JPH01160814A - Secondary battery - Google Patents

Abstract

PURPOSE:To obtain a secondary battery with high every density, long in charge- discharge cycle life, by using a specific carbonaceous material as the cathode in a secondary battery comprised of a separator holding the anode and electrolyte, the cathode, and active substance. CONSTITUTION:The objective secondary battery with a power-generating element housed therein. This power-generating element is comprised of: (a) the anode consisting of a transition metal calcogen compound, (b) a separator on which said anode is laid, (c) an electrolyte held by said separator, (d) the cathode on which said separator is laid, consisting of such a carbonaceous material as to have the following characteristics: (i) atom ratio H/C<0.10 (ii) spacing for (002) plane determined by the X-ray wide angle differactometory: d002... >=3.37Angstrom and <=3.75Angstrom (iii) crystallite size in the direction of C-axis: Lc... >=5Angstrom and <=150Angstrom (iv) total pore volume... >=1.5X10<-3>ml/g and (v) average pore radius... 8-100Angstrom (e) an active substance included in said anode and/or cathode, moving between them corresponding to charge and discharge reaction, consisting of lithium or a lithium-dominant alkali metal component.

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 that has high energy density, long charge/discharge cycle life, and excellent reliability.

(Prior Art and Problems) 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.

As such a secondary battery, for example, one in which a conductive polymer such as polyacetylene is used as a positive electrode or a negative electrode is known (Solid State Physics 17 [12] 753 (1982)). When used as a negative electrode, the electrode capacity becomes insufficient, and when used as a negative electrode, self-discharge is large and the characteristics after storage become unstable.

Moreover, the main component of the positive electrode body is TiS2. Efforts are being made to commercialize nonaqueous electrolyte secondary batteries, which are chalcogen compounds of reduced metals such as MoS2, and whose negative electrodes are Li or an alkali metal mainly composed of Li, because they have high energy density. There is.

An example of such a secondary battery is shown in FIG. 1, and FIG. 0 is a longitudinal sectional view of a button-type non-aqueous electrolyte secondary battery.

In the figure, l is the positive electrode body. The positive electrode body 1 is made by pelletizing or sheeting a mixture of the above-mentioned transition metal chalcogen compound powder and a binder such as polytetrafluoroethylene.

2 is a separator, for example, a porous polypropylene thin film,
It is made of a liquid-retentive material such as polypropylene nonwoven fabric, and is placed on the positive electrode body l. This separator 2 is made of LiCJ104. LiA sentence 04゜Li
It is impregnated with a non-aqueous electrolyte of a predetermined concentration in which an electrolyte such as BF4, LiPF6, or LiAsF6 is dissolved.

Reference numeral 3 denotes a negative electrode body placed on the positive electrode body l via the separator 2, and is made of Li foil or an alkali metal foil containing Li as a main component.

These positive electrode body 1, separator (non-aqueous electrolyte) 2, and negative electrode body 3 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 4 and a negative electrode can 5, and a battery is assembled. 6 is an insulating backing, and 7 is a current collector interposed between the positive electrode body l and the positive electrode can 4. This current collector 7 is usually made of nickel net,
It is composed of a stainless steel wire mesh, punched metal, or foam metal, and is crimped onto one side of a pelletized or sheeted positive electrode body l.

In the secondary battery having the conventional structure as described above, the following problems have occurred, and improvement thereof is required.

This is a problem based on the fact that 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 to the electrolyte, and during charging, these Li ions are converted into metal L! When this charge/discharge cycle is repeated, the metal Li deposited on the negative electrode body is deposited again.
becomes dendrite-like and grows, and finally,
The problem is that this dendrite-shaped metal Li deposit penetrates the separator and reaches the positive electrode body, causing a short circuit phenomenon. In other words, the problem is that the charge/discharge cycle life is short.

In view of the current situation, the present inventors have conducted intensive studies to develop a secondary battery that has higher energy density, longer charge/discharge cycle life, and can handle increased current consumption, and as a result, has developed the present invention. Reached.

(Means and effects for solving the problems) The secondary battery of the present invention includes a positive electrode body, a separator placed on the positive electrode body,
An electrolyte held in the separator, a negative electrode body placed on the separator, and an active material that is included in the positive electrode body and/or the negative electrode body and moves between the positive and negative electrode bodies in response to charge/discharge reactions. (a) the positive electrode body is made of a transition metal chalcogen compound, (b) the negative electrode body has a hydrogen/carbon atomic ratio of less than 0.10,
Interplanar spacing (d002) of (002) plane by line wide-angle diffraction method
3.37 Å or more and 3.75 Å or less, crystallite size in the C-axis direction (Lc) 5 Å or more and 150 Å or less, total pore volume of 1
,5X 10-3m17g or more and average pore radius 8~
Made of 100 carbonaceous materials.

(c) The active material is lithium or an alkali metal mainly composed of lithium.

The secondary battery of the present invention has the above-mentioned (a), (b),
(c), especially (b), and other elements may be the same as conventional secondary batteries.

First, the positive electrode body according to the present invention is made of a transition metal chalcogen compound, and the transition metal chalcogen compounds used include, for example, oxides and sulfides of V, Mo, Mn, Cr, Ti, etc. oxide, ■ sulfide, MO oxide, MO sulfide, Mn oxide, Cr oxide,
Ti oxides and Ti sulfides are preferred. More preferably, V20s, Vs Ot3, MO2, ■2S5
, VS2. MoS2. Mo53, MnO□, Cr30
s, Cr2O5, TiS2 and TiO2.

When the transition metal chalcogen compound described above is amorphous, amorphization is usually carried out using a melt quenching method. Moreover, an amorphous hydrogel can also be prepared and used. In the present invention, an amorphous substance refers to a substance in which no peaks due to crystals are observed when X-ray diffraction is performed. In other words, amorphization means that a broad halo that is amorphous in X-rays is observed. The amorphous material has a structure in which long-range order has disappeared, as confirmed by the diffraction pattern of the amorphous material. However, it has been confirmed from various analyzes that the short-range a order remains.

Furthermore, for the purpose of improving the charge-discharge cycle characteristics of the Na-layer, metal L is added to the above-mentioned transition metal chalcogen compound.
i or a transition metal can be added. The amount added is
Li is 50 mol% relative to the transition metal chalcogen compound
less than 30%, preferably less than 30% by mole, and the transition metal is less than 2% by mole.
It is less than 0 mol%, preferably less than 10 mol%.

The positive electrode body according to the present invention is manufactured, for example, as follows. That is, first, the above-mentioned transition metal chalcogen compound is pulverized into powder having a predetermined particle size. The volume average particle diameter is 500% or less, preferably 200 or less, more preferably 100 or less, particularly preferably 50 or less.

Further, the specific surface area is preferably 1rrI'/g or more,
More preferably torn'/g or more, particularly preferably 20rrf/g or more.

Usually, a predetermined amount of a binder is added to the transition metal chalcogen compound powder, and the two are sufficiently kneaded. As a binder,
Polytetrafluoroethylene powder, dispersion, polyolefin powder, etc. are used, and the preferable amount added is 1 to 1 O per transition metal chalcogen compound.
Weight%.

At this time, a powder of a conductive material such as graphite or carbon black may be added in an amount of less than 50% by weight, preferably less than 30% by weight, and more preferably 15% by weight based on the transition metal chalcogen compound.

The obtained kneaded product is pressure-molded to form a positive electrode body, but a foil produced by pressure-molding a transition metal chalcogen compound alone can also be used as a positive electrode body.

Next, the negative electrode body will be explained.

The negative electrode body is a powder compact made of a carbonaceous material, which will be described later. This carbonaceous material has a H/C (atomic ratio) of less than 0.10, d
002 is 3.37 A or more and 3.75 Å or less, Lc is 5 Å or more and 150 Å or less, total pore volume is 1, 5X IO-"
wJ/g or more and the average pore radius is specified with parameters of 8 to 100 people.

The H/C of the carbonaceous material used in the negative electrode body according to the present invention is preferably 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 other atoms/carbon atoms (atomic ratio) is preferably less than 0.10, more preferably is less than 0.05, particularly preferably 0
．． It is less than 03.

Further, the interplanar spacing d 002 of the (OO2) plane determined by X-ray wide-angle diffraction is preferably 3.39 Å or more and 3.70 Å.
The crystallite size Lc in the C-axis direction is preferably 10 Å or more and 80 Å or less, 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.

If any of H/C, doo2 and Lc deviates from the above range, the overvoltage at the negative electrode during charging and discharging will increase, and as a result, gas will be generated from the negative electrode, significantly reducing the safety of the battery. be damaged.

Furthermore, the charge/discharge cycle characteristics are also unsatisfactory.

Furthermore, the carbonaceous material used for the negative electrode body according to the present invention is
The total pore volume is preferably 2.0 x 10-3 d/g or more,
More preferably 3.0X10-"rd/g or more, particularly preferably 4.OXlo-3ml/g or more, and the average pore radius is preferably lO to 80A, more preferably 12 to 60A, particularly preferably 14 to There are 40 people.

If the total pore volume and average pore radius deviate from the above ranges, the amount of active material supported will decrease, and the capacity of the battery will decrease.

The total pore volume and average pore radius are determined by measuring the amount of gas adsorbed on the sample under equilibrium pressure using the constant volume method.

That is, in the present invention, the total pore volume and average pore radius mean those determined as follows.

The total pore volume is the relative pressure P/P determined using the constant volume method, assuming that the pores are filled with liquid nitrogen, for example.
, = 0.995 (P: vapor pressure of adsorbed gas + PQ: saturated vapor pressure of adsorbed gas at cooling temperature), calculate the total volume (Vads) of nitrogen gas adsorbed, and then use the following equation.

[In the formula, Pa is the atmospheric pressure (kgf/c+a2), T is the measurement temperature (K), and Vm is the molecular volume of the adsorbed gas (cm
"1 mol; 34.7 for N2), Vliq is the volume of liquid nitrogen (c 3)], the amount of liquid nitrogen filled in the pores (Vliq
).

Next, the average pore radius (γp) is determined by 1 from the value of Vliq obtained from the above formula (1) and the BET specific surface area (S) of the sample.
It is calculated by converting it using the following formula % formula %. Note that the pores are assumed to be cylindrical.

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

In other words, the distance 5Lo (= 2 d l
1o) is preferably 2.38 Å or more and 2.47 Å or less, more preferably 2.39 Å or more and 2.46 Å or less, particularly preferably 2.40 λ or more and 2.45 Å or less; crystallite size in the a-axis direction La is preferably 10 Å or more, more preferably 15 Å or more and 150 Å or less, particularly preferably 19 Å or more and 70 Å or less.

In addition, in Raman spectrum analysis using argon ion laser light with a wavelength of 5145 nm, the G value defined by the integral value of the spectral intensity in the wave number range of 1360 ± 100 cm-' is less than 2.5. Preferably, more preferably 0.1 to 1.5,
Particularly preferably, it is 0.2 to 1.2.

Furthermore, in electron spin resonance spectroscopy, it is preferable that the linewidth (ΔHpp) of the signal of the −th order differential absorption curve is 10 Gauss or more, or there is no signal with a linewidth of less than 10 Gauss.

The carbonaceous material used for the negative electrode body according to the present invention described above is
Although they can take various shapes, they are preferably particles with a particle size of 100 mm or less. Furthermore, the specific surface area is preferably ln
It is 17 g or more, more preferably 2 ml/g or more, particularly preferably 4 rn''/g or more. If the amount exceeds the above range, the amount of active material supported will decrease, and the capacity of the battery will decrease.

Such carbonaceous materials can be produced by firing one or more organic compounds such as organic polymer compounds, fused polycyclic hydrocarbon compounds, fused polycyclic hydrocarbon compounds, and polycyclic heterocyclic compounds. It can be manufactured by

Examples of such starting sources include, for example, cellulose resins; phenolic resins; acrylic resins such as polyacrylonitrile and poly(α-halogenated acrylonitrile); polyvinyl chloride, polyvinylidene chloride, polychlorinated vinyl chloride, etc. halogenated vinyl resin; polyamide-imide resin; polyamide resin; polyacetylene, poly(
Any organic polymer compound such as conjugated resin such as p-phenylene; for example, naphthalene, phenanthrene,
Anthracene, triphenylene, pyrene, chrysene.

naphthacene, picene, perylene, pentaphene.

A condensed polycyclic hydrocarbon compound formed by condensing two or more monocyclic hydrocarbon compounds with three or more members such as pentacene,
Alternatively, various pitches containing derivatives of the above compounds such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides, and mixtures of the above compounds; for example, indole and isoindole.

quinoline, isoquinoline, quinoxaline, phthalazine,
Carbazole, acridine, phenazine.

A fused heterocyclic compound formed by at least two or more 3-membered or more-membered monocyclic compounds such as phenanthrene bonded to each other, or bonded to one or more 3- or more-membered monocyclic hydrocarbon compounds, each of the above. Examples include derivatives of compounds such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides, as well as 1,2,4,5-tetracarboxylic acid of benzene, its dianhydrides, and its diimides.

Preferred are phenolic resins, cellulose resins, and acrylic resins, and more preferred are phenolic resins.

Next, the above-mentioned starting material is fired under the conditions described below. In other words, the adsorbed gas volume (V) at the relative pressure P/P0 = 0.995 (P and Pa have the same meanings as above), which was determined using the constant volume method in the same way as the total pore volume described above, is under an inert gas flow or under vacuum until the adsorbed gas capacity (Vo ) determined for the previous one is at least 1.5 times, preferably at least 3 times, more preferably at least 5 times, particularly preferably at least 10 times. , 350-1000°C. As the inert gas, for example, N2, Ar, He, etc. can be used, but N2 is preferable from the point of view of economy and the like. Further, the firing temperature is preferably 400 to 1000°C, more preferably 500 to 1000°C, and particularly preferably 600°C.
~1000°C 0 typically 2°C/hour ~ 500°C/min,
Preferably 5°C/hour to 100°C/min, more preferably 10°C/hour to 50°C/min, particularly preferably 20°C/hour to
The temperature was increased to the above-mentioned calcination temperature at a heating rate of 10° C./min, and then at that temperature.

Firing is carried out by holding for 1 minute to 10 hours, preferably 5 minutes to 8 hours, more preferably 10 minutes to 5 hours, particularly preferably 20 minutes to 3 hours.

Furthermore, the fired material is carbonized under an inert gas stream or under vacuum at a temperature of over 1000°C and below 3000°C. At this time, the 02 concentration in the system is preferably 110
00 ppm or less, more preferably 100 ppm or less,
Particularly preferably 1 ppm to 50 ppm. If the 02 concentration exceeds this range, good carbonization will not occur.

Next, after carbonization in the kiln, the target carbonaceous material can be obtained by pulverizing to a predetermined particle size by mechanical pulverization or the like.

Alternatively, carbon black may be used as a starting source and subjected to further treatment such as carbonization under appropriate conditions to produce a carbonaceous material.

In order to manufacture the negative electrode body according to the present invention from the carbonaceous material obtained in this way, it is carried out, for example, as follows.

The above-mentioned carbonaceous material is used alone or after being kneaded with a conductive material, a binder, etc., and then pressure-molded to form a negative electrode body. Examples of the conductive material used at this time include acetylene black, carbon black, expanded graphite, metal powder, etc. If necessary, these may be added in an amount of less than 50% by weight, preferably less than 30% by weight, based on the carbonaceous material. It is preferably added in an amount of 0.1 to 10% by weight. In addition, examples of the binder include polyolefin resins, fluorine-based resins such as polytetrafluoroethylene, etc., and these are used in an amount of 20% by weight based on the carbonaceous material.
less than 1% by weight, preferably from 1 to 10% by weight.

Next, we will discuss the active material. The active material in the secondary battery of the present invention is lithium or an alkali metal mainly composed of lithium. move back and forth between The active material is supported on the above-mentioned positive electrode body and/or negative electrode body in advance. As a method of supporting, for example, a method is applied in which a negative electrode body is immersed in an electrolytic solution containing a predetermined concentration of Li ions or alkali metal ions, and Li is used as a counter electrode as an anode to cause electrolysis using the negative electrode body as a cathode. can do. Further, in a similar manner, lithium or an alkali metal mainly composed of lithium can be supported on the positive electrode body. In addition to such an electrochemical method, the active material can be supported by a chemical method or a physical method. In addition, a battery cell is constructed by gluing a Li metal sheet to the negative electrode body,
Li metal can also be supported on the negative electrode body through a charge/discharge reaction.

The secondary battery of the present invention can be manufactured by incorporating the negative electrode body and the positive electrode body carrying the above-described active material together with other elements in a conventional manner. That is, the positive electrode body and the negative electrode body are faced to each other with a separator interposed between them, and the separator usually contains
A nonaqueous electrolyte in which Li metal salt or alkali metal salt is dissolved is held. The nonaqueous electrolyte used at this time is the one used in the conventional secondary battery described above. Alternatively, a solid electrolyte that is a conductor of Li ions or alkali metal ions can be interposed between the positive electrode body and the negative electrode body.

Thus, in the secondary battery of the present invention, the following reaction proceeds. In other words, during charging: In the positive electrode body, V205 (Li) →! V2 o, +xLi” +xe In the negative electrode body, C+xLi” +xe+CsLi.

During discharge: In the positive electrode body, V205 +xLi” +xe-+V20
5 (Li)X In the negative electrode body, the reaction is Cm Li +c+XL, t'' +Xe.

That is, in the secondary battery of the present invention, for example, a doping phenomenon of Li ions occurs in the negative electrode body during charging, and a dedoping phenomenon of Li ions supported on the negative electrode body occurs during discharging, resulting in reversible electricity generation. Since the chemical oxidation-reduction reaction progresses with charging and discharging, the formation of dendrite-shaped deposits that occur on the surface of the negative electrode when it is made of Li foil disappears.

In the present invention, single-element analysis, X-ray wide-angle diffraction, and electron spin resonance spectroscopy were carried out by the following methods.

"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.
2 The carbon content from the weight of the gas, and the generated H2O
Determine the hydrogen content from the weight of. In the Examples of the present invention described later, measurements were made using a PerkinElmer 240C elemental analyzer.

rXX-ray wide-angle diffraction (1) Interplanar spacing between (002) planes (do02) and interplanar spacing between (110) planes (dllo) If the carbonaceous material is in the form of a powder, it can be used as is, or if it is in the form of minute particles, it can be powdered in an agate mortar. Approximately 15% by weight of high-purity silicon powder for X-ray standards was added to the sample as an internal standard substance, mixed, packed into a sample cell, and a reflection type detector using CuKα rays made monochromatic with a graphite monochromator as a radiation source. Wide-angle X-ray diffraction curves are measured by the fractometer method. To correct the curve, the following simple method is used without making corrections regarding so-called Lorentz, polarization factors, 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. d 002 and dll by the following Bragg equation from the wavelength input of the CuKα ray.
Find O.

λ λ input: 1.54
18 people θ, θ': d002. The diffraction angle corresponding to dllO (
2) Crystallite size in c-axis and a-axis directions: Lc;
La 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-width β at a position half the peak height.

β'cosθ β°cosθ' There are various discussions about the shape factor K, but = 0.09
λ, θ, and θ' have the same meaning as in the previous section.

“Linewidth of electron spin resonance: ΔHPPJ The first-order differential absorption vector of electron spin resonance is JEOL
Measure in the X band using a JES-FE IX ESR spectrometer. Powdered samples are left as they are, and minute flake samples are pulverized in an agate mortar, with an outer diameter of 2 m1.
into a capillary tube with an outer diameter of 5III.
Put it in the R tube. During the modulation of the radio frequency magnetic field, the peak-to-peak line If@(ΔHpp) of the −th order differential absorption spectrum is taken as 6.3 Gauss and above 0, all performed at 23° C. in an air atmosphere.

Determine using M n ”/M g O standard sample.

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

(1) Manufacture of positive electrode body 80 g of MnO2 powder, 15 g of carbon black as a conductive material, and 5 g of powdered polytetrafluoroethylene as a binder were kneaded, and the resulting kneaded product was roll-formed to give a thickness. It was made into a sheet of 0.4 mrA.

One side of this sheet is a current collector with a wire diameter of 0. llll11
．． The positive electrode was crimped onto a 60 mesh stainless steel net.

(2) Manufacture of negative electrode body 108 g of orthocresol, rose formaldehyde F32
g and 240 g of ethyl cellosolve were charged into a reactor together with 10 g of sulfur #1 and reacted at 115° C. for 4 hours with stirring. After the reaction was completed, 17 g of Na HCOs and 30 g of water were added to neutralize. Then, the reaction solution was poured into two volumes of water while stirring at high speed, and the precipitated product was separated and dried to obtain 115 g of a linear high molecular weight novolak resin.

Put 225 g of the above novolac tree and 25 g of hexamine into a 500-mm agate container, add 5 agate poles with a diameter of 30 mm and 10 agate balls with a diameter of 20 mm, set it in a ball mill, and grind for 20 minutes. Mixed.

The thus obtained mixed powder of novolac resin and hexamine was heat-treated at 250° C. for 3 hours in N2 gas. Furthermore, set this thing in an electric heating furnace, and
The temperature was raised to 800°C at a rate of 250°C/hour under two gas flows. At the same temperature, the adsorbed gas capacity (V) was determined using the constant volume method at a relative pressure of P/Po = 0.995 (P and Po have the same meanings as above) before the temperature was raised. Thermal firing was performed until the capacity (Va) reached 5 times or more.

Next, the fired materials are placed in a separate electric furnace.

The temperature was raised to 1700° C. at a rate of 20° C./min under vacuum, and carbonization was carried out by heating at that temperature for an additional 1.5 hours.

The carbonized product thus obtained was placed in a 250-mm agate container, and one agate pole with a diameter of 30 mm and a diameter of 25 m were placed.
Three agate poles (3) and nine agate poles with a diameter of 20+a+e were placed in a ball mill and ground for 10 minutes to obtain a carbonaceous material with an average particle size of 46.9 mm.

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

Hydrogen/carbon (atomic ratio) = 0.04 d□o2 = 3.67A, Lc = 12.8 people ao (2d
002) = 2, 42 people, La = 20.9 people Total pore volume 4.96683X10-3 m//g (measured using liquid nitrogen using Autosorb manufactured by Yusen Ionics) BET specific surface area 4. 59572rn'/g Average pore radius 21.6150A 50+sg of a mixture of this carbonaceous material mixed with 7% by weight of polyethylene powder with a volume average particle size of 20- was pressure-molded to form pellets with a thickness of 0.5cm. .

(3) Assembly of the battery Place the above-mentioned positive electrode body in a stainless steel positive electrode can with the current collector facing down, place a polypropylene nonwoven fabric on top of it, and then add LiC04 at a concentration of 1 molar. A non-aqueous electrolytic solution dissolved in propylene carbonate was impregnated with a mixture of: Then, the negative electrode body was placed thereon to form a power generation element.

Note that the positive electrode body should be prepared at a concentration of 1 mol/min before being incorporated into the battery.
The sample was immersed in a Li-ion electrolyte solution prepared by the manufacturer, and subjected to an electrolytic treatment using the positive electrode body as a cathode and lithium as an anode. The electrolytic conditions were a bath temperature of 20°C and a current density of 1 mA/cm2. The electrolysis time was 10 hours. Through such treatment, the positive electrode body has a capacity of 6. This means that OmAh of Li is 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 at a constant voltage of 3 to 2 V and discharged at a constant resistance of -20 Ω, and the charging capacity and discharging capacity of the battery were measured at 5 cycles and 100 cycles. did. The results are shown in Table 1.

Comparative example 1 (1) Manufacture of positive electrode body A positive electrode body was manufactured in the same manner as in Example 1.

(2) Manufacture of negative electrode body mesoface pitch lOg at 300℃, 1.5ton/
It was heated and pressurized to am2 and formed into a sheet shape.

Next, this sheet was heated to 3000° C. at a rate of 1000° C./hour in N2 gas, further heated at this temperature for 1 hour, and then allowed to cool naturally. This fired product was pulverized in the same manner as in Example 1 to obtain a carbonaceous material with an average particle size of 500-.

As a result of analysis, this carbonaceous material had the following properties.

Hydrogen/carbon (atomic ratio) = 0.01 dQ02 = 3.38 people, Lc = 156 people lO - Cumulative pore volume of pores with pore radius of 250 people 1,5
This carbonaceous material powder was mixed with 7% by weight of polyethylene powder, and the mixture was compression molded into pellets with a thickness of 0.5 mm.

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

(4) Battery characteristics Battery characteristics were measured in the same manner as in Example 1 under the same conditions, and the results are also listed in Table 1.

Comparative Example 2 A battery was assembled in the same manner as in Example 1 except that Li metal foil was used as the negative electrode body, and battery characteristics were measured under the same conditions. The results are also listed in Table 1.

[Effects of the Invention] The secondary battery of the present invention has a long charge/discharge cycle life and is a highly reliable battery, so it can be repeatedly charged and discharged and can be used in various electronic devices.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a non-aqueous electrolyte secondary battery having a button-shaped structure. 1... Positive electrode body 2... Separator 3... Negative electrode body 4... Positive electrode can 5... Negative electrode can 6... Insulating backing 7... Current collector Figure 1

Claims (1)

[Claims] A positive electrode body, a separator placed on the positive electrode body, an electrolyte held in the separator, a negative electrode body placed on the separator, and the positive electrode body and/or the negative electrode body. (a) the positive electrode body is made of a transition metal chalcogen compound; b) The negative electrode body has a hydrogen/carbon atomic ratio of less than 0.10,
Interplanar spacing (d_0_0) of (002) plane by line wide-angle diffraction method
_2) 3.37 Å or more and 3.75 Å or less, crystallite size in the C-axis direction (Lc) 5 Å or more and 150 Å or less, total pore volume 1.5 x 10^-^3 ml/g or more, and average pore radius 8 to 100 Å, and (c) the active material is lithium or an alkali metal mainly composed of lithium.