JP3290229B2 - Battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery using a solid polymer electrolyte having excellent ionic conductivity.

[0002]

2. Description of the Related Art Recent microelectronics are
As typified by the power supply for memory backup of various electronic devices, as batteries are stored in electronic devices and integrated with electronic elements and circuits, batteries have become smaller, lighter, thinner and have higher energy density. There is a demand for a battery having the same. In the field of primary batteries, small and lightweight batteries such as lithium batteries have already been put into practical use, but their application fields are limited. Therefore, secondary batteries using non-aqueous electrolytes, which can be made smaller and lighter, have attracted attention as alternatives to conventional lead batteries and nickel-cadmium batteries. Nothing that satisfies practical properties such as has been found.

Therefore, the present inventors have proposed a thin battery having a small and light weight and a high energy density (thickness per unit cell of 100 to 5) using an ion conductive polymer compound thin film.
00 μm (sheet-shaped battery)], but when the ion-conductive polymer compound is used in the form of a thin film, it is necessary to produce a thin-film metallic lithium having a quality sufficiently comparable to that. Some technical difficulties and complicated battery manufacturing processes have become problems. Further, when used as a secondary battery, there has been a problem that the use of metallic lithium is limited due to problems such as generation of lithium dendrite and passivation of the interface.

[0004] Therefore, researches on lithium metal-containing alloys represented by lithium-aluminum, lithium-lead, and lithium-tin alloys have been actively conducted. However, as represented by a lithium-aluminum alloy,
Since the strength of these alloys is low, the electrodes are cracked or miniaturized by repeated charging and discharging, and thus the cycle characteristics are not improved.

As other methods for suppressing the generation of dendrite of lithium, studies have been made on the selection of an electrolyte salt, improvement of a separator, and the like. Attempts have been made to suppress lithium dendrite by laminating nonwoven fabrics and the like, but the solution has not been essentially solved.

[0006] Therefore, in many research institutions at present,
Intercalation of layered compounds as electrode active material,
In particular, research has been conducted on the use of doping phenomena, which do not cause a complicated chemical reaction in the course of the electrochemical reaction in charge and discharge, and therefore have extremely excellent charge-discharge cycle performance. There is expected.

On the other hand, conventionally, as a battery utilizing an electrochemical reaction or an electrochemical device other than a battery, that is, an electrolyte such as an electric double layer capacitor or an electrochromic element, a liquid electrolyte, particularly an organic electrolyte, is generally ionic. Liquid compounds have been used, but liquid electrolytes are liable to leak out of components, elute and volatilize electrode materials, and have problems such as long-term reliability. Was a problem.

In order to improve the liquid leakage resistance and the long-term storage stability, it is preferable to use an ion conductive polymer compound having a high ion conductivity, that is, a solid electrolyte.
As described above, the use of the conventional ion-conductive polymer compound has problems such as complicated battery manufacturing processes and restrictions on the use of lithium metal, and has excellent long-term reliability and safety, as well as high performance and high performance. It has been difficult to provide a small and lightweight battery having an energy density.

For example, this type of solid electrolyte includes a trifunctional polymer having a terminal acryloyl-modified alkylene oxide polymer chain, a low-molecular alkylene oxide copolymer, a polymer obtained by combining polyvinyl chloride, an electrolyte salt, and the like. Solid electrolyte (JP-A-3-177409)
Also, a solid electrolyte obtained by combining a terminal acryloyl-modified alkylene oxide polymer with an inorganic ion salt and an organic solvent such as propylene carbonate (JP-A-63-9463)
No. 501) are known, but they have problems in terms of both capacity and mechanical strength, and have not been able to produce a small and lightweight battery having a high energy density.

[0010]

DISCLOSURE OF THE INVENTION The present invention is directed to an improved ion-conductive polymer compound, which is free from liquid leakage, has excellent long-term reliability and safety, is compact, has high performance, It is an object to provide a battery having a high energy density.

[0011]

Means for Solving the Problems The present inventors have made intensive studies with the aim of solving the above-mentioned problems, and as a result, as a polymer electrolyte, an alkylene oxide polymer chain comprising a specific number or more of monomer units. By using a trifunctional terminal acryloyl-modified alkylene oxide polymer having the following formula, adding a solvent and an electrolyte salt in a specific ratio to the polymer, and crosslinking by actinic radiation such as photoelectrons and / or heating, Battery with excellent electrical strength, electrical conductivity comparable to conventional electrolytes, and a solid electrolyte free of solvent bleed-out, and excellent performance by using this as a solid electrolyte for batteries Were obtained, and the present invention was completed.

The battery of the present invention uses a solid electrolyte obtained by dissolving a trifunctional polymer compound together with an electrolyte salt in a solvent and crosslinking by irradiation with actinic radiation and / or heating. As a functional polymer compound,
A trifunctional terminal acryloyl-modified alkylene oxide polymer in which each functional polymer chain is a polymer chain represented by the general formula (1) is used, and the amount of the solvent used is such that the trifunctional terminal acryloyl-modified alkylene is used. It is characterized in that it is 220 to 950% by weight based on the oxide polymer.

[0013]

Embedded image (In the formula, R ′ represents an alkyl group having 1 to 6 carbon atoms, R ″ represents hydrogen or a methyl group. M and n each represent 0 or 1 or more, and m + n ≧ 35.)

In the present invention, the solid electrolyte is prepared by coating a mixture of the polymer, electrolyte salt and solvent (hereinafter referred to as a solid electrolyte composition) on an electrode material, and irradiating with active radiation and / or heating. May be used in a state where a solid electrolyte layer is formed by cross-linking, but it is preferable that the solid electrolyte layer is integrated with an electrode active material and used as a composite electrode. In this case, it is possible to increase the actual surface area of the active substance in contact with the electrolyte layer (separator) and the current collector, and it is possible to obtain a high-performance electrode with improved cycle characteristics.

A typical battery configuration is obtained by mixing the above-mentioned trifunctional acryloyl-modified alkylene oxide polymer with an electrolyte salt, a solvent and a positive electrode active material, and irradiating with actinic radiation and / or heating to crosslink. The solid electrolyte integrated with the positive electrode active material is a composite positive electrode, between the positive electrode and the negative electrode, a mixture of the trifunctional terminal acryloyl-modified alkylene oxide polymer, an electrolyte salt, and a solvent is irradiated with actinic radiation and / or The solid electrolyte obtained by crosslinking by heating is present as a separator.

By using as a separator a layer of a solid electrolyte (ion conductive polymer compound) obtained by mixing and cross-linking the above trifunctional terminal acryloyl-modified alkylene oxide polymer, an electrolyte salt and a solvent, lithium around the negative electrode can be obtained. Can be suppressed, and a separator having excellent mechanical strength and being thermally and electrochemically stable can be provided.

The "trifunctional terminal acryloyl-modified alkylene oxide polymer", which is a raw material of the solid electrolyte used in the battery of the present invention, is obtained by starting from a compound having three active hydrogens such as glycerol and trimethylolpropane. A trifunctional alkylene oxide polymer obtained by ring-opening polymerization of an alkylene oxide is further subjected to an esterification reaction with an unsaturated organic acid such as acrylic acid or methacrylic acid, or acrylic acid chloride or methacrylic acid chloride. Is a compound obtained by subjecting acid chlorides such as the above to a dehydrochlorination reaction, and specific examples thereof include a compound represented by the following formula (2).

[0018]

Embedded image Wherein R is the residue of a trifunctional starting material, R ′ is
6, an alkyl group R ″ represents hydrogen or a methyl group. M and n each represent 0 or a number of 1 or more, and m + n ≧ 3
5 )

The alkylene oxides used in the synthesis of the trifunctional alkylene oxide polymer include, for example, ethylene oxide, propylene oxide, butylene oxide, 1,2-epoxyhexane, 1,2-epoxyoctane and the like. Preference is given to ethylene oxide, propylene oxide or butylene oxide. Further, the number of monomer units is required to be 35 or more for each functional polymer chain of the trifunctional alkylene oxide polymer, that is, for the polyalkylene oxide chain. When the number of monomer units is less than 35, it is difficult to mix the solvent with the trifunctional terminal acryloyl-modified alkylene oxide polymer in an amount of 220% by weight or more to crosslink, and the mechanical properties of the crosslinked product are reduced. And the bleed out of the solvent on the surface of the crosslinked product is severe.

The "solvent" used for the solid electrolyte of the battery of the present invention may be any one which is compatible with the trifunctional terminal acryloyl-modified alkylene oxide polymer.
Either can be suitably used, but ethylene carbonate,
It is preferable to use one or more selected from the group consisting of propylene carbonate, γ-butyrolactone, dimethoxyethane, dimethyl sulfoxide, dioxolan, sulfolane and water.

The ratio of the solvent to the trifunctional terminal acryloyl-modified alkylene oxide polymer is from 220 to 9
When it is 50% by weight and less than 220% by weight, the conductivity of the obtained solid electrolyte is low. Conversely, if the content exceeds 950% by weight, the mechanical strength of the impregnated material is significantly reduced.

The "electrolyte salt" used for the solid electrolyte of the battery of the present invention includes lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium nitrate, lithium thiocyanate, lithium perchlorate, trifluoromethanesulfonic acid. Lithium, lithium tetrafluoroborate, lithium bistrifluoromethylsulfonylimide, lithium tristrifluoromethylsulfonylmethide, sodium thiocyanate,
Sodium perchlorate, sodium trifluoromethanesulfonate, sodium tetrafluorofluoride, potassium thiocyanate, potassium perchlorate, potassium trifluoromethanesulfonate, potassium tetrafluorofluoride, magnesium thiocyanate, magnesium perchlorate and trifluoromethane It is at least one selected from the group consisting of magnesium sulfonates, and the amount of the electrolyte salt used is preferably 1 to 30% by weight based on the solvent.

The solid electrolyte used in the battery of the present invention is prepared by mixing a uniform mixed solution containing a trifunctional terminal acroyl-modified alkylene oxide polymer, an electrolyte salt and a solvent with a knife coater.
It is obtained by uniformly coating the substrate with a bar coater, gravure coater, spin coater, or the like, followed by crosslinking by irradiation with high energy electromagnetic waves such as ultraviolet rays, visible rays, and electron beams or by heating. The mixed solution may be prepared by uniformly mixing a solvent in which an electrolyte salt is dissolved in advance with a trifunctional terminal acroyl-modified alkylene oxide polymer, or a solvent may be added to the trifunctional terminal acroyl-modified alkylene oxide polymer. May be manufactured by uniformly dissolving the electrolyte salt.

If necessary, a photopolymerization initiator such as trimethylsilyl benzophenone, benzoin, 2-methylbenzoin, 4-methoxybenzophenone, benzoin methyl ether, anthraquinone, benzoyl peroxide, methyl ethyl ketone peroxide may be added to the mixture. May be added.

As described above, it is preferable that the composite electrode is formed integrally with the electrode active material. In this case, a homogeneous mixed solution containing a trifunctional terminal acroyl-modified alkylene oxide polymer, an electrolyte salt and a solvent is used. (Solid electrolyte composition) is mixed with an electrode active material and irradiated with actinic radiation and / or
Alternatively, the polymer may be cross-linked by heating. At this time, carbon such as graphite, carbon black, and acetylene black, metal powder, and an electron conductive material such as a conductive metal oxide may be included.

The mixing ratio between the solid electrolyte composition and the electrode active material may be appropriately selected depending on the electrode active material. For example, in a battery utilizing intercalation of a layered compound, the ionic conductivity of the electrolyte is at a maximum. Is preferable, and in a battery utilizing the doping phenomenon, it is necessary to cope with a change in the ion concentration in the electrolyte due to charging and discharging.

In the battery of the present invention, the surface of the electrode material is coated with the solid electrolyte composition (or a blend of the electrode active material) and cross-linked, and a uniform solid electrolyte layer (or It is preferable to form a composite electrode), but in this case, any known coating means such as roll coating, doctor blade coating, spin coating, bar coating, cast coating and the like can be used.

Next, examples of the positive electrode active material used in the composite positive electrode of the present invention include the following battery electrode materials.
For _{example, CuO, Cu 2 O, Ag} 2 O, CuS, I metal compounds such as _{CuSO 4, TiS 2, SiO 2} , IV group metal compounds such as 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, CrO 3,} Cr 2 O 3, MoO 3, WO 3, SeO such ₂ VI
Group VII metal compounds such as MnO ₂ and Mn ₂ O _{3
Fe 2 O 3, FeO, Fe} 3 O 4, Ni 2 O 3, NiO, CoO 3, VIII group metal compound such as CoO, or the general formula Li _X MX _2, Li _x MN
For example, a lithium-cobalt-based composite oxide or a lithium-manganese-based composite oxide represented by _Y X ₂ (M and N are metals of Group I to VIII, and X is a chalcogen compound such as oxygen and sulfur) Metal compounds such as polypyrrole, polyaniline, polyparaphenylene, polyacetylene, and polyacene-based materials, and conductive materials such as pseudo-graphite structure carbonaceous materials, but are not limited thereto.

The negative electrode active material used for the negative electrode of the battery of the present invention includes lithium metal, lithium-aluminum alloy, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, wood alloy and the like. Although lithium metal-containing alloys are generally used,
The present invention is not limited to these, and an alkali metal such as sodium metal or an alloy thereof, or a conductive polymer such as polyacetylene or polythiophene, which can be doped with cations, can also be used. These may be used alone or in combination of two or more.

Further, examples of the negative electrode active material which is mixed with the solid electrolyte composition and cured to form a composite negative electrode include those exemplified as the negative electrode active material used for the negative electrode, and carbonaceous materials such as carbon. Can be Of course, the present invention is not limited to these, and these negative electrode active materials may be used alone or in combination of two or more. As for the carbonaceous material, the analysis result by X-ray diffraction or the like indicates that the lattice spacing (d002) is 3.35 to 3.40Å. The crystallite size in the a-axis direction is La 200Å or more. Lc 200mm or more True density 2.35 to 2.25g /
It is preferably carbon powder (average particle diameter of 15 μm or less) or carbon fiber fired at a temperature of 2,000 ° C. or more with anisotropic pitch of cm ³ .

In producing the composite positive electrode and / or the composite negative electrode, a dispersant and a dispersion medium may be added in order to obtain a uniform mixed dispersion. It is also possible to add auxiliary agents and the like. Furthermore, it is preferable to use materials such as aluminum, stainless steel, titanium, and copper as the positive electrode current collector plate, and it is preferable to use materials such as stainless steel, iron, nickel, and copper as the negative electrode current collector plate. preferable.

[0032]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. [Synthesis Example of Trifunctional Terminal Acryloyl-Modified Alkylene Oxide Polymer] Synthesis Example 1 (Compound A-1 ) In an autoclave of 7 liters (hereinafter, referred to as L), 92 g of glycerin (starting material) and potassium hydroxide (catalyst) 9.5 g) and ethylene oxide (4,700 g) were charged and reacted at 130 ° C. for 5 hours, and then neutralized and desalted to obtain a trifunctional ethylene oxide polymer (4,61 g).
0 g was obtained. Its molecular weight was 4,720 (calculated from the hydroxyl value). In a 2 L four-necked flask, 944 g (0.2 mol) of the above trifunctional ethylene oxide polymer,
65 g (0.9 mol) of acrylic acid, 500 g of toluene and 2 g of concentrated sulfuric acid were charged and reacted for 10 hours while distilling water under reflux while stirring, and then neutralized and desalted and purified. Then, toluene was distilled off to obtain a desired trifunctional terminal acryloyl-modified ethylene oxide polymer. Its molecular weight was 4,890 (calculated from GPC).

Synthesis Example 2 (Compound A-2) A 7 L autoclave was charged with 92 g of glycerin, 15.0 g of potassium hydroxide, 3,700 g of ethylene oxide and 1,240 g of propylene oxide.
After reacting for an hour, neutralization and desalting were performed to obtain 4,990 g of a trifunctional ethylene oxide-propylene oxide random copolymer. Its molecular weight is 5,02
0 (calculated from the hydroxyl value). In a 2 L four-necked flask, 1,004 g (0.2 mol) of the above trifunctional ethylene oxide-propylene oxide random copolymer, 65 g (0.9 mol) of acrylic acid, 500 g of toluene, and 3 g of concentrated sulfuric acid as a catalyst were placed. After charging, stirring, and reacting for 10 hours while distilling water under reflux, neutralization and desalting and purification were carried out, and toluene was distilled off to obtain the desired trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random. A copolymer was obtained. Its molecular weight is 5,180
(Calculated from GPC).

Synthesis Example 3 (Compound A-3) As shown in Table 1, the molecular weight was 7,290 (calculated from GPC) in the same manner as in Synthesis Example 2 except that the amounts of ethylene oxide and propylene oxide were changed. Was obtained as a trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random copolymer.

Synthesis Example 4 (Compound A-4) In a 20 L autoclave, 92 g of glycerin, 46 g of potassium hydroxide, 7,950 g of ethylene oxide and 5,250 g of propylene oxide were charged.
After reacting for 0 hour, neutralization and desalting were performed to obtain 13,270 g of a trifunctional ethylene oxide-propylene oxide random copolymer. Its molecular weight is 1
3,260 (calculated from the hydroxyl value). In a 3 L four-necked flask, 1,326 g (0.1 mol) of the above trifunctional ethylene oxide-propylene oxide random copolymer, 32.5 g (0.45 mol) of acrylic acid, and 1 part of toluene
000 g, and paratoluenesulfonic acid 10 as a catalyst
g while stirring and distilling water under reflux.
After reacting for 2 hours, neutralization and desalting purification were carried out, and toluene was distilled off to obtain a desired trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random copolymer. Its molecular weight was 13,420 (calculated from GPC).

Synthesis Example 5 (Compound A-5) In a 20 L autoclave, 92 g of glycerin, 51 g of potassium hydroxide, 3,980 g of ethylene oxide and 10,500 g of propylene oxide were charged, reacted at 115 ° C. for 12 hours, and then neutralized. And a desalting treatment to obtain 14,500 g of a trifunctional ethylene oxide-propylene oxide random copolymer. Its molecular weight is 1
4,520 (calculated from the hydroxyl value). In a 3 L four-necked flask, 1,452 g (0.1 mol) of the above trifunctional ethylene oxide-propylene oxide random copolymer, 32.5 g (0.45 mol) of acrylic acid, and 1 part of toluene
000 g and 10 g of p-toluenesulfonic acid as a catalyst
After stirring for 10 hours while distilling off water under reflux, neutralization and desalting purification were carried out, and toluene was distilled off to obtain the desired trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random copolymer. A polymer was obtained. Its molecular weight was 14,680 (calculated from GPC).

Synthesis Example 6 (Compound A-6) In a 30 L autoclave, 134 g of trimethylolpropane (starting material), 68 g of potassium hydroxide and 10,600 g of ethylene oxide were charged.
Allowed to react for hours. Then, propylene oxide 8,80
After adding 0 g and reacting at 110 ° C. for further 15 hours, neutralization and desalting were performed to obtain trifunctional ethylene oxide
19,500 g of a propylene oxide block copolymer was obtained. Its molecular weight was 19,420 (calculated from the hydroxyl value). In a 3 L four-necked flask, 1,942 g (0.1 mol) of the above trifunctional ethylene oxide-propylene oxide block copolymer and 39 g of methacrylic acid were added.
(0.45 mol), 1,200 g of toluene and 20 g of p-toluenesulfonic acid as a catalyst were stirred and reacted for 10 hours while distilling off water under reflux, then neutralized and desalted and purified. Was distilled off to obtain a desired trifunctional terminal methacryloyl-modified ethylene oxide-propylene oxide block copolymer. Its molecular weight is 1
9,630 (calculated from GPC).

Synthesis Example 7 (Compound A-7) As shown in Table 1, except that propylene oxide was used alone as the alkylene oxide, a compound having a molecular weight of 8,970 (calculated from GPC) was obtained in the same manner as in Synthesis Example 2. A trifunctional terminal acryloyl-modified propylene oxide polymer was obtained.

Synthesis Example 8 (Compound A-8) A 20 L autoclave was charged with 134 g of trimethylolpropane (starting material), 48 g of potassium hydroxide and 11,900 g of butylene oxide.
Allowed to react for hours. Next, neutralization and desalting are performed,
12,000 g of a trifunctional butylene oxide polymer was obtained. Its molecular weight was 12,030 (calculated from the hydroxyl value). In a 3 L four-necked flask, 1,203 g (0.1 mol) of the above trifunctional butylene oxide polymer, 33 g (0.46 mol) of acrylic acid, and 1,500 g of toluene
Then, 30 g of paratoluenesulfonic acid was charged as a catalyst, and the mixture was reacted for 10 hours while distilling water under stirring and reflux, then neutralized and desalted and purified, and toluene was distilled off to obtain a target trifunctional terminal. An acryloyl-modified butylene oxide polymer was obtained. Its molecular weight is 12,200 (GPC
Calculated from).

Synthesis Example 9 (Compound A-9) As shown in Table 1, except that ethylene oxide and butylene oxide were used as the alkylene oxide, Synthesis Example 2 was used.
7,700 molecular weight (calculated from GPC)
Was obtained as a trifunctional terminal acryloyl-modified ethylene oxide-butylene oxide random copolymer.

Synthesis Example 10 (Compound A-10) In a 10 L autoclave, 92 g of glycerin, 24 g of potassium hydroxide, 6,970 g of propylene oxide and 1,100 g of butylene oxide were charged.
The reaction was performed for 5 hours. After completion of the reaction, neutralization and desalting were performed to obtain 8,100 g of a trifunctional propylene oxide-butylene oxide random copolymer. Its molecular weight was 8,145 (calculated from the hydroxyl value). In a 2 L four-necked flask, add the above trifunctional propylene oxide-
814.5 g (0.1 mol) of a butylene oxide random copolymer, 39 g (0.45 mol) of methacrylic acid, 1,000 g of toluene and 5 g of sulfuric acid as a catalyst were charged, and stirred.
After reacting for 10 hours while distilling off water under reflux, neutralization and desalting and purification were performed, and toluene was distilled off to obtain a desired trifunctional terminal methacryloyl-modified propylene oxide-butylene oxide random copolymer. Was. Its molecular weight was 8,360 (calculated from GPC).

Synthesis Example 11 (Compound B-1: Comparative Example) In a 5 L autoclave, 92 g of glycerin, 11 g of potassium hydroxide, 2,640 g of ethylene oxide and 870 g of propylene oxide were charged and reacted at 115 ° C. for 8 hours. Next, neutralization and desalting were performed to obtain 3,580 g of a trifunctional ethylene oxide-propylene oxide random copolymer. Its molecular weight is 3,60
0 (calculated from the hydroxyl value). In a 2 L four-necked flask, 720 g (0.2 mol) of the above trifunctional ethylene oxide-propylene oxide random copolymer, 65 g (0.9 mol) of acrylic acid, 1,000 g of toluene, and 5 g of paratoluenesulfonic acid as a catalyst After stirring for 10 hours while distilling off water under reflux, neutralization and desalting purification were carried out, and toluene was distilled off to obtain the desired trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random copolymer. A polymer was obtained. Its molecular weight was 3,760 (calculated from GPC).

Synthesis Example 12 (Compound B-2: Comparative Example) Trimethylolpropane 13 was placed in a 5 L autoclave.
4 g, potassium hydroxide 5.4 g, ethylene oxide 1,3
20 g and 350 g of propylene oxide were charged.
The reaction was performed at 5 ° C. for 5 hours. Next, neutralization and desalting were performed to obtain 1,790 g of a trifunctional ethylene oxide-propylene oxide random copolymer. Its molecular weight was 1,800 (calculated from the hydroxyl value). 3L
In the four-necked flask, the above trifunctional ethylene oxide
900 g (0.5 mol) of a propylene oxide random copolymer, 162 g (2.25 mol) of acrylic acid, 1,000 g of toluene and paratoluenesulfonic acid 5 as a catalyst
g, and the mixture was reacted for 10 hours while distilling water under stirring and reflux. After neutralization and desalination purification, toluene was distilled off and the desired trifunctional terminal acryloyl-modified ethylene oxide-propylene oxide random was distilled off. A copolymer was obtained.
Its molecular weight was 1,960 (calculated from GPC).

Synthesis Example 13 (Compound B-3: Comparative Example) A 10 L autoclave was charged with 92 g of glycerin, 20 g of potassium hydroxide, 1,352 g of ethylene oxide and 4,330 g of butylene oxide.
Allowed to react for hours. Next, neutralization and desalting are performed,
5,730 g of a trifunctional ethylene oxide-butylene oxide random copolymer was obtained. Its molecular weight is 5,
740 (calculated from the hydroxyl value). A 2-L four-necked flask was charged with 574 g (0.1 mol) of the above trifunctional ethylene oxide-butylene oxide random copolymer, 39 g (0.45 mol) of methacrylic acid, 1,000 g of toluene, and 5 g of sulfuric acid as a catalyst. After reacting for 10 hours while distilling water under stirring and reflux, neutralization and desalting and purification are performed, and toluene is distilled off to obtain a target trifunctional terminal acryloyl-modified ethylene oxide-butylene oxide random copolymer. Obtained. Its molecular weight is 5,930 (GP
C). Table 1 shows the structure of the trifunctional terminal acryloyl-modified alkylene oxide polymer obtained in each synthesis example.
Shown in

[0045]

[Table 1]

[Synthesis Example of Positive Electrode Active Material] Stirrer, thermometer,
In a 1 L four-necked flask equipped with a condenser and a dropping funnel,
20 g of aniline, 18 ml of hydrochloric acid and 250 ml of water were added.
After cooling to 0 ° C., a solution of 49 g of ammonium persulfate dissolved in 120 g of water was added dropwise from a dropping funnel over 4 hours. After the addition, the mixture was further stirred for 1 hour. Thereafter, the precipitate was collected by filtration, washed with water until the washing liquid became neutral, and further washed with ethanol until the washing liquid became transparent. The washed material was dried under vacuum to obtain 10.2 g of dark brown undoped polyaniline. 10 g of the undoped polyaniline is added to N
-Methyl-2-pyrrolidone was dissolved in 300 g and reduced by adding 2 g of phenylhydrazine. After completion of the reaction, the precipitate was reprecipitated with acetone. The precipitated solid was separated by filtration, washed with acetone, and dried to obtain 8.0 g of a gray cathode active material (hereinafter, referred to as "reduced polyaniline").

Example of Battery Production Example 1 8 g of reduced polyaniline was used as a positive electrode active material, and 1 part by weight of a trifunctional terminal acryloyl-modified ethylene oxide polymer (Compound A-1) and 4 parts by weight of propylene carbonate were used. And 2 g of a solid electrolyte composition before crosslinking, consisting of 0.4 parts by weight of lithium perchlorate and 2 g of carbon black (Ketjen Black EC600J), and in a nitrogen atmosphere, pulverized and mixed well using a ball mill, Thickness 2
It is cast on a stainless steel plate having a diameter of 0 μm and a diameter of 12 mm, and is subjected to an electro-curtain type electron beam irradiation apparatus (output: 200).
(KV, irradiation dose 5 Mrad)
Was obtained. The solid electrolyte composition before cross-linking was further applied onto the positive electrode by a wire coater, and cross-linked using an electron beam irradiation device in the same manner as above to form a solid electrolyte layer having a thickness of 50 μm. Next, the above solid electrolyte layer was bonded to metallic lithium (thickness: 50 μm, diameter: 12 mm) and sealed in a fluororesin cell shown in FIG. 2 to obtain a new lithium battery. As a result of the measurement, the open circuit voltage of this battery was 3.
The discharge capacity was 4 V and the discharge capacity was 110 mA · h / g. Incidentally, this property is comparable to existing lithium batteries using a liquid electrolyte.

Examples 2 to 9 and Comparative Examples 1 and 2 Batteries were obtained in exactly the same manner as in Example 1 except that the composition of the solid electrolyte before crosslinking was changed as shown in Table 2. Table 2 shows the characteristics of the obtained battery.

[0049]

[Table 2]

Comparative Example 3 An attempt was made to obtain a positive electrode in exactly the same manner as in Example 1 except that Compound B-1 was used instead of Compound A-1, but crosslinking was insufficient. Also, just in case, cross-linking was attempted with the solid electrolyte composition before cross-linking alone, but it did not become a solid electrolyte and a battery could not be produced.

Comparative Example 4 An attempt was made to obtain a positive electrode in exactly the same manner as in Example 1 except that Compound B-2 was used in place of Compound A-1 and the amount of propylene carbonate was changed to 3 parts by weight. . In this case, the same result as in Comparative Example 3 was obtained.

Comparative Example 5 A battery was prepared in exactly the same manner as in Example 1 except that Compound B-3 was used instead of Compound A-1 and the amount of propylene carbonate was changed to 3 parts by weight. Liquid was observed, and a practical battery could not be obtained.

Example 10 A sheet-shaped battery of the present invention was manufactured according to the following procedures a) to c). a) An 85:15 (weight ratio) mixture X of manganese dioxide (cathode active material) and acetylene black (conductive agent), and 10% of compound A-3, lithium perchlorate, propylene carbonate and azobisisobutyronitrile: 1: 25: 0.
05 (weight ratio) mixture Y was prepared, and
They were mixed in a dry inert gas atmosphere at a ratio of 10: 3 (weight ratio). Next, this mixture is cast-coated on a current collector having a conductive carbon film formed on the surface of a positive electrode current collector plate made of stainless steel, and then left at 100 ° C. for 1 hour in a dry inert gas atmosphere. To obtain a composite positive electrode. The thickness of the composite positive electrode film formed on the positive electrode current collector was 60 μm. b) Lithium metal was used as a negative electrode active material of the battery, and was pressed on a negative electrode current collector plate made of stainless steel. Next, a 30: 6: 150: 0.05 (weight ratio) mixture of compound A-3, lithium perchlorate, propylene carbonate, and azobisisobutyronitrile is cast-coated on the lithium metal and dried. It was left at 100 ° C. for 1 hour in an inert gas atmosphere to cure. The thickness of the solid electrolyte layer thus obtained was 20 μm. c) the solid electrolyte / lithium / negative electrode current collector obtained in b);
By contacting the positive electrode current collector plate / composite positive electrode obtained in a), the sheet battery of FIG. 1 was produced. 1 is a positive electrode current collector plate made of stainless steel, which also serves as an exterior, 2 is a composite positive electrode using the solid electrolyte of the present invention, 3 is the solid electrolyte of the present invention, and 4 is metal lithium. Negative electrode, 5 negative electrode current collector plate made of stainless steel (also serves as exterior)
It is. Reference numeral 6 denotes a sealing material made of modified polypropylene.

Comparative Example 6 A sheet-shaped battery was produced in the same manner as in Example 10 except that polyethylene glycol triacrylate was used instead of Compound A-1. The electrode area of the sheet-shaped battery of Example 10 and Comparative Example 6 can be variously changed depending on the manufacturing process.
Manufactured an electrode having an electrode area of 100 cm ² . The initial discharge characteristics when these sheet batteries were discharged at 25 ° C. at 0.1 mA / cm ² and the discharge characteristics after storage at 60 ° C. for 100 days were examined. FIG. 3 shows the discharge characteristics (initial discharge characteristics) immediately after the cell fabrication,
FIG. 4 shows the discharge characteristics after storage at 60 ° C. for 100 days. As is clear from the results shown in FIGS. 3 and 4, the sheet-shaped battery of Example 10 of the present invention had better initial discharge characteristics and discharge characteristics after storage at 60 ° C. for 100 days than the sheet-shaped battery of Comparative Example 6. It is recognized that it is excellent.

Example 11 A sheet-shaped battery was manufactured according to the following procedure. a) An 85:15 (weight ratio) mixture X of vanadium pentoxide (cathode active material) and acetylene black (conductive agent), and 10 parts of compound A-4, lithium hexafluoroarsenate, ethylene carbonate and 2-methyltetrahydrofuran : 1: 1
0:30 (weight ratio) mixture Y was prepared, and these mixtures were mixed in a dry inert gas atmosphere at a weight ratio of 10: 3. Next, the obtained mixture is cast-coated on a current collector having a conductive carbon film formed on the surface of a positive electrode current collector made of stainless steel, and left at 100 ° C. for 1 hour in a dry inert gas atmosphere. And cured. The thickness of the composite positive electrode film formed on the positive electrode current collector plate is 6
It was 0 μm. b) Lithium metal was used as a negative electrode active material of the battery, and was pressed on a negative electrode current collector plate made of stainless steel. Next, a 30: 6: 30: 60 (weight ratio) mixture of compound A-4, lithium hexafluoroarsenate, ethylene carbonate and 2-methyltetrahydrofuran is cast-coated on the lithium metal, and dried and inert. The composition was cured by leaving it at 100 ° C. for 1 hour in a gas atmosphere.
The thickness of the solid electrolyte layer thus obtained was 20 μm. c) the solid electrolyte / lithium / negative electrode current collector obtained in b);
By contacting the positive electrode current collector / composite positive electrode obtained in a), a sheet-shaped battery similar to that in Example 10 was obtained.

Comparative Example 7 A sheet-like battery was produced in the same manner as in Example 11, except that polyethylene glycol triacrylate was used instead of Compound A-2. The electrode area of the sheet batteries of Example 11 and Comparative Example 7 can be variously changed depending on the manufacturing process.
One having a size of 00 cm ² was produced. Using this sheet-shaped battery, a charge / discharge cycle test was performed at 25 ° C. and a constant current of 50 μA / cm ² . The charge end voltage is 3.2V, the discharge end voltage is
A charge / discharge cycle test was performed at 2.0 V. FIG. 5 shows the relationship between the number of charge / discharge cycles and the battery capacity. As is clear from the results of FIG. 5, the sheet-shaped battery of Example 11 of the present invention shows superior charge-discharge cycle characteristics as compared with the sheet-shaped battery of Comparative Example 7.

[0057]

The battery of the present invention has no liquid leakage, which is a concern when a liquid electrolyte is used, and has a large electric capacity and excellent mechanical strength. It can be used reliably as a power supply, camera power supply, pacemaker power supply, etc. In the present invention, the specific surface area of the active material in contact with the electrolyte layer (separator) and the current collector is obtained by integrating the special solid electrolyte composition with the positive electrode active material to form a composite positive electrode as described above. Is increased, and an extremely high-performance electrode can be obtained. Also, as the electrolyte layer (separator), the use of the above-mentioned solid electrolyte makes it possible to suppress the generation of lithium dendrite, and has excellent mechanical strength and is thermally and electrochemically stable. ) Can be obtained. Therefore, it is possible to manufacture an electrochemically optimal composite electrode and electrolyte, and not only to improve the workability of the battery manufacturing process,
The performance of the battery can be improved.

[Brief description of the drawings]

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

FIG. 2 is a schematic view of a test cell for evaluating characteristics of the battery of the present invention.

FIG. 3 is a graph showing initial discharge characteristics of the sheet batteries obtained in Example 10 and Comparative Example 6 when discharged at 25 ° C. and 0.1 mA / cm ² .

FIG. 4 is a graph showing the discharge characteristics of the sheet batteries obtained in Example 10 and Comparative Example 6 after storage at 60 ° C. for 100 days when discharged at 25 ° C. and 0.1 mA / cm ² .

FIG. 5 is a graph showing the relationship between the number of charge / discharge cycles at 25 ° C. and the battery capacity of the sheet batteries obtained in Example 11 and Comparative Example 7.

[Description of Signs] 1 Positive electrode current collector 2 Composite positive electrode 3 Solid electrolyte 4 Negative electrode 5 Negative electrode current collector 6 Sealing material 11 Current collector 12 Positive electrode 13 Solid electrolyte 14 Negative electrode 15 Current collector 16 Positive electrode lead wire 17 Negative electrode lead wire

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Ido 2-1-1-18 Kibogaoka, Konan-cho, Koga-gun, Shiga Prefecture (56) References JP-A-3-177409 (JP, A) JP-A-3-238771 (JP , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01M 10/40 H01M 4/02-4/04

Claims (7)

(57) [Claims] 1. A method comprising mixing a trifunctional polymer compound with an electrolyte salt and a solvent, and irradiating and / or heating with actinic radiation.
A trifunctional terminal acryloyl-modified alkylene oxide polymer in which the trifunctional polymer compound contains a polymer chain represented by the following general formula (1) as each functional polymer chain in a solid electrolyte obtained by crosslinking. Wherein the solvent is used in an amount of 220 to 950% by weight based on the polymer. Embedded image (However, R ′ represents an alkyl group having 1 to 6 carbon atoms, R ″ represents hydrogen or a methyl group. M and n each represent 0 or 1 or more, and m + n ≧ 35.) 2. The above trifunctional terminal acryloyl-modified alkylene oxide polymer is mixed with an electrolyte salt, a solvent, and a positive electrode active material, and irradiated with active radiation and / or heated.
A solid electrolyte integrated with the positive electrode active material obtained by crosslinking is used as a composite positive electrode, and a mixture of the above-mentioned trifunctional terminal acryloyl-modified alkylene oxide polymer, an electrolyte salt and a solvent is supplied between the positive electrode and the negative electrode. 2. The battery according to claim 1, wherein a solid electrolyte obtained by crosslinking by irradiation and / or heating is present as a separator. 3. The method according to claim 1, wherein the negative electrode comprises a mixture of the trifunctional terminal acryloyl-modified alkylene oxide polymer, an electrolyte salt and a solvent, which is irradiated with actinic radiation and / or heated.
3. The battery according to claim 2, wherein the battery is a composite anode containing a solid electrolyte obtained by crosslinking. 4. The battery according to claim 2, wherein the composite positive electrode and / or the composite negative electrode contains an electron conductive material. 5. The battery according to claim 1, wherein the solvent is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethoxyethane, dimethyl sulfoxide, dioxolan, sulfolane, and water. 6. The electrolyte salt according to claim 1, wherein the electrolyte salt is lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium nitrate, lithium thiocyanate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium tetrafluorofluoride, bistrifluoro. Lithium methylsulfonylimide,
Lithium tristrifluoromethylsulfonylmethide, sodium thiocyanate, sodium perchlorate, sodium trifluoromethanesulfonate, sodium tetrafluorofluoride, potassium thiocyanate, potassium perchlorate, potassium trifluoromethanesulfonate, potassium tetrafluorofluoride 2. The battery according to claim 1, wherein the battery is at least one selected from the group consisting of magnesium thiocyanate, magnesium perchlorate and magnesium trifluoromethanesulfonate. 7. The method according to claim 1, wherein the electrolyte salt is 1 to 5 with respect to the solvent.
2. The battery according to claim 1, which is used in a proportion of 35% by weight.