JPH01274360A - Secondary battery - Google Patents

Abstract

PURPOSE:To obtain high capacity and enable large current discharge by providing active material made of alkali metal such as lithium and a support made of carbon material, and setting the atomic ratio of hydrogen to carbon less than a predetermined value and a spacing at a predetermined face obtained by an X-ray wide angle diffraction method and the size of crystallite in a C-axis direction within a specific range, respectively. CONSTITUTION:A positive electrode 2 is housed in a positive electrode can 1 serving as a positive electrode terminal in such a way as to be seated on the bottom of the can 1. A negative electrode 4 is arranged oppositely to the positive electrode 2 through a separator 3. The separator 3 for holding an electrolyte is formed with non woven fabrice made of polyolefine resin having an excellent liquid retaining property. Active material is made of lithium or alkali metal including mainly lithium. A support is made of carbon material and expanded graphite, wherein the atomic ratio of hydrogen to carbon is less than 0.10. A spacing at a (002) face obtained by an X-ray wide angle diffraction method is 3.37Angstrom or more and 3.75Angstrom or less, and crystallite in a C-axis direction is 5Angstrom or more and 150Angstrom or less in size.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a secondary battery, and more particularly, to a secondary battery with high energy density (high energy density, long charge/discharge cycle life), and high reliability.

(Prior Art) In recent years, with the development of electronic devices, there has been an increasing demand for the development of secondary batteries that are small, lightweight, have high energy density, and can be repeatedly charged and discharged.

In order to develop such batteries, research has been carried out on batteries that use conductive polymers such as polyacetylene as the positive and/or negative electrodes, and batteries that use these conductive polymers as the positive electrode and Li metal as the negative electrode. It has been.

In addition, the main components of the positive electrode body are T i S t , Mo
Efforts are being made to commercialize a secondary battery that is a chalcogen compound of a transition metal such as St, and whose negative electrode body is Li or an alkali metal mainly composed of Li, because it has a high energy density.

(Problem to be solved by the invention) However, in the case of a secondary battery that uses a conductive polymer as a positive electrode, the electrode capacity is insufficient, and when it is used as a negative electrode, the battery self-discharge is large, and after storage, This causes the inconvenience that the characteristics become unstable.

On the other hand, in a secondary battery using Li as a negative electrode, a problem arises because the negative electrode body is a Li foil or an alkali metal foil mainly composed of Li.

That is, when the battery is discharged, Li from the negative electrode body becomes Li ions and moves into the electrolyte solution, and during charging, these Li ions become metal Li and are deposited on the negative electrode body again, but this charge-discharge cycle is repeated. As a result, the metal Li deposited becomes dendrite-like. Since this dendrite-like Li is an extremely active substance, it decomposes the electrolyte, resulting in the disadvantage that the charge/discharge cycle characteristics of the battery deteriorate. If this continues to grow, the dendrite-like metal Li deposits will eventually penetrate the separator and reach the positive electrode body, causing a short circuit phenomenon. In other words, the problem arises that the charge/discharge cycle life is short.

Therefore, attempts have been made to add powders such as graphite or carbon black to the negative electrode body as a conductive agent in order to lower the internal impedance of the battery, but the problem is that the decomposition of the electrolyte is accelerated and the stability of the battery is impaired. has arisen.

In order to avoid such problems, attempts have been made to construct the negative electrode by using a carbonaceous material obtained by firing an organic compound as a carrier and supporting Li or an alkali metal mainly composed of Li. By using such a negative electrode body, the precipitation of Li dendrites has been prevented, but on the other hand, a battery incorporating this negative electrode body has a much higher discharge capacity than a primary battery of the same size. Furthermore, the magnitude of self-discharge was not necessarily reduced to a satisfactory level.

Under such circumstances, it is an object of the present invention to provide a high-capacity secondary battery that has higher energy density, longer charge/discharge cycle life, and can cope with increased current consumption.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present inventors have conducted intensive research on negative electrode bodies, and as a result, the negative electrode body has been developed as a support made of a carbonaceous material and expanded graphite, which will be described later. The present invention was achieved based on the discovery that a structure in which the active material is supported on the body is effective in achieving the above-mentioned objectives9.

That is, the secondary battery of the present invention includes a negative electrode body consisting of an active material and a carrier supporting the active material, and (1) the active material is lithium or an alkali metal mainly composed of lithium. (2) The support has (a) a hydrogen/carbon atomic ratio of less than 0.10: and.

(b) Interplanar spacing (d) of (002) plane by X-ray wide-angle diffraction method
o. 2) is 3.37 Å or more and 3.75 Å or less: and the crystallite size (Lc) in the C-axis direction is 5 Å or more and 150 Å or less: and expanded graphite.

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 conventional secondary batteries.

In the negative electrode body according to the present invention, the active material is Li or L.
Although it is an alkali metal mainly composed of i, this active material is
The negative electrode body moves in and out in response to charging and discharging the battery.

The carrier for the active material constituting the negative electrode body in the present invention is made of a mixture of a carbonaceous material and expanded graphite having the characteristics described below.6 The carbonaceous material used for the carrier is (a) Hydrogen/carbon atoms Ratio (H/C) is less than 0.10:
and (b) the spacing (d) of the (002) plane by X-ray wide-angle diffraction method
,. 2) is 3.37 Å or more and 3.75 Å or less: and the crystallite thickness (Lc) in the C-axis direction is 5 Å or more and 150 A or less: It is a carbonaceous material specified by these parameters. .

Regarding parameter (a), H/C is preferably 0.
It is less than 0.07, more preferably less than 0.05.

This carbonaceous material may contain other atoms such as nitrogen, oxygen, halogen, etc., but the atomic ratio of (atoms other than hydrogen and carbon)/(carbon atoms) is preferably 0.
．． It is less than 10, more preferably less than 0.07, particularly preferably less than 0.05.

Regarding the parameter (b), (the interplanar spacing (d, .2) of the 0021 plane is preferably 3.39 Å or more and 3.70 Å or more.
Å or less, more preferably 3.41 Å or more and 3.68 Å or less: the crystallite size Lc in the C-axis direction is preferably 10 Å or more and 80 Å or less, and more preferably 12 Å or more and 7
The thickness is 0 Å or less, particularly preferably 15 Å or more and 60 Å or less.

These variations, namely H/C,d,. If either 1 or Lc deviates from the above range, the overvoltage at the negative electrode body during charging and discharging becomes large (as a result, gas is generated from the negative electrode body, significantly impairing the safety of the battery. Not only that, but the charge/discharge cycle characteristics also deteriorate.

Further, it is preferable that the carbonaceous material used for the carrier of the negative electrode body according to the present invention has the characteristics described in the first section.

That is, in Raman spectrum analysis using argon ion laser light with a wavelength of 5145, the G value defined by the following formula is preferably less than 2.5,
More preferably, it is 0.1 to 1.5, particularly preferably 0.2 to 1.2.

Here, the G value refers to the wavelength 514 for the carbonaceous material mentioned above.
In the spectral intensity curve recorded on the chart when five people performed Raman spectrum analysis using argon ion laser light, the wave number was 1580 ± 100 cm-'
It refers to the value obtained by dividing the integral value of the spectral intensity (area intensity) within the range of 1360±100c+m-' by the area intensity within the wavenumber range of 1360±100c+m-', and corresponds to a measure of the degree of graphitization of the carbonaceous material.

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

Furthermore, it is desirable that the carbonaceous material used for the carrier of the negative electrode body according to the present invention satisfies the following conditions.

That is, in X-ray wide-angle diffraction analysis, the distance a o (= 2 d
r lo) is preferably 2.38 to 2.47, more preferably 2.39 to 2.46, particularly preferably 2,40 to 2,45: the crystallite size in the a-axis direction La is preferably 10 to 150 people, more preferably 1
The number is 5 to 100 people, particularly preferably 19 to 70 people.

Further, when electron spin resonance spectroscopy is performed on this carbonaceous material, it is preferable that the line width (ΔHpp) of the signal of the −th order differential absorption curve is 10 Gauss or more or does not have a signal of less than 10 Gauss. .

Further, the carbonaceous material constituting the carrier of the negative electrode body according to the present invention described above can take various shapes, but may have a particle size of 100
The particle size is preferably 4 μm or less, preferably 4 g/g or more.

The above-mentioned carbonaceous material can be obtained by heating and decomposing an organic compound at a temperature of 300 to 3000[deg.] C. under a flow of an inert gas, carbonizing it, and pulverizing it if desired.

Examples of starting organic compounds include cellulose resins, phenolic resins, acrylic resins such as polyacrylonitrile and poly(α-halogenated acrylonitrile); polyvinyl chloride, polyvinylidene chloride, and polychlorinated vinyl chloride. Halogenated vinyl resins such as; polyamideimide resins: polyamide resins: polyacetylene,
Any organic polymer compound such as a conjugated resin such as poly(p-phenylene): for example, naphthalene.

A fused cyclic hydrocarbon compound formed by condensing two or more monocyclic hydrocarbon compounds with three or more members, such as phenanthrene, anthracene, triphenylene, pyrene, chrysene, naphthacene, tocene, perylene, pentaphene, and pentacene, or , derivatives of the above compounds such as carboxylic acids, carboxylic acid anhydrides, carboxylic acid imides, various pitches based on mixtures of the above compounds, indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine. , carbazole.

Condensation in which heteromonocyclic compounds with 3 or more membered rings such as acridine, phenazine, and zenatridine are bonded to each other (two or more of them are bonded to each other, or are bonded to one or more monocyclic hydrocarbon compounds with 3 or more membered rings) Heterocyclic compounds, derivatives of the above compounds such as carboxylic acids, carboxylic anhydrides, and carboxylic imides, and benzene and its derivatives such as carboxylic acids, carboxylic anhydrides, and carboxylic imides, namely L, 2. Examples include 4.5-tetracarboxylic acid, its dianhydride, or its diimide.

Alternatively, a carbonaceous material such as carbon black may be used as a starting source, and this may be further heated to appropriately advance carbonization to form the carbonaceous material constituting the carrier of the negative electrode body according to the present invention.

Since the active material carrier constituting the negative electrode body according to the present invention is made of a mixture of the above-mentioned specific carbonaceous material and expanded graphite, expanded graphite will be described next.

Expanded graphite plays a role as a conductive material.1 The expanded graphite used in the present invention is a highly crystalline graphite such as scaly natural graphite or Quiche graphite, concentrated sulfuric acid, concentrated nitric acid, potassium chlorate, heavy A strong acid such as potassium chromate or potassium permanganate is applied to form a so-called graphite intercalation compound in which acid molecules enter between graphite layers, which is then washed with water to form a residual compound, and then heated to about 1000℃. It is obtained by rapidly heating graphite to a high temperature to decompose the acid and significantly expand graphite.

Graphite intercalation compounds are created by allowing donors (alkali metals, alkaline earth metals, etc.) and acceptors (halogens, acids, etc.) to act as a third component on the surface expansion of secondary graphite, thereby forming donor and acceptor molecules. is formed by penetrating between graphite layers.

Depending on how the third component (referred to as intercalant) enters, it is differentiated into 1st stage (intercalant penetrates into all layers), 2nd stage (intercalant penetrates every other layer), etc.

In particular, in the graphite-alkali metal intercalation compound (for example, Rb, Cs, etc. are used as the alkali metal), the 1st stage (C, M (M; K, Rb.

Cs) is attracting attention because it has a golden color and exhibits superconductivity at extremely low temperatures. Furthermore, when a Lewis acid (A s F s, 5bFs, etc.) is used as an intercalant, an electrical conductivity comparable to that of copper is achieved, and the possibility of use as a highly conductive material is being discovered.

However, the graphite intercalation compound in the -shell is unstable in air, and therefore there are still problems in its practical application. However, some graphite intercalation compounds do not completely decompose in air and the intercalant remains between the layers, forming a so-called residual compound.

Expanded graphite utilizes this phenomenon, and when acid molecules remaining in a portion of the interlayers are rapidly heated to about 1000°C, they are released from the interlayers.

At the same time, graphite expands to 50 to 300 times its apparent thickness in the plane stacking direction (C-axis direction).

When this material is used as a thin graphite sheet by compression or roll forming, it has characteristics such as heat resistance and high thermal conductivity, as well as excellent compression resilience, stress relaxation, and self-lubricating properties, so it can be used as an industrial material. Wide (used.

A feature of the present invention is that the above-mentioned expanded graphite is used as a conductive material in the support for the active material constituting the negative electrode body. This made it possible to lower the internal impedance of the battery without disassembling it, significantly improving the stability and reliability of the battery.

The expanded graphite used in the present invention uses a strong acid such as concentrated sulfuric acid or concentrated nitric acid as an impedance, and has an expansion ratio of 50 to 50.
300 times, and its specific surface area is preferably 1-100rn''7g.

The above-mentioned expanded graphite is added to the above-mentioned carbonaceous material in a proportion of less than 50% by weight, preferably less than 30% by weight, particularly preferably 15% by weight.

Note that the carrier constituting the negative electrode body according to the present invention may contain a binder, other conductive material, etc. in addition to the above-mentioned carbonaceous material and expanded graphite.

As the binder, less than 30% by weight, preferably less than 10% by weight of powder such as polyolefin resin can be added.

Further, as other conductive materials, acetylene black, carbon black, metal powder, etc. can be added in an amount of less than 30% by weight, preferably less than 10% by weight.

The carrier for the active material of the negative electrode body according to the present invention is produced, for example, by mixing a predetermined amount of the above-mentioned carbonaceous material and expanded graphite powder, and press-molding the mixture into a desired shape.

Mixing is performed using a mixer blender such as a Henschel mixer, or a mixing machine such as an automatic mortar, ball mill, or Raikai machine, and molding is performed by compression molding using an ordinary press molding machine.

Next, an active material is supported on the support obtained as described above to form a negative electrode body.

Supporting methods at this time include chemical methods, electrochemical methods, and physical methods. For example, the above-mentioned powder compact is placed in an electrolytic solution containing a predetermined concentration of Li ions or alkali metal ions. A method of electrolytic impregnation in which a carrier is immersed and lithium is used as a counter electrode, and the carrier is used as an anode.Simply, the carrier is immersed in an electrolytic solution while the carrier and lithium are in electrical contact with each other. , a method of supporting by self-discharge reaction, etc. can be applied.

Note that such active material may be supported not only on the carrier of the negative electrode body but also on the carrier of the positive electrode body or on both electrodes.

Next, the structure of the secondary battery of the present invention will be explained with reference to FIG. 1. In FIG. It is installed and stored. This positive electrode body is not particularly limited, but is preferably made of a metal chalcogen compound that releases or acquires alkali metal cations such as Li ions during charging and discharging reactions. Examples of such metal chalcogen compounds include vanadium. oxide, vanadium sulfide,
Examples include molybdenum oxides, molybdenum sulfides, manganese oxides, chromium oxides, titanium oxides, titanium sulfides, and composite oxides and composite sulfides thereof. Preferably, Crs os , Vz os ,
Vs Ors, Vow, Cry Os, Mn0z
, Ti1t, MoV z Oa, Ti5-1V, S,
, M o S l .

Mo sl , VSi , Cro, *sVo, tssi
, Cro, B Va, B S 2, etc. In addition, oxides such as Li COOx and W Os, Cu
S, F e o, xsV o. tssx, Naa, +
Sulfides such as CrS*, NiPSs, FePSs
Phosphorus, sulfur compounds such as VSe*, N b Se
Selenium compounds such as s can also be used.

Among the above metal chalcogen compounds, substantially amorphous transition metal chalcogen compounds are particularly preferred.

A positive electrode body (2) and a negative electrode body (4) are opposed to each other with a separator (3) interposed therebetween.

The separator (3) that holds the electrolyte is made of a material with excellent liquid retention properties, such as a nonwoven fabric made of polyolefin resin. This separator (3) is prepared by adding LiCε04°L to an aprotic organic solvent such as propylene carbonate, 1°3-dioxolane, or 1,2-dimethoxyethane.
iBF4. LiAsF5. It is impregnated with a non-aqueous electrolyte of a predetermined concentration in which an electrolyte such as LiPFa is dissolved.

Furthermore, a solid electrolyte that is a conductor of Li or alkali metal ions can be interposed between the positive electrode body and the negative electrode body.

The negative electrode body (4) has an active material supported on a support made of a mixture of a carbonaceous material and expanded graphite having the above-mentioned characteristics, and is mounted in a negative electrode can (5) which also serves as a negative electrode terminal. ing.

These positive electrode body (2), separator (3), and negative electrode body (4) constitute a power generation element as a whole. Then, this power generation element is housed in a battery container consisting of a positive electrode can (1) and a negative electrode can (5), and a battery is assembled.

6 is an insulating backing that separates the positive and negative electrode bodies, and the battery is sealed by bending the opening of the positive electrode can (1) inward.

Thus, in the secondary battery of the present invention, the following reaction proceeds.

During charging: In the positive electrode body, MnO, (Li)
s (Li) Also, during discharge, a dedoping phenomenon of Li ions supported on the negative electrode body occurs,
A reversible electrochemical redox reaction progresses with charging and discharging.

By carrying and releasing Li ions in this manner, the charge/discharge cycle of the battery is repeated.

In the secondary battery of the present invention, by using a carrier made of the above-mentioned carbonaceous material and expanded graphite for the negative electrode body, it is possible to lower the internal impedance of the battery without decomposing the electrolyte. As a battery with improved stability and high reliability, it exhibits excellent characteristics never seen before.

In addition, in the present invention, each measurement of elemental analysis, X-ray wide-angle diffraction, and electron spin resonance spectrum was performed by the following method.

"Elemental Analysis" Samples were dried under reduced pressure at 120° C. for about 15 hours, then dried at 100° C. for 1 hour on a hot plate in a dry box. The CO generated by combustion was then sampled in an aluminum cup in an argon atmosphere.
□ Calculate the carbon content from the weight of the gas, and also calculate the generated H, O
Determine the hydrogen content from the weight of. In the practical examples of the present invention described later, measurements were made using a PerkinElmer 240C elemental analyzer.

"X-ray wide-angle diffraction" (1) Interplanar spacing (d, .2) of (002) plane and (11
0) Interplanar spacing (d,,,1) If the carbonaceous material is powder, it is used as is, or if it is in the form of minute pieces, it is powdered in an agate mortar, and approximately 15% by weight of x#! standard height is added to the sample. Pure silicon powder is added as an internal standard substance, mixed, packed into a sample cell, and a wide-angle X-ray diffraction curve is measured using a reflection diffractometer method using CuKa rays made monochromatic with a graphite monochromator as a radiation source. The correction involves the so-called Lorentzian, polarization factor,
The following simple method is used without making any corrections for absorption factors, atomic scattering factors, etc. That is, baselines of curves corresponding to (002) and (110) diffraction are drawn, and the real intensities from the baseline are plotted again to obtain correction curves for the (002) and (110) planes. Find the midpoint of the line segment where a line parallel to the angular axis drawn at two-thirds of the peak height of this curve intersects with the diffraction curve, correct the angle at the midpoint using an internal standard, and calculate this. The wavelength λ of the CuKa line is
and do by the following Bragg equation. , and d++
. seek.

+1.5418 people θ, θ': d0゜z, d z. The diffraction angle corresponding to (2
) Crystallite size in c-axis and a-axis directions: Lc; L
a In the corrected diffraction curve obtained in the previous section, the size of the crystallite in the C-axis and a-axis directions is determined from the following equation using the so-called half value β at the position half the peak height.

β・cosθ There are various discussions about the shape factor K, but = 0.90
was used. The circles, θ, and θ' have the same meanings as in the previous section.

[Linewidth of electron spin resonance spectrum: ΔHppJ Temporary differential absorption vector of electron spin resonance is JEOL JE
Measure at X band using S-FE LX ESR, 2, pectrometer. Powdered samples are left as they are, and minute flake samples are pulverized in an agate mortar and placed in a capillary tube with an outer diameter of 2 mm, and the capillary tube is then placed in an ESR tube with an outer diameter of 51 III. The modulation width of the high-frequency magnetic field is 6.3 Gauss, and the linewidth (ΔHpp) between the peaks of the −th order differential absorption spectrum is M n
/ M g O Determined using O standard sample.

(Example) The present invention will be explained below with reference to Examples.

Problems (1) Production of positive electrode body 5 g of MnO* powder calcined at 470°C and 0.5 g of powdered polytetrafluoroethylene were kneaded, and the resulting mixed wire product was roll-formed to a thickness of 0.5 g. It was made into a 4 mm sheet.

The single-sided current collector of this sheet has a wire diameter of 0.1 mm, 60
It was crimped onto a mesh stainless steel net to serve as a positive electrode.

(2) Manufacture of negative electrode body (2-1) Manufacture of carbonaceous material 108 g of orthocresol, 32 g of paraformaldehyde
g and 240 g of ethyl cellosolve were charged into a reactor together with 10 g of sulfuric acid and reacted at 115°C for 4 hours with stirring.After the reaction was completed, 0.17 g of NaHC and 30 g of water were added to neutralize the mixture.Next, the mixture was stirred at high speed. The reaction solution was poured into water 2e, and the precipitated product was filtered and dried to obtain 115 g of a linear high molecular weight novolac resin.

5 g of the above novolak resin and 25 g of hexamine
The mixture was placed in a 00 mff agate container, and 5 agate balls each having a diameter of 30 mm and 10 agate balls each having a diameter of 20 mm were placed in a ball mill, and the mixture was ground and mixed for 20 minutes.

The thus obtained mixed powder of novolac resin and hexamine was heat-treated at 250° C. for 3 hours in N2 gas. Furthermore, this heat-treated product was set in an electric heating furnace, and N
, 950°C at a heating rate of 200°C/hour while flowing gas.
The temperature was raised to 0.degree. C., and the temperature was maintained for an additional 1.5 hours for firing, and then allowed to cool naturally.

Next, the fired material is placed in a separate electric furnace at 25℃/
The temperature was raised to 2000° C. at a temperature increase rate of 1.5 min, and the temperature was maintained for an additional 1.5 hours to carry out carbonization.

The carbonized product thus obtained was placed in a 25011I2 agate container, and 1 agate ball with a diameter of 30 am, 3 agate balls with a diameter of 25 mm, and 9 agate balls with a diameter of 20 mm were placed in the ball mill, and the mixture was set in a ball mill. 1
Grinding was continued for 0 minutes, and 4 agate balls each having a diameter of 20 mm were added, and grinding was continued for 25 minutes.

This carbonaceous material had the following characteristics as a result of analysis such as elemental analysis, X-ray wide-angle diffraction, and Raman spectrum.

Hydrogen/carbon (atomic ratio) = 0.04 do. i = 3.66 people, Lc = 13.0 people ao (2do
ot l =2.42 people.

La = 21.0 people.

(2-2) Production of expanded graphite Add 200 ml of a@acid to 20.0 g of scaly natural graphite,
The mixture was stirred and mixed at 50°C for 300 hours to form a graphite-sulfuric acid intercalation compound.Then, this mixture was washed with water, dried, and rapidly heated to 1000°C to obtain 20.0 g of expanded graphite.

The expanded graphite thus obtained had the following properties.

Intercalant (sulfuric acid) 600ppm Specific surface area 10m
”/g (2-3) Manufacture of support (2-1) Carbonaceous material powder (average particle size 15
μm) 9.5g of expanded graphite powder (average particle size lOμm)
After mixing 14.25 g and 0.5 g of polyethylene powder, compression molding was performed to obtain a sheet-like carrier having a thickness of 0.5 mm.

(3) Assembly of the battery The above-mentioned positive electrode body was installed in a stainless steel positive electrode can with the current collector facing down, and after placing a polypropylene nonwoven fabric as a separator on it, Li Cl2O was placed thereon.
, was impregnated with a non-aqueous electrolytic solution prepared by dissolving 1 mol/β in propylene carbonate. Then, the negative electrode body was placed thereon to form a power generation element.

In addition, before incorporating the positive electrode into the battery, the concentration of the positive electrode is 1 mol/
Immersed in Li ion electrolyte of ε, using the positive electrode body as an anode,
It was subjected to electrolytic treatment using lithium as a cathode. Electrolytic treatment is
The bath temperature was 20°C, the current density was 1 mA/crn'', and the electrolysis time was 10 hours, and the capacity of the positive electrode was 6.0mAh.
of Li was supported.

In this way, a button-shaped secondary battery as shown in FIG. 1 was manufactured.

(4) Characteristics of the battery The battery manufactured in this way was repeatedly charged with a constant current of 0.5 mA and discharged with an Ω resistance for 20 to 20 cycles. Capacity was measured. The results are shown in Table 1.

land comparison father-in-law (1) Manufacture of positive electrode body A positive electrode body was manufactured in the same manner as in the example.

(2) Manufacture of negative electrode body In addition to the carbonaceous material manufactured in the same manner as in the example, natural graphite powder (cp-B manufactured by Nippon Graphite ■) was used instead of expanded graphite.
) was used, but a negative electrode body was produced in the same manner as in the example.

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

(4) Battery characteristics Measure the battery characteristics under the same conditions as in the example,
The results are also listed in Table 1.

[Effects of the Invention] As is clear from the above explanation, the secondary battery of the present invention has a long charge/discharge cycle life (and during charging, the active material Li or an alkali metal mainly composed of Li is stabilized). Since it can be fixed on a carrier in such a form, stable high capacity, that is, large current discharge is possible, and the battery is highly reliable, so its industrial value is great.

Although the explanation so far has been made regarding a secondary battery having a button-shaped structure, the technical concept of the present invention is not limited to this structure, and for example, it can be applied to a secondary battery having a cylindrical, flat, or square shape. It can also be applied to secondary batteries.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of a secondary battery having a button-shaped structure, which is an embodiment of the present invention.

Claims (1)

[Scope of Claims] A secondary battery comprising a negative electrode body comprising an active material and a carrier supporting the active material, wherein: (1) the active material is lithium or an alkali metal mainly composed of lithium; (2) The support has (a) a hydrogen/carbon atomic ratio of less than 0.10: and (b) an interplanar spacing (d) of the (002) plane determined by X-ray wide-angle diffraction
_0_0_2) is 3.37 Å or more and 3.75 Å or less, and the crystallite size in the c-axis direction (Lc) is 5 Å or more and 150 Å
A secondary battery comprising a carbonaceous material and expanded graphite.