JP2801599B2 - Rechargeable battery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a secondary battery, and more particularly, to a secondary battery having a small size, a long charge / discharge cycle life, and a stable high capacity.

(Prior art) A secondary battery in which the main component of the positive electrode body is a transition metal chalcogen compound such as TiS ₂ or MoS ₂ and the negative electrode body is Li or an alkali metal mainly composed of Li has a high energy density. Therefore, commercialization efforts are being made.

Also, a conductive polymer such as polyacetylene is used for the positive electrode body,
Secondary batteries using Li or an alkali metal mainly composed of Li for the negative electrode body have also been studied.

(Problems to be Solved by the Invention) However, in such a secondary battery, the negative electrode body is
There is a problem based on the fact that it is a Li foil or an alkali metal foil mainly containing Li.

In other words, when the battery is discharged, Li becomes Li ions from the negative electrode body and moves into the electrolytic solution, and when charged, these Li ions become metallic Li and are deposited again on the negative electrode body, but this charge / discharge cycle is repeated. And the metal Li deposited therewith becomes dendritic. This dendritic Li
Is an extremely active substance, which breaks down the electrolyte,
As a result, there arises a disadvantage that the charge / discharge cycle characteristics of the battery deteriorate. When this further grows, finally, the dendrite-like metal Li deposit penetrates through the separator and reaches the positive electrode body, causing a problem that a short-circuit phenomenon occurs. In other words, there is a problem that the charge / discharge cycle life is short.

In order to avoid such a problem, an attempt has been made to constitute the negative electrode body by using a carbonaceous material obtained by calcining an organic compound as a support and carrying Li or an alkali metal mainly composed of Li on the support.

The use of such an anode body has prevented the precipitation of Li dendrite, but on the other hand, batteries incorporating this anode body have a much higher discharge capacity than primary batteries of the same size. And the magnitude of self-discharge was not necessarily reduced to a satisfactory level.

An object of the present invention is to provide a secondary battery having a larger battery capacity and improved self-discharge characteristics under such circumstances.

[Constitution of the Invention] (Means for Solving the Problems) The inventors of the present invention have conducted intensive studies on the negative electrode body in order to solve the above-mentioned problems. As a result, the negative electrode body was made of a carbonaceous material described later and an active material described later. The fact that the active material is supported on a support made of a material obtained by mixing an alloyable metal and / or an alloy of the active material with a powder obtained by mixing the active material is effective for achieving the above-described object. Heading, the present invention has been reached.

That is, the secondary battery of the present invention includes a negative electrode body including an active material and a support for supporting the active material. (1) The active material is lithium or an alkali metal mainly containing lithium. (2) the carrier has the following: (a) (a) the hydrogen / carbon atomic ratio is less than 0.15; and (b) the plane spacing (d ₀₀₂ ) of the (002) plane by X-ray wide-angle diffraction is 3.37. Å or more; and a carbon material having a crystallite size (Lc) of 150Å or less in the c-axis direction, and having a volume average particle diameter of 100 μm or less and a specific surface area of 1 m ² / g or more. [(A) group], and (b) a powder of a metal which can be alloyed with the active material and / or an alloy of the active material, having a volume average particle size of 30 μm
And a material obtained by mixing the following particles [(b)].

The battery of the present invention is characterized in that the negative electrode body has the above-described configuration, and other elements may be the same as the conventional secondary battery.

In the negative electrode body according to the present invention, the active material is Li or Li.
The active material enters and exits the negative electrode body in response to charging and discharging of the battery.

The active material carrier constituting the negative electrode body in the present invention,
It is composed of a mixture of a carbonaceous material [group (a)] having the characteristics described below and a metal [/ b] group of a metal and / or alloy of the active material, which will be described later.

 First, the group (a) will be described.

(A) The carbonaceous materials used in the group include (a) an atomic ratio of hydrogen / carbon (H / C) of less than 0.15; and (b) a plane spacing (d ₀₀₂ ) of (002) planes by X-ray wide-angle diffraction. ) Is 3.37 ° or more; and the crystallite size (Lc) in the c-axis direction is 150 ° or less. In the carbonaceous material, other atoms, for example, atoms of nitrogen, oxygen, halogen and the like are preferably at most 7 mol%, more preferably at most 4 mol%, particularly preferably at most 2 mol%.
It may be present in a proportion of at most mol%.

H / C is preferably less than 0.10, more preferably less than 0.07, particularly preferably less than 0.05.

The spacing (d ₀₀₂ ) of the (002) plane is preferably 3.39.
~ 3.75 °, more preferably 3.41 to 3.70 °, particularly preferably 3.45 to 3.70 °, most preferably 3.51 to 3.70 °; the crystallite size Lc in the c-axis direction is preferably 5 to 150
Å, more preferably 10-80Å, particularly preferably 12-70
Å.

If any of these parameters, i.e., H / C, d ₀₀₂ and Lc, deviates from the above range, the overvoltage at the time of charging and discharging in the negative electrode body increases, and as a result, gas is generated from the negative electrode body. Not only does the safety of the battery significantly deteriorate, but also the charge / discharge cycle characteristics deteriorate.

Further, the carbonaceous material used for the support of the negative electrode body according to the present invention preferably has the following characteristics.

That is, in Raman spectrum analysis using an argon ion laser beam having a wavelength of 5145 °, the following formula: Is preferably less than 2.5, more preferably less than 2.0, particularly preferably 0.2 or more
It is less than 1.2, most preferably 0.3 or more and less than 1.0.

Here, the G value refers to the above-mentioned carbonaceous material at a wavelength of 5145 °.
In the spectrum intensity curve recorded in the chart when the Raman spectrum analysis was performed using the argon ion laser light of the above, the integrated value (area intensity) of the spectrum intensity within the range of the wave number of 1580 ± 100 cm ⁻¹ was calculated as the wave number of 1360 ± 1. 100cm ^-1
Of the carbonaceous material, which is equivalent to a measure of the degree of graphitization of the carbonaceous material.

That is, the carbonaceous material has a crystalline portion and an amorphous portion, and the G value is a parameter indicating the ratio of the crystalline portion in the carbonaceous structure.

Further, the carbonaceous material used for the support of the negative electrode body according to the present invention preferably satisfies the following conditions.

That is, the distance a ₀ (= 2d ₁₁₀ ) of the (110) plane in the X-ray wide-angle diffraction analysis, which is twice the plane spacing (d ₁₁₀ ), is preferably 2.38 ° to 2.47 °, more preferably 2.39 ° to 2.46 °; a
The size La of the crystallite in the axial direction is preferably 10 ° or more, more preferably 15 ° to 150 °, and particularly preferably 19 ° to 70 °.
It is.

The above-mentioned carbonaceous material can be obtained by heating and decomposing an organic compound under a flow of an inert gas at a temperature of 300 to 3000 ° C. to carbonize the organic compound.

Specific examples of the organic compound serving as a starting source include cellulose resins; phenol resins; acrylic resins such as polyacrylonitrile and poly (α-acrylonitrile halide); polyvinyl chloride, polyvinylidene chloride;
Halogenated vinyl resin such as polychlorinated vinyl chloride; polyamideimide resin; polyamide resin; any organic polymer compound such as conjugated resin such as polyacetylene or poly (p-phenylene); for example, naphthalene, phenanthrene, anthracene, A condensed cyclic hydrocarbon compound obtained by condensing two or more monocyclic hydrocarbon compounds having three or more rings with each other, such as triphenylene, pyrene, chrysene, naphthalene, picene, perylene, pentaphene, and pentacene; Various pitches whose main components are derivatives such as acids, carboxylic anhydrides, carboxylic imides, and mixtures of the above compounds; for example, indole, isodol, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenathridine of A condensed heterocyclic compound formed by bonding at least two or more heterocyclic monocyclic compounds having three or more membered rings to each other, or a monocyclic hydrocarbon compound having one or more three-membered rings or more; Derivatives such as acids, carboxylic anhydrides, carboxylic imides, and derivatives such as benzene and its carboxylic acids, carboxylic anhydrides, and carboxylic imides, that is, 1,2,4,5-tetracarboxylic acids, Dianhydride or its diimide; and the like.

In addition, a carbonaceous material such as carbon black may be used as a starting source, and the carbonaceous material may be further heated to appropriately promote carbonization to form a carbonaceous material constituting a support of the negative electrode body according to the present invention.

The carbonaceous material used in the carrier according to the present invention, that is, the group (a) has a volume average particle diameter of the carbonaceous material of 100 μm.
m or less, the specific surface area is 1 m ² / g or more, preferably the volume average particle size is 70 μm or less, the specific surface area is 3 m ² / g or more,
More preferably, the volume average particle diameter is 50 μm or less, and the specific surface area is 5 m ² / g or more.
It is a group of particles having a specific surface area of 7 m ² / g or more and 200 m ² / g or less.

When the volume average particle diameter exceeds 100 μm and the specific surface area is smaller than 1 m ² / g, the capacity and output as an electrode decrease.

Next, a metal that can be alloyed with the active material constituting the group (b),
Next, an active material alloy will be described.

As described above, since the active material is Li or an alkali metal mainly composed of Li, it is usually preferable to use a metal that can be alloyed with Li.

As such a metal, for example, aluminum (A
l), lead (Pb), zinc (Zn), tin (Sn), bismuth (B
i), indium (In), magnesium (Mg), gallium (Ga), cadmium (Cd), silver (Ag), silicon (S
i), boron (B), gold (Au), platinum (pt), palladium (Pd), antimony (Sb), etc., or an alloy thereof, preferably Al, Pb, Bi and Cd,
More preferably, they are Al, Pb, and Bi.

Further, among metals that can be alloyed with Li, other elements in addition to the above-mentioned metals are contained in a range of 50 mol% or less, preferably in a range of 30 mol% or less, more preferably in a range of 10 mol% or less. May be.

The composition (molar composition) of the alloy of the active material is represented by, for example, Li _x M (where x is a molar ratio to the metal M). As the other metal used as M, one or more of the above-mentioned metals can be used. The alloy may contain other elements in addition to the above-mentioned metals in a range of 50 mol% or less, preferably 30 mol% or less, and more preferably 10 mol% or less.

In Li _x M, x preferably satisfies 0 <x ≦ 9, more preferably 0.1 ≦ x ≦ 5, further preferably 0.5 ≦ x ≦ 3, and particularly preferably 0.7 ≦ x ≦ 2. . When x is smaller than this range, the amount of the active material carried is too small, and the capacity of the battery becomes small. When x is larger than this range, the charge / discharge cycle characteristics of the battery deteriorate.

One or more alloys can be used as the active material alloy (Li _x M).

(B) powder of an alloy of the above-mentioned active material and an alloy of the active material and / or the active material used in the present invention;
The group has a volume average particle size of 30 μm or less, preferably 10 μm or less, more preferably 7 μm or less, particularly preferably 0.5 μm or less.
It is composed of a particle group of not less than μm and not more than 5 μm.

The carrier constituting the negative electrode body according to the present invention comprises the above-mentioned carbonaceous material [group (a)] and a powder of an alloy of a metal and / or an active material which can be alloyed with the active material [group (b)]. is a mixture, preferably satisfies the volume average particle diameter of the (a) group mu _(a) and group (b) having a volume average particle diameter of mu _(B) is _{μ (B) ≦ μ (a} ), further mu _(B), more preferably satisfy the ^{_{≦ 1/2 μ (a)}} , μ is particularly preferred to satisfy the ^{_{(B) ≦ 1/5 μ}} (a).

The mixing ratio of the groups (a) and (b) is such that the proportion of the group (a) in the mixture is preferably 30% by weight or more and 95% by weight or more.
The content is more preferably 50% to 93% by weight, particularly preferably 60% to 92% by weight, and most preferably 70% to 90% by weight.

Further, as a mixture of the groups (a) and (b),
A mixture of group (a) and an active material and a powder of an alloyable metal or a mixture of group (a) and an active material alloy powder is preferable.

As a method for obtaining the carrier, for example, a method of uniformly mechanically mixing the powder of the group (a) and the powder of the group (b) and press-molding the same; Is coated with the powder of the group (a), and then molded.

As a method of further supporting the active material on the negative electrode body comprising the support obtained as described above, there are a chemical method, an electrochemical method, a physical method, and the like. A method in which the above-mentioned powder compact is immersed in an electrolytic solution containing an alkali metal ion and electrolytic impregnation is performed by using lithium as a counter electrode and electrolytically impregnating the carrier as an anode. A method in which lithium is electrically contacted and dipped in an electrolytic solution, a method in which lithium powder is mixed in the process of obtaining a molded body of a carrier, and the like can be applied.

By doing so, Li ions or alkali metal ions are doped into the carbonaceous material of the support, and further included in at least a part of the metal that can be alloyed with the active material in the support and supported thereon. . The supporting of the active material may be performed not only on the support of the negative electrode body but also on the support of the positive electrode body or on both electrodes.

Further, the preferred amount of the active material carried on the carrier of the negative electrode body according to the present invention is preferably: (1) 1 to 20% by weight based on the group (a);
And more preferably 3 to 10% by weight; and (2) 1 to 80% by mole, more preferably 5 to 60% by mole, particularly preferably 10 to 50% by mole based on the group (b).
Most preferably, it is 20 to 50 mol%.

When the supported amount of the active material in the negative electrode body is smaller than the range defined in the above (1) and (2), the supported amount of the active material is too small to decrease the capacity of the battery. The change in the volume of the negative electrode body due to the discharge is increased, which results in poor current collection, and facilitates the formation of lithium dendrite, thereby shortening the charge / discharge cycle life.

The carrier constituting the negative electrode body according to the present invention may contain a conductive agent, a binder, and the like in addition to the above-described groups (a) and (b).

As the conductive agent, expanded graphite, metal powder and the like can be added usually in an amount of less than 50% by weight, preferably in an amount of less than 30% by weight.

The binder may contain less than 30% by weight, preferably less than 10% by weight, of a powder such as a polyolefin resin.

Next, the configuration of the secondary battery of the present invention will be described with reference to the drawings. In the figure, the positive electrode can (1) also serves as the positive electrode terminal
A positive electrode body (2) is set in and housed at the bottom of the positive electrode can (1). The cathode body is not particularly limited, but is preferably made of, for example, a metal chalcogen compound which releases or acquires an alkali metal cation such as Li ion along with a charge / discharge reaction. Such metal chalcogen compounds include vanadium oxides, vanadium sulfides,
Molybdenum oxides, molybdenum sulfides, manganese oxides, chromium oxides, titanium oxides, titanium sulfides, composite oxides thereof, composite sulfides, and the like can be given. _{Preferably, Cr 3 O 8, V 2} O 5, V 6 O 13, VO 2, Cr 2 O 5,
MnO ₂ , TiO ₂ , MoV ₂ O ₈ , TiS ₂ , V ₂ S ₅ , MoS ₂ , MoS ₃ , VS ₂ , C
r _0.25 V _0.75 S ₂ , Cr _0.5 V _0.5 S _{2 and the} like. Also, LiCo
O _2, WO oxides such as _{3, CuS, Fe 0.25 V 0.75} S 2, Na 0.1 CrS 2
Sulfide, NiPS ₃ , phosphorus such as FePS ₃ , sulfur compound, VS
Selenium compounds such as e ₂ and NbSe ₃ can also be used. Further, an amorphous metal chalcogen compound, particularly, an amorphous V ₂ O ₅ can be used.

The negative electrode body (4) faces the positive electrode body (2) and the separator (3).

The separator (3) holding the electrolytic solution is made of a material having excellent liquid retaining properties, for example, a nonwoven fabric of a polyolefin resin. The separator (3) is provided with an aprotic organic solvent such as propylene carbonate, 1,3-dioxolan, 1,2-dimethoxyethane, or the like, with LiClO ₄ , LiBF ₄ , LiAsF ₅ ,
It is impregnated with a non-aqueous electrolyte of a predetermined concentration in which an electrolyte such as LiPF ₆ is dissolved.

Further, a solid electrolyte which is a conductor of Li or an alkali metal ion can be interposed between the positive electrode body and the negative electrode body.

The negative electrode body (4) is obtained by supporting an active material on a support made of a mixture of the groups (a) and (b) having the above-described characteristics, and is provided in a negative electrode can (5) also serving as a negative electrode terminal. Has been laid.

The positive electrode body (2), the separator (3), and the negative electrode body (4) constitute a power generating element as a whole. Then, the power generation element is incorporated in an electronic container including the positive electrode can (1) and the negative electrode can (5), and a battery is assembled.

Reference numeral 6 denotes an insulating packing for separating the positive and negative electrode bodies. The battery is sealed by bending the opening of the positive electrode can (1) inward.

In the secondary battery of the present invention, release of Li ions (or alkali metal ions mainly composed of Li) carried at the time of discharging occurs in the negative electrode body, and at the time of charging, the release of Li ions to the carbonaceous material in the carrying body occurs. By accumulating Li ions in at least a part of the metal which can be alloyed with Li and the dope, the Li ions are supported on the support of the negative electrode.

The charging / discharging cycle of the battery is repeated by carrying and releasing such Li ions.

In the secondary battery of the present invention, by using a support made of a mixture of the above-mentioned carbonaceous material and an alloy of the active material and / or an alloy of the active material for the negative electrode body, a large amount of the active material can be added to the negative electrode body. In addition, since it is possible to smoothly carry and release the active material at the time of charging and discharging, it is possible to exhibit unprecedented excellent characteristics.

In the present invention, each measurement of elemental analysis and X-ray wide-angle diffraction was performed by the following methods.

“Elemental analysis” The sample was dried under reduced pressure at 120 ° C. for about 15 hours, and then dried at 100 ° C. for 1 hour on a hot plate in a dry box. Then, sampling is performed on an aluminum cup in an argon atmosphere, and the carbon content is determined from the weight of CO ₂ gas generated by combustion, and the hydrogen content is determined from the weight of H ₂ O generated. In the examples of the present invention described later, the measurement was performed using a Perkin Elmer 240C elemental analyzer.

"X-Ray Wide Angle Diffraction" (1) Spacing between ( ₀₀₂ ) planes (d ₀₀₂ ) and (110) plane (d ₁₁₀ ) When the carbonaceous material is a powder, as it is Powdered in a mortar, about 15% by weight of the sample, high-purity silicon powder for X-ray standard as an internal standard substance was added and mixed, filled in a sample cell, and a monochromatized CuKα ray with a graphite monochromator was used as a radiation source. A wide-angle X-ray diffraction curve is measured by a reflection type diffractometer method.
For the correction of the curve, the following simple method is used without correcting so-called Lorentz, polarization factor, suction factor, atomic scattering factor and the like. That is, the base line of the curve corresponding to the (002) and (110) diffractions is drawn, and the substantial intensity from the base line is re-plotted to obtain a correction curve for the (002) plane and the (110) plane. The midpoint of the line where the line parallel to the angle axis drawn to two-thirds of the peak height of this curve intersects the diffraction curve is determined, the angle of the midpoint is corrected by the internal standard, and this is repeated. twice the precious obtains the d ₀₀₂ and d ₁₁₀ from the wavelength of the CuKα line λ by the Bragg equation follows.

λ: 1.5418Å θ, θ ': diffraction angle corresponding to d ₀₀₂ , d ₁₁₀ (2) Crystallite size in c-axis and a-axis directions: Lc; La In the corrected diffraction curve obtained in the preceding section, the peak height C axis and a using a so-called half width β at half the position of
The size of the crystallite in the axial direction is determined by the following equation.

Although there are various arguments about the shape factor K, K = 0.90 was used. λ, θ and θ ′ have the same meaning as in the previous section.

(Examples) Hereinafter, the present invention will be described with reference to examples.

Example (1) Production of Positive Electrode Body 5 g of MnO ₂ powder fired at 470 ° C. and 0.5 g of powdered polytetrafluoroethylene were kneaded, and the obtained kneaded product was roll-formed into a sheet having a thickness of 0.4 mm. .

One side of this sheet was pressed against a 60-mesh stainless steel net having a wire diameter of 0.1 mm as a current collector to form a positive electrode.

The obtained positive electrode body was immersed in a Li ion electrolyte having a concentration of 1 mol /, and subjected to an electrolytic treatment using the positive electrode body as an anode and lithium metal as a cathode. Electrolysis treatment is at a bath temperature of 20 ° C and a current density of 0.
The reaction was performed under the condition of 5 mA / cm ² , and 4 mAh of Li was supported on the positive electrode body.

(2) Production of negative electrode body Cellulose powder was set in an electric heating furnace, and heat-treated
While flowing N ₂ gas at a rate of 200 / hour per kg,
The temperature was raised to 950 ° C. at a temperature rising rate of ° C./hour, and the temperature was further maintained for 1 hour for firing, followed by natural cooling.

Next, the fired material is set in another electric furnace,
The temperature rises to 1800 ° C at a rate of
Hold for a time to perform carbonization.

The carbonaceous material thus obtained has the following characteristics as a result of elemental analysis, X-ray wide-angle diffraction, and Raman spectrum analysis.The particle size distribution and the specific surface area determined by the BET method are as follows. Was.

Hydrogen / carbon (atomic _{ratio) = 0.05 d 002 = 3.75Å,} Lc = 21Å a 0 (2d 110) = 2.41Å, La = 23Å, G value 0.7, a volume average particle diameter = 10.7 BET specific surface area = 28 m ² / g Next, 10% by weight of aluminum powder [group (b)] having a volume average particle size of 5 μm was mixed with the carbonaceous material powder [group (a)]. Further, 5% by weight of a polyethylene powder having a volume average particle size of 5 μm was mixed and then compression-molded to a thickness of 0.5 μm.
A 5 mm pellet-shaped carrier was used.

The obtained support was immersed in a Li ion electrolyte having a concentration of 1 mol /, and subjected to an electrolytic treatment using the support as an anode and lithium metal as a cathode. Electrolysis treatment is at a bath temperature of 20 ° C and a current density of 0.
The operation was performed under the condition of 5 mA / cm ² , and 12 mAh of Lr was carried on the carrier to obtain a negative electrode body.

(3) Battery assembly The above-described positive electrode body was mounted on a stainless steel positive electrode tube with the current collector facing down, and a polypropylene nonwoven fabric as a separator was placed thereon, and then LiClO ₄ was concentrated there. 1
A non-aqueous electrolyte solution dissolved in propylene carbonate at mol / l was impregnated. Then, the above-mentioned negative electrode body was mounted thereon to form a power generating element.

Thus, a button type secondary battery as shown in the figure was manufactured.

(4) Battery characteristics The battery manufactured in this manner was repeatedly charged / discharged at a constant current of 500 μA and a voltage regulation of an upper limit of 3.3 V and a lower limit of 1.8 V, and the charge / discharge cycle was evaluated. The performance of the battery at 100 cycles was examined and the results are shown in Table 1.

Further, after the completion of the charge in the sixth cycle, the circuit was opened, left at 20 ° C. for 90 days, and then discharged. The performance of the battery in the sixth cycle was compared with the performance in the previous five cycles and shown in Table 2.

Comparative Example 1 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example 1, and Li was supported.

(2) Production of negative electrode body A carbonaceous material produced in the same manner as in Example 1 [(a)
Group] alone, and without adding the Al powder [(b) Group], except that a carrier was produced in the same manner as in Example 1, and Li was carried to obtain a negative electrode body.

(3) Battery assembly A battery was assembled in the same manner as in Example 1.

(4) Battery Characteristics Battery characteristics were measured under the same conditions as in Example 1, and the results are shown in Tables 1 and 2.

Example 2 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example 1 and supported Li.

(2) Production of negative electrode body To a carbonaceous material powder [group (a)] produced in the same manner as in Example 1, 15 powders of a Li / Al alloy having a Li content of 18.4% by weight (volume average particle size of 3 μm) were added. % By weight, and 7% by weight of polyethylene powder having a volume average particle diameter of 2 μm, and then compression molded to obtain a 0.5 mm thick pellet-shaped negative electrode body.

(3) Battery assembly A button-type secondary battery as shown in the figure was manufactured in the same manner as in Example 1.

(4) Battery Characteristics Battery characteristics were measured under the same conditions as in Example 1, and the results are shown in Tables 1 and 2.

Example 3 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example 1. By the same electrolytic treatment as in Example 1, 10 mAh of Li was carried on the positive electrode body.

(2) Production of negative electrode body The phenol resin powder was set in an electric heating furnace, and N ₂ gas was flowed at a rate of 200 / hour per 1 kg of the heat-treated material.
The temperature was raised to 1000 ° C. at a rate of 200 ° C./hour, and the temperature was further maintained for 1 hour for firing, followed by natural cooling.

Next, the fired material is set in another electric furnace,
Temperature to 2100 ° C at a heating rate of
Hold for a time to perform carbonization.

The carbonaceous material thus obtained has the following characteristics as a result of elemental analysis, X-ray wide-angle diffraction, and Raman spectrum analysis.The particle size distribution and the specific surface area determined by the BET method are as follows. Was.

Hydrogen / carbon (atomic _{ratio) = 0.04 d 002 = 3.59Å,} Lc = 15Å a 0 (2d 110) = 2.42Å, La = 22.7Å, G value 0.8, a volume average particle size = 15.2μm, BET specific surface area = 18m ² / g Then, 7.5% by weight of an aluminum powder having a volume average particle diameter of 5 μm [Group (b)] and a powder of a Li / Al alloy (Li content: 18.5% by weight, 7.5% by weight (volume average particle size 5 μm) [group (b)] was mixed.
Further, 5% by weight of a polyethylene powder having a volume average particle size of 5 μm was mixed with the mixture, followed by compression molding to obtain a 0.5 mm-thick pellet-shaped negative electrode body.

(3) Battery assembly A button-type secondary battery as shown in the figure was manufactured in the same manner as in Example 1.

(4) Battery Characteristics Battery characteristics were measured under the same conditions as in Example 1, and the results are shown in Tables 1 and 2.

Comparative Example 2 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example 3. In addition, 16 mAh of Li was supported on the positive electrode body by the same electrolytic treatment as in Example 1.

(2) Production of negative electrode body A carbonaceous material produced in the same manner as in Example 3 [(a)
Group], and Al powder and Li / Al alloy powder [(b)
A negative electrode body was manufactured in the same manner as in Example 3 except that [Group] was not added.

(3) Battery assembly A battery was assembled in the same manner as in Example 3.

(4) Battery Characteristics Battery characteristics were measured under the same conditions as in Example 3, and the results are shown in Tables 1 and 2.

[Effects of the Invention] As is clear from the above description, the secondary battery of the present invention has a long charge / discharge cycle life, good charge / discharge characteristics at large currents, and has an active material of Li when charged. Or
Since the alkali metal mainly composed of Li can be fixed to the carrier in a stable form, stable high capacity, that is, large current discharge is possible. Its industrial value is great.

Although the description so far has been made with respect to a secondary battery having a button-shaped structure, the technical concept of the present invention is not limited to this structure. For example, the secondary battery may have a cylindrical shape, a flat shape, a square shape, or the like. Can be applied to the secondary battery.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a button type secondary battery according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Positive electrode can, 2 ... Positive electrode body 3 ... Separator 4, ... Negative electrode body 5 ... Negative electrode can, 6 ... Insulating packing

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Yui 1 Toho-cho, Yokkaichi-shi, Mie, Mitsubishi Yuka Co., Ltd. New Materials Research Laboratories (72) Inventor Kuniaki Inada 3-4-1 Minamishinagawa, Shinagawa-ku, Tokyo No. Toshiba Battery Co., Ltd. (72) Katsuharu Ikeda, Inventor 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Co., Ltd. (72) Hiroyoshi Nose 3-4-1, Minamishinagawa, Shinagawa-ku, Tokyo No. Toshiba Battery Co., Ltd. (56) References JP-A-63-114056 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 4/64-4/84 H01M 4 / 02,4 / 04

Claims (1)

(57) [Claims] 1. A secondary battery comprising a negative electrode body comprising an active material and a carrier for supporting the active material, wherein (1) the active material is lithium or an alkali metal mainly composed of lithium; 2) The carrier comprises: (a) (a) an atomic ratio of hydrogen / carbon of less than 0.15; and (ii) a spacing (d ₀₀₂ ) of (002) planes by X-ray wide-angle diffraction method of 3.37 ° or more; And a particle group of a carbonaceous material comprising a carbonaceous material having a crystallite size (Lc) of 150 ° or less in the c-axis direction, a volume average particle diameter of 100 μm or less, and a specific surface area of 1 m ² / g or more; b) a powder of a metal that can be alloyed with the active material and / or an alloy of the active material, the material being obtained by mixing particles having a volume average particle diameter of 30 μm or less. Rechargeable battery.