JP2957202B2 - 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 a negative electrode body by using a carbonaceous material obtained by calcining an organic compound as a carrier and carrying Li or an alkali metal (active material) mainly composed of Li on the carrier. ing. 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.

Furthermore, during the manufacturing process, a process of preliminarily supporting an active material on a support made of a carbonaceous material by an electrochemical method or the like is required, which poses a problem from the viewpoint of efficient production of a battery.

An object of the present invention is to provide a secondary battery having a larger battery capacity and improved self-discharge characteristics under such a circumstance, and an object of the present invention is to omit a step of loading an active material on a carrier. Is what you do.

(Means for Solving the Problems) The present inventors have conducted intensive studies on the negative electrode body in order to solve the above-mentioned problems, and as a result, the negative electrode support was formed by the carbonaceous particles described later and the lithium-aluminum alloy particles. The fact that the mixture is effective for achieving the above-mentioned object has been found, and the present invention has been achieved.

That is, the secondary battery of the present invention includes a negative electrode carrier of an active material obtained by previously mixing particles of a carbonaceous material and particles of a lithium-aluminum alloy. (1) The active material is lithium or lithium. (2) the carbonaceous material has (a) an atomic ratio of hydrogen / carbon of less than 0.15; and (b) a plane spacing (d) of (002) planes by X-ray wide-angle diffraction.
₀₀₂ ) is 3.37 ° or more; and the crystallite size (Lc) in the c-axis direction is 150 ° or less; and (3) the lithium content of the lithium-aluminum alloy is
16% by weight or more and 50% by weight or less;

The battery of the present invention is characterized in that the negative electrode carrier 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 particles of a carbonaceous material having characteristics described later and particles of a lithium-aluminum alloy.

The carbonaceous material used for the carrier includes: (a) an atomic ratio of hydrogen / carbon (H / C) of less than 0.15; and (ii) a spacing (d) between (002) planes by X-ray wide-angle diffraction.
₀₀₂ ) 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 °; the crystallite size Lc in the c-axis direction is preferably 5 to 150 °, more preferably 10 to 80 °, particularly preferably 12 °. It is ~ 70Å.

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.

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 ), which is twice the spacing (d ₁₁₀ ) of the (110) plane in the X-ray wide-angle diffraction analysis, 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.

Further, the carbonaceous material preferably has a volume average particle size.
It is desirable that the particles have a size of 200 μm or less, more preferably 0.5 μm or more and 150 μm or less, and particularly preferably 2 μm or more and 100 μm or less.

The carbonaceous material preferably has pores therein, and the total pore volume is preferably 1.5 × 10 ⁻³ ml / g or more. More preferably, the total pore volume is 2.0 × 10 ⁻³ ml / g or more, further preferably 3.0 × 10 ⁻³ ml / g, particularly preferably 4.0 × 10 ⁻³ ml.
/ g or less.

The total pore volume and the average pore diameter described below are determined by measuring the amount of adsorbed gas (or desorbed gas) on the sample under several equilibrium pressures using a constant volume method.

The total pore volume is determined from the total amount of gas adsorbed at a relative pressure P / P ₀ = 0.995, assuming that the pores are filled with liquid nitrogen.

P: vapor pressure of adsorbed gas (mmHg) P _1: Filling the pores with the saturation vapor pressure of adsorbed gas at cooling temperature (mmHg) Further adsorbed amount of nitrogen gas (V _Ads) the following equation (1) The total pore volume is determined by converting to the amount of liquid nitrogen (V _liq ) used.

Where P _a is the atmospheric pressure (kgf / cm ^2), T is temperature (° K),
V _m is the molecular volume of the adsorbed gas (34.7 cm ³ / mol for nitrogen)
It is.

Further, the carbonaceous material used for the negative electrode of the present invention has pores therein, the average pore radius: r _p is preferably 8～100A. More preferably 10-80 °, even more preferably
It is 12-60 °, particularly preferably 14-40 °.

Average pore radius: r _p is, V _liq determined from equation (1)
From the BET specific surface area: S, and is calculated using the following equation (2).

Here, it is assumed that the pores are cylindrical.

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;
A halogenated vinyl resin such as polychlorinated vinyl chloride; a polyamideimide resin; a polyamide resin; any organic polymer compound such as a 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, naphthacene, picene, perylene, pentaphen, 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, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, Fenatrige A condensed heterocyclic compound formed by bonding at least two or more heterocyclic monocyclic compounds having three or more rings to each other, or bonding to one or more monocyclic hydrocarbon compounds having three or more three-membered rings; Derivatives such as carboxylic acids, carboxylic anhydrides, and carboxylic imides; and benzene and its derivatives such as carboxylic acids, carboxylic anhydrides, and carboxylic imides, that is, 1,2,
4,5-tetracarboxylic acid, its dianhydride or its diimide; or toluene, xylene 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 active material carrier constituting the negative electrode body according to the present invention,
Since it is composed of a mixture of the particles of the specific carbonaceous material described above and the particles of the lithium-aluminum alloy,
The aluminum alloy will be described.

The lithium-aluminum alloy particles have a lithium content of 16% by weight or more and 50% by weight or less. Preferably the lithium content is between 20% and 48% by weight, more preferably the lithium content is between 22% and 45% by weight, even more preferably the lithium content is between 24% and 42% by weight, most preferably 26% by weight. Not less than 40% by weight.

The lithium content of lithium-aluminum alloy particles
If the content is less than 16% by weight, the amount of lithium pre-loaded on the support is too small to reduce the capacity of the battery, while if the content of lithium exceeds 50% by weight, the alloy becomes rich in flexibility, and It becomes difficult to make the aluminum mother alloy into granules by grinding or the like.

The particles of the lithium-aluminum alloy have a volume average particle size of preferably 300 μm or less, more preferably 150 μm or less, further preferably 1 μm or more and 100 μm or less, particularly preferably 5 μm or more and 70 μm or less.

Lithium-aluminum alloy is a lithium chloride bath,
It can be produced by a method of electrolysis using aluminum as a cathode, a method of simultaneously melting and alloying aluminum and lithium, and the like.

The lithium-aluminum alloy master alloy thus produced is formed into particles by a method such as mechanical pulverization.

The carrier constituting the negative electrode body according to the present invention is a mixture of the above-described particles of the carbonaceous material and the particles of the lithium-aluminum alloy, and the compounding ratio is preferably a ratio of the lithium-aluminum alloy in the mixture. Is 10% by weight or more 70
% By weight, more preferably from 15% by weight to less than 60% by weight, more preferably from 20% by weight to less than 50% by weight, particularly preferably from 25% by weight to less than 50% by weight, most preferably from 30% by weight to 45% by weight Is less than.

Here, if the ratio of the lithium-aluminum alloy in the carrier is excessively increased in order to increase the amount of the active material carried, the charge / discharge cycle of the electrode decreases.

As a method for obtaining the carrier, for example, a method of mechanically mixing a powder of a carbonaceous material and a powder of a lithium-aluminum alloy is preferable.In addition, the surface of the alloy powder is used as a core and the surface thereof is coated with the carbonaceous material powder. There are a covering method, a method of adding a carbonaceous material powder to a molten alloy, mixing and cooling and solidifying the mixture.

Further, there is a method of mixing Al, Li and a carbonaceous material powder, then increasing the temperature to dissolve Al and Li, and alloying the mixture in a uniformly mixed state.

In the support obtained by this method, the active material is supported on the carbonaceous material itself during the process.

Further, when a battery is configured using the negative electrode body made of the carrier obtained as described above, the active material in an alloy state is diffused into the carbonaceous material in the carrier of the negative electrode and is carried in a fixed amount. State.

Thus, the amount of lithium previously supported on the negative electrode support is preferably 0.030 g or more per 1 g of the support.
0.250 g or less, more preferably 0.060 g or more and 0.20 g or less, further preferably 0.070 g or more and 0.15 g or less, particularly preferably
0.075 g or more and 0.12 g or less, most preferably 0.080 g or more and 0.100
g or less.

Thus, in the negative electrode body according to the present invention, the active material is previously supported on the support.

The carrier constituting the negative electrode body according to the present invention is made of a mixed material of the above-mentioned carbonaceous material particles and lithium-aluminum alloy particles, but may contain a conductive agent, a binder and the like. .

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.

Further, the binder may be added with a powder such as a polyolefin resin in an amount of less than 50% by weight, preferably less than 30% by weight, particularly preferably 5% by weight or more and less than 10% by weight.

Next, the configuration of the secondary battery of the present invention will be described with reference to FIG. In the figure, a positive electrode body (2) is mounted and accommodated in a lower part of a positive electrode can (1) in a positive electrode can (1) also serving as a positive electrode terminal. 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 oxide, vanadium sulfide, molybdenum oxide, molybdenum sulfide, manganese oxide, chromium oxide, titanium oxide, titanium sulfide and the like. Complex oxides, complex sulfides, and the like can be given. Preferably, Cr ₃ O ₈ , V ₂ O ₅ , V ₆ O ₁₃ , V
_{O 2, Cr 2 O 5,} MnO 2, TiO 2, MoV 2 O 8, TiS 2, V 2 S 5, MoS 2, M
oS ₃ , VS ₂ , Cr _0.25 V _0.75 S ₂ , Cr _0.5 V _0.5 S ₂ and the like.
Also, oxides such as LiCoO ₂ and WO ₃ , CuS, Fe _0.25 V
Sulfides such as _0.75 S ₂ and Na _0.1 CrS ₂ , phosphorus such as NiPS ₃ and FePS ₃ , sulfur compounds, selenium compounds such as VSe ₂ and NbSe ₃ can also 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) includes an aprotic organic solvent such as propylene carbonate, 1,3-dioxolan, and 1,2-dimethoxyethane, and LiClO ₄ , LiBF ₄ , and LiAsF.
₅ , 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 one in which an active material is supported on a support made of a mixture of particles of a carbonaceous material having the above-described characteristics and particles of a lithium-aluminum alloy, and a negative electrode can (5) also serving as a negative electrode terminal. ).

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 a battery container including the positive electrode can (1) and the negative electrode can (5), and a battery is assembled.

(6) is 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.

The secondary battery of the present invention is assembled with the above-described configuration. After the assembly, the secondary battery is discharged to allow the positive electrode to support the active material Li contained in the lithium-aluminum alloy in the negative electrode support.

Thereafter, at the time of charging, in the negative electrode body, Li ions are carried on the negative electrode carrier by doping Li ions into the carbonaceous material in the carrier and accumulation of Li ions in the lithium-aluminum alloy. Releases Li ions.

In addition, at the time of discharging, in the negative electrode body, Li ions are released from the carbonaceous material in the support and the lithium-aluminum alloy, and the Li ions are supported in the positive electrode body.

Alternatively, after the secondary battery of the present invention is assembled in the above-described configuration, the lithium in the lithium-aluminum alloy of the negative electrode carrier is allowed to be supported on the carbonaceous material of the negative electrode carrier by a self-discharge reaction after being left as it is. Can be.

Thereafter, at the time of discharge, Li ions in the carrier are released in the negative electrode body, and Li ions are carried in the positive electrode body.

Also, during charging, the negative electrode body carries Li ions on the carrier, and the positive electrode body releases Li ions.

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

The secondary battery of the present invention can support a large amount of the active material on the negative electrode by using a support made of a mixture of the above-described carbonaceous material and a lithium-aluminum alloy for the negative electrode body. Has made it possible to smoothly carry out and release the active material smoothly, so that it can exhibit excellent charge / discharge characteristics with an unprecedented large capacity.

Furthermore, since the secondary battery of the present invention can be assembled, in particular, lithium as an active material can be supported on the negative electrode support in the form of a lithium-aluminum alloy, the supporting step can be omitted, and efficient production of the battery becomes possible. It is extremely advantageous industrially.

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 type elemental analyzer.

"X-ray wide angle diffraction" (1) Spacing between ( ₀₀₂ ) planes (d ₀₀₂ ) and spacing between (110) planes (d ₁₁₀ ) When the carbonaceous material is powder, as it is Powdered in an agate mortar, about 15% by weight of the sample to high purity silicon powder for X-ray standard was added as an internal standard substance, mixed, filled in a sample cell, and the monochromatized CuKα ray with a graphite monochromator was used as a radiation source. The 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, absorption factor, atomic scattering factor and the like. That is, the base lines of the curves corresponding to the (002) and (110) diffractions are drawn, and the substantial intensities from the base lines are re-plotted to obtain correction curves for the (002) and (110) planes. 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 corrected. twice the diffraction angle to determine 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) Size of crystallite in c-axis and a-axis directions: −Lc; La In the corrected diffraction curve obtained in the preceding section, C-axis and a using the so-called half width β at half the peak height
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, λ, θ and θ ′ using K = 0.90 have the same meaning as in the previous section.

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 current collector, a stainless steel net having a wire diameter of 0.1 mm and 60 mesh, to form a positive electrode.

(2) Production of negative electrode body The particles of crystalline cellulose were set in an electric heating furnace, heated to 1,000 ° C at a heating rate of 200 ° C / hr under N ₂ flow, and further heated to 1,000 ° C.
C. for 1 hour. Then, after allowing to cool, the particles of the obtained carbonaceous material were set in another electric furnace, and subjected to 1,000 ° C / N ₂ flow.
The temperature was increased to 1,800 ° C. at a rate of hr. 1 at 1800 ℃
Hold for hours.

The carbonized material thus obtained was placed in a 500 ml agate container, and two agate balls having a diameter of 30 mm, six agate balls having a diameter of 25 mm, and 16 agate balls having a diameter of 20 mm were charged and ground for 3 minutes.

The carbonaceous material had the following characteristics as a result of analysis such as elemental analysis, X-ray wide-angle diffraction, particle size distribution, and non-surface area measurement.

Hydrogen / carbon (atomic _{ratio) = 0.04 d 002 = 3.59Å Lc} = 14Å a 0 (2d 110) = 2.41Å La = 25Å volume average particle diameter = 35.8Mm specific surface area (BET) = 8.2m ² / g The carbonaceous material Powder of lithium-aluminum alloy with lithium content of 33% by weight (volume average particle size 20μm)
Was mixed at a rate of 37% by weight. Furthermore, the average particle size is 2
After mixing 5% by weight of a polyethylene powder having a thickness of 5 μm, the mixture was compression-molded to obtain a 1 mm-thick pellet-shaped support.

(3) Battery assembly The above-described positive electrode body was placed on a stainless steel positive electrode can with the current collector facing down, and a polypropylene non-woven fabric as a separator was placed thereon, and LiClO ₄ was placed there. A non-aqueous electrolytic solution dissolved in propylene carbonate at a concentration of 1 mol / 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 FIG. 1 was manufactured.

(4) Battery Characteristics The battery manufactured in this manner was discharged at a constant current of 0.5 mA until the battery voltage reached 1.0 V.

Thereafter, the battery is charged at a constant current of 250 μA until the battery voltage reaches 3.3 V, and thereafter, the voltage is regulated by the upper limit of 3.3 V and the lower limit of 1.8 V to 250 μA.
A preliminary charge / discharge cycle of 5 cycles was performed at a constant current of A.

Thereafter, charge and discharge were repeated at a constant current of 500 μA in a range of an upper limit of 3.3 v and a lower limit of 1.8 v, and cycle evaluation was performed. Table 1 shows the performance at the 50th cycle and the 100th cycle.

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

(2) Production of Negative Electrode Body A powder of a lithium-aluminum alloy (volume average diameter: 20 μm) having a lithium content of 14% by weight was mixed with the carbonaceous material particles produced in the same manner as in the example at a ratio of 37% by weight.
Further, 5% by weight of a polyethylene powder having an average particle size of 2 μm was mixed with the mixture, followed by compression molding to obtain a pellet-shaped support having a thickness of 1 mm.

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

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

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

(2) Production of Negative Electrode Body A powder of a lithium-aluminum alloy (volume average diameter: 20 μm) having a lithium content of 14% by weight was mixed with the carbonaceous material particles produced in the same manner as in the example at a ratio of 74% by weight.
Further, 5% by weight of a polyethylene powder having an average particle size of 2 μm was mixed with the mixture, followed by compression molding to obtain a pellet-shaped support having a thickness of 1 mm.

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

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

Comparative Example 3 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example.

(2) Production of Negative Electrode Body A powder of a lithium-aluminum alloy having a lithium content of 60% by weight (volume average diameter: 0.3 mm) was mixed with particles of the carbonaceous material produced in the same manner as in the example at a ratio of 17.3% by weight. .
Further, 5% by weight of a polyethylene powder having an average particle size of 2 μm was mixed with the mixture, followed by compression molding to obtain a pellet-shaped support having a thickness of 1 mm.

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

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

Comparative Example-4 (1) Production of Positive Electrode Body A positive electrode body was produced in the same manner as in Example.

(2) Production of Negative Electrode Body A powder of a lithium-aluminum alloy (volume average diameter: 20 μm) having a lithium content of 14% by weight was mixed with the carbonaceous material particles produced in the same manner as in the example at a ratio of 37% by weight.
Further, 5% by weight of a polyethylene powder having an average particle size of 2 μm was mixed with the mixture, followed by compression molding to obtain a pellet-shaped support having a thickness of 1 mm.

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

Prior to incorporating the battery, the negative electrode
It was immersed in an electrolytic solution having an ion concentration of 1 mol / and subjected to electrolytic treatment using the pellets as an anode and metal Li as a cathode.
The electrolytic treatment was performed at a bath temperature of 20 ° C. and a current density of 0.5 mA / cm ² , and together with lithium in the lithium-aluminum alloy, the same amount of lithium as in the example was carried on the carrier.

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

(Effect of the Invention) As is clear from the above description, the secondary battery of the present invention
Since the required amount of lithium, which is an active material, is preliminarily supported on the negative electrode carrier in the form of a lithium-aluminum alloy, the step of supporting lithium on the electrode by electrolytic treatment or the like in battery production can be omitted, and the performance is improved. It has a long discharge cycle life, good charge / discharge characteristics at large currents, and is a smooth active material during charge / discharge.
Since the loading and release of Li or an alkali metal mainly composed of Li can be repeated, excellent charge / discharge characteristics can be exhibited with a large capacity, which has not been achieved in the past.

Although the description so far has been made with respect to a secondary battery having a button-shaped structure, the technical idea of the present invention is not limited to this structure, and for example, a cylindrical shape, a flat shape, a rectangular shape, etc. It can also be applied to secondary batteries.

[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

Continuation of the front page (72) Inventor Kuniaki Inada 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation (72) Inventor Katsuharu Ikeda 3-4-1-10 Minamishinagawa, Shinagawa-ku, Tokyo East (56) References JP-A-3-115110 (JP, A) JP-A-3-114149 (JP, A) JP-A-1-160814 (JP, A) JP-A-1-161675 ( JP, A) JP-A-1-161677 (JP, A) JP-A-63-226882 (JP, A) JP-A-63-69155 (JP, A) JP-A-61-111907 (JP, A) JP-A-62-226563 (JP, A) JP-A-61-91865 (JP, A) JP-A-62-113365 (JP, A) JP-A-63-216267 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) H01M 4/02 H01M 4/04 H01M 4/58 H01M 10/40

Claims (3)

(57) [Claims] 1. A secondary battery comprising a negative electrode carrier of an active material obtained by previously mixing particles of a carbonaceous material and particles of a lithium-aluminum alloy, wherein (1) the active material is mainly composed of lithium or lithium. (2) the carbonaceous material has (a) an atomic ratio of hydrogen / carbon of less than 0.15; and (b) a plane spacing (d ₀₀₂ ) of (002) planes by X-ray wide-angle diffraction. 3.37 ° or more; and the crystallite size (Lc) in the c-axis direction is 150 ° or less; (3) The ratio of the lithium-aluminum alloy in the mixture of the carbonaceous material particles and the lithium-aluminum alloy particles Wherein the secondary battery is 10% by weight or more and 70% by weight or less. 2. The lithium-aluminum alloy according to claim 1, wherein the lithium content is 16% by weight or more and 50% by weight or less.
2. The secondary battery according to 1. 3. The secondary battery according to claim 1, wherein the lithium-aluminum alloy has a lithium content of 22% by weight or more and 45% by weight or less.