JPH0439860A - Secondary battery electrode - Google Patents

Abstract

PURPOSE:To obtain a high capacity of electrode, excellent charge and discharge cycle property and flexibility by forming carrier composed of specific carboneous material, metal to form alloy with active material or alloy grains containing active material and fiber-like organic high polymer binder to carry alkaline metal as active material thereon. CONSTITUTION:Active material is carried on carrier composed of a mixture of carboneous material, metal possible to form alloy with active material or alloy containing active material and fiber-like organic high polymer. That is, the carrier composed of the carboneous material, satisfied by the ratio of hydrogen atoms to carbon atoms being less than 0.15, face-to-face spaces being 3.37Angstrom or wider by a x-ray wide-angle diffracting method and the sizes of crystallites in a (c)-axial direction being 220Angstrom or smaller, metal to form alloy with active material or alloy grains containing active material, and fiber-like organic high polymer binder, is formed to carry alkaline metal as active material thereon. It is thus possible to obtain a flexible electrode for a secondary battery with a high capacity and excellent charge and discharge cycle property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electrode for a secondary battery that has a high capacity and excellent charge/discharge characteristics. More specifically, the present invention relates to a flexible alkali metal secondary electrode that can be used as a spiral electrode to configure a cylindrical secondary battery or as a thin sheet-shaped electrode to configure a sheet-type secondary battery.

(Prior art) It has been proposed to use conductive polymers such as polyacetylene as electrodes for notium secondary batteries, but conductive polymers lack the amount of Li ion doping, that is, electrode capacity and stable charge/discharge characteristics. .

Furthermore, attempts have been made to use lithium metal in the negative electrode of lithium secondary batteries, but in this case the charge/discharge cycle characteristics become extremely poor.

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

In order to avoid such problems, attempts have been made to construct a negative electrode by using a carbonaceous material obtained by baking an organic compound as a carrier, and supporting an alkali metal, mainly lithium, as an active material on this carrier. By using such a negative electrode, the charge/discharge cycle characteristics of the negative electrode are dramatically improved. However, on the other hand, the negative electrode molded body using this carbonaceous material as a carrier has poor flexibility and is not easily formed into a sheet. A satisfactory shape or spiral electrode could not be obtained.

(Problems to be Solved by the Invention) Based on this technical background, the present invention has been developed based on the above technical background.
The object of the present invention is to provide a negative electrode for a secondary battery that has excellent charge/discharge cycle characteristics and flexibility.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present inventors have conducted extensive research on negative electrodes, and have found that it is possible to form an alloy with a carbonaceous material and an active material. An electrode structure in which an active material is supported on a support made of a mixture of a metal or an alloy containing an active material and a fibrous organic polymer is extremely effective for achieving the above-mentioned purpose. They discovered this and arrived at the present invention.

That is, the electrode of the present invention has the following characteristics: (a) the hydrogen/carbon atomic ratio is less than 0.15, and (b) the interplanar spacing (d) of the (002) plane measured by X-ray wide-angle diffraction
002) is 3.37 Å or more and the crystallite size (Lc) in the C-axis direction is 220 Å or less, (2) particles of a metal or alloy containing an active material that can form an alloy with an active material, and (3) A carrier made of a fibrous organic polymer binder is formed, and an alkali metal is supported as an active material on this carrier.

The secondary battery electrode of the present invention is characterized by a negative electrode having the above-described configuration, and other elements can be configured in the same manner as conventional secondary battery electrodes.

In the negative electrode according to the present invention, the active material is an alkali metal, preferably lithium. For example, in the case of lithium, this active material repeatedly changes into Li ions and metallic lithium as the battery is charged and discharged.

In the present invention, the carbonaceous material used as a support for the active material constituting the electrode body has (a) a hydrogen/carbon atomic ratio (H/C) of less than 0.15;
and (b) the spacing (d) of the (002) plane by X-ray wide-angle diffraction method
ooz) is 3.37 Å or more, and the crystallite size (Lc) in the C-axis direction is 220 Å or less.

It has the characteristics of The carbonaceous material preferably contains other atoms such as nitrogen, oxygen, halogen, etc. in an amount of 7 mol% or less, more preferably 4 mol% or less, particularly preferably 2 mol% or less.
It may be present in a proportion of less than mol%.

H/C is preferably less than 0.10, more preferably 0
．． It is less than 07, particularly preferably less than 005.

The spacing (d, .2) of the (002) plane is preferably 3.3
8 Å or more, more preferably 3.39 to 3.75 people, even more preferably 3.41 to 3.70 people, particularly preferably 3
．． 45 to 3.70 people.

The crystallite size Lc in the C-axis direction is preferably 180 Å or less, more preferably 5 to 150, and even more preferably 1
0 to 80 people, particularly preferably 12 to 70 people.

These parameters, namely H/C,d,. If either 2 or Lc deviates from the above range, the overvoltage at the electrode body during charging and discharging will increase, and as a result, gas will be generated from the electrode body, significantly impairing the safety of the battery. In addition, the charge/discharge cycle characteristics also deteriorate.

Furthermore, it is preferable that the carbonaceous material used for the carrier of the electrode body according to the present invention has the following characteristics.

That is, in Raman spectrum analysis using argon ion laser light with a wavelength of 5145, the G value defined by the following formula is preferably less than 2.5,
More preferably less than 2.0, particularly preferably 0
．． 2 or more and less than 1.2.

Here, the G value is the wavelength of 5145 for the carbonaceous material mentioned above.
In the spectrum intensity curve recorded on the chart when Raman spectrum analysis was performed using human argon ion laser light, the integral value (area intensity) of the spectrum intensity within the range of wave number 1580 ± 100 cm-' is calculated as wave number 1
It refers to the value divided by the area intensity within the range of 360±100 co+-', and corresponds to a measure of the degree of graphitization of the carbonaceous material.

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

Furthermore, it is desirable that the carbonaceous material used for the carrier of the electrode body according to the present invention satisfies the following conditions:
That is, the (110) lattice spacing dll in X-ray wide-angle diffraction analysis. twice the distance a.

(2dl,.) is 2.38 to 2.47 people, more preferably 2.39 to 2.46 people, and the crystallite size La in the a-axis direction is preferably 10 Å or more, more preferably 1
5 to 150 people, particularly preferably 19 to 70 people.

Furthermore, this carbonaceous material can take any form such as granular or fibrous, but granular or fibrous forms are preferable.

The granules preferably have a volume average particle size of 300P or less, more preferably 0.2P or more and 200P or less, even more preferably 0.5P or more and 150P or less, particularly preferably 2P or more and 100P or less, and most preferably 5P or more and 60F.
The particles are as follows.

Furthermore, this carbonaceous material has pores inside, and the total pore volume is preferably 1.5X10-"-/g or more, more preferably the total pore volume is 2.0x10-"-/g or more.
"wl/g or more, more preferably 3.0XIO-"d
/g or more and 8 x 10 bows - 7g or less, particularly preferably 4.
0XIO-"m!'/g or more and 3 x 1O-"d/g or less.

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

The total pore volume is determined from the total amount of gas adsorbed at a relative pressure P/P0: 0.995, assuming that the pores are filled with liquid nitrogen.

P, vapor pressure of adsorbed gas (mmHg) Po, saturated vapor pressure of adsorbed gas at cooling temperature (mmHg)
) Furthermore, from the amount of nitrogen gas adsorbed (V,,,), the following (1)
Using the formula, the amount of liquid nitrogen filled in the pores fv+,
, l to determine the total pore volume.

p, v, , vllll V1□= (1)T Here, P and T are atmospheric pressure (kgf/cm2
) and temperature (K), and v and a are the molecular volumes of the adsorbed gas (34.7 cm''/mol for nitrogen).

Further, the carbonaceous material used for the carrier of the electrode body according to the present invention has pores inside, and the average pore radius (γ,) is 8.
It is preferable that the number of participants is 100 to 100 people. More preferably 10
~80 people, more preferably 12-60 people, particularly preferably 14-40 people.

The average pore radius (γ,) is V determined from equation (1) above.
1□, and the BET specific surface area S, by calculating using the following equation (2).

Here, it is assumed that the pore is cylindrical.

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:
Phenol resins: Acrylic resins such as polyacrylonitrile and poly(α-halogenated acrylonitrile): Halogenated vinyl resins such as polyvinyl chloride, polyvinylidene chloride, and chlorinated polyvinyl chloride: Polyamide-imide resins; Polyamide resins; Polyacetylene, poly Any organic polymer compound such as a conjugated resin such as (p-phenylene): a monomer with three or more members such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, chrysene, naphthacene, bicene, perylene, pentaphene, and pentacene. Fused cyclic hydrocarbon compounds formed by condensing two or more ring hydrocarbon compounds with each other: Or derivatives of the above compounds such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides: Various types containing mixtures of the above compounds as main components pitch; at least two or more 3-membered or more heteromonocyclic compounds such as indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, and phenanthrene are bonded to each other, or one or more A fused heterocyclic compound formed by bonding with a monocyclic hydrocarbon having 3 or more members.2 Derivatives of the above compounds such as carboxylic acids, carboxylic acid anhydrides, and carboxylic acid imides; and benzene or its carboxylic acids and carboxylic acid anhydrides. , derivatives such as carboxylic acid imides, e.g.
Examples include derivatives such as 2.4.5-tetracarboxylic acid, its dianhydride or its diimide.

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

The carrier constituting the secondary battery electrode of the present invention is made of the above-mentioned carbonaceous material, a metal capable of forming an alloy with the active material, an alloy containing the active material, and a mixture with a fibrous organic polymer. .

As the active material, an alkali metal, preferably lithium, is used. An alloy of lithium is used, more preferably lithium is used in combination with a metal with which it can be alloyed.

Taking a lithium alloy as an example, the metal used as 6M whose composition (molar composition) is expressed as L 1x M (where X is the molar ratio to metal M) is, for example, alumina A, (Aff ), lead (Pb), zinc (Zn), tin (Sn), bismuth (Bi), indium (In), magnesium (Mg), gallium (Ga
), cadmium (Cd), silver (Ag), silicon (Si)
, boron (B), gold (Au), platinum (Pt), palladium (Pd), antimony (Sb), etc., preferably Aff, Pb, In, Bi and Cd, more preferably Aβ, Pb , In, and particularly preferably Au2.

In 6Li and M, which may contain other elements in addition to the above-mentioned metals in an amount of 50 mol% or less, X preferably satisfies O<x≦9, more preferably 0. 1≦X≦5, more preferably 0.5
≦X≦3, particularly preferably 0.7≦X≦2.

As the active material alloy (Li, M), one type or two or more types of alloys can be used.

As the metal that can be alloyed with the active material, one or more of the above gold KM can be used.

Metal (M) that can be alloyed with the active material or alloy of the active material (L
ixM) exists in the form of particles or attached to the above-mentioned carbonaceous material.

The mixed composition of the above carbonaceous material and a metal (M) capable of forming an alloy with the active material or an alloy of the active material (LixM) is such that the active material and the alloy are mixed with 100 parts by weight of the carbonaceous material. An alloy of metals or active materials that can be formed,
Preferably 70 parts by weight or less, more preferably 2 parts by weight or more and 60 parts by weight or less, even more preferably 5 parts by weight or more and 50 parts by weight or less.
It is preferably 10 parts by weight or more and 45 parts by weight or less, most preferably 15 parts by weight or more and 40 parts by weight or less.

Such metal particles have a volume average particle size of 0.27Ji
1 or more and 200P or less, more preferably 0.3
P or more and 1507111 or less, more preferably 0.5F
m or more and 100F, particularly preferably lpI or more and 60F or less.

In addition, gold ME (M) or an alloy of active materials (LixM), which can form an alloy with an active material in the form of a thin layer coated on the surface of the particles of the carbonaceous material mentioned above, is also available.
It is also possible that there exists.

Alternatively, it is also possible that a metal (M) or an alloy of the active material (LixM) that can be alloyed with the active material is included in the particles of the carbonaceous material mentioned above.

A metal (M) or an alloy of an active material (LixM) that can form an alloy with a particulate active material and the aforementioned carbonaceous material particles or those having a fibrous form are mechanically Can be mixed.

In addition, methods for coating the surface of the particles or fibers of the carbonaceous material with a thin layer of metal (M) or alloy (LixM) that can be alloyed with the active material include vapor deposition, plating, and thermal spraying. be.

Furthermore, as a method for incorporating the metal (CM) or alloy (LixM) of the active material that can be alloyed with the active material into the particles of the carbonaceous material, etc., there is a method of incorporating the metal (M) into the particles of the carbonaceous material, etc. A method of impregnating and thermally decomposing an organometallic compound,
A method of thermally decomposing and carbonizing an organic compound using metal (M) particles as a nucleus is used.

The above-mentioned carbonaceous material, active material, metal (M) capable of forming an alloy, or a mixture of the alloy (Li, M) containing the active material are bound together in a form in which fibrous organic polymers are entangled. , to maintain its shape as a carrier.

The fibrous organic polymer preferably has an average diameter of 30F or less, more preferably 20F or less, and even more preferably 15F or less.
F or less, most preferably 10P or less. The average length of the fibers is preferably 100 mm or less, more preferably 70 mm or less, and even more preferably 0.3 mm or more and 50 mm or less.
am or less, particularly preferably 0.5 mm or more and 20 mm or less, and most preferably 0.7 mm or more and 5II11 or less.

A particularly preferred form of the fibrous organic polymer is one in which the fibers are composed of fine fibers (fibrils) with an average diameter of less than IOF, more preferably 5P or less, particularly 3P or less.

Alternatively, the organic polymer fibers may be in the form of fibrils (powder having tentacle-like ultrafine fibrils).

In any case, the average diameter of the organic polymer fibers is preferably at most % of the average particle diameter of the carbonaceous material particles, more preferably at most 2, even more preferably at least % o o and at most 0, particularly preferably at least z0%. It is as follows.

Further, when the carbonaceous material is also fibrous, the average fiber diameter of the organic polymer fibers is preferably at most % of the average diameter of the fibers of the carbonaceous material, more preferably at most Z, and even more preferably at most.

. It is preferably between Z0 and Z0%, and Z0% and below.

These thin fibers intertwine and form the aforementioned carbonaceous material,
A metal (CM) that can be alloyed with the active material or an alloy of the active material (L
i, M) can be combined.

The organic polymer fiber is preferably one that does not contain fluorine atoms, but fluorine atoms are not preferred because they may react with the alkali metal of the active material.

The fibrous organic polymers used in the present invention include polyethylene, polypropylene, ethylene and α having 3 to 12 carbon atoms.
- Copolymers with olefins, copolymers with ethylene and vinyl acetate, copolymers with propylene and ethylene, copolymers with propylene and α-olefins having 4 to 12 carbon atoms,
Examples include polyesters such as polyethylene terephthalate, polyamides, and the like.

Ultrafine fibers of organic polymers with an IOF of less than 1 m, furthermore, 5 or less, particularly 3F or less, can be produced by the following method.

(1) Solution flash method A method of obtaining reticulated ultrafine fibers by explosively ejecting an organic polymer solution from a high pressure side to a low pressure at a temperature above the boiling point of the solvent.

(2) Emulsion flash spinning 1 A method of obtaining ultrafine fibers by jetting out a dispersion of an organic polymer solution or jetting out a dispersion of heat-softened particles of an organic polymer.

(3) Melt blowing method A method of obtaining ultrafine fibers by blowing away a melted organic polymer with high-velocity gas.

(4) Turbulent flow forming method A method of obtaining ultrafine fibers by coagulating an organic polymer liquid under turbulent flow conditions in which shearing force is applied.

(5) Polymer array fiber dissolution method In the fiber cross section, the l component (island) is highly distributed among other components (sea), and from the polymer array fiber, which is uniformly continuous in the fiber axis direction, the sea A method of creating ultrafine fibers by dissolving ingredients.

Further, the blending ratio of the organic polymer fiber and the mixture of the above-mentioned carbonaceous material and gold @ (M) capable of forming an alloy with the active material or the alloy of the active material (LixM) is determined by the above-mentioned carbonaceous material. and a metal (M) that can be alloyed with the active material or an alloy of the active material (LixM), preferably 40 parts by weight or less, more preferably 0.1 parts by weight of the organic polymer fiber. Parts by weight or more and 30 parts by weight or less, more preferably 0.42 parts by weight or more and 20 parts by weight or less, particularly preferably 0.3 parts by weight or more and 10 parts by weight or less, most preferably 0.
．． It is 5 parts by weight or more and 7 parts by weight or less.

The above-mentioned carbonaceous material may take any form such as particulate or fibrous form as described above, but preferably particulate form. A mixture of this carbonaceous material, a metal that can be alloyed with the active material, or an alloy of the active material, and organic polymer fibers are mechanically mixed and formed into a sheet-like electrode by a processing method such as roll molding or compression molding. can do.

It is also possible to form a sheet-like electrode by using a metal gauze made of nickel or the like as a current collector and a support during forming, and press-bonding it to the gauze.

Methods for supporting the active material on the support include chemical methods, electrochemical methods, physical methods, etc. For example, the support may be placed in an electrolytic solution containing a predetermined concentration of alkali metal cations, preferably Li ions. A method of electrolytic impregnation using lithium as a counter electrode and using the support as an anode, a method of mixing an alkali metal powder, preferably lithium or a lithium alloy in the process of obtaining a molded support, etc. are applied. be able to.

Alternatively, an alkali metal, preferably lithium metal sheet can be laminated to a molded body of a carrier to form an electrode, and this can be charged and discharged while being incorporated into a battery to support an alkali metal, preferably lithium.

The amount of alkali metal, preferably lithium, previously supported on the negative electrode carrier in this way is preferably 0.030 parts by weight or more and 0.250 parts by weight or less, more preferably 0.030 parts by weight or more and 0.250 parts by weight or less, per 1 part by weight of the carrier 0.060 parts by weight or more. ,2
0 parts by weight or less, more preferably 0.070 parts by weight or more and 0.15 parts by weight or less, particularly preferably 0.075 parts by weight or more and 0.12 parts by weight or less, most preferably o, oso
It is not less than 0.100 parts by weight.

The secondary battery electrode of the present invention is usually used as a negative electrode, and is opposed to a positive electrode with a separator interposed therebetween.

Since the secondary battery electrode of the present invention has excellent flexibility and bending strength, it can be applied as an electrode for various sheet-shaped, prismatic, and cylindrical batteries.

For example, as shown in Fig. 1, a positive electrode body (1) and a negative electrode body (2) of the present invention are rolled into a spiral shape so as to face each other with a separator (3) interposed therebetween, and this is housed in a cylindrical can. , it can be a cylindrical secondary battery.

This positive electrode body is not particularly limited, but is preferably made of a metal chalcogen compound that releases or acquires alkali metal cations such as Li ions during charging and discharging reactions. Examples of such metal chalcogen compounds include vanadium. oxide, vanadium sulfide, molybdenum oxide, molybdenum sulfide, manganese oxide,
Examples include chromium oxides, titanium oxides, titanium sulfides, and composite oxides and composite sulfides thereof. Preferably, Crm Os, Vo Os, v60. s,
■○,, Crx Os t MnOx, Ti0-1M
OV * Os, T i S *, V m S s, M
OSl, Mo Ss, VS*,
Cro, xsVa, ysS3, Cro, s Vo
, s S z, etc. Also, LiCo Oz, Woe
oxides such as CuS, Feo, asVo, ysSx,
Sulfides such as Nao, + Cr5t, N1PSs, Fe
Phosphorus such as PSs, ionic compounds, V S e z, N
Selenium compounds such as bSe s can also be used.

Further, conductive polymers such as polyaniline and polypyrrole can be used.

The separator (3) that holds the electrolyte is made of a material with excellent liquid retention properties, such as a nonwoven fabric made of polyolefin resin. This separator (3) is made of LiCβ04. L
It is impregnated with a non-aqueous electrolyte at a predetermined temperature in which an electrolyte such as iBF4, L i AS s, L i P F s or the like is dissolved.

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

(Function) In the secondary battery configured in this way, active material ions are supported on the carrier during charging in the negative electrode, and active material ions in the carrier are released during discharging, so that the charge/discharge electrode is The reaction progresses.

On the other hand, for the positive electrode, when a metal chalcogen compound is used, active material ions are released into the positive electrode body during charging, and the active material ions are supported during discharging, thereby progressing the electrode reaction during charging and discharging.

Alternatively, when a conductive polymer such as polyaniline is used for the positive electrode, the counter ions of the active material ions are supported on the positive electrode body during charging, and the counter ions of the active material ions are released from the positive electrode body during discharging. The reaction progresses.

A battery reaction accompanying charging and discharging of a battery proceeds by such a combination of electrode reactions of the positive electrode body and the negative electrode body.

(Effects of the Invention) The secondary battery electrode of the present invention has a support comprising particles of the carbonaceous material described above, particles of a metal capable of forming an alloy with the active material or an alloy containing the active material, and a fibrous organic polymer binder. It has an alkali metal, preferably lithium, supported on the body, and can be shaped into a flexible sheet electrode, which can then be spirally shaped and applied to a cylindrical secondary battery. . It can also be applied as an electrode for thin sheet batteries or square batteries. Therefore, the present invention provides an electrode that enables a secondary battery with high capacity, high output, and excellent charge/discharge cycle characteristics.

(Examples) Hereinafter, the present invention will be explained by Examples and Comparative Examples. Note that the present invention is not limited to this example.

In the present invention, elemental analysis and wide-angle X-ray diffraction measurements were carried out by the following methods.

[Elemental analysis] The sample was dried under reduced pressure at 120° C. for about 15 hours, and then dried at 100° C. for 1 hour on a hot plate in a dry box. 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 also the generated H80
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.

"X-ray wide-angle diffraction" (1) Interplanar spacing (d, .2) of (002) plane and (11
0) Interplanar spacing (a,,,,) If the carbonaceous material is a powder, it is used as it is, or if it is in the form of minute pieces, it is powdered in an agate mortar, and the amount of high purity for X-ray standards is about 15% by weight based on the sample. Add and mix silicon powder as an internal standard substance, fill it in a sample cell, and measure the wide-angle X-ray diffraction curve using the reflection diffractometer method using CuKa rays made monochromatic with a graphite monochromator as a radiation source. Correction of 6 curves. In this case, the following simple method is used without making corrections for so-called Lorentz factors, polarization factors, absorption factors, atomic scattering factors, etc. That is, by drawing the baselines of the curves corresponding to (002) and (110) diffraction, and plotting the real intensity from the baseline again, the (002) and (110) planes are
10) Obtain a correction curve for the surface. 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 d002 and d1□ by the following Bragg equation from the wavelength λ. seek.

λ: 1.5418 people θ, θ': d0゜l dll. Diffraction angle (2) corresponding to
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 crystallites in c-axis and a-axis directions is Find the size using the following formula.

K · λ β · COSθ β · cosθ' There are various discussions regarding the shape factor K, but K=090 was used. Well, θ and θ' have the same meaning as in the previous section.

Example 1 (1) Synthesis of carbonaceous material Crystalline cellulose granules (average radius of about 1 mm) were set in an electric heating furnace, heated to 1000°C at a rate of 250°C/hour under nitrogen gas flow, and further heated to 1000°C. It was held for 1 hour.

Thereafter, the obtained carbonaceous material particles were set in another electric furnace and heated to 1800°C at a heating rate of 1000°C/hour under nitrogen gas flow, and further maintained at 1800°C for 1 hour. .

The carbonaceous material thus obtained was placed in a 500-mm agate container, and two agate balls with a diameter of 30 mm and a diameter of 25 m were placed.
6 agate balls with a diameter of 20 mm and 16 agate balls with a diameter of 20 mm were added and crushed for 3 minutes.

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. a = 3.59 people, Lc = 14 people ao (2d'
+to )=2.41. La=25 people volume average particle size=4
0P Specific surface area (BET) = 8.2 m''/g (2) Preparation of mixture of carbonaceous material and aluminum particles 30 parts by weight of aluminum particles with a volume average particle diameter of 15F are added to 100 parts by weight of the above carbonaceous material particles. 1 part and mixed mechanically.

(3) Forming a sheet-like carrier Adding 10 parts by weight of 0.03 denier polypropylene fibers cut into 10 mm length to 100 parts by weight of the above mixture of carbonaceous material and aluminum particles,
Mixed mechanically. While rolling this with a roll,
Pressed onto mesh nickel wire mesh at a temperature of 120℃,
A sheet-like carrier with a thickness of 0.4 μm was prepared.

(4) Addition of lithium to the above support The above support is electrolytically treated in a propylene carbonate solution of 1 mol/I2 LiCl204 using lithium metal as one electrode and a counter electrode to form an active material. A negative electrode body was manufactured by supporting lithium. The electrolytic treatment conditions were a bath temperature of 20°C, a current density of 0, and a current density of 7 mA/Cm'', and lithium equivalent to 830 + aAh was supported on the negative electrode body.

(5) Manufacture of positive electrode body 10 g of MnOx powder calcined at 470°C and 1 g of powdered polytetrafluoroethylene were mixed, and the resulting mixed wire was roll-formed to form a sheet with a thickness of 0.4 mm. did.

(6) Battery assembly A sheet-like electrode in which lithium is supported on a carrier made of a mixture of carbonaceous material, aluminum particles, and fibrous organic polymer described above is interposed with a polypropylene nonwoven fabric as a separator, and as a positive electrode, a nonwoven fabric made of polypropylene is interposed as a separator. Sheet-like electrodes made of MnOs were stacked, formed into a spiral shape as shown in FIG. 1, and housed in a stainless steel cylindrical can.

In the separator, 1 mol/ff- of Li Cl2O4
A battery cell as shown in FIG. 1 was assembled by impregnating a propylene carbonate solution and sealing the battery cell.

(7) Characteristics of the battery Regarding the battery manufactured in this way, the battery voltage was 1.5 mA at a constant current of 20 mA. The battery was discharged until it reached OV. After that, charge the battery with a constant current of 20 mA until the battery voltage reaches 3.3 ■, and then perform preliminary charging and discharging with a constant current of 20 mA for 55 minutes with potential regulation of an upper limit of 3.3 V and a lower limit of 1.8 ■. The cycle was carried out.

After sowing, charging and discharging were repeated between 3.3 V and 1.8 V at a constant current of 25 mA (7) to perform cycle evaluation. Table 1 shows the performance at the 6th cycle and the 60th cycle.

Comparative Example 1 A battery was constructed in the same manner as in Example 1 except that a lithium metal sheet was used instead of the negative electrode in Example 1.

The characteristics of the battery are shown in Table 1.

While the coulombic efficiency at the 60th cycle significantly decreased in Comparative Example 1, no change was observed in Example 1 compared to the 6th cycle.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the structure of a battery of Example 1. 1...Positive electrode body 2...Negative electrode body 3. Separate lake (including electrolyte) procedural amendment Heisei

Claims (1)

[Claims] 1. (1) The following characteristics (a) the hydrogen/carbon atomic ratio is less than 0.15, and (b) the interplanar spacing (d) of the (002) plane measured by X-ray wide-angle diffraction
_0_0_2) is 3.37 Å or more and the crystallite size (Lc) in the C-axis direction is 220 Å or less; (2) particles of a metal that can form an alloy with an active material or an alloy containing an active material; (3) A secondary battery electrode characterized in that a carrier made of a fibrous organic polymer binder is formed and an alkali metal is supported as an active material on the carrier.