JPH06251801A - Secondary battery - Google Patents

Abstract

PURPOSE:To improve long-time reliability by using specifically composed ionic compound with another anion than PFs for a battery formed of ionic conduction polymer compound. CONSTITUTION:Ionic conduction polymeric compound used for an electrolytic layer 3 contains organic compound, which is expressed by Formula I and/or Formula II, at least. In the Formulas, R1 through R6 are low order alkyl groups with the number of hydrogen or carbon being one or more, and (m), (n), (k), (l) are integers, m>=1, n>=0, n/m=0 to 5, k>=3, 1/k=0 to 5. The ionic conduction polymer compound is ionic compound with another anion than PFe6<->, that is polymeric compound which has a bridge network structure formed by polymerizing ionic compound with soluble organic compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary 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. In the field of primary batteries, small and lightweight batteries such as lithium batteries have already been put into practical use, but their fields of use are limited. Therefore, a secondary battery using a non-aqueous electrolyte that can be made smaller and lighter has attracted attention as a battery that replaces the conventional lead battery and nickel-cadmium battery. Many research institutes are still studying it because of the fact that nothing satisfying the practical physical properties has been found.

Now, in designing a battery that is smaller, lighter, has a high energy density, and has a high reliability, it is necessary to separately study the following problems. 1) Electrode active material and electrode problem 2) Electrolyte problem Regarding the problem 1) described above, the present inventor called a thin battery (thickness per unit cell is 100 to 500 μm (sheet-shaped battery)) However, it has been technically difficult to produce thin-film metallic lithium having a quality that can be sufficiently applied to it, and the manufacturing process of the battery becomes complicated. Furthermore, when used as a secondary battery, there has been a problem that the use of metallic lithium is restricted due to problems such as generation of dendrite of lithium and passivation of the interface. Therefore, lithium-aluminum, lithium-lead, lithium-metal-containing alloys represented by lithium-tin alloys have been actively researched, but as represented by lithium-aluminum alloys, these alloys are Since the strength is low, the electrodes are cracked and miniaturized due to repeated charging and discharging, so that the cycle characteristics are not improved.

Therefore, at present, many research institutes have been particularly researching materials utilizing the intercalation or doping phenomenon of a layered compound as an electrode active material, and in particular, in the above concept, a carbonaceous material is used as an electrode. The example of using it as an active material has also appeared as a solution to problems such as cycle characteristics and self-discharge characteristics of electrode active materials. The characteristics of this carbonaceous material are high doping capacity, low self-discharge rate, excellent cycling characteristics, and most notably, a base potential very close to that of metallic lithium.

On the other hand, 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. Ion-conducting polymer compounds that are currently being researched include homopolymers or copolymers of ethylene oxide as a basic unit, linear polymers, reticulated crosslinked polymers, or comb polymers. For the purpose of increasing the conductivity, 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 reticulated crosslinked polymer,
It is useful because it has high mechanical strength and good ionic conductivity at low temperatures. Electrochemical cells using the above ion-conductive polymer compounds are widely described in patent documents and the like, for example, U.S. Pat.No. 4,303,748 (1981) by Armand et al. And North (North). US Pat. No. 4,589,197 (1986) and Hooper
No. 4,547,440 (1985) and the like.
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. Therefore, as a simple method for improving the ionic conductivity, an ionic conductive polymer as represented by, for example, JP-A-59-149601, JP-A-58-75779 and U.S. Pat. A method has been proposed in which an organic solvent (particularly preferably a high dielectric constant organic solvent) is added to the compound to maintain the solid state. As a result, the ionic conductivity is surely improved, but the film strength is remarkably increased. descend.

Further, when the above-mentioned ion-conductive polymer compound is applied as an electrolyte of an electrochemical device, it is necessary to reduce the thickness of the electrolyte 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. For example, a method of casting a solution of an ion-conductive polymer compound to evaporate and remove the solvent, a method of coating a polymerizable monomer or macromer on a substrate and heating polymerization, or curing by irradiation with actinic rays. There is a way. However, although it is possible to form a uniform thin film by using the above method, when the ion conductive polymer compound thin film is actually laminated between electrodes and the battery or electrochromic device is assembled, the thin film is compressed. There was a problem that it was damaged by deformation and a slight short circuit occurred. Therefore, in order to make the ion conductive polymer compound layer into a uniform thin film, it is important to improve its mechanical properties together with ion conductivity.

Further, the following problems occurred during curing by irradiation with the above-mentioned actinic rays. That is, during the above curing, the polymerizable monomer and a specific ionic compound (for example, Li
PF ₆ ) causes a side reaction, which lowers the ionic conductivity and mechanical properties of the above ion-conductive polymer compound, and when the positive electrode is composed of a positive electrode active material such as LiCoO _2. When the negative electrode is composed of carbonaceous material,
Problems such as generation of a passive film on the surface of the positive electrode active material and the carbonaceous material occur, which causes a phenomenon such as a significant decrease in battery performance.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a battery using an ion-conductive polymer compound, which has extremely high workability and is free from the risk of liquid leakage to the outside, and has long-term reliability and safety. A secondary battery having high performance, and further a small and lightweight secondary battery having high performance and high energy density are provided.

[0011]

In order to achieve the above-mentioned object, the present invention is an ion-conducting polymer compound composed of a polymer substance in which at least one ionic compound is dissolved, The ion conductive polymer compound is: at least an organic compound represented by the following chemical formula 1 or / and the following chemical formula 2.

[0012]

(Wherein 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 and n ≧ 0,
n / m is an integer in the range of 0 to 5. )

[0013]

Embedded image (R ₄ , R ₅ and R ₆ are hydrogen atoms or lower alkyl groups having 1 or more carbon atoms, k and l are k ≧ 3, l ≧ 0,
Indicates an integer in the range of 1 / k = 0 to 5. )

[0014]: PF ₆ ^- anion other than a are ionic compounds: the ionic compound capable organic compound optionally dissolved: at least, the high molecular weight ethylene polymer and / or high molecular weight ethylene - propylene oxide random copolymer A polymer compound forming a crosslinked network structure by a polymerization reaction, comprising the following (A), (B) or (B '), (C) a) at least an electrochemically active substance and the ion conductive polymer. A composite positive electrode (A) composed of a compound, optionally an electronically conductive substance, and a binder made of an organic compound optionally dissolved and / or dispersed in a solvent; (b) at least a carbonaceous material and the ionic conductivity thereof. Consists of a polymer compound, optionally an electron-conducting substance, and optionally a binder consisting of an organic compound dissolved and / or dispersed in a solvent. A composite negative electrode (B) or an alkali metal negative electrode (B ′); c) an electrolyte (C) comprising at least one kind of the ion conductive polymer compound, and the composite positive electrode (A) and the composite negative electrode ( As a method for forming at least one of B) and the electrolyte (C), the first invention is to form an electrode and an electrolyte by irradiation with ionizing radiation.

A second invention is to use an ionic compound which is BF ₄ ⁻ as the anion other than PF ₆ ⁻ .

Further, the composite positive electrode (A) is used as an electrochemically active substance, Li _a Co _b Ni _1-b O ₂ (0 <a ≦
1, 0 ≦ b ≦ 1) or Li _1-C Mn _2-d (D) _d
O ₄ (0 ≦ c ≦ 1, 0 <d ≦ 0.5 where (D) is
At least one element selected from the group consisting of Ni, Mo, Fe, and Cr. ) Selected from at least one of the above-mentioned ion-conducting polymer compounds, optionally an electron-conducting substance, and optionally a binder comprising an organic compound dissolved and / or dispersed in a solvent. According to the third aspect of the invention, the above object is achieved by providing an electrode by mixing the electrochemically active substance and the ion conductive polymer compound.

[0017] PF ₆ ^- when using an ionic compound having an anion is, for example, the reaction shown below is believed to have occurred.

[0018]

[Chemical 3]

As described above, in order to generate HF, when the positive electrode is made of a positive electrode active material such as LiCoO ₂ and the negative electrode is made of a carbonaceous material, the positive electrode active material and the carbonaceous material are produced. This causes the formation of a passive film on the surface of the material, and these phenomena occur in the form of an increase in internal impedance of the battery, for example, self-discharge during long-term storage and a decrease in battery capacity due to cycling. Further, the deterioration of the ionic conductivity and mechanical properties of the above-mentioned ion-conducting polymer compound has been a serious problem. Therefore, as described in the claims, by using an ionic compound having an anion other than PF ₆ ⁻ , a reaction using the above ion-conductive polymer compound does not occur in the reaction shown in Chemical formula 3 above. It has become possible to improve the long-term reliability of.

Next, as the ionic compound which is soluble in the polymer compound, shown in claim 1, PF ₆ ^-
Other anions are desirable. For example, LiCl
O ₄ , LiBF ₄ , LiAsF ₆ , LiI, LiBr, Li ₂ B ₁₀ Cl ₁₀ , LiCF ₃ S
_{O 3, LiCF 3 CO 2,} LiSCN, NaI, NaSCN, NaBr, NaClO 4,
Inorganic ion salts containing one of Li, Na, or K such as 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 NClO ₄ , (nC ₄ H ₉ ) ₄ N
_{I, (C 2 H 5)} 4 N-maleate, (C 2 H 5) 4 N-benzoate, (C 2 H 5) 4 N
-Quaternary ammonium salts such as phtalate, organic ion salts such as lithium stearyl sulfonate, sodium octyl sulfonate, lithium dodecylbenzene sulfonate, etc.
Any of them is an anion other than PF ₆ ⁻ . Two or more kinds of these ionic compounds may be used in combination.

Next, in the present invention, as described in claim 1, the ion-conductive polymer compound is allowed to contain a substance capable of dissolving the above-mentioned ionic compound contained in the ion-conductive polymer compound. Alternatively, the inclusion of this type of substance can significantly improve the ionic conductivity without changing the basic skeleton of the polymer compound.

As the organic compound capable of dissolving the ionic compound, cyclic carbonate such as propylene carbonate and ethylene carbonate; cyclic ester such as γ-butyrolactone; tetrahydrofuran or its derivative, 1,3-dioxane, 1,2. -Ethers such as dimethoxyethane and methyl diglyme; nitriles such as acetonitrile and 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 above-mentioned mixing ratio of the ionic compound is 0.0001 to 5.0 mol / liter of the ionic compound with respect to the organic compounds of the above chemical formulas 1 and 2, and is 0 among them. It is preferably 0.005 to 2.0 mol / liter. 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.

The mixing ratio of the ionic compound is
The appropriate compounding ratio differs depending on the electrode active material. For example,
In the battery using intercalation of the layered compound, it is preferable that the ionic conductivity of the electrolyte is around the maximum, and in the battery using the conductive polymer that utilizes the doping phenomenon as the electrode active material, It is necessary for the discharge to be able to respond to changes in the ion concentration in the electrolyte.

The above: The method of containing the ionic compound is not particularly limited.

A method of dissolving an organic compound such as [Chemical Formula 1] in an organic solvent such as methyl ethyl ketone and uniformly mixing, and then reducing the pressure in a vacuum to allow the compound to be contained in the above organic compound, or the above: After dissolving the ionic compound,

A method of uniformly mixing with an organic compound such as [Chemical Formula 1] may also be mentioned.

In the above: high molecular weight ethylene oxide-propylene oxide random copolymer, the composition ratio (molar ratio) of ethylene oxide unit (EO) and propylene oxide unit (PO) is 0 <(PO) /
The range of (EO) ≦ 5 is desirable, but the range is not particularly limited.

When a binder comprising an organic compound dissolved and / or dispersed in a solvent is used as described in the claims, a binder solution prepared by dissolving the organic compound in the solvent is added to the electrode active material or the above-mentioned material. An electrode active material, the above-mentioned ion-conductive polymer compound, or the like is used in a method in which an ion-conductive polymer compound or the like is dispersed as a coating liquid or in a dispersion liquid of the organic compound and a dispersant for dispersing the organic compound. A method of using a dispersion of the above as a coating solution is generally used, but the method is not limited thereto.

Examples of the above organic compounds 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 for 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 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.
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, the above ion-conductive polymer compound (organic compound represented by Chemical formula 1 or 2) is added to the electrolyte layer (separator).
It is possible to suppress the generation of lithium dendrites in the peripheral portion of the composite negative electrode, and it is possible to provide a thermally and electrochemically stable electrolyte layer which is excellent in mechanical strength. .

As the positive electrode active material used in the composite positive electrode (A) of the present invention, the following battery electrode materials can be mentioned as described in the claims. That is, when a carbonaceous material is used as the negative electrode active material (in the case of the composite negative electrode (B) in the claims of the present invention), a metal chalcogenite compound typified by conventional TiS ₂ , MoS ₂ or the like is used in a battery. There is a problem of low voltage. Therefore, as described in the claims, Li _a Co _b Ni _1-b
O ₂ (0 <a ≦ 1, 0 ≦ b ≦ 1) or Li _1- CM
n _2-d (D) _d O ₄ (0 ≦ c ≦ 1, 0 <d ≦ 0.5 where (D) is at least one element selected from the group consisting of Ni, Mo, Fe, and Cr. It is desirable to be selected from at least one of. Particularly representative examples include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O _{4, and the} like. The reason is as follows. 1) The battery voltage is 3.9V to 4.2V. 2) When a carbonaceous material is used as the negative electrode active material (in the case of the composite negative electrode (B) according to the claims of the present invention), a voltage change (about 1 V vs. Li / Li ⁺ ) due to charging and discharging of the carbonaceous material itself. ), The working voltage should be sufficiently practical. 3) When a carbonaceous material is used as the negative electrode active material, Li ions necessary for the charge / discharge reaction of the battery have already been contained in the form of, for example, LiCoO ₂ , LiNiO ₂ or the like before the battery is assembled.

Further, examples of the negative electrode active material (carbonaceous material) used for the composite negative electrode (B) include the following battery electrode materials. That is, carbonaceous materials such as carbon, [for example, the above-mentioned carbonaceous materials are analyzed by X-ray diffraction; lattice spacing (d002) 3.35 to 3.40 Å crystallite size in the a-axis direction La 200 Å or more c-axis Direction crystallite size Lc 200 Å or more True density 2.00 to 2.25 g / cm
³ Also, carbon powder (average particle diameter of 15 μm or less) or carbon fiber obtained by firing an anisotropic pitch at a temperature of 2000 ° C. or higher is preferable, but it is not limited to these ranges. ] Or lithium metal-containing alloys such as lithium metal, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloys, but are not limited thereto. These negative electrode active materials can be used alone or in combination of two or more.

Regarding the method of disposing the composite positive electrode (A) and composite negative electrode (B) of the present invention on the positive electrode current collector and the negative electrode current collector, for example, roll coating such as an applicator roll, doctor It is desirable to apply a uniform thickness using a means such as a blade method, spin coating, or 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 completely different characteristics 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.

When producing the composite positive electrode (A) and the composite negative electrode (B), several kinds of dispersants and dispersion media can be added in order to obtain a uniform mixed dispersion system. Further, it is possible to add a thickener, a bulking agent, an adhesion aid, and the like.

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.

[0037]

EXAMPLES The details of the present invention are described below with reference to examples, but the present invention is not limited thereto. Example 1 A sheet-shaped battery of Example 1 was manufactured according to the following procedure. a) LiCoO ₂ was used as a positive electrode active material of the battery, acetylene black was used as a conductive agent, and a mixture of a dimethylformamide solution of polyacrylonitrile and an organic compound represented by the following chemical formulas 4 and 5 was used as a composite positive electrode.

[0038]

[Chemical 4]

[0039]

[Chemical 5]

The method for producing this composite positive electrode is as follows. That is, LiCoO ₂ and acetylene black 8
A mixture of a 5:15 weight ratio and a mixture of polyacrylonitrile dimethylformamide solution (2 wt% solution) in a dry inert gas atmosphere, 2.4:
Mixed in a weight ratio of 2 (mixture I). This mixture I
And 10 parts by weight of an organic compound obtained by mixing the organic compounds of the above chemical formulas 4 and 5 in a ratio of 3.5: 6.5, 1 part by weight of lithium tetrafluoroborate, 10 parts by weight of 1,2-dimethoxyethane and γ- A mixture II was obtained by mixing 10 parts by weight of butyrolactone with a mixture of 10 parts by weight in a dry inert gas atmosphere. The mixture II was cast by screen coating on a current collector having a conductive carbon film formed on the surface of a positive electrode current collector plate made of aluminum. Then, the composite positive electrode was formed by irradiating an electron beam with an electron dose of 12 Mrad in a dry inert gas atmosphere. The thickness of the composite positive electrode coating film formed on the positive electrode current collector was 60 μm.

B) Next, in order to form an ion-conductive polymer compound on the composite positive electrode, an organic compound 30 is prepared by mixing the organic compounds of Chemical formulas 4 and 5 in a weight ratio of 3.5: 6.5. Parts by weight and 6 parts by weight of lithium tetrafluoroborate,
A mixture of 32 parts by weight of 1,2-dimethoxyethane and 32 parts by weight of γ-butyrolactone was cast by screen coating on the above composite positive electrode in a dry inert gas atmosphere, and then electron-exposed in a dry inert gas atmosphere. The ion conductive polymer compound layer was cured by irradiating it with an electron beam having a dose of 8 Mrad. The thickness of the electrolyte layer thus obtained was 25 μm.

C) Carbon powder was used as the negative electrode active material of the battery, and a mixture of the xylene solution of the ethylene-propylene-cyclopentadiene copolymer and the organic compounds of the above chemical formulas 4 and 5 was used as the composite negative electrode. .

The method for producing this composite negative electrode is as follows. That is, carbon powder and ethylene-propylene-
Toluene solution of cyclopentadiene copolymer (2 wt
% Solution) were mixed in a dry inert gas atmosphere in a weight ratio of 2: 5 (mixture III). This mixture III, and
10 parts by weight of an organic compound obtained by mixing the organic compounds of the above chemical formulas 4 and 5 in a ratio of 3.2: 6.8, 1 part by weight of lithium tetrafluoroborate, 10 parts by weight of 1,2-dimethoxyethane and γ-
A mixture IV was obtained by mixing with a mixture of 10 parts by weight of butyrolactone in a dry inert gas atmosphere at a weight ratio of 8: 2. The mixture IV was cast by screen coating on a negative electrode current collector plate made of stainless steel. Then, the composite negative electrode was formed by irradiating an electron beam with an electron dose of 12 Mrad in a dry inert gas atmosphere. The composite negative electrode formed on the negative electrode current collector had a thickness of 30 μm.

D) Next, in order to form an ion-conductive polymer compound on the composite negative electrode, an organic compound 30 prepared by mixing the organic compounds of Chemical formulas 4 and 5 in a weight ratio of 3.5: 6.5. Parts by weight and 6 parts by weight of lithium tetrafluoroborate, 1,
A mixture of 32 parts by weight of 2-dimethoxyethane and 32 parts by weight of γ-butyrolactone was cast by screen coating on the above composite negative electrode in a dry inert gas atmosphere, and then an electron dose of 8 Mrad was applied in a dry inert gas atmosphere. Was irradiated with the electron beam to cure the ion conductive polymer compound layer. The thickness of the electrolyte layer thus obtained was 25 μm.

FIG. 1 is a sectional view of the sheet-like battery of the present invention. In the figure, 1 is a positive electrode current collector made of aluminum,
It also serves as the exterior. Reference numeral 2 denotes a composite positive electrode, in which manganese dioxide was used as a positive electrode active material, acetylene black was used as a conductive agent, and ethylene-propylene-1,3-cyclohexadiene copolymer was used as a binder and the above organic compound. Further, 3 is an electrolyte layer made of the ion conductive polymer compound of the present invention. Reference numeral 4 is metallic lithium, and 5 is a negative electrode current collector made of stainless steel, which also serves as an exterior. 6 is a sealing agent made of modified polypropylene.

Comparative Example 1 The sheet-shaped battery of Comparative Example 1 is
A sheet-like battery was manufactured in the same manner as in the sheet-shaped battery of Example 1 except that lithium hexafluorophosphate was used instead of lithium tetrafluoroborate of Example 1.

The electrode area of the sheet-shaped batteries of Example 1 and Comparative Example 1 can be variously changed depending on the manufacturing process. In this example, the electrode area was 100 cm ² . Using these sheet batteries,
50μA / cm ² constant current / constant voltage charge and 50μ at ℃
A charge / discharge cycle test of A / cm ² constant current discharge 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. 2 shows the relationship between the number of charge / discharge cycles and the battery capacity of the sheet-shaped battery immediately after cell preparation and after storage at 60 ° C for 100 days. As can be seen from FIG. 2, 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.

In the sheet-shaped battery of Comparative Example 1, since HF was produced by the above-mentioned reaction, a passive film was produced on the surface of LiCoO _{2 and the} surface of the carbonaceous material, and due to the increase in the internal impedance of the battery, the cycle was generated. It seems that the battery capacity is being reduced due to.

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 descriptions relate primarily to the use of lithium, the use of other alkali metals such as sodium is also within the scope of the invention.

[0051]

As is apparent from the above description, in the battery using the ion conductive polymer compound of the present invention, P
F ₆ ^- The use of ionic compound having an anion other than, without reaction described above occurs, HF
Therefore, it is possible to improve the long-term reliability of the battery using the above ion-conductive polymer compound. Therefore, it becomes possible to produce an electrochemically optimal composite electrode and electrolyte. 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 the relationship between the number of charge / discharge cycles and the battery capacity of the sheet-shaped battery of Example 1 and the sheet-shaped 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 (3)

[Claims] 1. An ion-conducting polymer compound composed of a polymer substance in which at least one ionic compound is dissolved, wherein the ion-conducting polymer compound is: / And an organic compound represented by the following Chemical formula 2 (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 an integer in the range 0-5. ) [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 k ≧ 3, l ≧ 0, and 1 / k =
Indicates an integer in the range 0-5. ): An ionic compound which is an anion other than PF ₆ ⁻ : an organic compound capable of dissolving the ionic compound of: a polymer compound which forms a crosslinked network structure by a polymerization reaction, and comprises the following (A) and (B): Alternatively, (B ′), (C) a) A composite positive electrode (A) composed of at least an electrochemically active substance and the ion-conductive polymer compound; (b) At least a carbonaceous material and a high ion-conductive property. A composite negative electrode (B) or an alkali metal negative electrode (B ') composed of a molecular compound; (c) an electrolyte (C) comprising at least one kind of the ion conductive polymer compound, and the composite positive electrode ( A secondary battery formed by irradiating at least one of A), a composite negative electrode (B) and an electrolyte (C) with ionizing radiation. 2. The anion other than PF ₆ ⁻ is BF ₄
^The secondary battery according to claim 1, wherein the ionic compound is-. 3. The composite positive electrode (A) comprises Li _a Co _b Ni _{1 -b} O ₂ (0 <a ≦ 1,0) as an electrochemically active substance.
≦ b ≦ 1) or Li _1-C Mn _2-d (D) _d O
₄ (0 ≦ c ≦ 1, 0 <d ≦ 0.5 where (D) is N
It is at least one element selected from the group consisting of i, Mo, Fe, and Cr. ) Selected from at least one of
3. The ion-conducting polymer compound, optionally an electron-conducting substance, and a binder comprising an organic compound dissolved and / or dispersed in a solvent, according to claim 1 or 2. Secondary battery.