm, dried and rolled
7 and a polyethylene porous membrane separator 19 having a thickness of 25 μm are wound as shown in FIG.
It is stored in a 47 mm battery can and 1 M LiPF 6 is used as the electrolyte.
Its properties were evaluated using ₆ / EC-DMC.

The test conditions were as follows: charge / discharge rate: 1 C, charge end voltage: 4.2 V, discharge end voltage: 2.5 V. As a result, an energy density of 300 wh / l (battery volume) was obtained, showing stable performance up to 300 cycles.

[0039]

The effects obtained by using the negative electrode obtained by the present invention, that is, the powder in which the fine particles of the metal forming the alloy with lithium on the carbon particles are carried in the negative electrode are as follows.

First, by interposing a metal between the carbon particles, (1) the electric conductivity is improved and the charge / discharge reaction speed is improved. (2) Since the charge / discharge capacity of the alloy formed with lithium as the additive metal can be used, the theoretical capacity of graphite is 372 m.
Values exceeding Ah / g are obtained. (3) Since the supporting metal covers the reaction site on the surface of the carbon particles that causes the irreversible capacity, the irreversible capacity is reduced. (4) Since the discharge capacity is increased, the output density of the battery is naturally increased. (5) (1)
In addition, the cycle characteristics are improved, and the heat dissipation property of the assembled battery can be improved.

[Brief description of drawings]

FIG. 1 is a cycle characteristic diagram of a conventional negative electrode and an improved negative electrode.

FIG. 2 is a cycle characteristic diagram of a copper fiber-added negative electrode and a non-added negative electrode.

FIG. 3 is a cycle characteristic diagram of a negative electrode according to the present invention.

FIG. 4 is a configuration diagram of a cylindrical battery of the present invention.

[Explanation of symbols]

 1 Cycle characteristics of conventional negative electrode 2 Cycle characteristics of improved negative electrode 3 Cycle characteristics of copper fiber-added negative electrode 4 Cycle characteristics of non-added negative electrode 5 Cycle characteristics of negative electrode according to the present invention 15 Positive electrode 16 Positive electrode terminal 17 Negative electrode 18 Negative electrode terminal 19 Separator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Horiba 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Ren Muranaka 7-chome, Omika-cho, Hitachi-shi, Ibaraki No. 1 in Hitachi, Ltd. Hitachi Research Laboratory

Claims (8)

[Claims] 1. In a lithium secondary battery having a capacity of 0.5 wh or more and 50 kwh or less, a negative electrode of a single battery constituting the secondary battery has a current collector of carbon particles carrying a metal forming an alloy with lithium. The lithium secondary battery is capable of being discharged for 15 minutes or more at an output of energy density of 350 w / kg (battery weight) or more. 2. A lithium secondary battery comprising a pair of a positive electrode and a negative electrode, a separator interposed between the positive and negative electrodes, and an electrolyte solution in which the positive and negative electrodes and the separator are immersed, wherein the negative electrode forms an alloy with lithium. The carbon particles supporting the metal are held by a current collector, and the carbon particles have a surface spacing (d002) of 3.354 to 3.36 by an X-ray diffraction method.
A lithium secondary battery having a size of 9Å and a crystal size (Lc) in the C-axis direction of 300Å or more. 3. A lithium secondary battery comprising a pair of a positive electrode and a negative electrode, a separator interposed between the positive and negative electrodes, and an electrolyte solution in which the positive and negative electrodes and the separator are immersed, wherein the negative electrode forms an alloy with lithium. A lithium secondary battery characterized in that carbon particles supporting a metal are held by a current collector, and the carbon particles have a specific surface area of 0.1 to 30 m ² / g or more. 4. A lithium secondary battery comprising a pair of a positive electrode and a negative electrode, a separator interposed between the positive and negative electrodes, and an electrolyte solution in which the positive and negative electrodes and the separator are immersed, wherein the negative electrode forms an alloy with lithium. The carbon particles supporting the metal are held by a current collector, and the carbon particles have a surface spacing (d002) of 3.354 to 3.36 by an X-ray diffraction method.
9Å, the crystal size (Lc) in the C-axis direction is 300Å or more, and the specific surface area is 0.1 to 30 m ² / g or more,
The metal forming an alloy with lithium has a particle size of 1000.
Lithium secondary battery characterized by being Å or less. 5. An electric vehicle, which is driven by a motor having the lithium secondary battery according to claim 2 as a power source. 6. The charge / discharge rate of the lithium secondary battery is
The electric vehicle according to claim 5, which has an energy density of 1 C or more and 300 wh / l (battery volume) or more. 7. A motorcycle, which is driven by a motor using the lithium secondary battery according to claim 1 as a power source. 8. The charge / discharge rate of the lithium secondary battery is
The motorcycle according to claim 7, which has an energy density of 1 Wh or more and 300 wh / l (battery volume) or more.