JPH04206168A - Secondary battery - Google Patents

Abstract

PURPOSE:To increase reliability during charge/discharge in a secondary battery, in which an active material is Li or alkaline metal composed mainly of Li, by constituting a negative electrode body especially of a carbonaceous material having specific H/C atomic ratio and crystal structure and an inorganic silicon compound. CONSTITUTION:Li or alkaline metal composed mainly of Li is used as an active material. The chief ingredient of a positive electrode body 6 is transition metal oxide such as MnO2 or V2O5, transition metals such, as LiCoO2 and a compound oxide of alkaline metal. A negative electrode body 4 has a specific structure, and H/C atomic ratio is less than 0.15, and spacing (d002) of (002) plane by means of an X-ray wide angle rotation method is 3.37Angstrom or more, and size Lc of crystallite in the C axial direction is 150Angstrom or less. A layer of a carbonaceous material containing Si or SiO2 and/or the like by 0.05-1.2weight% is coated over the surface of the carbonaceous material. According to this constitution, a battery capacity is not reduced so significantly, so that a secondary battery having high reliability during charge/discharge can be 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 having a long charge/discharge cycle life and a stable high capacity.

[Prior art] The main component of the positive electrode body is a transition metal oxide such as M n 02, ■205, MoC2, or Li, co 02, Li
Secondary batteries, which are composite oxides of transition metals and alkali metals such as MnaOs and LIM n 204, and whose negative electrode body is lithium or an alkali metal mainly composed of lithium, have a high energy density, so efforts are being made to commercialize them. is being paid.

An example of a secondary battery is shown in FIG. 3, and FIG. 6 is a longitudinal cross-sectional view of a cylindrical secondary battery of AA size.

In the figure, (1) is a bottomed cylindrical metal container that also serves as a negative electrode terminal and has an insulating plate (2) arranged at the bottom. A cylindrical power generation element (3) is housed within this container (1). This power generation element (3) includes a negative electrode body (4) made of metallic lithium and a porous polypropylene thin film containing 1 mol of Li.
A separator (5) impregnated with propylene carbonate in which Cl204 is dissolved and a positive electrode body (6) are laminated in this order to form a strip, and this strip is spirally wound.

In addition, the positive electrode body (6) has a structure in which a positive electrode mixture (10) is coated through conductive resin layers (9) on both sides of a current collector (8) to which lead terminals (7) are connected. .

An insulating sealing plate (11) is placed near the opening of the container (1).
) The lead terminal (7) is connected to the inner sealing plate (13) by spot welding.

Note that the negative electrode body (4) has a nickel foil lead terminal (
14), and the lead terminal (14) is connected to the inner surface of the container (1) by spot welding.

[Problems to be Solved by the Invention] However, in such a secondary battery, a problem arises because the negative electrode body is itself an alkali metal foil such as a lithium foil.

In other words, when the battery is discharged, lithium is transferred from the negative electrode body to L1.
It becomes an ion and moves into the electrolyte and is doped into the positive electrode body. During charging, this doped ion becomes metallic lithium and is deposited on the negative electrode body again, but if this charge-discharge cycle is repeated, As a result, metallic lithium becomes dendrite-like. This is because the metal such as stainless steel or nickel that is the current collector of the positive electrode forms a local battery with lithium, causing partial dissolution of the current collector metal, and as a result, the current collector is not dissolved. This is because the metal lithium to be electrodeposited becomes dendrite-like because it is concentrated in a certain area.

Since this dendrite-like lithium is an extremely active substance, it decomposes the electrolyte, resulting in a disadvantage that the charge/discharge cycle characteristics of the battery deteriorate. As this grows further, eventually this dendrite-like metallic lithium deposit penetrates the separator and reaches the positive electrode body.
A problem arises in that a short circuit phenomenon occurs. In other words, there is a problem that the charge/discharge cycle life is short.

The second problem is based on the fact that the main component of the positive electrode body is a transition metal oxide or a composite compound of this and an active material. That is, since the voltage of the battery system during charging and discharging of the battery is 3 to 4 V, the metal lithium electrode is rapidly inactivated, and the electrolyte on the negative electrode body is rapidly decomposed. As a result, when deep discharge is involved, the battery capacity decreases significantly after several charge/discharge cycles, making it unusable.

Against this background, the present invention aims to provide a secondary battery that is highly reliable during charging and discharging cycles without impairing battery capacity.

[Means for Solving the Problems] As a result of extensive research to solve the above problems, the present inventors have developed a positive electrode body whose main component is a transition metal oxide or a composite oxide of this and an active material. In addition, using an active material carrier in which a carbonaceous material having the characteristics described below is coated on a current collector metal as a negative electrode body, and containing an inorganic silicon compound therein, is extremely effective for achieving the above-mentioned purpose. We have discovered the fact that this is the case, and have arrived at the present invention.

That is, 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 the positive electrode body and/or the separator. or a power generating element consisting of an active material that moves between the positive and negative electrode bodies in response to charge/discharge reactions included in the negative electrode body; (a) the active material is lithium or mainly composed of lithium; (b) The positive electrode body has a transition metal oxide or a composite oxide of a transition metal and the active material as a main component.

(c) The negative electrode body has at least (a) a hydrogen/carbon atomic ratio of less than 015, and (b) an interplanar spacing (d) of the (002) plane measured by X-ray wide-angle diffraction.
,,2) A carbonaceous material layer containing 0.05 to 1.2% by weight of an inorganic silicon compound in a carbonaceous material containing a crystal structure in which the crystallite size (Lc) in the C-axis direction is 337 Å or more and the crystallite size (Lc) in the C-axis direction is 150 Å or less. is formed by adhering to the metal surface of the current collector.

In the battery of the present invention, the negative electrode body has a specific hydrogen/hydrogen content as described above.
It is characterized by being composed of a carbonaceous material having a carbon atomic ratio and crystal structure and an inorganic silicon compound, and other elements may be the same as conventional secondary batteries.

In the battery of the present invention, the active material is lithium or an alkali metal mainly composed of lithium, and this active material moves in and out of the positive and negative electrode bodies as the battery is charged and discharged.

As the positive electrode body, a transition metal oxide or a composite oxide of a transition metal and the active material lithium or an alkali metal mainly composed of lithium is used. Transition metal oxides include MnOz, ■205, MoOs, etc., and composite oxides of transition metals and alkali metals include L
i Coo□, L IM n z Os, L IM n
20a etc. are exemplified.

When using a transition metal oxide as a positive electrode body, M n O
Taking z as an example, electrolytic M n Ox is heated at 300 to 460°C
In the case of v208 and Mo Ox, commercially available special grade reagents are calcined for 4 to 10 hours at a temperature range of 100 to 120°C. It may be used after drying for 5 to 10 hours.

In the case of a composite oxide of a transition metal and an alkali metal, the positive electrode body can be manufactured as follows.

Taking Li Coo * as an example, Li*COs powder and basic cobalt carbonate are mixed in a predetermined amount with a Li/Co molar ratio of 11, and heated in air at 900°C for 6 hours, for example. The obtained composite oxide is washed with distilled water and dried before use.

These transition metal oxides or the above composite oxides are pulverized to a predetermined particle size, and then a predetermined amount of a binder is added and the two are thoroughly kneaded. As the binder, olefin resins such as polytetrafluoroethylene, polyethylene, polypropylene, copolymers of ethylene-propylene-diene compounds, etc., or polystyrene can be used, and binders can be used in the form of powders or in dispersion in organic solvents. Used in version form or as a solution. The preferred amount of the binder added is 1 to 10% by weight based on the transition metal oxide or composite oxide of transition metal and alkali metal. If the amount of the binder added is too large, the electrical resistance of the obtained positive electrode body will become high, which is disadvantageous, and if the amount is too small, the binding effect will not be exhibited.

At this time, less than 50% by weight of a powder of a conductive material such as graphite or carbon black can be added to the above-mentioned transition metal oxide or composite oxide of a transition metal and an alkali metal. The amount added is preferably less than 30% by weight, more preferably less than 15% by weight.

The obtained crosstalk material is molded to a predetermined thickness and then pressurized to integrate it with the positive electrode current collector, or it is applied and dried on the current collector and integrated.

The current collector can be made of the metal that constitutes the current collector, such as wire mesh or punched metal such as stainless steel or nickel, either as it is or by depositing a current collecting layer made of powder of nickel, titanium, etc. You may also create one.

The conductive resin layer described above is formed by dispersing a conductive agent such as metal powder or carbon black in a solution such as a polyolefin resin, applying the dispersed solution to a metal core, and drying it.

Examples of the polyolefin resin used here include polyethylene and polypropylene, and in addition, polyacrylic acid can be used. Examples of the conductive agent in the conductive resin layer include powders of acetylene black, carbon black, titanium carbide, nickel, cobalt, and the like.

Furthermore, a carbonaceous material having the following characteristics is used for the negative electrode body.

This carbonaceous material has a H/C (atomic ratio) of less than 0.15, d
It is specified by the parameters of oaa of 3.37 Å or more and Lc of 150 Å or less. Furthermore, the carbonaceous material of this negative electrode body preferably has an H/C of less than 0.10, more preferably less than 0.07, and particularly preferably less than 0.05.

Also, do. 2 is preferably 3.39 to 3.75 people, more preferably 3.41 to 3.70 people. Further L
c is preferably 8 to 100 people, more preferably 10 to
There are 70 people.

H/C is 0.15 or more, do. If a carbonaceous material in which 2 is less than 3.37 or Lc is greater than 150 is used as a negative electrode body, the overvoltage f)5 during charging and discharging in the negative electrode body becomes large, and as a result, the negative electrode body Gas is generated from the battery, significantly impairing the safety of the battery and making the charge/discharge cycle characteristics unsatisfactory.

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

That is, in Raman spectrum analysis using argon ion laser light with a wavelength of 5145, it is preferable that the G value defined by the following formula is less than 2.5,
More preferably it is less than 20, particularly preferably 0.
It is 2 or more and less than 1.2, most preferably 0.3 or more and less than 1.0.

Here, the G value refers to the wavelength 514
When five people performed Raman spectrum analysis using argon ion laser light, in the spectrum intensity curve recorded on the chart, 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±100 cm-' by the area intensity within the wave number range of 1360±100 cm-', 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 is a parameter indicating the ratio of the crystalline portion in this carbonaceous structure. If this value deviates from the above-mentioned range, the number of charge/discharge cycles and absolute capacity will decrease.6 Furthermore, it is preferable that the carbonaceous material used in the negative electrode body according to the present invention satisfy the following conditions.

That is, the crystallite size (La) in the a-axis direction determined by X-ray wide-angle diffraction analysis is preferably 10 Å or more,
More preferably 15 to 150 people, particularly preferably 18 people
~70 people.

Also, (110) obtained in the same X-ray wide-angle diffraction
The distance ao (=2d+1°), which is twice the distance between the surfaces dzo, is preferably 2.38 Å or more, more preferably 2,
There are 39 to 2,46 people.

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

Examples of starting organic compounds include cellulose, phenolic resin, polyacrylonitrile,
Acrylic resins such as poly(α-halogenated acrylonitrile); halogenated vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polychlorinated vinyl chloride, polyamideimide resins: polyamide resins: polyacetylene, poly(p-) unilene) Any organic polymer compound such as a conjugated resin such as: For example, a monocyclic hydrocarbon with three or more members such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, chrysene, naccene, bicene, perylene, pentaphene, and pentacene. Fused cyclic hydrocarbon compounds formed by condensing two or more compounds with each other; or derivatives of the above compounds such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides; various pitches containing mixtures of the above compounds as main components; : At least two heteromonocyclic compounds having three or more members such as indole, isoindole, quinoline, inquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, and phenanthrene are bonded to each other, or one or more three Condensed heterocyclic compounds formed by bonding with monocyclic hydrocarbons having more than one member ring, derivatives such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides of each of the above compounds; further benzene and its carboxylic acids, carboxylic acid anhydrides, Derivatives such as carboxylic acid imides, ie 1.2.4.5-tetracarboxylic acid, its dianhydride or its diimide, etc. can be mentioned.

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

A carbonaceous material with such a crystal structure has 0 inside it.
．． By previously containing 05 to 1.2% by weight of silicon or a silicon compound such as silicon dioxide, it is possible to prevent a decrease in the transfer efficiency of Li ions caused by repeated charging and discharging of the battery. This tendency becomes noticeable during long-term charging and discharging, or when charging and discharging the battery after long-term storage.

The reason for this is that silicon or a silicon compound contributes to stabilizing the structure of the carbonaceous material. Examples of silicon compounds include SiC2,5iO1SiS2°SiC, SiF4.
5iFs, mullite ceramics (low An content), quartz glass and crystallized glass (e.g. L12
0・AR20,,5i02)+71 powder is exemplified, and 5
102 and mullite ceramics are preferred. In addition,
The amount of inorganic silicon compound added is 0.0 to the carbonaceous material.
5 to 1.2% by weight, and from the results, preferably 0
．． The range is 0.05 to 0.50% by weight. If it exceeds 12% by weight, the conductivity of the carbonaceous material negative electrode will be impaired, resulting in an increase in internal resistance and a decrease in cycle characteristics. Also, 00
If it is less than 5%, the effect of improving the strength of the negative electrode body is insufficient, causing swelling of the negative electrode body and increasing internal resistance.

The volume average particle size of the inorganic silicon compound is preferably 05 to
30-1, particularly preferably 1.0 to 2.0 units.

It is preferable to add it to the carbonaceous material when kneading the slurry as in the example below, but the inorganic silicon compound is powdered at the same time as the carbonaceous material is ground in a ball mill in an agate container. You can also add and mix.

The negative electrode body according to the present invention can be manufactured as follows. That is, the above-mentioned carbonaceous material is ground into powder to a predetermined particle size (e.g., volume average particle size of 5 to 40P), and this powder, inorganic silicon compound powder, and binder are mixed in a predetermined ratio (e.g., weight ratio). , 95-80: 0.08-0.96
: 5 to 20), and the mixed wire is formed into a sheet as it is, and is plated with nickel, iron, or nickel in the shape of a wire mesh, expanded metal, punched metal, metal foil, etc. used as a current collector. Either the mixture is attached to a metal such as iron or stainless steel and integrated, or the mixture is made into a slurry, applied to a current collector, and dried.

As the binder to be used, the same polymer as exemplified as the binder for the positive electrode body is used in the same form.

The preferable amount of the binder added is 1 to 10% based on the carbonaceous material.
Weight%. If the amount of the binder added is too large, the electrical resistance of the obtained negative electrode carbonaceous material will be high (which is disadvantageous), and if the amount is too small, the binding effect will not be exhibited.

In this case, a conductor made of powder of a conductive material such as graphite, carbon black, or nickel may be formed on the surface of the current collector. Its thickness is preferably 5-50p+
It is e.

[Examples of the Invention] The present invention will be described below with reference to Examples and Comparative Examples. Note that the present invention is not limited to this example.

In the present invention, elemental analysis and xI! Each measurement of wide-angle diffraction was carried out 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 H2O
The hydrogen content was determined from the weight. In the Examples of the present invention described later, measurements were made using a PerkinElmer 240C elemental analyzer.

"X-ray wide-angle diffraction" (1) Interplanar spacing (dooz) of (002) plane and (110
) Surface spacing (d,,.) If the carbonaceous material is a powder, it is used as is, or if it is in the form of minute pieces, it is powdered in an agate mortar, and high-purity silicon for X-ray standards is added at a concentration of approximately 15% by weight based on the sample. Powder was added as an internal standard substance, mixed, packed into a sample cell, and using a graphite monochromator as a monochromatic CuKa ray as a radiation source, and a wide-angle X-ray diffraction curve was measured using a reflection diffractometer method. Correction of the 0 curve. The so-called Lorentzian polarization factor,
Corrections regarding absorption factors, atomic scattering factors, etc. were not performed, and the following simple method was used. That is, by drawing the baseline of the curve corresponding to the (002) and (110) diffraction, and replotting the real intensity from the baseline, the (002) and (110) planes are
10) A correction curve for the surface was obtained. 3 of the peak height of this curve
Find the midpoint of the line segment where a line parallel to the angular axis drawn at half the height intersects the diffraction curve, correct the angle of the midpoint using an internal standard, make this twice the diffraction angle, and use the CuKa line d 002 and d z by the following Bragg equation from the wavelength λ. 6 E: 1.5418 people θ, θ': d0゜3. Diffraction angle (2
) Size of crystallites 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 was determined from the following equation using the half-width β at a position half the peak height.

β°CO8θ There are various discussions about the shape factor K, but K=0.90
was used. However, θ and θ' have the same meaning as in the previous section.

Example 1 [1] Production of positive electrode body (6) 34 g of lithium carbonate powder and 10 g of basic cobalt carbonate powder
0 g (Li/Co molar ratio = 1:1) were mixed and the mixture was heated at 800° C. for 4 hours to synthesize Li Co O*. The amount of Li in the obtained Li Co Oz is Co
The molar ratio to o□ was approximately 1.

22 g of this Li Co O* powder, 1.5 g of powdered polytetrafluoroethylene, and 0.5 g of acetylene black as a conductive agent were kneaded, and the resulting mixed wire was roll-formed to form a sheet with a thickness of 0.4 mm ( 10).

6g of acetylene black, 25% by weight of polyacrylic acid
Mix 8 g of the aqueous solution containing 160 g of methanol,
A conductive resin slurry was prepared. This is wire diameter 081
A conductive resin layer (9) was obtained by applying the mixture to a current collector (8) made of a stainless steel net having a mesh size of 60 mm and drying it.

One side of the above-mentioned sheet)-(10) is crimped onto this current collector (8) to form a strip-shaped positive electrode body (6), and a titanium foil lead terminal ( 7
) was established.

[2] Production of negative electrode body (4) 108 g of orthocresol, 32 g of paraformaldehyde
g and 240 g of ethylene gelcol monoethyl ether
was charged into a reactor with 10 g of sulfuric acid, and while stirring, 1
After the completion of the 0 reaction at 15°C for 4 hours, N a HC
17 g of Os and 30 g of water were added to neutralize, and the mixture was ground and mixed for 20 minutes.

The powder obtained by mixing hexamine with the thus obtained novolac resin 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 the temperature was raised to 950°C at a temperature increase rate of 200°C/hour while flowing N2 gas at a rate of 20Off/hour per 1 kg of the heat-treated product. After being held and fired for an additional 15 hours, it was allowed to cool naturally.

Next, set the fired material in a separate electric furnace and heat it to 25°C.
The temperature was raised to 2000°C at a heating rate of /min, and maintained at that temperature for an additional 15 hours to carry out carbonization.

The carbonaceous material obtained in this way was
It was ground to a particle size of . Next, a slurry was prepared by dispersing 18 g of the above carbonaceous material and 0.019 g of silicon dioxide powder with a purity of 999% and a volume average particle size IP in 490 g of a methanol solution in which 25 g of polyacrylic acid was dissolved.
Apply it on the surface of a 30F thick stainless steel plate (15),
By drying, a negative electrode body (4) having a carbonaceous material layer containing 01% by weight of 5iO- based on the carbonaceous material and having a thickness of 20F+ on each side was obtained.

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

Hydrogen/carbon (atomic ratio) = 0.04 do. 2 = 3.59 people + Lc = 14 people a o (2d
zo ) = 2.41 people La = 25 people: Volume average particle size =
38P Specific surface area (BET) = 8.2rn”7g [3] Battery assembly Positive and negative electrode bodies (4) and (6) formed in this way
were sequentially laminated with a separator (5) made of a thin polypropylene film interposed therebetween to form a strip, and this strip was spirally wound to form a power generation element (3). Hereinafter, by the usual method,
A battery of the same size was constructed.

Example 2 [1] Production of positive electrode body (6) Commercially available electrolytic manganese dioxide was fired in a heating furnace at a temperature of 460°C for 5 hours, crystal water in the manganese dioxide was removed, and 22 g was collected. did. 2.2 g of powdered polytetrafluoroethylene and 2.2 g of acetylene black as a conductive agent were mixed with this, and a positive electrode route having a wall thickness of 4 mm was formed by roll molding. This was crimped onto a current collector (8) having a conductive resin layer (9) similar to that used in Example 1, and lead terminals (7) were attached in the same manner as in Example 1.

This positive electrode body (6) was mixed with Li Coo in an organic solvent of propylene carbonate using a lithium metal plate as a counter electrode.
of electrolyte dissolved in 1 mol/12,
Apply a current of 250 mA for 10 hours at
The positive electrode body (6) was doped with lithium in an amount equivalent to mAh.

[2] Manufacture of negative electrode body (4) After hydrolyzing the purified valve with mineral acid, it was filtered and the residue was washed with water. After dispersing the cellulose in an aqueous solution containing carboxymethyl cellulose,
By spray drying, granules with a volume average particle size of 1 ml11 were obtained. This was heated to 1000°C in an electric furnace under a flow of N2 gas at a temperature and humidity of 250°C/hour, and further heated to 1000°C for 1 hour.
After holding for a period of time, it was cooled. Furthermore, this heat-treated product was placed in another electric furnace and heated to 1000°C/100°C while flowing N2 gas.
The temperature was raised to 1700° C. at a rate of 1 hour, and the temperature was maintained for an additional 1 hour for firing. The obtained carbonaceous material was pulverized for 3 minutes using a ball mill in an agate container.

This carbonaceous material had the following characteristics.

Hydrogen/carbon (atomic ratio) = 0. ．． 04 doox =3.60 people: Lc==21 people a O(2
dllo ) = 2.41 people La = 24 people; volume average particle size = 36.7FJa specific surface area (BET) = 7.8rrI
''/g 18 g of the carbonaceous material thus obtained was dispersed in a methanol solution of 490 mm containing 25 g of polyacrylic acid, and further added with commercially available reagent grade silicon dioxide with a purity of 99% and a volume average particle size IP of 0. Add .095g and mix.
It was made into a slurry. This is used as a current collector (15cm
) and dried to obtain a negative electrode body (4) having a carbonaceous material layer with a thickness of 20 layers on both sides.
), the S i Oz content is 0.50
Weight%.

[3] Battery assembly A AA-sized battery was assembled in the same manner as in Example 1.

Example 3 [1] Production of positive electrode body (6) Commercially available special grade reagent vanadium oxide (V, Ofi)
Example 2
and powdered polytetrafluoroethylene and a conductive agent in the same weight, respectively, and carried out in the same manner as in Example 2 to obtain a positive electrode body (6) having the same structure.

In order to dope this positive electrode body (6) with lithium, using the same lithium counter electrode and electrolyte as in Example 2,
The positive electrode body (6) was doped with lithium equivalent to 0 mAh.

[2] Negative electrode body (4) A carbonaceous material obtained by heating mesoface pitch to 2600°C under a N2 gas flow and holding it at 2500°C for 1 hour was placed in an agate container similar to that used in Example 2. It was ground for 3 minutes using a ball mill.

This carbonaceous material had the following characteristics.

Hydrogen/carbon (atomic ratio) = Q, Q3 do. 2 = 3.40 people: Lc = 87 people a o (2d
zo ) = 241 people La = 81 people 1 volume average particle diameter = 27.3P specific surface area (B
ET) = 10.1g/g 18g of carbonaceous material thus obtained and purity 99.9
% by weight, silicon dioxide 0.19 with volume average particle size 1.5P
The negative electrode body (4
) was obtained.

[3] Battery assembly A AA size battery was assembled in the same manner as in Example 1.

Example 4 [1] Production of positive electrode body (6) In the same manner as in Example 1, a positive electrode body of Li Co 02 was obtained.

[2] Manufacture of negative electrode body (4) Using 18 g of carbonaceous material obtained from novolac resin in the same manner as in Example 1 and having the same characteristic values, mullite with a volume average particle size of 2P was added as an inorganic silicon compound. Ceramics (A220s ・SiO□1 weight ratio 37:
63) A negative electrode body containing 0.5% by weight of SiO□ based on the carbonaceous material was obtained in the same manner as in Example 1 except that 0.15g was added.

[3] Assembly of battery Using the above positive electrode body (6) and negative electrode body (4), Example 1
I assembled a AA size battery in the same way.

Comparative Example 1 The same positive electrode body as in Example 1 was used. The negative electrode body was prepared in the same manner as in Example 1, except that the amount of 5iO- added to the carbonaceous material was 0.003% by weight. Hereinafter, a AA size battery was assembled in the same manner as in Example 1.Comparative Example 2 The same positive electrode body as in Example 1 was used. The negative electrode body was prepared in the same manner as in Example 1 except that the amount of 5102 added to the carbonaceous material was 1.5% by weight. Thereafter, AA size batteries were assembled in the same manner as in Example 1.

Comparative Example 3 The same positive electrode body as in Example 1 was used. A AA size battery was assembled in the same manner as in Example 1 except that metallic lithium was used as the negative electrode body instead of the carbonaceous material.

The nonaqueous solvent secondary batteries of Examples 1 to 4 of the present invention and Comparative Examples 1 to 3 thus obtained were charged with a current of 900 mA at room temperature of 20°C for 7 hours, and then charged for 2.8 hours. The battery capacity was measured, with the process of discharging until the discharge voltage reached . As a result, a characteristic diagram shown in FIG. 2 was obtained. In addition, in the figure, A is the characteristic line of the non-aqueous solvent secondary battery of Example 1, B is Example 2, C is Example 3, D is the characteristic line of the non-aqueous solvent secondary battery of Example 4, E is Comparative Example 1, and F is Comparative Example. 2. G is comparative example 3
As is clear from FIG. 2, which shows the discharge capacity retention curve of the non-aqueous solvent secondary battery, the discharge capacity retention rate of the secondary batteries of each example according to the present invention decreases as the number of cycles increases. It is gentle and has excellent discharge characteristics. On the other hand,
In the secondary batteries of Comparative Examples 1 to 3, the discharge capacity retention rate decreased significantly as the number of cycles increased. In particular, when the number of cycles approaches 300, the discharge capacity retention rate decreases extremely.

Furthermore, regarding the distribution of the discharge capacity retention rate at the time when the above-mentioned discharge capacity retention rate characteristic evaluation test was conducted for 200 cycles for 100 pieces each of the non-aqueous solvent secondary batteries of Examples of the present invention and Comparative Example 1.2. The results of the investigation are shown in Table 1. In addition, it is the average value of the battery capacity of 100 non-aqueous solvent secondary batteries in Table 1 or each Example and Comparative Example, and δ represents the standard deviation obtained from each of the above-mentioned capacity values.

Table 1 x 100%) As is clear from Table 1, the secondary battery of this example had less variation in discharge capacity retention rate than the secondary battery of the comparative example, and the performance of each battery improved. , and are uniform, indicating that the battery performance is stabilized by the present invention.

[Effects of the Invention] The secondary battery of the present invention has an active material layer obtained by supporting lithium as an active material or an alkali metal mainly composed of lithium, using a carbonaceous material having the above-mentioned crystal structure as a support. When the negative electrode body is a lithium sheet itself, the formation of dendrite-shaped deposits on the surface of the negative electrode body is avoided.

Furthermore, as a feature of the present invention, by adding an inorganic silicon compound to the carbonaceous material, swelling during doping of lithium to the negative electrode body due to charging and discharging is suppressed, and active material is smoothly loaded and released during charging and discharging. Since the battery of the present invention can be used repeatedly, it can exhibit an unprecedented high capacity and excellent charge/discharge characteristics.

Although the explanation so far has been made regarding a secondary battery having a cylindrical structure, the technical concept of the present invention is not limited to this structure, and may be applied to a secondary battery having a coin shape, a flat shape, a square shape, etc. It can be applied to secondary batteries.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a secondary battery with a cylindrical structure that is an example of the present invention, and FIG. 2 is a relationship between charging and discharging cycles and capacity retention rates of batteries in each example and each comparative example of the present invention. FIG. FIG. 3 is a longitudinal sectional view of a conventional secondary battery. 1... Metal container 9... Conductive resin layer 2...
...Bottom insulating plate 1o...Positive electrode mixture 3...Power generation element 11 -Metal sealing plate 4...Negative electrode body
12...Insulating backing 5...Separator
13... Inner facing plate 6°゛°゛ Positive electrode body 14
...Lead terminal 7 ...Lead terminal 15...
- Stainless steel plate 8...Current collector A-D...Discharge capacity maintenance rate curve E-G of the batteries of Examples 1 to 4 according to the present invention...Discharge of the batteries of Comparative Examples 1 to 3 Capacity maintenance rate curve Figure 3

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 active material is lithium or an alkali metal mainly composed of lithium. Yes; (b) the positive electrode body has a transition metal oxide or a composite oxide of a transition metal and the active material as a main component; (c) the negative electrode body has at least (a) a hydrogen/carbon atomic ratio of 0; (b) The interplanar spacing (d
0.05 to 1.2% by weight of an inorganic silicon compound is contained in a carbonaceous material containing a crystal structure in which _0_0_2) is 3.37 Å or more and the crystallite size (Lc) in the c-axis direction is 150 Å or less. 1. A secondary battery comprising: a carbonaceous material layer deposited on a metal surface of a current collector;