JPH01161676A - Secondary battery - Google Patents

Abstract

PURPOSE:To heighten energy density and to lengthen charge-discharge cycle life by specifying the total specific surface area, micropore specific surface area, and the ratio of the micropore specific surface area to the total specific surface area of a carbon material for a negative electrode. CONSTITUTION:A positive electrode is formed with a transition metal chalcogen compound. A negative electrode 3 is formed with a carbon material in which the atomic ration of hydrogen to carbon is less than 0.10, spacing (d002) of face (002) by an X-ray wide angle diffraction method is 3.37-3.75Angstrom , crystalline size (Lc) in C axis is 5-150Angstrom , micropore specific surface area is 0.8m<2>/g or more, the total specific surface area is 1m<2>/g or more, and the ratio of the micropore specific surface area to the total specific surface area is 0.05-0.9. An active material is lithium or alkali metals mainly comprising lithium. A battery having long charge-discharge cycle life and high reliability is obtained.

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.

Such secondary batteries include, for example, those using conductive polymers such as polyacetylene for the positive and negative electrodes (Japanese Unexamined Patent Publication No. 5
6-136419) is known, but when a conductive polymer is used for the positive electrode, the electrode capacity is insufficient, and when used for the negative electrode, self-discharge is large and the characteristics after storage are poor. This causes the inconvenience of stability.

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,
The separator 2 is made of a liquid-retentive material such as polypropylene nonwoven fabric, and is placed on the positive electrode 1. Aprotic organic solvents such as LiAu04, LiAu04.

It is impregnated with a non-aqueous electrolyte of a predetermined concentration in which an electrolyte such as LiBF4, 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 1 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. In other words, when the battery is discharged, Li from the negative electrode body becomes Li ions and moves to the electrolytic solution, and during charging, these ions become metallic 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 and grows, and eventually the dendrite-shaped metal Li deposits penetrate the separator and reach the positive electrode body, causing a short circuit phenomenon. be. 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 (dQo2) of (002) plane by line wide-angle diffraction method
3.37 Å or more and 3.75 A or less, crystallite size in the C-axis direction (Lc) 5 Å or more and 150 Å or less, mesopore specific surface area 0, 8rn'/g or more, micropore specific surface area 1 m
''/g or more and mesopore specific surface area/total specific surface area is 0.0
5 to 0.9, and (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), and (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 examples of the transition metal chalcogen compound used include 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 V 205 , V a Ou, vO□, v2
S3. VS2, MoS2, MoS3, MnO
2, Cr306. They are Cr2O5, TiS2 and TiO2.

When the transition metal chalcogen compound described above is amorphous, amorphization is usually carried out using a melt quenching method. In addition, an amorphous hydrogel can be prepared and used. The amorphous substance according to the present invention refers to a substance in which no peaks due to crystals are observed when X-ray diffraction is performed, i.e. The amorphization is confirmed by an X-ray diffraction pattern having an amorphous broad halo, and the amorphous material has a structure in which long-range order has disappeared. However, various analyzes have confirmed that short-range 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.
1 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.
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. Its volume average particle diameter is 500Q or less, preferably 200Q or less, more preferably 100. Especially preferably, the number of houses is 50 or less.

Further, the specific surface area is preferably 1 m''/g or more, more preferably 10 m''/g or more, particularly preferably 20 m''/g or more.
m″/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 preferred amount added is 1 to 10% based on the 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 mixed wire material 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 Å or more and 3.75 Å or less, Lc is 5 Å or more and 150 A or less, mesopore specific surface area is 0.8 m'/g or more, and micropore specific surface area is 1rr? /g or more, and the mesopore specific surface area/total specific surface area is specified by a parameter of 0.05 to 0.9.

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 (002) plane determined by X-ray wide-angle diffraction is preferably 3.39 A or more and 3.70 Å.
The crystallite size Lc in the C-axis direction is preferably 10 Å or more and 80 A 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, d o02 and Lc deviate from the above ranges, the overvoltage at the negative electrode during charging and discharging will increase, and as a result, gas will be generated from the negative electrode and the safety of the battery will be compromised. Significantly 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 mesopore specific surface area is preferably 1.0 m''/g or more, more preferably 1.1 rrf/g or more, particularly preferably 1,2 rrf/g or more, and the micropore specific surface area is preferably 2 m''/g or more, even more preferably is 3m''/
g or more. In addition, the mesopore specific surface area/total specific surface area is preferably 0.08 to 0, g, more preferably 0.1
-0.6, particularly preferably 0.12-0.4.

If the mesopore specific surface area, micropore specific surface area, and mesopore specific surface a/total specific surface area deviate from the above-mentioned ranges, the amount of active material supported in the negative ellipse made of this carbonaceous material will decrease, and the capacity of the battery will decrease. .

In addition, in the present invention, the mesopore has a pore radius of IOA.
A micropore has a pore radius of 10 Å.
means the following pores:

The mesopore specific surface area was calculated using de Boer's 1-plot method (J, H, de Boer, et al.,
, J. Golloid Interface Scj
, 21, 405, 1966).

That is, for the thickness t (A) of the adsorbed gas layer, which is determined by the following equation (where P represents the vapor pressure of the adsorbed gas and Po represents the saturated vapor pressure of the adsorbed gas at the cooling temperature), Plot the total gas amount (t/g) and calculate the second
A t-plot diagram as shown in the figure was drawn, the slope S (tan θ) of the upper straight line portion was determined, and the amount of adsorbed gas was determined by converting it into the amount of liquid nitrogen using the following formula.

T [where Pa is the atmospheric pressure (kgf/am”), T is the measurement temperature (K), and Vm is the molecular volume of the adsorbed gas (c1
131 mol; 34.7 for N2), Vads is the total amount of gas adsorbed (cm”/g), Vliq is the liquid volume (c113), then the micropore specific surface area (S m1cro) is BET
The difference between the total specific surface area (S BET) determined by the method and the mesopore specific surface area (St: )) (SBET - S L)
I asked for it from d.

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 ao (= 2 d 11
0) 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 Å or more and 2.45 Å or less;
The crystallite size La in the a-axis direction 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 0.1-1.5,
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 have various shapes, they are preferably particles with a diameter of 100° or less, and more preferably have a specific surface area of Ld.
/g or more, more preferably 2 m''/g or more, particularly preferably 4 m''/g or more. If it deviates from 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, inquinoline, 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. That is, under an inert gas flow or vacuum with an oxygen concentration of 2 to 50,000 pp, at a heating rate of 5 ° C / hour to 200 ° C / minute,
Examples of inert gases used include N2,
Although Ar, He, etc. can be used, N2 is preferable from the point of view of economy and the like. In addition, the oxygen concentration is preferably 3 to 1
10000pp, more preferably 5 to 11000pp
, particularly preferably 10 to 500 ppm, and the firing temperature is preferably 600 to 1000°C, more preferably 700 to 1000°C. The heating rate is preferably 5
°C/hour ~ 100 °C/min, more preferably lO °C/hour ~
50°C/min, particularly preferably 20°C/hour to 10°C/min,
Particularly preferably, the firing temperature is 20°C/hour to 10°C/minute, and the firing temperature is preferably maintained at the above-mentioned firing temperature for 5 minutes to 8 hours, more preferably 10 minutes to 5 hours, particularly preferably 20 minutes to 3 hours. Firing is carried out by

Further, the fired material is carbonized under an inert gas stream or under vacuum at an oxygen concentration of 11,000 pp or less and a temperature of more than 1,000°C and 3,000°C or less for 1 minute or more. At this time, the 02 concentration in the system is preferably 500 p
pm or less, more preferably 1 to 100 pp+w, particularly preferably 2 to 80 pp+w. If the 02 concentration exceeds this range, good carbonization will not be carried out. Also, the carbonization temperature is preferably 1200 to 2800°C, more preferably 1600 to 2500°C, and the time for holding at that temperature is preferably 5 minutes to 8 hours, more preferably lO
The time period is from minutes to 5 hours, particularly preferably from 20 minutes to 3 hours.

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

Furthermore, in addition to the steps of thermal calcination, carbonization, and pulverization, 002
It is also possible to add an activation step of heating at a temperature of 500 to 1500° C. in an oxidizing gas atmosphere such as oxidizing gas atmosphere.

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., and 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. Preferably it is added in an amount of 0.1-10% by weight. In addition, examples of the binder include polyolefin resins, fluorine resins such as polytetrafluoroethylene, etc., and these are added in an amount of 20% by weight based on the carbonaceous material.
less than 1% by weight, preferably 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 made to be compatible with the above-mentioned positive electrode body and/or negative electrode body in advance. As a method of supporting, for example, the negative electrode body is immersed in an electrolytic solution containing Li ions or alkali metal ions at a predetermined concentration, Li is used as a counter electrode, and the negative electrode body is used as a cathode to cause electrolysis. Can be applied. Furthermore, lithium or an alkali metal mainly composed of lithium can be supported on the positive electrode body in a similar manner. 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 Li metal onto 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. That is, during charging: In the positive electrode body, V20S (Li) + V20B +xLi” +xe In the negative electrode body, C+xLi” +xe+C@Lix During discharging: In the positive electrode body, V205 +xLi◆+xe−+V205
(Li).

In the negative electrode body, Ce　Li　−+C+xLi”+xe! This is the reaction.

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 Since the electrochemical redox reaction proceeds 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 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. Co
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.

rX-ray wide-angle diffraction" (1) Interplanar spacing between (002) planes (d002) and interplanar spacing between (110) planes (d110) If the carbonaceous material is in the form of a powder, it can be treated as is; if it is in the form of minute pieces, it can be treated in an agate mortar. Powdered, high-purity silicon powder for X-ray standards is added to the sample in an amount of about 15% by weight as an internal standard substance, mixed, packed in a sample cell, and CuKa rays made monochromatic with a graphite monochromator are used as a radiation source, and reflected. To correct the zero curve of measuring a wide-angle X-ray diffraction curve using the formula diffractometer method, the following simple method is used without making corrections for 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 CuKa line.
Find O.

Input: 1.5418 people θ, θ': do02. 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 value β at the position half the peak height.

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

“Linewidth of electron spin resonance: ΔHPPJ Partial 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 is, and minute flake samples are powdered in an agate mortar to an outer diameter of 2 mm.
+ into a capillary tube, and then attach the capillary to an ESR with an outer diameter of 5 cm.
Put it in the tube. The peak-to-peak linewidth (ΔHpp) of the −th order differential absorption spectrum is 6.3 Gauss during the modulation of the high-frequency magnetic field.
n”/MgO is determined using a standard sample.

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

(1) Manufacture of positive electrode body Mn0 280g, acetylene black 5 as conductive material
g and 0.5 g of powdered polytetrafluoroethylene as a binder were kneaded, and the resulting kneaded product was roll-formed to form a sheet with a thickness of 0.4 mm.

One side of this sheet is used as a current collector with a wire diameter of 0.1ml11.
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
A reactor was charged with 240 g of ethyl cellosolve and 240 g of sulfuric acid and reacted at 115° C. for 4 hours with stirring. After the reaction was completed, 317 g of NaHCO 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.

5 g of the above novolak resin and 25 g of hexamine
The mixture was placed in a No. 00 agate container, and 5 agate poles with a diameter of 30 mm and 10 agate poles with a diameter of 20 g 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 was set in an electric heating furnace, and N2 gas was flowed until the oxygen concentration in the system became 50 ppm, and then heated at 250°C while flowing N2 so that the oxygen concentration in the system became 20 to 70 ppm. 500℃ at a speed of /hour
The temperature was further increased to 900° C. at a rate of 200° C./hour, and the temperature was maintained for 1.5 hours for firing, and then allowed to cool naturally.

Next, the fired material was set in another electric furnace, and after vacuum degassing, N2 gas was flowed to bring the oxygen concentration in the system to 10 ppm. Furthermore, the temperature was raised to 1800 °C at a rate of 25 °C/min while flowing N2 so that the oxygen concentration in the system was 5 to 20 ppm, and carbonization was performed by heating at the same temperature for an additional 1.5 hours. .

The carbonized product thus obtained was placed in a 250-mm agate container, and one agate ball with a diameter of 301 mm and a 25-mm diameter agate ball were placed.
One agate ball with a diameter of 20 mm and an agate ball 11 with a diameter of 20 mm were placed in a ball mill and ground for 15 minutes to obtain a carbonaceous material with an average particle size of 41.3.

As a result of single-element analysis, X-ray wide-angle diffraction, etc., this carbonaceous material had the following characteristics.

Hydrogen/carbon (atomic ratio)=0.04 ct002=3. st people, L c = 13.1 people a
o(2d002)=2, 42 people, La=21.1λ
BET specific surface area 4.59572 m''/g Also, using an autosorb manufactured by Yuyuri Ionics, the adsorption crosstalk (using nitrogen gas; temperature 77K) was determined, and it was calculated based on the thickness t (A) of the adsorbed gas layer. Total amount of gas adsorbed (+J/g
) was plotted, and a t,-plot as shown in FIG. 3 was drawn.

In Fig. 3, the slope of the upper straight line part is determined, and the mesopore specific surface area is determined using it, which is 1.22357r.
It was 7g.

Next, the micropore specific surface area was found to be 3.37215.
m″/g, and mesopore specific surface area/total specific surface area is 0.
It was 266.

A mixture of 7% by weight of polyethylene powder with a volume average particle size of 2o was mixed into this carbonaceous material to form a mixture with a thickness of 0.
．． It was made into a pellet between five layers.

(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 LiCuOa to it at a concentration of 1 mol/liter. It was impregnated with a non-aqueous electrolyte dissolved in propylene carbonate. 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 of 1 ml, and subjected to an electrolytic treatment using the positive electrode body as a cathode and lithium as 7 nodes. The electrolytic conditions were a bath temperature of 20°C and a current density of 1 mA/c+g2. The electrolysis time was 10 hours. As a result of this treatment, Li with a capacity of 6.0 h was supported on the positive electrode body.

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 10g at 300℃, 1.5ton/
It was heated and pressurized to a height of cm2 and formed into a sheet.

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 characteristics.

Hydrogen/carbon (atomic ratio) = 0.01 dQg2 = 3.38 people, Lc = 156A Cumulative pore volume of pores with pore radius of 10 to 250 people 1.5X1
Less than 0-3 ml/g This carbonaceous material powder and 7% by weight of polyethylene powder were mixed and the whole was compression molded to a thickness of 0.
It was made into 5mm pellets.

(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 cross-sectional view of a non-aqueous electrolyte secondary battery with a button-shaped structure, FIG. 2 is a conceptual diagram of a t-plot, and FIG.
The figure is a t-plot diagram of the carbonaceous material used in the secondary battery of the present invention. 1... Positive electrode body 2... Separator 3... Negative electrode body 4... Positive electrode can 5... Each negative electrode 6... Insulating backing 7... Current collector

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. In a secondary battery with a built-in power generation element comprising an active material included in the positive and negative electrode bodies that moves between the positive and negative electrode bodies in response to charging and discharging 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 (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, mesopore specific surface area of 0.8 m^2/g or more, micropore specific surface area of 1 m^2/g and (c) a secondary material made of a carbonaceous material having a mesopore specific surface area/total specific surface area of 0.05 to 0.9, and (c) the active material being lithium or an alkali metal mainly composed of lithium. battery.