JPH07302615A - Battery - Google Patents

Abstract

PURPOSE:To practically satisfy shut-down performance, ion conductivity, and mechanical property by constituting a composite positive electrode and a composite negative electrode with ion conductive polymer compounds each having a specific composition. CONSTITUTION:An electrolyte of a battery consists of an ion conductive compound containing at least one kind of ionic compound in a dissolved state, and a composite positive electrode and a composite negative electrode use an ion conductive compound as constituting materials. The ion conductive compound is at least one of the following (1) to (4). (1) at least one organic compound represented by formulas I-III, (2) an ionic compound, (3) an organic compound capable of dissolving an ionic compound, and (4) polyolefin powder or a polyolefin fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery which operates reversibly at ambient temperature, and relates to improvement of electrolyte, positive electrode and negative electrode.

[0002]

2. Description of the Related Art Recently, as microelectronics has been used, as represented by a power source for memory backup of various electronic devices, a battery has been miniaturized in accordance with the storage of the battery in the electronic device and the integration with electronic elements and circuits. There is a demand for batteries that are lighter in weight, thinner, and have a higher energy density. Therefore, as a battery replacing the conventional lead battery and nickel-cadmium battery, primary batteries and secondary batteries using a non-aqueous electrolyte that can be made smaller and lighter have been attracting attention, but the cycle characteristics of the electrode active material, Many research institutions are currently studying it in order to further improve the practical physical properties such as self-discharge characteristics.

In such a flow, the present inventors have
In designing batteries that are smaller, lighter, have higher energy density, and have higher reliability, the following problems are separately examined. 1) Problems of Electrode Active Material and Electrode 2) Problems of Electrolyte The present invention has been found as a result of mainly considering the above-mentioned improvement in 2).

The above problem 2) is as follows. That is, as an electrolyte for a battery or an electrochemical device other than a battery that has conventionally used an electrochemical reaction, that is, an electric double layer capacitor, an electrochromic element, etc., a ionic compound is generally dissolved in a liquid electrolyte, particularly an organic electrolyte. Although liquid electrolytes have been used, liquid electrolytes are prone to liquid leakage to the outside of parts, elution of electrode substances, volatilization, etc., so problems such as long-term reliability and scattering of electrolytes in the sealing process, etc. Was a problem.

Therefore, in order to improve the liquid leakage resistance and the long-term storage stability, an ion conductive polymer compound having high ion conductivity has been reported, and further research is being conducted as one of the means for solving the above problems. It is being advanced.

The ion-conducting polymer compounds currently being studied are homopolymer or copolymer linear polymers having ethylene oxide as a basic unit, reticulated cross-linked polymers, comb polymers, etc. For the purpose of increasing the ionic conductivity of the polymer, it has been proposed and practiced to prevent the crystallization by using a crosslinked polymer or a comb polymer. In particular, the ion-conductive polymer compound using the above-mentioned network cross-linked polymer is useful because it has high mechanical strength and good ionic conductivity at low temperatures. Electrochemical cells using the above ion-conductive polymer compounds have been widely described in patent documents and the like, for example, US Pat. No. 4,303,748 (1981) by Armand et al.
And North US Pat. No. 4,589,197 (1986) and Hooper et al. US Pat. No. 4,547,440 (198).
5) etc. One of the characteristics of these cells is that an ion-conductive polymer compound obtained by dissolving an ionic compound in a polymer material having a polyether structure is used.

However, in order to use the above-mentioned ion-conductive polymer compound as an electrolyte for batteries using electrochemical reaction or electrochemical devices other than batteries, high ion conductivity and good mechanical properties (mechanical strength) are used. , And flexibility), but these two characteristics are in conflict. That is, in most of the above-mentioned patent documents, since the ionic conductivity at room temperature or lower is below the practical range, it is the current situation to operate mainly at a raised temperature.

Then, as a simple method for improving the ionic conductivity, for example, JP-A-59-149601 and JP-A-58-7.
There has been proposed a method of maintaining a solid state by adding an organic solvent (particularly preferably a high dielectric constant organic solvent) to an ion conductive polymer compound, as represented by 5779 and US Pat. No. 4,792,504. However, as a result, the ionic conductivity is certainly improved, but the film strength is significantly reduced.

Further, when the above ion-conductive polymer compound is applied as an electrolyte of an electrochemical device, it is necessary to make the electrolyte thin so as to reduce the internal resistance. In particular, for the present inventors, a thin battery (or a sheet-like battery) that is a battery that is smaller, lighter, and has a higher energy density.
It can be said that the above-mentioned thinning is a very important issue in designing a battery called. In the case of the above ion-conductive polymer compound, a uniform thin film can be easily processed into an arbitrary shape, but that method becomes a problem.

Therefore, the inventors of the present invention, as disclosed in Japanese Patent Application Laid-Open No. 4-245170, apply a polymerizable monomer or macromer containing an inorganic compound whose surface is hydrophobized onto a substrate and heat-polymerize it. Alternatively, a method of curing by irradiation with actinic rays was proposed. However, even in the case of using the above method, when the ion-conductive polymer compound thin film is actually laminated between the electrodes and the battery or the electrochromic element is assembled, the electrolyte layer is damaged by compression deformation, There was a case where a slight short circuit occurred. Therefore, in order to make the above ion-conductive polymer compound layer into a uniform thin film, improvement of its mechanical properties is important together with ion conductivity.

On the other hand, when an abnormal current flows due to an external short circuit or incorrect connection of the battery, the internal temperature of the battery rises remarkably, and in the worst case, there is a risk of causing a serious accident such as ignition or explosion. .

In order to avoid such a danger, it has been proposed to use a polyethylene porous film or a polypropylene porous film as a separator in a lithium battery (JP-A-60-23954, JP-A-2-). 75151, etc.). The reasons for using these porous separators are: a) It is usually located between the positive electrode and the negative electrode to prevent a short circuit between both electrodes. b) When the internal temperature of the battery rises due to an abnormal current, the battery is melted at a predetermined temperature to increase its electric resistance to interrupt the current and prevent an excessive temperature rise to ensure safety.

When there is an abnormal temperature rise such as b), the function of ensuring the safety of the battery by interrupting the current due to the increase of the electric resistance and avoiding ignition and rupture is generally called a shutdown characteristic, This is an essential property for battery separators. It is important for the lithium battery separator to have this shutdown characteristic, but it is necessary that the electric resistance is started at an appropriate temperature (hereinafter, that temperature is referred to as a shutdown start temperature) and the increased electric resistance is appropriate. It is also required to maintain a high temperature. If the shutdown start temperature is too low, the electrical resistance will start to increase with a slight temperature rise inside the battery, which is impractical. If it is too high, safety will be insufficient.

However, it has been difficult to impart the above-mentioned shutdown characteristics to the above-mentioned ion-conductive polymer compound. The reasons are: c) In order to improve the ionic conductivity and mechanical properties, the main component is a cross-linked polymer of polyether, and the shutdown property does not appear at an appropriate temperature. Even when the shutdown characteristic appears, the effect is small or the reaction at the time of appearance is slow, so that it is not possible to cope with the abnormal temperature rise. d) Since the crosslinked polymer of polyether and Li ions are associated with each other, it is difficult to give the polymer itself a shutdown property. And so on.

[0015]

DISCLOSURE OF THE INVENTION The present invention provides a small and lightweight battery using an ion-conductive polymer compound, which is extremely superior to conventional batteries in the following points. That is, 1) It has long-term reliability without any fear of liquid leakage to the outside. 2) It is extremely safe even when an abnormal current occurs. 3) High performance, high energy density and extremely high workability. Is.

[0016]

In order to achieve the above-mentioned object, the present invention is a battery comprising a composite positive electrode, an electrolyte, and a composite negative electrode or an alkali metal-based negative electrode, wherein the electrolyte is At least one ionic compound is contained in a dissolved state and is composed of an ion-conductive polymer compound, and both the composite positive electrode and the composite negative electrode have the above-mentioned ion-conductive polymer compound as a constituent material. A first invention is that the conductive polymer compound is composed of at least one of the following. : At least the following chemical formula 1 and / or the following chemical formula 2
Or / and an organic compound represented by the following chemical formula 3

[0017]

[Chemical 1] (R ₁ , R ₂ and R ₃ are hydrogen or a lower alkyl group having 1 or more carbon atoms, m and n are numbers m ≧ 1, n ≧ 0 and n / m = 0 to 5)

[0018]

[Chemical 2] (R ₄ , R ₅ and R ₆ are hydrogen or a lower alkyl group having 1 or more carbon atoms, s and t are numbers in the range of s ≧ 3, t ≧ 0 and t / s = 0 to 5)

[0019]

[Chemical 3] (R ₇ and R ₈ are hydrogen or a lower alkyl group having 1 or more carbon atoms, and p ₁ , p ₂ , p ₃ , q ₁ , q ₂ and q ₃ are p ₁ ≧ 3, p ₂ ≧ 3 and p _{3 respectively.} ≧ 3, q ₁ ≧ 0, q ₂ ≧ 0,
q ₃ ≧ 0, q ₁ / p ₁ = number in the range of 0 to 5, q ₂ / p ₂
= 0 to 5 and q ₃ / p ₃ = 0 to 5 and p ₁ + q ₁ ≧ 10, p ₂ + q ₂ ≧ 10, p ₃
It shows that + q ₃ ≧ 10. )

: Ionic compound: Organic compound capable of dissolving ionic compound: Polyolefin powder or polyolefin fiber

Further, as a method for forming the composite positive electrode, the electrolyte and the composite negative electrode, the second invention is to form an electrode and an electrolyte by irradiation with actinic radiation such as ionizing radiation. The above object is achieved by providing an electrode by mixing and an ion-conductive polymer compound.

In the present invention, the electrolyte is
Since it is composed of the ion-conductive polymer compound of, the shutdown property, the ion-conductivity, and the mechanical property of the conventional ion-conductive polymer solid electrolyte satisfy three practical requirements at the same time. .

That is, in the present invention, the above-mentioned: polyolefin powder melts at a predetermined temperature when the internal temperature of the battery rises due to an abnormal current and shuts off the current due to an increase in electric resistance. It was
Therefore, even when the above problems occur, it is possible to avoid ignition and rupture and improve the safety of the battery.

In addition, dendrite formation is suppressed when lithium metal is used for the negative electrode, and liquid leakage resistance and eventually long-term reliability are improved. In addition, since the mechanical strength of the electrolyte is also improved, it is possible to prevent a minute short circuit during cell preparation and during charge / discharge cycles, which makes it possible to improve charge / discharge cycle characteristics and to manufacture high-performance electrodes.

Therefore, by using the above-mentioned ion-conductive polymer compound as an electrolyte, it is possible to suppress the generation of dendrites of lithium, and the electrolyte has an excellent mechanical strength and is stable thermally and electrochemically (separator). ) Can be provided.

Further, when the composite negative electrode is used, it is possible to suppress the generation of dendrite of lithium in the peripheral portion of the composite negative electrode, and also to provide an electrolyte layer which is excellent in mechanical strength and is thermally and electrochemically stable. It is possible to

These factors are also included: a) The inclusion of the polyolefin powder or polyolefin fiber of the present invention. b) Because the above ion-conductive polymer compound is composed of at least the organic compounds represented by Chemical Formulas 1 to 3 above. And so on.

The above-mentioned ionic compound which is soluble in the polymer compound thus obtained is, for example, LiCl.
O ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiI, LiBr, Li ₂ B ₁₀ C
l ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiSCN, NaI, NaSCN, NaB
Inorganic ionic salt containing one of Li, Na, or K such as r, NaClO ₄ , KClO ₄ , KSCN, (CH ₃ ) ₄ NBF ₄ , (CH ₃ ) ₄ NBr, (C
₂ H ₅ ) ₄ NClO ₄ , (C ₂ H ₅ ) ₄ NI, (C ₃ H ₇ ) ₄ NBr, (nC ₄ H ₉ ) ₄ NCl
O ₄ , (nC ₄ H ₉ ) ₄ NI, (C ₂ H ₅ ) ₄ N-maleate, (C ₂ H ₅ ) ₄ N-benzo
and quaternary ammonium salts such as ate and (C ₂ H ₅ ) ₄ N-phtalate, and other organic ion salts. Two or more kinds of these ionic compounds may be used in combination.

Next, in the present invention, the ion conductive polymer compound may contain an organic compound capable of dissolving the ionic compound contained in the ion conductive polymer compound,
By including this kind of substance, the ionic conductivity can be remarkably improved without changing the basic skeleton of the polymer compound. Above: Cyclic carbonic acid esters such as propylene carbonate and ethylene carbonate; cyclic esters such as γ-butyrolactone; tetrahydrofuran or its derivatives, 1,3-dioxane, 1,2-dimethoxyethane. ,
Ethers such as methyl diglyme; acetonitrile,
Examples thereof include nitriles such as benzonitrile; dioxolane or a derivative thereof; sulfolane or a derivative thereof alone or a mixture of two or more thereof. However, it is not limited to these. Moreover, the compounding ratio and the compounding method are arbitrary.

The mixing ratio of such an ionic compound is
The ionic compound is in a ratio of 0.0001 to 5.0 mol / liter, and more preferably 0.005 to 2.0 mol / liter with respect to the organic compounds of Chemical formula 1, Chemical formula 2, and Chemical formula 3 above. Is preferred. If the amount of the ionic compound used is too large, an excess ionic compound, for example, an inorganic ionic salt, does not dissociate, but merely mixes, resulting in a decrease in ionic conductivity. In addition, the compounding ratio of the ionic compound varies depending on the electrode active material. For example, in a battery using intercalation of a layered compound, it is preferable that the ionic conductivity of the electrolyte is around the maximum, and in a battery using a conductive polymer that utilizes a doping phenomenon as an electrode active material. It is necessary that the ion concentration in the electrolyte can be changed by charging and discharging.

The above: The method of containing the ionic compound is not particularly limited. For example, the organic compound represented by the above chemical formula 1 is dissolved in an organic solvent such as methyl ethyl ketone and uniformly mixed, and then vacuum reduced pressure is applied to the above organic compound. Examples thereof include a method of incorporating the ionic compound in a compound, a method of dissolving the ionic compound in an organic compound capable of dissolving the ionic compound, and then uniformly mixing with the organic compound represented by Chemical formula 1 above.

Above: Examples of the polyolefin powder include polyethylene powder and polypropylene powder. In the present invention, polyethylene fine powder is considered to be particularly promising for the purpose of improving shutdown characteristics and mechanical characteristics. However, it is not limited to these.

Examples of the above-mentioned polyolefin powder include Mielon XM-220, a fine particle / ultra high molecular weight polyolefin powder manufactured by Mitsui Petrochemical Co., Ltd., and flow beads manufactured by Sumitomo Seika Chemicals. By using these polyolefin powders, the ion-conductive polymer compound has the following features.

I) The average particle size is 10 to 30 μm, which is different from general polyolefin powders.
When mixed with, it has excellent dispersibility and is uniformly dispersed in the above ion-conductive polymer compound, so that good shutdown characteristics are exhibited. ii) The above-mentioned polyolefin powder has a melting point of 109-1.
Since it is 36 ° C., the shutdown characteristic is well expressed. iii) As in the case of i), the polyolefin powder is uniformly dispersed in the ion-conductive polymer compound, so that there is no place where the mechanical properties are partially increased as in the conventional case.

Above: Examples of the polyolefin fiber include polyethylene fiber and polypropylene fiber, and polyethylene fiber is considered to be particularly promising. Also,
The above-mentioned polyolefin fiber can be crushed if necessary. Examples of the polyolefin fibers include polyolefin micropore fibers manufactured by Ube Nitto Kasei Co., Ltd. By using these polyolefin fibers, the ion conductive polymer compound has the following features. iv) Since it has a relatively large pore size and a high porosity, the above-mentioned penetrates into the inside of the pores, and the polyolefin fiber and the above-mentioned are uniformly present in the ion-conductive polymer compound. The shutdown characteristics are well expressed. v) The above-mentioned polyolefin fiber has a melting point of 109 to 136 ° C. as in ii).
Therefore, the shutdown characteristic is well expressed. v
i) Since the polyolefin fiber is contained in the ion conductive polymer compound, its mechanical strength is improved as compared with the conventional one. Further, unlike in iv), the polyolefin fibers are uniformly distributed in the ion-conductive polymer compound, so that there is no place where the mechanical properties are partially increased as in the conventional case.

When the composite positive electrode and the composite negative electrode are manufactured, several kinds of dispersants and dispersion media are used to obtain a uniform mixed dispersion type coating liquid, or various characteristics of the composite positive electrode and the composite negative electrode (charge / discharge). Also, a binder for improving the cycle characteristics) can be added. Further thickener,
It is also possible to add a bulking agent, an adhesion aid, and the like.

When a binder composed of an organic compound dissolved and / or dispersed in a solvent is used, a binder solution prepared by dissolving the organic compound in a solvent is charged with an electrode active material, the above ion-conductive polymer compound, or the like. A method of using the dispersed material as a coating liquid, or a dispersion liquid of the organic compound and a dispersant for dispersing the organic compound, in which the electrode active material, the ion conductive polymer compound, or the like is dispersed. However, the method is not limited to these.

Examples of the above organic compound include the following. That is, acrylonitrile, methacrylonitrile, vinylidene fluoride, vinyl fluoride,
Examples thereof include polymers such as chloroprene, vinyl pyridine and its derivatives, vinylidene chloride, ethylene, propylene, cyclic dienes (eg, cyclopentadiene, 1,3-cyclohexadiene) and copolymers of the above organic compounds. It is not limited to.

Regarding the method of disposing the ion conductive polymer of the present invention on the surface of the composite positive electrode and the surface of the composite negative electrode, for example, roll coating such as an applicator roll, doctor blade method, screen coating, spin coating, etc. It is desirable to apply a uniform thickness using a means such as a bar coder, but it is not limited thereto. By using these means, it is possible to arrange them on the surface of the composite positive electrode and the surface of the composite negative electrode in any thickness and in any shape.

Further, as the positive electrode active material used in the composite positive electrode of the present invention, the following battery electrode materials can be mentioned. That is, group I metal compounds such as CuO, Cu ₂ O, Ag ₂ O, CuS and CuSO ₄ , group IV metal compounds such as TiS ₂ , SiO ₂ and SnO, V
_{2 O 5, V 6 O 12} , VO X, Nb 2 O 5, Bi 2 O 3, V metal compounds such as _{Sb 2 O 3, Cr0 3,} Cr 2 O 3, MoS 2, WO 3, SeO 2 , etc. VI
Group VII metal compounds such as MnO ₂ and Mn ₂ O ₃
Group VIII metal compounds such as Fe ₂ O ₃ , FeO, Fe ₃ O ₄ , Ni ₂ O ₃ , NiO, CoS ₂ , and CoO, or general formulas Li _X MX ₂ , Li _X
MN _Y X ₂ (M and N are metals of groups I to VIII, X is a chalcogen compound such as oxygen and sulfur), and the like.
For example, a metal compound such as a lithium-cobalt-based composite oxide or a lithium-manganese-based composite oxide, a conductive polymer compound such as polypyrrole, polyaniline, polyparaphenylene, polyacetylene, or a polyacene-based material, a pseudo-graphite structure carbonaceous material Materials and the like, but are not limited to these.

Examples of the negative electrode active material used for the composite negative electrode or the alkali metal negative electrode include the following battery electrode materials. That is, as the carbonaceous material such as carbon, for example, the results of analysis of the above carbonaceous material by X-ray diffraction and the like are shown in Table 1 below, and carbon powder obtained by firing an anisotropic pitch at a temperature of 2000 ° C. or more ( Average particle size 15 μm or less), or carbon fiber, or lithium metal-containing alloy such as lithium metal, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloy However, the present invention is not limited to these. These negative electrode active materials can be used alone or in combination of two or more.

[0042]

[Table 1]

Regarding the method of disposing the composite positive electrode and composite negative electrode of the present invention on the positive electrode current collector and the negative electrode current collector, for example, roll coating such as applicator roll, doctor blade method, spin coating, It is desirable to apply a uniform thickness using a means such as a bar coder, but it is not limited thereto. In addition, when these means are used, it is possible to increase the actual surface area of the electrochemically active substance in contact with the electrolyte layer and the current collector. It can be arranged in any thickness and in any shape.

In these cases, carbon such as graphite, carbon black, and acetylene black is used as needed (the carbon here has a completely different characteristic from the carbon in the above-mentioned negative electrode active material). ) And a conductive material such as a metal powder or a conductive metal oxide can be mixed in the composite positive electrode and the composite negative electrode to improve electron conduction.

The ionizing radiation described in the claims is γ
Rays, X-rays, electron rays, neutron rays and the like can be mentioned. The method of using these ionizing radiations in cross-linking the ion conductive polymer compound is very efficient. That is,
In addition to the energy efficiency of the ionizing radiation, for example, when forming an electrolyte (an electrolyte that permeates into the electrolyte layer and the composite positive electrode) composed of an ion conductive polymer compound,
Since the degree of cross-linking of the ion-conductive polymer compound can be easily controlled, it becomes possible to prepare an electrochemically optimal electrode and electrolyte by controlling the dose of the ionizing radiation. .

The positive electrode current collector plate is preferably made of a material such as aluminum, stainless steel, titanium or copper, and the negative electrode current collector plate is preferably made of a material such as stainless steel, iron, nickel or copper, but is not particularly limited thereto. Absent.

[0047]

EXAMPLES The details of the present invention are described below with reference to examples, but the present invention is not limited thereto.

(Example 1) FIG. 1 is a sectional view of a sheet-like battery of Example 1 of the present invention. In the figure, 1 is a positive electrode current collector made of aluminum, which also serves as an exterior. An electron conductive layer is provided on the surface of the composite positive electrode side. Reference numeral 2 denotes a composite positive electrode, in which LiCoO ₂ was used as a positive electrode active material, acetylene black was used as a conductive agent, and polyacrylonitrile was used as a binder. Further, 3 is an electrolyte layer made of the ion conductive polymer compound of the present invention. 4 is a composite negative electrode,
Carbon powder was used as the negative electrode active material, and ethylene was used as the binder.
A propylene-cyclopentadiene copolymer was used.
Reference numeral 5 denotes a negative electrode current collector plate made of rolled copper, which also serves as an exterior. No. 6 is a sealing agent made of modified polypropylene.

The sheet-shaped battery of Example 1 has the following a) to
It is formed through the process of i). a) The composite positive electrode is formed as follows. That is, a mixture of LiCoO ₂ as a positive electrode active material and acetylene black as a conductive agent in a weight ratio of 85:15 and a mixture of a dimethylformamide solution of polyacrylonitrile (2 wt% solution) as a binder were mixed with each other. The mixture was mixed at a weight ratio of 2.4: 2 in an active gas (inert gas having a dew point of −60 ° C. or lower; hereinafter abbreviated as inert gas) (mixture B ₁ ).

This mixture B ₁ and the above Chemical Formula 4, Chemical Formula 5, and Chemical Formula 6
10 parts by weight of an organic compound prepared by mixing 3: 5: 2 of the above organic compound, 1 part by weight of lithium tetrafluoroborate, 10 parts by weight of 1,2-dimethoxyethane and 10 parts of γ-butyrolactone.
Mixed with 1 part by weight in an inert gas atmosphere
Mixture B ₂ was obtained by mixing in a weight ratio of 7: 3.

[0051]

[Chemical 4]

[0052]

[Chemical 5]

[0053]

[Chemical 6]

B) The above mixture B ₂ was cast by screen coating on a current collector having an electron conductive layer formed on the surface of aluminum. Then, after completely removing dimethylformamide in an inert gas atmosphere, an accelerating voltage of 2
The composite positive electrode was formed by irradiating with an electron beam of 50 kV and an electron dose of 12 Mrad. The thickness of the composite positive electrode coating film formed on the positive electrode current collector was 60 μm.

C) Next, in order to form an ion conductive polymer compound on the composite positive electrode, the above chemical formula 4, chemical formula 5, chemical formula 6
25 parts by weight of an organic compound prepared by mixing the organic compound of 4) in a weight ratio of 4: 4: 2, 5 parts by weight of lithium tetrafluoroborate,
26 parts by weight of 1,2-dimethoxyethane and 27.5 parts by weight of γ-butyrolactone and flow beads LE-1080
A mixture of 16.5 parts by weight (manufactured by Sumitomo Seika Chemicals Co., Ltd.) was cast on the composite positive electrode by screen coating in an inert gas atmosphere, and then an accelerating voltage of 250 kV in an inert gas atmosphere. The ion conductive polymer compound layer was cured by irradiating it with an electron beam having an electron dose of 8 Mrad. The thickness of the electrolyte layer thus obtained was 25 μm.

D) The composite negative electrode is formed as follows. That is, in an inert gas atmosphere, a toluene solution of a carbon powder as a negative electrode active material and a copolymer of ethylene-propylene-cyclopentadiene as a binder (2
wt% solution) was mixed in an inert gas atmosphere at a weight ratio of 2: 5 (mixture C ₁ ).

This mixture C ₁ and the above Chemical Formula 4, Chemical Formula 5, and Chemical Formula 6
10 parts by weight of an organic compound prepared by mixing 3: 5: 2 of the above organic compound, 1 part by weight of lithium tetrafluoroborate, 10 parts by weight of 1,2-dimethoxyethane and 10 parts of γ-butyrolactone.
Mixed with 1 part by weight in an inert gas atmosphere
Mixture C ₂ was obtained by mixing in a weight ratio of 8: 2.

E) These mixtures C ₂ were cast by screen coating on a negative electrode current collector plate made of rolled copper. Then, after completely removing xylene in an inert gas atmosphere, an accelerating voltage of 250 kV and an electron dose of 12 Mr.
The composite negative electrode was formed by irradiating an electron beam of ad. The composite negative electrode formed on the negative electrode current collector has a thickness of 30.
was μm.

F) Next, in order to form an ion conductive polymer compound on the composite negative electrode, the above chemical formula 4, chemical formula 5, chemical formula 6
25 parts by weight of an organic compound prepared by mixing the organic compound of 4) in a weight ratio of 4: 4: 2, 5 parts by weight of lithium tetrafluoroborate,
26 parts by weight of 1,2-dimethoxyethane and 27.5 parts by weight of γ-butyrolactone and flow beads LE-1080
A mixture of 16.5 parts by weight (manufactured by Sumitomo Seika Chemicals, Ltd.) was cast on the above composite negative electrode by screen coating in an inert gas atmosphere, and then an accelerating voltage of 250 kV in an inert gas atmosphere. The ion conductive polymer compound layer was cured by irradiation with an electron beam having an electron dose of 8 Mrad. The thickness of the electrolyte layer thus obtained is 25
was μm.

G) The electrolyte layer / composite negative electrode / negative electrode current collector obtained in step f) was brought into contact with the positive electrode current collector / composite positive electrode / electrolyte layer obtained in step c). Thus, the sheet-shaped battery of Example 1 of the present invention was manufactured.

(Example 2) A sheet-like battery was prepared by the same procedure as in Example 1 except that Miperon XM-220 was used instead of the flow beads LE-1080 in c) and f) of Example 1. .

(Example 3) A sheet-like battery was produced in the same procedure as in Example 1 except that the following parts were changed in c) and f) of Example 1. That is, in c) and f), in order to form the ion conductive polymer compound on the composite positive electrode and the composite negative electrode, the above chemical formula 4, chemical formula 5,
26.5 parts by weight of an organic compound prepared by mixing the organic compound of Chemical formula 6 in a weight ratio of 4: 4: 2, 5.2 parts by weight of lithium tetrafluoroborate, 28 parts by weight of 1,2-dimethoxyethane and γ- A mixture of 28.3 parts by weight of butyrolactone and 12 parts by weight of polyethylene microporous fiber (manufactured by Ube Nitto Kasei Co., Ltd.) was used.

(Comparative Example 1) In Example 1), except that the flow beads LE-1080 were not used in the steps c) and f),
A sheet-shaped battery was manufactured in the same procedure as in Example 1.

The electrode area of the sheet-shaped batteries of Examples 1 to 3 and Comparative Example 1 can be variously changed depending on the manufacturing process, but in this description, the electrode area is 100 c.
m ² was produced.

(External Short Circuit Test) The sheet-shaped batteries of Examples 1 to 3 and Comparative Example 1 were short-circuited at both electrodes in the atmosphere at 25 ° C., and after 5 minutes, the surface of the aluminum positive electrode current collector which also served as the exterior. The temperature was measured. The results are shown in Table 2. Also,
At the same time, the current value flowing in the circuit was also measured. The result is shown in FIG.

[0066]

[Table 2]

As can be seen from the results of Table 2 and FIG. 2, the sheet batteries of Examples 1 to 3 have excellent shutdown characteristics as compared with the sheet battery of Comparative Example 1. Therefore, the sheet-shaped battery of the present invention has higher safety in the whole battery as compared with the conventional one.

(Charge / Discharge Cycle Test) Using the sheet batteries of Examples 1 to 3 and Comparative Example 1, 100 μm at 25 ° C.
A / cm ² constant current / constant voltage charge and 100 μA / cm
^{2 A} constant current discharge charge / discharge cycle test was performed. A charge / discharge cycle test was conducted with a charge end voltage of 4.1V and a discharge end voltage of 2.7V. FIG. 3 shows the relationship between the number of charge / discharge cycles and the battery capacity. As can be seen from FIG. 3, the sheet-shaped battery of the present invention exhibits excellent charge / discharge cycle characteristics as compared with the sheet-shaped battery of the comparative example. The reason for this is that Li dendrite is not generated in the periphery of the composite negative electrode during the charge / discharge cycle. As a result, there is no slight short circuit and the charge / discharge cycle efficiency remains almost 100%. It is considered to be something.

Although not explicitly shown in this embodiment,
Furthermore, thin electrodes can be produced by various methods such as pressing, sputtering, suspension, coating, etc., which makes it possible to increase the actual surface area of the active substance in contact with the electrolyte layer and the current collector.

Although the above examples and various other statements relate primarily to the use of lithium, the use of other alkali metals such as sodium is also within the scope of the invention.

[0071]

As is clear from the above description, since the electrolyte layer is composed of the above-mentioned ion-conductive polymer compound, the electrolyte layer has a shutdown characteristic compared to the conventional ion-conductive polymer solid electrolyte. The ionic conductivity and the mechanical properties simultaneously satisfy the practicability.

Therefore, 1) It has long-term reliability without any fear of liquid leakage to the outside. 2) It is extremely safe even when an abnormal current occurs. 3) High performance, high energy density and extremely high workability. From these, the workability of the battery manufacturing process and the performance of the battery can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sheet-shaped battery of the present invention.

FIG. 2 is a graph showing a time change of a current value flowing in a circuit after an external short circuit in the sheet batteries of Examples 1 to 3 and the sheet battery of Comparative Example 1.

FIG. 3 is a graph showing the relationship between the number of charge / discharge cycles and the battery capacity of the sheet batteries of Examples 1 to 3 and the sheet battery of Comparative Example 1.

[Explanation of symbols]

 1 Positive Electrode Current Collector 2 Composite Positive Electrode 3 Electrolyte 4 Composite Negative Electrode 5 Negative Current Collector 6 Sealing Material

Claims (1)

[Claims] 1. A battery comprising a composite positive electrode, an electrolyte, and a composite negative electrode or a negative electrode mainly composed of an alkali metal, wherein the electrolyte contains at least one ionic compound in a dissolved state. In the battery, which is made of a conductive polymer compound, wherein the composite positive electrode and the composite negative electrode both have the ion conductive polymer compound as a constituent material, the ion conductive polymer compound has the following structure. A battery comprising at least one of ,. : At least the following chemical formula 1 and / or the following chemical formula 2
Or / and an organic compound represented by the following chemical formula 3 (R ₁ , R ₂ and R ₃ are hydrogen atoms or lower alkyl groups having 1 or more carbon atoms, m and n are m ≧ 1, n ≧ 0, n / m =
Indicates a number in the range 0 to 5. ) [Chemical 2] (R ₄ , R ₅ and R ₆ are hydrogen atoms or lower alkyl groups having 1 or more carbon atoms, k and l are s ≧ 3, t ≧ 0, t / s =
Indicates a number in the range 0 to 5. ) [Chemical 3] (R ₇ and R ₈ are hydrogen atoms or lower alkyl groups having 1 or more carbon atoms, and p ₁ , q ₁ , p ₂ , q ₂ , p ₃ and q ₃ are p ₁ ≧ 3, p ₂ ≧ 3 and p, respectively. ₃ ≧ 3, q ₁ ≧ 0, q ₂
≧ 0, q ₃ ≧ 0, q ₁ / p ₁ = number in the range of 0 to 5, q ₂
/ P _{2 is} a number in the range of 0 to 5, q ₃ / p ₃ is a number in the range of 0 to 5, and p ₁ + q ₁ ≧ 10, p ₂ + q ₂ ≧ 1
0, p ₃ + q ₃ ≧ 10. ): Ionic compound: Organic compound capable of dissolving ionic compound: Polyolefin powder or polyolefin fiber