JPS5971268A - Battery - Google Patents

Abstract

PURPOSE:To improve flatness of discharge voltage and life cycle and thereby easily reduce the size and cost of a battery, by using a composite material consisting of an acethylene high polymer, conductive material, and mesh material formed like a sheet for at least one electrode. CONSTITUTION:A composite material consisting of an acethylene high polymer of 100pts.wt., a conductive material of under 1-5pts.wt. and mesh material formed like a sheet of 1-500pts.wt. is used for at least one electrode of this battery. The acethylene high polymer is usually used in the form of powder, short fiber of minute segment, or in the form where a dopant is doped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a composite comprising at least 100 parts by weight of an acetylene polymer, 1 part by weight or more and less than 5 parts by weight of a conductive material, and 1 to 500 parts by weight of a sheet-like network. It relates to a battery used for one electrode.

Acetylene polymers obtained by polymerizing acetylene using a so-called Ziegler-Natsuta catalyst consisting of a transition metal compound and an organometallic compound are useful as electrical/electronic devices because their electrical conductivity is in the semiconductor region. It is already known that it is an organic semiconductor material. However, the acetylene polymer obtained in this way does not melt even when heated, and it easily undergoes oxidative deterioration under heating, so it cannot be molded using the usual molding methods used for thermoplastic resins. . Furthermore, no solvent has been found that dissolves this acetylene polymer. Therefore, conventional methods for producing practical molded products of acetylene high polymers include (a) pressure molding of powdered acetylene high polymers;
and (b) a method of obtaining a membranous acetylene polymer having a fibrous microcrystalline (fibril) structure by polymerizing and simultaneously forming it into a membrane under special polymerization conditions (Japanese Patent Publication No. 48-32581).
, was limited to.

However, method (a) only yields molded products with low mechanical strength, while method (b) has the advantage of having high mechanical strength compared to molded products obtained by method p). However, the bulk density of the acetylene polymer molded product obtained is at most 0.60 I/cc (true specific gravity = 1.20 gc, c), and there is a drawback that only a porous film can be obtained. Ta.

The powdered acetylene polymer molded product obtained by the method (a) above is mixed with BF3, BCl3, HCl1C12, SO2,
When chemically treated with electron-accepting compounds (acceptors) such as NO2, HCN102, and NO, the electrical conductivity increases to a maximum of 3.
It is already known that the electrical conductivity increases by an order of magnitude, and conversely, when treated with electron-donating compounds (donors) such as ammonia or methylamine, the electrical conductivity decreases by up to four orders of magnitude (D, J
, Berets et al., Trans-
FaradySoc, 64. 823 (196
8) ).

In addition, in the film-like acetylene polymer obtained by the method (b), ■2, C12, Br2, ■C11■BrXASF6
By chemically doping electron-accepting compounds such as , SbF', PF6, etc. or electron-donating compounds such as Nas K, Li, the electrical conductivity of the acetylene polymer can be increased from 1σ9 to 1core'Ω-1. It is already known that dl can be freely controlled over a wide range [
J, C, S, Chem Commu, , 578
(1977), Phys, Rev. Lett.
, ,Figure 11098 (1977), J, Am.
Chem.

Soc, , Ion, 1013 (1978),
J, Chem, Phys, 69.5098 (19
78)). The idea of using this doped film-like acetylene polymer as an anode material for primary batteries has already been proposed (Molecular Metals
, NATO Conference 5eries,
5eries VI, 471-489 (197
8)).

On the other hand, in addition to the above chemical doping method, electrochemical CIO;, BF7, AsF, -1cF;so;
.

A method for producing p-type and n-type conductive acetylene polymers by doping anions such as BF7 and cations such as N+ (R1: alkyl group) into acetylene polymers has already been developed [J , C, S, Che
m, Commu, 1979594. C&ENJan
, 26. 39 (1981), J, C, S, Ch.
em, Commu. , 1981 317). A rechargeable battery using electrochemical doping using a film-like acetylene polymer obtained by the method (b) has been reported (Paper Presented
at the International.

nnalconference on Low Dim
nationalSynthetic Metals,
Hersinger, Denmark.

10-15. August 1980).

This battery is obtained by the method (b), for example, 0.1 m
Two sheets of acetylene polymer film with a thickness of m are used as positive and negative electrodes respectively, and when these are immersed in a tetrahydro 7 run solution containing lithium iodide and connected to a 9V DC power supply, lithium iodide is electrolyzed. , the acetylene polymer film of the anode is doped with iodine, and the acetylene polymer film of the cathode is doped with lithium. This electrolytic doping corresponds to the charging process. When a load is connected to the two doped electrodes, lithium ions and iodine ions react to generate electricity. In this case, the open circuit voltage (Voc) is 2.8V, and the short circuit current density is 5mA/
c/L, and when a tetrahydrofuran solution of lithium perchlorate is used as the electrolyte, the open circuit voltage is 2.5V.
, the short-circuit current density was about 3 mA/cIl.

This battery uses an acetylene polymer as its electrode material, which is easy to reduce weight and size, so it is attracting attention as an inexpensive battery that has high energy density and is easy to reduce weight and size. There is. However, the acetylene polymers used in these known documents were porous membrane-like acetylene polymers produced by the method (b) above. This film-like acetylene high polymer is difficult to process, and the film thickness of the film-like acetylene high polymer produced by this method is at most 200 μm, and for practical purposes, a film with a thickness larger than this is required. Moreover, the mechanical strength of this film is not necessarily sufficient. Furthermore, the performance of secondary batteries produced using this film as electrodes, such as cycle life, voltage loss during discharge, and charging/discharging efficiency, was not necessarily satisfactory. Therefore, the use of known batteries using the membrane-like acetylene polymer produced by the method (b) as an electrode material has been extremely limited. On the other hand, when a powdered compound is used as an electrode material, it is common practice among those in the industry to prepare a three-component composition containing the powdered compound, a conductive material such as carbon black, and a binder such as Teflon under pressure. It is known to use molded articles as electrodes. However, this method requires heating and pressure molding in order to bring out the effect of the binder used, which is a complicated operation and is difficult to use in systems that use organic solvents for the electrolyte. However, the bonding agent dissolves or swells in the solvent, and the shape of the electrode is destroyed after long-term use, resulting in a short cycle life.

When a powdered acetylene high polymer is used as an electrode material, it has the advantage of being moldable, but it also has the same drawbacks as the general case described above. It has the disadvantage of being easily susceptible to oxidative deterioration during heating, and it is difficult to form powdered acetylene high polymers into electrodes using methods known to those skilled in the art. There has been a desire to establish a battery that is lightweight, easy to downsize, and inexpensive, with electrodes that have high mechanical strength, high energy density, flatness during discharge, and good cycle life.

In view of the above points, the present inventors discovered that the electrode has high mechanical strength and high energy density, has good cycle life and voltage flatness during discharge, and is easy to reduce weight and size. The present invention was completed as a result of various studies to obtain an inexpensive battery.

That is, the present invention provides 100 parts by weight of an acetylene polymer,
1 part by weight or more and less than 5 parts by weight of conductive material and 1 to 5 parts by weight
The present invention relates to a battery in which at least one electrode is made of a composite made of 0.00 parts by weight of a sheet-like mesh material.

The composite used as an electrode in the present invention has an arbitrary film thickness and has sufficient mechanical strength without using a binder, so it can be used as an electrode using conventional acetylene polymers. Compared to the case where a secondary battery is used, the advantages of a secondary battery include: (11) good voltage flatness during discharge; (iii) less self-discharge. , On the other hand, in the case of secondary batteries, (1) high energy density, (11) good voltage flatness during discharge, low OiD self-discharge, and 6V) long life after repeated charging and discharging. It has the advantage of being long.

In order to maximize the advantages of the present invention, it is preferable to use it as an electrode for a secondary battery.

The acetylene polymer used in the present invention can be in any form as long as it is in the form of a powder, minute particles, or short fibers, but it is preferably in the form of a powder with an average particle size of 0.5 cIrL or less or in the form of long fibers. Examples include acetylene polymers in the form of minute particles or short fibers with an average particle size of 5 clrL or less, and particularly preferred are those with an average particle size of 0.2 c.
It can be in the form of a powder with a length of IrL or less, or in the form of minute pieces or short fibers with a length of 2 crIL or less.

Specific examples of methods for producing these acetylene polymers include the method of Natta et al. (Atti, Acad, Naz
l.

Linci, Rend, C1asse Sci,
Fi s, Mat, Nat, 25. 3 (195
8)), the method of Hatano et al. [J, Polym, Sci.
, 51°526 (1961)), the method of Ueda et al. [J
, Polym.

Sci, A2. 3347 (1964)), Pez
method (U, S.

P, No. 4228060] and a method already proposed by some of the present inventors [Japanese Patent Application Laid-Open No. 55-129404, open/close
55-145710], but is not necessarily limited to these methods. moreover,
As a method other than the above, a membrane-like swollen acetylene high polymer produced by a method already proposed by some of the present inventors [JP-A-56-115305] is mechanically crushed into pieces with a length of 5 cIrL or less. A method of forming short fibers is also useful. In the present invention, since the acetylene high polymer is used in the form of powder, short fibers, or minute pieces, it is not only easier to mold than using a film-like acetylene high polymer, but also the quality of the molded product is uniform. Battery performance using the molded product as an electrode is also good.

The acetylene polymer in the form of powder, short fibers, or minute pieces used in the present invention can be either amorphous or crystalline, but fibrous microcrystals (fibrils)
Those having a structure are preferable.

Further, in the present invention, any sheath transformer composition can be used.

The electrically conductive material used in the present invention has an electrical conductivity of 1O-5fl''·α-1 or more, preferably 10-3Ω-
1.crjL1 or more, particularly preferably 1σ2Ω-”-c
Specific examples thereof include carbon black, acetylene black, graphite metal, and charcoal fiber. Preferred specific examples include carbon black, acetylene black, and graphite; Particularly preferred examples include carbon black and acetylene black.

Although any shape of the conductive material can be used, powder-like and fibrous-like materials are preferred because of their ease of moldability, and powder-like materials are particularly preferred.

The proportion of the conductive material in the composite is 1 part by weight or more and less than 5 parts by weight, preferably 2 parts by weight or more and less than 5 parts by weight, based on 100 parts by weight of the acetylene high polymer.

If the proportion of the conductive material in the composite is less than 1 part by weight per 100 parts by weight of the acetylene polymer, the effect of the addition of the conductive material is small and sufficient battery performance cannot be obtained. On the other hand, if the proportion of the conductive material in the composite is 5 parts by weight or more based on 100 parts by weight of the acetylene high polymer, the mechanical strength of the composite decreases, and batteries using this composite as electrodes Not only does this have the disadvantage of decreasing the cycle life of the battery (11), but it is also undesirable because the energy density per unit weight of the electrode of the battery decreases.

The sheet-like mesh material that can be used in the present invention includes:
Rope and fabric made of synthetic resins such as polyethylene, polypropylene, polystyrene, polyvinyl alcohol, polyester, polyurethane, and nylon, natural materials such as cotton and silk, and inorganic materials such as asbestos, glass, and ceramics. Examples include cloth and non-woven fabrics, but
It is not necessarily limited to these. A sheet-like mesh material is preferred because it is lightweight when used as an electrode.

The proportion of the sheet-like network in the composite is from 1 part by weight to 500 parts by weight, preferably from 1 part by weight to 300 parts by weight, per 100 parts by weight of the acetylene high polymer used.

If the proportion of the sheet-like network in the composite is less than 1 part by weight per 100 parts by weight of the acetylene high polymer, the mechanical strength of the composite will be low, and the cycle of a battery using this composite as an electrode will be impaired. This has the disadvantage of shortening the lifespan. On the other hand, if the ratio of the sheet-like ((2) net-like material in the composite exceeds 500 parts by weight per 100 parts by weight of the acetylene high polymer, the weight of the electrode itself increases, and This is not preferable because the energy density of

The composite of the present invention is produced by (1) mechanically crushing the film-like acetylene polymer produced by the method (b) above, mixing it with an electrically conductive material using a ball mill, etc., and then combining this mixture with a sheet-like material. (il) A method in which a conductive material is placed in a catalyst solution in advance and acetylene is polymerized in the presence of the conductive material. Method of processing such as pressing or calendering with sheet-like net-like material, 0+0
A gel-like or swollen acetylene polymer containing an organic solvent and a conductive material are thoroughly mixed in a ball mill, etc., and then this mixture and a sheet-like network are layered and molded by a method such as pressing or calendering. In this method, a powdered or short fibrous acetylene polymer containing an organic solvent and a conductive material are thoroughly mixed in a ball mill, etc., and then this mixture is layered with a sheet-like net material, and then pressed or calendered, etc. (■) A powdered or short fibrous acetylene polymer containing no organic solvent and a conductive material are thoroughly mixed in a ball mill, etc., and then this mixture is layered with a sheet-like network. (vi) Acetylene polymer obtained by drying or freeze-drying a gel-like or swollen acetylene polymer and an electrically conductive material are molded together by a method such as pressing or calendering.
A method of thoroughly mixing in a mill etc. and then pressing or calendering this mixture together with a sheet-like mesh (vI
It can be produced by a method such as mixing the acetylene high polymer and the conductive material in advance in a ball mill, etc., and then pressing or calendering this mixture and a sheet-like network, but these methods are not necessarily required. It is not limited to.

When producing the composite of the present invention, the mixing step and the pressing or calendering step may be carried out in the presence or absence of an organic solvent, but it is better to carry out the process in the presence of an organic solvent. This is preferable because a composite with better mechanical strength can be obtained, and the performance of a battery using this composite as an electrode is also excellent.

The organic solvent used is not particularly limited as long as it does not react with the acetylene polymer, but aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, ethers, esters, lactones, alcohols, etc. are usually used. . These organic solvents used for polymerization of acetylene polymers or catalyst removal can also be used as they are.

The amount of the organic solvent used in the present invention is in the range of 500 parts by weight or less, preferably in the range of 200 parts by weight or less, based on 100 parts by weight of the acetylene polymer.

The electrodes of the battery of the present invention include not only a composite consisting of an acetylene polymer, a conductive material, and a sheet-like network, but also a conductive acetylene polymer obtained by doping this acetylene polymer with a dopant; Composites of electrically conductive materials and sheet-like networks can also be used as electrodes. In addition, after forming a composite consisting of an acetylene high polymer, a conductive material, and a sheet-like material ((5), a dopant is doped into the acetylene high polymer by an appropriate method to form a conductive acetylene high polymer. However, when the composite of the present invention is used as an electrode for a primary battery, it is necessary to use a composite using a conductive acetylene polymer.

The doping method may be either chemical doping or electrochemical doping.

Dopants used in chemical doping include various conventionally known electron-accepting and electron-donating compounds, namely (I) halogens such as iodine, bromine and bromine iodide; (6) pentafluoride; Metal halides such as arsenic, antimony pentafluoride, silicon tetrafluoride, phosphorus pentachloride, phosphorus pentafluoride, aluminum chloride, aluminum bromide and aluminum fluoride, (7) sulfuric acid, nitric acid, fluorosulfuric acid, trifluoromethanesulfuric acid and protic acids such as chlorosulfuric acid, ■ oxidizing agents such as sulfur trioxide, nitrogen dioxide, Schiff (16) fluorosulfonyl peroxide, □□□A
gcA! o4, cvi tetracyanoethylene, tetracyanoquinodimethane, floranil, 2,3-dichloro-
Examples include 5,6-dicyazparabenzoquinone, 2,3-diprome-5,6-dicyazparabenzoquinone, and the like. As dopants to be electrochemically doped, (i) PF6-1SbF,,',AsF,-1
SbCla 'j Anionic dopants such as (all effective as dopants to provide P-type conductive acetylene polymers) and (
ff) Cation dopants such as alkali metal ions such as Li+Na'' and K'', quaternary ammonium ions such as R4N+ (R: hydrocarbon group having 1 to 20 carbon atoms), etc.
All of them are effective as dopants for providing an n-type conductive acetylene polymer), but are not necessarily limited to these.

Specific examples of compounds providing the above-mentioned anionic dopants and cationic dopants include LiPF6, Li
SbF6, LiAsF6, LiC10, NaI, Na
PF,, Na5bFo, NaAsF6% NaCAO
4, KI, KPFa, KS bFa, KA s F
6, KC104, [(n-Bu)4ME”・(ASF
6)-1[(n-Bu)+N)”・(PFa)
-1[(n-Bu)4N:]+・C704, Li
Examples include AsF6 and LiBF4, but are not necessarily limited to these. These dopants may be used alone or in combination of two or more.

Anion dopants other than the above are pressure anions, and cation dopants other than the above are biryllium or pyridinium cations represented by the following formula (I): (wherein, X is an oxygen atom or a nitrogen atom , π is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, R' is a halogen atom or an alkyl group having 1 to 10 carbon atoms, and R' is a halogen atom or an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 6 to 15 carbon atoms. 15 aryl groups, m is O when X is an oxygen atom, and 1 when X is a nitrogen atom. n is 0 or 1 to
It is 5. ) or a carbonium cation represented by the following formula (6): 8./ and [wherein R1, R2, and R3 are hydrogen atoms (R1, R2,
R3 is not a hydrogen atom at the same time), carbon number 1 ~
15 alkyl group, allyl group, aryl group having 6 to 15 carbon atoms or 10R5 group, provided that R5 is an alkyl group having 1 to 10 carbon atoms or aryl group having 6 to 15 carbon atoms R4 is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, and 6 to 1 carbon atoms.
5 is an aryl group. ]09).

The HF2 anion used usually has the following general formula % formula %
(): () () ) [However, in the above formula, RXR// is a hydrogen atom or a carbon number is 1
-15 alkyl group, C6-15 alkyl group (a
R'' is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an oxygen atom or a nitrogen atom, and n is 0 or a positive integer of 5 or less. M is an alkali metal] by dissolving the compound (hydrogen fluoride salt) in an appropriate organic solvent.Specific examples of the compound represented by the above formula (g) and M are H4N-HF2, Bu'jN +
HF2, Na-HF2, K HF2, Li-HF
2 and (20) The pyrylium or pyridinium cation represented by the above formula (I) is a cation represented by the formula (I) and C1
! O,-,BF;,AlCl4-1FeC4-1SnC
4+, pB-1PC41SbFo-1ASF, rXCF
sSOM, HF, - etc. (7) 7. It can be obtained by dissolving the salt with =on in a suitable organic solvent. A specific example of such a salt is Emi (21).

Specific examples of carbonium cations represented by the above formula (6) or
C+-1HC+, C6) T,, C+ can be.

II II 0 0 These carbonium cations can be obtained by dissolving salts of them and anions (carbonium salts) in a suitable organic solvent. Typical examples of anions used here include r! s;, AIJCI! 4-1AlBr3C
11-1FeC114-1SnC1ls-1PF, -1
PC76-1SbCla-1SbF6-1CZO,-1
Specific examples of carbonium salts include (C6H5) s C-BF4, (CH
3) 3C-BF4, HCO-AlC4, HCO-BF
4, Cn H, and Co' 5nC75.

The amount of dopant doped into the acetylene polymer in the composite is determined by the repeating unit CH in the acetylene polymer.
It is 2 to 40 mol% per mol, preferably 4 to 40 mol%.
It is 30 mol%, particularly preferably 5 to 20 mol%. 40 mol% even if the amount of doped dopant is 2 mol% or less
Even with the above, it is not possible to obtain a battery with a sufficiently large discharge capacity.

The electrical conductivity of the acetylene polymer before doping is 10-8 to 1O-9Ω-1 in the cis form.
The electrical conductivity of the conductive acetylene polymer obtained by doping with a dopant is about 10-9 to 10'Ω-1, and is 10-4Ω-1·m-1 in the case of a transformer type.
°, in the range of L-1. In general, the electrical conductivity of the conductive acetylene polymer obtained by doping is preferably greater than 10'Ω-1·cIfL-1 when used as an electrode for a secondary battery. When used as an electrode of 10-9 to about 1σ4(23)Ω-1・cIrt-1,
It may be larger than -1.il.

The amount of doping can be freely controlled by measuring the amount of electricity flowing during electrolysis. The doping can be carried out either under constant current, constant voltage or under varying conditions of current and voltage. The current value, voltage value, doping time, etc. during doping depend on the bulk density and area of the acetylene polymer molded product, the type of dopant, the type of electrolyte, and the required electrical conductivity of the acetylene polymer. It cannot be categorically defined as it varies depending on the degree.

In a battery using the composite of the present invention as an electrode, the electrolytic solution used can be either an aqueous solution or a non-aqueous solution, but is preferably one in which the dopant is dissolved in a non-aqueous organic solvent. The organic solvent mentioned here is preferably one that is aprotic and has a high dielectric constant.

For example, ethers, ketones, nitriles, amines,
Amides, sulfur compounds, chlorinated hydrocarbons, esters, (24) phosphate ester compounds, phosphite ester compounds,
Carbonates, nitro compounds, sulfolane compounds, etc. can be used, and among these, ethers, ketones, nitriles, chlorinated hydrocarbons, carbonates, and sulfolane compounds are preferred. Representative examples of these include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, monoglyme, acetonitrile, propionitrile, 4-methyl-2-pentanone, butyronitrile, 1,2-dichloroethane, γ-
Butyrolactone, dimethoxyethane, methylformate, propylene carbonate, ethylene carbonate,
Dimethylformamide, dimethylsulfoxide, dimethylthioformamide, sulfolane, methylsulfolane,
Examples of these organic solvents include, but are not limited to, dimethylsulfolane, ethyl phosphate, methyl phosphate, ethyl phosphite, methyl phosphite, etc. These organic solvents may contain one or more types. It may also be used as a mixed solvent.

In a battery using the composite of the present invention as an electrode, the supporting electrolyte of the electrolyte used is the same as that used in the electrochemical doping described above, and the doping conditions are Conventionally known methods (J,
C, S, , Chem.

Commu, 1981. , 317).

In the battery of the present invention, in addition to the electrolyte described above, a highly ion conductive organic solid electrolyte made of polyethylene oxide and NaI, NλSCN, etc., or a paste made by simply mixing an electrolyte (dopant) and an organic solvent may also be used. be able to.

In addition, the concentration of the supporting electrolyte used in the battery of the present invention cannot be unconditionally defined because it varies depending on the type of positive electrode or negative electrode used, charging/discharging conditions, operating temperature, type of supporting electrolyte, type of organic solvent, etc. , usually in the range of 0.001 to 10 mol/l.

In the present invention, an acetylene polymer or a composite of a conductive acetylene polymer obtained by doping the acetylene polymer with a dopant, a conductive material, and a sheet-like network is used as the (1) positive electrode or ( 11) Can be used as an active substance for negative electrodes or for both positive and negative electrodes.

Among the examples of (1) in which the composite of the present invention was used as a positive electrode, (
These include a) a type in which negative electrode active material ions are doped into the composite (positive electrode) during discharge, and (b) a type in which negative electrode active material ions are doped into the composite (positive electrode) during discharge.

Preferred types of secondary batteries used in the present invention include:
Examples include the types 01D and (b) of (4), and particularly preferably the 0 width type.

Examples of the negative electrode active material in the case of type (1) include those in which a metal having a Pauling electronegativity of not exceeding 16 is used as the negative electrode active material.

Metals used as cathode active materials include lithium,
Examples include alkali metals such as sodium, aluminum, magnesium, and the like. Among them, lithium and aluminum are preferred. These metals may be used in the form of a sheet as in a general lithium battery, or the sheet (27) may be crimped onto a nickel or stainless steel mesh.

To give a specific example of the secondary battery of the present invention, as an example of (1), if the acetylene polymer is (CH)X, (C
H) x (positive electrode) / LiC, gO4 (electrolyte) / Li
(negative electrode), [(CH)+0.06(CAO+) o,
o6)x (positive electrode)/LiClO4 (electrolyte)/Li
(negative electrode), (11) is an example of ((CIE-I)x+
α] (negative electrode) / Li BF4 (electrolyte) / L
i (correct wI), 1i) (7) Example Toshiteha [(CH)+
O"" (CAO+)-□, 024) X (positive electrode)
/ (n-Bu,, N)+・(cgo4)-(electrolyte) / C(n-Bu4N)i;,024 (CH
)-”24+0.06)X (negative electrode), C(CH) (PFa)''O
,. 6]X (positive electrode)/(n-Bu, N)+・(PFa)
-(electrolyte)/[(n-Bu,N) paleo,. 6 (CH
)-0〇6]X (negative electrode), [(CH)+0.050 (
C704,)δ. 5o]X (positive electrode) / (n-Bu4
．． N)++0.020 ・(C104,)'(electrolyte)/I(CH) (
czo+)6o2o]X (negative electrode), C(n-Bu,,N
)(i, 02 (CH)-”2]X (positive electrode) / (
n -Bu, N)+-(cxo+)-(electrolyte)
/ [(n-Bu,,N)(j07 (CH)-”
7:)x (negative electrode), C(CH) (Is)”
""0]x (positive electrode)/Nal+0.010 (28) -0,010 (electrolyte)/((CH) (Na) )(
negative electrode +0.010 ), etc.

In addition, there are also devices in which the composite of the present invention is used in one pole and a conventionally known conductive polymer such as poly(paraphenylene), poly(2゜5-chenylene), polypyrrole, etc. is used in the other electrode. This can be given as a specific example.

In the primary battery of the present invention, a composite of a conductive acetylene polymer, a conductive material, and a sheet-like network is used as a positive electrode active material, and a metal whose Pauling electronegativity does not exceed 1.6 is used as a negative electrode active material. I can list the ones used as. Metals used as negative electrode active materials include alkali metals such as lithium and sodium, aluminum,
Examples include magnesium and alloys thereof.

Among these, lithium and aluminum and alloys of lithium and aluminum are preferred. These metals may be used in the form of a sheet like those of general lithium batteries, or the sheet may be crimped onto a nickel or stainless steel mesh.

In the present invention, if necessary, a porous membrane made of synthetic resin such as glass, polyethylene, or polypropylene, natural fiber paper, cotton nonwoven fabric, or the like may be used as a diaphragm.

In addition, the acetylene polymer used in the present invention undergoes an oxidation reaction when exposed to oxygen, reducing the performance of the battery, so the battery must be sealed and substantially oxygen-free. is preferred.

A battery using, as an electrode, the acetylene polymer of the present invention or a composite made of a conductive acetylene polymer obtained by doping the acetylene polymer with a dopant, a conductive material, and a sheet-like reticular material has high energy. It has high density, long cycle life, and good self-discharge rate, voltage flatness, and charge/discharge efficiency. Furthermore, the battery of the present invention is lightweight, compact, and has a high energy density, so it is ideal for use in portable devices, electric vehicles, gasoline vehicles, and power storage batteries.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 [Composite production experiment] 11 glass auto-machines equipped with a blade-type mechanical stirrer
200ml of toluene in a crepe under nitrogen atmosphere11 2ml of tetrabutoxytitanium! (5,9 mmol) and triethylaluminum 2 ml (14,6 mmol)
1) was charged, and polymerization was carried out with stirring at an acetylene partial pressure of 0.9 kg/i and a polymerization temperature of -20°C for 2 hours.

At the same time as acetylene gas was introduced, it turned reddish-purple and was about 1 m long.
m of short fibrous acetylene polymers began to form.

After the polymerization was completed, the produced short fibrous acetylene polymer was placed on a glass filter and thoroughly washed with about 11 toluene solvent to remove the catalyst. After catalyst removal, the short fibrous acetylene polymer contained 52% by weight of toluene. This toluene-containing short fibrous acetylene polymer 20.89 and carbon black powder (electrical conductivity 21Ω-"cnl") 0.45.9
were mixed in a Bo/lz-mill (31). Next, this mixture was applied to a cotton non-woven fabric (
300℃ at room temperature.
To! It was pressed at a pressure of 9/ffl and then degassed under vacuum. The resulting composite of acetylene high polymer, Kotton nonwoven fabric, and carbon black with a film thickness of 150 μm is a mixture of acetylene high polymer and carbon black sandwiched between Kotton nonwoven fabric, and the surface of the composite is had a metallic luster. In addition, the proportion of cotton nonwoven fabric in this composite is 1% of the acetylene high polymer.
The amount was 50 parts by weight relative to 00 parts by weight.

The yield of acetylene high polymer obtained by this polymerization method is 13
g, the cis content is 76%, and the electrical conductivity at room temperature (DC two terminal method) is 5. I X 1σ6Ω-1・d
It was l. In addition, when the obtained short fibrous acetylene high polymer was observed using a scanning electron microscope, it was found that the acetylene high polymer was composed of fibrous microcrystals (fibrils) with a diameter of 200 to 4 ooX.
It had a structure consisting of.

[Battery experiment]

(32) From the composite of the acetylene polymer, carbon black, and cotton nonwoven fabric obtained by the above method, a width of 0.5 mm was obtained.
Two small pieces with a length of 2.0 cm were cut out of cIrL and mechanically crimped and fixed to a platinum wire to form a positive electrode and a negative electrode, respectively. A sulfolane solution with a concentration of LiBF of 10 mol/l was used as the electrolyte under constant current (0.5 mA/l).
ff1) for 2 hours (131 mol of electricity corresponding to a doping amount of 7 mol%), and after charging, immediately discharged under a constant current (0.5 mA/ffl) until the voltage was 1.
．． When the battery reached OV, it was charged again under the same conditions as above, and a repeated charging/discharging test was performed.
The number of repetitions was possible up to 450 times.

As a result of the first repeated charge/discharge test, the theoretical energy density for 1 kg of the active material used was 133W-
hr/kg, and the charge/discharge efficiency was 95%.

Further, the ratio of the amount of electricity discharged until the voltage decreased to 1.5 V during discharge to the total amount of electricity discharged was 91%.

Comparative Example 1 [Manufacturing experiment of acetylene high polymer] Acetylene high polymer and carbon were prepared in exactly the same manner as in Example 1, except that pressing was not performed using the cotton nonwoven fabric used in the production of the composite in Example 1. A black complex was obtained. [Battery experiment] Using the composite of acetylene high polymer and carbon black obtained in the above method, a battery charge/discharge cycle experiment was conducted in exactly the same manner as in Example 1. Charging became impossible. When the composite was taken out after the test, it was found that the molded product had been destroyed, and part of it was analyzed by elemental analysis and infrared spectroscopy, and it was found that it had suffered oxidative deterioration.

As a result of the first repeated charge/discharge test, the energy density for 1 kg of the active material used was 111 W -hr.
/ kg, and the charging/discharging efficiency was 79%.

Further, the ratio of the amount of electricity discharged until the voltage decreased to 1.5V during discharge to the total amount of electricity discharged was 73%.

Comparative Example 2 The weight of the mixture of toluene-containing acetylene high polymer and acetylene black used in Example 1 was 20.8 g of toluene-containing acetylene high polymer and acetylene block powder O.
, Sg was used, but the composite was manufactured and battery experiments were conducted in exactly the same manner as in Example 1. As a result of battery experiments, charging and
It was possible to repeat the discharge up to 251 times. When the electrode complex was taken out after the test, it was found to have been destroyed.

As a result of the first repeated charge/discharge test, the theoretical energy density for 1 kg of active material used was 118 W-h.
The charge/discharge efficiency was 84% at r/kg. Also, when the voltage is 1. , the ratio of the amount of electricity discharged until the voltage decreased to 5 V to the total amount of electricity discharged was 80%.

Example 2 [Composite production experiment] II equipped with the blade-type mechanical stirrer used in Example 1
500 ml of toluene, 0.2 m7 (0.59 mmol) of tetrabutoxytitanium, and 2 ml (14.6 mmol) of triethylaluminum (35
), and polymerization was carried out at an acetylene partial pressure of 1.6 kg/C/l and a polymerization temperature of 30° C. for 1 hour with stirring. Simultaneously with the introduction of acetylene gas, black powdery acetylene aggregates with a particle size of approximately 0.1 mm began to form.

After the polymerization was completed, the resulting powdery acetylene polymer was placed on a glass filter and washed with about 11 toluene solvents to remove the catalyst. After catalyst removal, the powdered acetylene polymer contained 47% by weight toluene.

This toluene-containing powdered acetylene polymer 9,4.9
and acetylene black (electrical conductivity is 46Ω″1・Cl)
n-1) 0.2. ! 9 were mixed in a ball mill.

Next, this mixture was placed on a 100 mesh polyethylene net and pressed at room temperature under a pressure of 2 tons/7 to obtain a composite. The resulting composite of acetylene high polymer, acetylene black, and polyethylene net is a mixture of acetylene high polymer and acetylene black sandwiched between polyethylene nets, and the surface of the composite has a metallic luster. had. Further, the proportion of the polyethylene net in this composite was 45 parts by weight based on 100 parts by weight of the acetylene high polymer.

[Battery experiment]

From the composite of acetylene high polymer, acetylene black, and polyethylene net obtained by the above method, two small pieces with a width of 0.5 c1rL and a length of 2.0 cm were cut out, and the two pieces were attached to separate platinum wires. 8(Bu4N)+(
PF6) - A 3-methylsulfolane solution with a concentration of 0.5 mol/l was used as the electrolyte under constant current (0.5 mA
/cyi) (doping amount 9 mol%)
(amount of electricity equivalent to ), a constant current (0,
A repeated charging/discharging test was conducted in which the battery was discharged at a voltage of 5 mA/cnl) and when the voltage reached IV, it was charged again under the same conditions as above, and it was possible to repeat up to 467 times.

The theoretical energy density for 1 kg of active material used is 1.66 W-hr/kg, and the charge/discharge efficiency is 92
%Met. Further, the ratio of the amount of electricity discharged until the voltage decreased to 1.5 V during discharge to the total amount of electricity discharged was 88%.

Example 3 The toluene-containing powdery acetylene polymer obtained by polymerization in Example 2 was vacuum-dried at room temperature to degas toluene. A composite of an acetylene polymer, acetylene black, and a polyethylene net was produced in exactly the same manner as in Example 2, except that the obtained dry powdered acetylene polymer 5.3I was used. The proportion of the polyethylene net in this composite was 45 parts by weight based on 100 parts by weight of the acetylene high polymer. [Battery experiment] was conducted in exactly the same manner as in Example 2 using this composite. Mitsuru・
When a discharge repetition test was conducted, it was possible to repeat the discharge up to 313 times.

As a result of the first repeated test, the active material used l k
The theoretical energy density for g is 155W・hr/k
g, and the charging/discharging efficiency was 86%. Also, the voltage during discharge is 1. , the ratio of the amount of electricity discharged until the voltage decreased to 5 V to the total amount of electricity discharged was 80%.

Comparative Example 3 A composite of acetylene high polymer and acetylene high polymer was produced in exactly the same manner as in Example 2, except that the polyethylene net used in the production of the composite in Example 2 was not used. [Battery experiment] was conducted in exactly the same manner as in Example 2 using the composite. When repeated charging and discharging tests were conducted, charging became impossible after the 133rd time. When the electrode complex was taken out after the test, it was found that the membrane had been destroyed, and part of it was analyzed by elemental analysis and infrared spectroscopy, and it was found that it had deteriorated.

In addition, the theoretical energy density is 106 W-hr/kg,
The charging/discharging efficiency was 59%. Further, the ratio of the amount of electricity discharged until the voltage decreased to 1.5V during discharge to the total amount of electricity discharged was 75%.

Comparative Example 4 Acetylenezo (39) used in the production of the composite in Comparative Example 3 An electrode was created by pressing an acetylene polymer in exactly the same manner as in Comparative Example 3, except that no rack was used, and the electrode was used to create an electrode. When the battery was subjected to repeated charging/discharging experiments in exactly the same manner as in Comparative Example 3, charging became impossible at the 63rd repetition.

After the test, when I took out the film-like acetylene polymer, I found that
The membrane was destroyed, and part of it was analyzed by elemental analysis and infrared spectroscopy, and it was found that it had suffered extensive oxidative deterioration.

The theoretical energy density for 1 kg of active material used is 1
At 0.3 W-hr/kg, the charging/discharging efficiency was 57%. Further, the ratio of the amount of electricity discharged until the voltage decreased to 1.5V during discharge to the total amount of electricity discharged was 63%.

Example 4 [Doping experiment] A small piece with a width of 0.5 CTL and a length of 2.0 cm was cut out from the composite produced in Example 1, and was mechanically crimped and fixed to a platinum wire to serve as an anode. A platinum plate was used as the other electrode, and the concentration of 13u4 N-13F'4 was o5.
Doping was carried out for 5 hours under a constant current (1.0 mA) using a propylene carbonate solution of l/l as the electrolyte. After the doping was completed, the doped composite containing the acetylene high polymer as its main component was repeatedly washed with propylene carbonate, and then vacuum-dried. The composition of the doped acetylene polymer in this composite was determined by elemental analysis to be [CH(BF,)0.16)x, and its electrical conductivity (direct current four-terminal method) was 125Ω-1·dl.

[Battery discharge experiment]

A battery was constructed using the BF:total composite obtained by the above method as a positive electrode active material and lithium as a negative electrode active material.

FIG. 1 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a button-type battery, which is a specific example of the present invention, in which 1 is a brass container plated with Ni, 2 is a disk-shaped lithium negative electrode with a diameter of 23 mm, and 3 is a circular porous polypropylene diaphragm with a diameter of 26 mm, 4 is a circular felt made of carbon fiber with a diameter of 26 mm, 5 is a positive electrode, and 6 is a Teflon sheet having holes with an average diameter of 2 μm (manufactured by Sumitomo Electric Industries, Fluoropore FP-200)
), 7 is a Teflon container having a circular cross section, 8 is a Teflon ring for fixing the positive electrode, and 9 is an N1 lead wire.

The positive electrode active material (BF, a composite containing an i-doped conductive acetylene polymer) was placed in the lower four parts of the container 1, and a porous circular Teflon sheet 6 was placed over the electrode, and then a Teflon sheet was placed. It was fixed by tightening with ring 8. The felt 4 was placed in the upper four parts of the container 1 and overlapped with the positive electrode, and after being impregnated with an electrolytic solution, the lithium negative electrode 2 was placed through the gap M3 and tightened with the container 7 to produce a battery. The electrolyte was Bu dissolved in distilled dehydrated propylene carbonate,
N-IF.

A 1 mol/l solution of was used.

The open circuit voltage of the battery thus produced was 3.7V.

When this battery was discharged at a constant current of 0.3 mA in an argon atmosphere, the relationship between discharge time and voltage was as shown by curve (a) in the diagram.

Comparative Example 5 A composite of acetylene high polymer and carbon black was produced in exactly the same manner as in Example 4, except that the cotton nonwoven fabric used in the production of the composite in Example 4 was not used.
Using this, doping was carried out in exactly the same manner as in Example 4. Next, when a primary battery discharge experiment was conducted using the obtained composite containing the doped acetylene high polymer, the result was as shown in curve (b) in FIG.

Example 5 [Composite production experiment] In a 300 ml three-tube flask, 1 oomz of toluene and 2 ml of tetrabutoxytitanium were added under a nitrogen atmosphere.

Add 2TLl of triethylaluminum and leave it at -78°C, and the partial pressure of acetylene gas is 1 kg/ai.
T: Acetylene was polymerized for 2 hours to obtain 5.2 g of a sheet-like acetylene high polymer swollen with toluene solvent. Next, 1007 d of toluene was added while the temperature was kept at -78°C to wash the high polymer, and the supernatant liquid was extracted with a syringe. This operation was repeated seven times to remove the catalyst. Next, this acetylene high polymer was mixed with a mechanical stirrer.
0m1! Parabruf (43) Transfer to a lasco, add 300 TL of toluene, and heat at -78°C.
The frame was opened by rotating a stirrer under a nitrogen atmosphere, and then degassed to obtain a dry acetylene polymer in the form of short fibers with a length of about 1 mm. The log particles of this high polymer and 0.45 g of carbon black were thoroughly mixed in a ball mill, and then this mixture was placed on a 100-mesh polypropylene mesh and pressed at room temperature under a pressure of 1 ton/d, resulting in a metallic luster. A flexible composite film was obtained. The proportion of the polypropylene mesh in this composite was 30 parts by weight based on 100 parts by weight of the acetylene high polymer.

[Battery experiment]

[
When a battery experiment was conducted, it was possible to repeat charging and discharging 531 times. In addition, as a result of the first repeated charge/discharge test, the theoretical energy density was 129 W-hr/
kg, and the charging/discharging efficiency was 92%.

Comparative Example 6 (44) A composite of acetylene high polymer and carbon black was produced in exactly the same manner as in Example 5, except that the polypropylene mesh used in Example 5 for producing the composite was not used. . [Battery experiment] was conducted in exactly the same manner as in Example 5 using this composite. As a result, the repetition of charging and discharging stopped at the 217th time, and the theoretical energy density was 92.
W-hr/kg, charge/discharge efficiency was 66%.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a button-type battery, which is an example of the present invention, and FIG. 2 is a 4th embodiment of the present invention.
and FIG. 9 is a diagram showing the relationship between battery discharge time and voltage in Comparative Example 5. 1... Container 2... Lithium negative electrode 3... Diaphragm 4... Felt 5... Positive electrode 6... Porous Teflon sheet 7...
Teflon container 8...Teflon ring 9...Ni lead wire Patent applicant Showa Denko Co., Ltd. Hitachi Ltd. Representative Patent attorney Sei Kikuchi

Claims (1)

[Claims] 100 parts by weight of acetylene high polymer, 1 part by weight or more, 5
A battery in which at least one electrode comprises a composite comprising less than parts by weight of a conductive material and 1 to 500 parts by weight of a sheet-like mesh.