JP2002358822A - Polymeric solid electrolyte - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymeric solid electrolyte with excellent ion conductivity and stability against metallic lithium. SOLUTION: The polymeric solid electrolyte contains polyalkyleneimine with HN bonding part to which, alkylene oxide is bonded, and the polyalkyleneimine has a side chain structure. Recommended ratio of primary, secondary, and tertiary amine contained in polyalkyleneimine is 10-60:20-70:5-50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymer solid electrolyte used for batteries, electrochromic devices, capacitors, sensors, and the like, and more particularly, to a polymer solid electrolyte comprising a polyalkyleneimine to which an alkylene oxide has been added. .

[0002]

2. Description of the Related Art With the development of portable electronic devices such as portable telephones, notebook computers and camcorders in recent years, various batteries such as nickel hydrogen batteries and lithium ion secondary batteries have been developed. However, since all of these batteries use a liquid electrolyte, electrolyte dissipation (liquid leakage),
There are problems in terms of safety, design freedom, and the like. Therefore,
As a solution to these problems, a battery using a polymer compound as an electrolyte material, that is, a battery provided with a polymer solid electrolyte (hereinafter, referred to as a “polymer electrolyte battery”) has attracted attention.

[0003] Polymer electrolyte batteries are excellent in solving the above-mentioned problems in conventional batteries such as lithium ion secondary batteries, but often have insufficient characteristics when incorporated into batteries. In particular, improvements in ionic conductivity are strongly desired. That is, since the solid polymer electrolyte has relatively low ionic conductivity, loss of electric energy when incorporated into a target system is large. In addition, unlike a conventional lithium ion secondary battery, a polymer solid electrolyte is characterized by the possibility that metallic lithium can be used for the negative electrode. Gender is an important factor. Therefore, improvement in stability against metallic lithium is also strongly desired. In other words, poor stability against metallic lithium means that the battery constituted using the solid polymer electrolyte has a short durability period.

As a technique developed with a primary focus on solving these problems, there has been proposed a polymer structure characterized by comprising a main chain composed of linear polyethyleneimine and a side chain containing polyethylene oxide. (Japanese Unexamined Patent Publication
JP-A-329793, JP-A-8-69817). Specifically, JP-A-6-329793 discloses the following formula (1):

[0005]

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Wherein X is O = C = NR ² -NH-C
O- (R ² is an arylene chain or an alkylene chain)
In a diisocyanate piece terminated compounds represented, R ¹
Is a lower alkyl group, and m is an integer of 3 to 100). A polymer compound in which a compound represented by the following formula is bonded to an NH group of polyethyleneimine (hereinafter also referred to as “PEI”) whose main chain is disclosed: I have. Also, JP-A-8-69817
In the publication, a side chain composed of a linear or branched polymer having ethylene oxide as a repeating unit is added to the main chain PEI, the following formula (2):

[0007]

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[0008] A dendrimer type polymer compound represented by the following formula is disclosed. However, the characteristics of the conventional polymer compound cannot be said to be sufficient, and further development of a polymer solid electrolyte has been desired.

[0009]

SUMMARY OF THE INVENTION The present invention has been completed in view of the above problems, and has as its object to provide a solid polymer electrolyte having excellent ionic conductivity and stability against metallic lithium. .

[0010]

All of the polymer compounds described in the above documents have a structure in which a side chain containing polyethylene oxide is bonded to PEI. The structure of PEI is described in JP-A-6-329793. It is specified that the structure of the publication is linear. Also, JP-A-8-69
No. 817 does not specifically state that the polymer is linear, but the structure of the core portion (PEI portion) is disclosed only for the linear structure, and PEI itself has a dendrimer shape. Is not disclosed at all.

The inventors of the present invention have conducted intensive studies on the ionic conductivity and stability of metallic lithium of a solid polymer electrolyte. As a result, PEI having a dendrimer shape was used, and a predetermined amount of ethylene oxide was grafted onto the NH bond of the PEI. It has been found that by using a polymerized polymer compound, excellent ion conductivity and stability against metallic lithium can be obtained, and the present invention has been completed.

That is, the present invention relates to a method for producing a polyalkyleneimine having an N
A polymer solid electrolyte comprising a polyamine polyether polyol in which an alkylene oxide is added to an H bonding site, wherein the polyalkyleneimine has a branched structure. At this time, the ratio of the primary amine, the secondary amine and the tertiary amine contained in the polyalkylenimine is primary amine: secondary amine: tertiary amine = 10-60: 20-
70: 5 to 50 is preferred.

[0013]

DETAILED DESCRIPTION OF THE INVENTION First, the NH bonding site (R-NH-R or RN) of the polyalkylenimine constituting the present invention is described.
Present as H _2: wherein, R is described the structure of the polyamines polyether polyol formed by adding alkylene oxide to hydrogen are not atoms).

The polyalkyleneimine is not particularly limited, but preferably has 2 to 4 carbon atoms contained in the alkylene unit constituting the polyalkyleneimine. Examples of such polyalkylene imines include:
Polyethylene imine, polypropylene imine, polybutylene imine, polyisopropylene imine or a copolymer of these monomers (ethylene imine-propylene imine copolymer, ethylene imine-butylene imine copolymer, etc.). Imines are preferred. When the structure of a specific polyalkyleneimine is exemplified, the following formula (3):

[0015]

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(Wherein R^ThreeAre the same or different
Len group (-CH_TwoCH_Two-, -CH_TwoCH _TwoCH_Two-, -C
H_TwoCH_TwoCH_TwoCH_Two-, -CH_TwoCH (CH_Three)-Etc.)
X and y are integers of 1 or more)
It has a structure. Has such a branched structure
When polyethyleneimine is used, the added polyethylene
Because the lenoxide chains spread more randomly,
Structure in which crystallization is unlikely to occur even if the Tylene oxide chain is long
Has taken. Therefore, compared to conventional compounds,
High conductivity and stability against lithium metal
It is thought to be better.

The battery using the solid polymer electrolyte according to the present invention has excellent stability against metallic lithium, and in some cases, in a stability test, the battery has a resistance to 100% with respect to the first potential.
The potential after the repetition may be 1.2 times or less. The stability test can be evaluated by the following method. First, a symmetric cell using metal lithium as an electrode (Li / polymer solid electrolyte / L
Prepare i). A current having a constant current density is caused to flow through the symmetric cell for a fixed time, and then a current having the same constant current density is caused to flow from a reverse direction for a fixed time. The potential between the electrodes at this time is measured. With this as one cycle, the same test is repeated up to 100 cycles. The stability of the polymer solid electrolyte to Li is evaluated based on the change in potential during this time. In particular,
The initial potential is 1 V when measured at a current density of 0.1 mA / hcm ² , and the potential after 1.1 cycles is 1.1 V
, The potential after 100 cycles is evaluated as 1.1 times.

The PEI according to the present invention has a branched structure as shown in the above formula (3), and includes a primary amine, a secondary amine and a tertiary amine in the structure. The ratio of each amine number to the total number of primary amines (NH ₂ ), secondary amines (NH) and tertiary amines (N) should be in the following range in consideration of the ionic conductivity of the solid polymer electrolyte. Is preferred. That is, the primary amine is 10 to 60
%, More preferably 20 to 50%. The amount of the secondary amine is preferably 20 to 70%, more preferably 30 to 60%. The tertiary amine is preferably 5 to 50%, and 10 to 40%.
% Is more preferable. The ratio of primary amine, secondary amine and tertiary amine is ¹³ CN of polyethyleneimine.
It can be determined by utilizing the fact that each carbon adjacent to the primary amine, secondary amine, and tertiary amine shows a different chemical shift when the MR is measured.

The weight average molecular weight of the polyalkylenimine is not particularly limited, but if the molecular weight is too low, the inherent properties (dispersion, stability, water resistance, etc.) of the polymer may not be obtained, and the molecular weight is too high. The viscosity may increase and handling may be inconvenient. In this respect, the weight average molecular weight is preferably 150 or more, more preferably 300 or more, and particularly preferably 600 or more. The upper limit is preferably 2,000,000 or less, more preferably 500,000 or less, even more preferably 10,000 or less,
It is particularly preferred that it is 5000 or less. These polyalkylenimines can be synthesized using the method described below. A commercially available compound such as Epomin (registered trademark) SP-018, SP-006, SP-003 manufactured by Nippon Shokubai Co., Ltd. may be used.

The polyamine polyether polyol according to the present invention is characterized in that the amino group contained in the polyalkyleneimine structure is added to the amino group in an amount of 0.5 to 2 with respect to 1 mol of NH bond.
About 00 moles of alkylene oxide is added. In consideration of the easiness of the production process and the easiness of the operation, it is preferable that 5 to 500 mol of alkylene oxide is added to 1 mol of NH bond. As a specific example, ten -NH-, the polyalkyleneimine containing six -NH _2, includes 22 pieces of NH bond.
Therefore, when 1 mol of the polyalkyleneimine is used, the case where 220 mol of the alkylene oxide is added corresponds to the case where 10 mol of the alkylene oxide is added to 1 mol of the NH bond. The alkylene oxide addition method is not particularly limited, but is preferably 0.5 to 1.5 mol, more preferably 0.7 to 1.2 mol, and still more preferably 0.85 mol per mol of NH bond.
It is preferable to add up to 1.05 mol without a catalyst. Thereafter, when further adding an alkylene oxide, it is preferable to add a catalyst. There are no particular restrictions on the catalyst used at this time, but NaOH, KOH, Na
Alkaline catalysts such as OCH ₃ are preferred. The structure when an alkylene oxide is added, for example, when ethylene oxide is added, NH is represented by the general formula N- (C
H ₂ CH ₂ O) _n -H. There is no particular limitation on the distribution of the length of the alkylene oxide-added portion present as the polyalkylene oxide, but it is generally preferable that the length distribution is irregular in order to obtain more excellent ion conductivity.

The alkylene oxide is not particularly limited, but preferably has 2 to 4 carbon atoms contained in the alkylene unit constituting the polyalkylene oxide. Examples of such polyalkylene oxides include ethylene oxide, propylene oxide, isopropylene oxide, butylene oxide, isobutylene oxide, etc., and among these, ethylene oxide or propylene oxide is preferred from the viewpoint of reactivity and production cost. Preferably, ethylene oxide is more preferable. The alkylene oxide may be used alone or in combination with a plurality of alkylene oxides. When used in combination, a product in which the alkylene oxide is added blockwise, randomly or alternately can be obtained.

Next, an embodiment of the method for producing a polyamine polyether polyol according to the present invention will be described with reference to an example in which ethylene oxide is added to polyethyleneimine. However, it does not exclude the use other than polyethyleneimine and ethylene oxide,
When other starting compounds are used, they can be produced according to the following method. In such a case, the conditions may be appropriately optimized according to the compound used.

Ethyleneimine which is a raw material of PEI having a branched structure is generally represented by the following formula (4):

[0024]

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It is prepared by an intramolecular condensation reaction of monoethanolamine represented by the formula:

First, monoethanolamine is vaporized, diluted with an inert gas (nitrogen, argon, etc.) as necessary, and introduced into the catalyst layer as a raw material gas. At this time, ammonia, steam, hydrogen, or the like may be added for the purpose of suppressing a side reaction. The reaction pressure is not particularly limited, and may be any of reduced pressure, normal pressure, and increased pressure.
The reaction temperature is generally between 300 and 500C. The space velocity of the raw material gas needs to be appropriately determined according to the concentration of monoethanolamine, the type of catalyst used, and the like, and cannot be uniquely defined, but is usually about 50 to 5000 h ^-1 . Examples of the catalyst include niobium and tantalum catalysts; silicon-alkali metal and / or alkaline earth metal catalysts; phosphorus-alkali metal and / or alkaline earth metal catalysts; silicon / phosphorus-alkali metal / alkaline earth metal catalysts. Examples of the catalyst include a catalyst in which the catalyst composition is supported on ceramics or the like. As a result, monoethanolamine causes an intramolecular dehydration reaction to produce ethyleneimine.

The reaction mixture containing ethylene imine formed by the intramolecular dehydration reaction can be collected using a collecting agent. As the collecting agent, an amine compound is preferable, and monoethanolamine used as a raw material is particularly preferable. In the reaction mixture, ammonia as an impurity,
Light amines such as methylamine and ethylamine,
Acetonitrile, ketones such as acetaldehyde, Schiff bases formed by reaction of acetaldehyde with monoethanolamine, and the like may be included. These impurities can be removed by a known technique such as distillation or extraction with an organic solvent. Thus, ethyleneimine having a reduced impurity concentration can be obtained.

By performing a polymerization reaction using such ethyleneimine as a monomer, PEI having a complicated branched structure represented by the above formula (3) can be obtained. The polymerization is carried out by reacting ethyleneimine at 0 to 200 ° C. in the presence of an effective amount of an acid catalyst (such as HCl). Furthermore, ethyleneimine may be subjected to addition polymerization based on the synthesized PEI. The polymerization method of ethyleneimine is not limited to the above-mentioned method, and is disclosed in JP-B-43-8828 and JP-B-49-3.
Known techniques such as the method described in JP-A-3120 and JP-T-2000-501775 may be considered.

As a reaction system, a batch system, a semi-batch system, a continuous flow system and the like can be used. In the case of the batch type, since the viscosity of the reaction liquid increases during the production of the polymer, a stirring blade for high viscosity (for example, Max Blend Blade manufactured by Sumitomo Heavy Industries, Ltd.) was provided for heat removal, diffusion, and reaction promotion. It is preferred to use a stirred reactor. Further, in order to increase the efficiency of heat removal, it is preferable to polymerize ethyleneimine under reflux using a vertical tube type cooler. Impurities are removed from the obtained PEI by bubbling treatment or evaporation treatment after adding water.

Subsequently, ethylene oxide is added at the NH bonding site. Hereinafter, one embodiment of the addition of ethylene oxide will be described.

A) Supply of PEI to Stirred Reactor PEI having a branched structure is supplied to a stirred reactor provided with stirring blades. The method of supplying PEI to the stirred reactor is not particularly limited, and any consideration generally required for compounds in general may be used. The supply amount of PEI cannot be unambiguously determined because it is determined by the internal volume of the stirred reactor, the compound used, and the like.
It is appropriate to supply about 50% by volume. PEI may be supplied alone or, in some cases, together with a solvent such as water or acetone. However, when added together with the solvent, it is necessary to pay attention to the generation of impurities due to the reaction with active hydrogen in the solvent. In addition, the solution containing PEI preferably has a small difference from the polarity of the supplied ethylene oxide in consideration of the solubility and distribution equilibrium of ethylene oxide in the gas phase in the liquid phase.

The shape of the stirred reactor is not limited.
No. There are no particular restrictions on the scale of the stirred reactor,
In order to obtain the effect of the present invention industrially, the inside of the stirred reactor is required.
1m in volume^ThreePreferably 5 m^ThreeIs over
More preferably 10 m ^ThreeAbove all
preferable. The reaction solution is stirred inside the stirring reactor.
Is preferably provided. Commercially available stirrer
Specific examples of the reactor include Supermix HR-10
0, HR-320, HR-500i (all
Machinery Co., Ltd.), Sun Meller (Mitsubishi Heavy Industries, Ltd.)
Manufactured), VCR (manufactured by Mitsubishi Heavy Industries, Ltd.), bend leaf
(Manufactured by Yakko Sangyo Co., Ltd.), Max Blend, Tornay
De, super blend (manufactured by Sumitomo Heavy Industries, Ltd.),
Full Zone, Log Bone (Shinko Pantech Co., Ltd.)
Products), twisted lattice wings (manufactured by Hitachi, Ltd.)
I can do it.

B) Supply of ethylene oxide 0.85 to 1 mol per mol of NH group contained in PEI.
The reaction is carried out by directly mixing 05 mole equivalents of ethylene oxide or, if necessary, diluting with a solvent (such as water or acetone). However, when added together with the solvent, it is necessary to pay attention to the generation of impurities due to the reaction with active hydrogen in the solvent. At this time, if the reaction temperature is too low, the reaction rate becomes slow, and if it is too high, the amount of impurities generated may increase. In this respect, the reaction temperature is preferably 100 to 180 ° C, and more preferably 120 to 170 ° C. Ethylene oxide addition can be performed in the presence of a solvent,
It may be added without solvent. It is difficult to define the preferred ethylene oxide supply rate because it varies depending on the reaction system and the stirred reactor, but it is preferable to supply the ethylene oxide so that the gas phase pressure does not exceed a certain value. Specifically, it is appropriate to supply the pressure so as to be about 0.5 to 10 kg / cm ² . Examples of the method of supplying ethylene oxide include a method of showering and a method of providing an injection port on a lid or an upper portion of an inner wall.

During the ethylene oxide addition reaction, the reaction solution is stirred by a blade provided inside the stirring reactor. The atmosphere in the stirred reactor during the reaction may be supplied under reduced pressure to supply alkylene oxide, and most of the atmospheric gas may be alkylene oxide gas. To reduce the explosiveness of the alkylene oxide, an atmosphere such as nitrogen or argon may be used. After the substitution with the active gas, the supply of the alkylene oxide may be started.

The stirring power cannot be uniquely defined because it is a numerical value to be appropriately selected depending on the type of the blade, the type of ethylene oxide to be added, and the type of PEI. From the viewpoint of suppressing a decrease in speed, the stirring power is suitably 0.2 to ³ kW / m ³ , and more preferably 0.5 to 2.5 kW / m ³ .
It is not necessary to keep the stirring power constant, and the stirring power may be changed according to the reaction conditions.

C) Addition of catalyst A catalyst such as NaOH, KOH and NaOCH ₃ is added to the system. The catalyst may be added as it is, or may be added after being dissolved in water or methanol. At this time, if the added amount of the catalyst is too small, the reaction rate becomes slow, and if it is too large, the amount of generated impurities may increase. From this viewpoint, the amount of the catalyst added is 0.1 to 1 mol of the NH group contained in the PEI of the charged raw material.
It is preferred to add from 02 to 0.40 molar equivalents,
More preferably, 0.1 to 0.25 molar equivalents are added. From the viewpoint of suppressing generation of impurities, it is most preferable to use KOH as a catalyst. When a catalyst is added using a solvent, it is preferable to volatilize the catalyst by degassing and / or heating. The catalyst may be added from the initial ethylene oxide addition stage. By adding the catalyst from the initial stage of ethylene oxide addition, the distribution of the added EO chain can be sparse.

D) Supply of Ethylene Oxide Ethylene oxide and / or propylene oxide in an amount of 2 to 500 mole equivalents per mole of NH group contained in PEI, as it is, or diluted with a solvent if necessary At a temperature of 200 ° C., preferably 15
The reaction is carried out at a temperature of 0 to 175 ° C. The pressure during the reaction is preferably about 2.5 to 8 kg / cm ² . The supply of ethylene oxide can be divided into two or more parts,
When adding 0 mol or more of ethylene oxide, it is preferable to divide it twice or more.

E) Neutralization of catalyst Aging is performed at a temperature of about 100 to 170 ° C. for about 0.5 to 3 hours, and a carboxylic acid having 2 to 6 carbon atoms (CH ₃ COOH, CH ₃ CH ₂ COOH, (CH ₃ ) ₂
CHCOOH, CH ₃ CH (OH) COH, etc.), phosphoric acid, hydrochloric acid, sulfuric acid, etc., at about 40 to 60 ° C.

F) Purification of Product The impurities contained in the resulting product are removed by bubbling an inert gas such as nitrogen or argon. The removal of impurities may be performed by adding a volatile solvent such as water or ethanol to the polyamine polyether polyol in an amount of 1 to 10% by mass, and reducing the pressure to 0 to 0.01 MPa at 100 to 170 ° C. These may be used in combination, for example, by using water while passing nitrogen through 0 to 0.
The pressure is reduced to 01 MPa to deodorize. The deodorization time is preferably from 1 to 8 hours, more preferably from 3 to 5 hours. Instead of or in combination with bubbling, impurities in the reaction solution may be removed by simple distillation, thin film distillation or spray drier treatment. In addition, simple distillation means batch distillation without a rectification part, and can be implemented by a general apparatus. The thin film distillation can be performed using a Hickman type distillation machine, a falling film type distillation machine, a rotor tray type distillation machine, a brush type molecular still, and the like, and is performed under the conditions of a pressure of 0.1 mmHg or less and a temperature of 100 to 200 ° C. That is appropriate. The spray drier treatment can be performed by spraying the target substance from the upper part and blowing hot air inert gas at 100 to 200 ° C from the lower part. In this case, since the target is granulated and dried, the evaporation surface area is large, the contact time between the droplets and the hot air can be shortened, and the deterioration of the target due to the heat load can be reduced. Other deodorizing methods include activated carbon, molecular sieves, porous polymers, zeolites and the like. However, it is necessary to keep in mind that post-treatment after use is required when deodorizing using these.

The resulting polyamine polyether polyol can be further modified or crosslinked with a monomer or polymer having a reactive substituent by utilizing a primary or secondary amino group or a hydroxyl group. Examples include quaternization with an epoxy group, isocyanate group, carboxylic anhydride, aziridine group, epichlorohydrin, alkyl chloride, etc., esterification or amidation with a carboxylic acid, Michael addition with an unsaturated monomer, and the like. Can be Examples of the compounds that can be used include carboxylic acid group-containing monomers such as (meth) acrylic acid and maleic acid, (meth) acrylic acid esters having 1 to 20 carbon atoms, and alkyl allyl ethers having 1 to 20 carbon atoms. And isocyanates such as (meth) acrylic acid chloride, glycidyl (meth) acrylate, methylene chloride, dimethyl sulfate, diethyl sulfate, and toluylene diisocyanate.

The most preferable combination when producing the polyamine polyether polyol by the above operations a) to f) is as follows: the catalyst is KOH, and the catalyst amount is N in PEI.
The addition temperature of ethylene oxide is from 0.1 to 0.25 mole equivalent per mole of H group, and the addition temperature of ethylene oxide is from 150 to 175 ° C. a)
When the processes (1) to (4) are performed, a polyamine polyether polyol having a relatively uniform length of polyethylene oxide portion can be obtained.

When the polyamine polyether polyol according to the present invention is used as a solid polymer electrolyte, the polyamine polyether polyol contains an electrolyte salt.

In the present invention, the electrolyte salt refers to a compound having electrical conductivity in a solid polymer electrolyte. Specific examples of the electrolyte salt include LiBF ₄ , LiPF ₄ , and LiPF ₄ .
N (CF ₃ SO ₂ ) ₂ , LiN (CF ₂ CF ₂ SO ₂ ), Li
NH ₂ , LiF, LiCl, LiBr, LiI, LiC
N, LiClO ₄ , LiNO ₃ , C ₆ H ₅ COOLi, Na
Cl, NaBr, NaF, NaI, NaClO ₄ , Na
CN, H _{2 and the} like. The electrolyte salt is preferably uniformly dispersed in the solid polymer electrolyte, and the method for dispersing the salt may be either directly mixed with the polyamine polyether polyol in a solid state or mixed after being dissolved in a solvent. . Further, the mixing concentration of the electrolyte salt is preferably from 0.01 to 50% by mass, more preferably from 0.1 to 20% by mass, based on the mass of the polyamine polyether polyol. A plasticizer is added to the inside of the solid polymer electrolyte as needed. Thereby, the ionic conductivity of the electrolyte can be increased, and particularly, the ionic conductivity at a low temperature can be increased. As the plasticizer, propylene carbonate, ethylene carbonate, n-methylpyrrolidone,
Methyl formate, γ-butyl lactone, tetrahydrofuran, glyme (dimethoxyethane), diglyme,
Examples thereof include tetraglyme, polyethylene glycol, dimethyl sulfoxide, dioxane, dimethyl carbonate, and diethyl carbonate.

Next, the action of the solid polymer electrolyte according to the present invention will be described by taking lithium ions as an example. An atom having an unshared electron pair such as an oxygen atom included in the polyamine polyether polyol structure has a weak negative charge. Lithium ions are trapped and stabilized by the interaction (chelating effect) of the negatively charged oxygen atoms. At this time, since the interaction between the lithium ion and the oxygen atom is not strong enough that the lithium ion does not move stably near the oxygen atom,
Lithium ions are easily transferred to adjacent oxygen atoms. By repeating this behavior continuously, lithium ions can move inside the electrolyte, and as a result, a current flows inside the solid polymer electrolyte.

When a positive electrode material and a negative electrode material are joined to the polymer solid electrolyte according to the present invention to prepare a polymer electrolyte battery, the positive electrode material is LiMn ₂ O ₄ , L
iCoO ₂ , LiFe ₂ O ₄ , Li ₂ Cr ₂ O ₇ , Li ₂ Cr
O _{4 and the} like. The negative electrode material of the polymer electrolyte battery includes, but is not limited to, carbon, lithium metal, and the like. The shape of the negative electrode material may be a flat plate, a corrugated plate, a rod, a powder, or the like. The microstructure of the negative electrode material may be a laminate, a sphere, a fiber, a spiral, a fibril, or the like. As the exterior material, an aluminum foil, an aluminum evaporated organic film, or the like can be used. Examples of the material of the organic film include polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon, and polyethylene tetrafluorate. As the current collector, various known materials such as copper and aluminum can be used.

The polymer electrolyte battery according to the present invention can be used as a single cell composed of a positive electrode, a negative electrode and a polymer solid electrolyte, or can be used as a stack cell or a battery pack in which cells are stacked. At this time, a resin film or a metal foil is sandwiched between the single cells. As the material of the resin film, high-density polyethylene, low-density polyethylene, polypropylene, polyethylene tetrafluorate, polybutylene tetrafluorate, polyvinylidene chloride, polyvinyl chloride, 6,6-nylon, 6,
Examples thereof include 12-nylon, polytetrafluoroethylene, perfluoroalkylsulfonic acid, polypyrrole, polystyrene, and polystyrene-butadiene copolymer. Examples of the metal foil include copper, aluminum, iron, nickel, magnesium, zinc, silicon, iron oxide, and copper oxide.
Of these, a single material may be used, and composite formation by vapor deposition or lamination may be performed. Note that the present invention is not limited to these materials. In the above description, the lithium polymer battery has been described, but the polymer solid electrolyte according to the present invention does not limit the application to the lithium polymer battery.

The film formation of the polymer solid electrolyte is not limited, but can be performed, for example, by the following method. First, the obtained polymer was dissolved in N, N-dimethylformamide, and an electrolyte salt was added to the polymerization solution in an amount of 1% based on the weight of the polymer.
About 10 to 10% by mass is added to obtain an ion conductor solution. After casting this on a glass plate, it is heated on a hot plate and dried using a vacuum dryer. Thereby, a solid polymer electrolyte is obtained.

[0048]

EXAMPLES Examples and comparative examples according to the present invention will be described below.

<Synthesis Example 1: Compound (I)> Polyethyleneimine (Epomin SP-003 manufactured by Nippon Shokubai Co., Ltd.) 3
0.0 g (0.1 mol) was charged into a 3 L autoclave and heated to 150 ° C. Thereafter, ethylene oxide was added by feeding 25.9 g (0.59 mol) of ethylene oxide. Next, the temperature is lowered to 80 ° C. to 49% K
After charging 2.5 g (0.05 mol) of OH, the temperature was raised to 165 ° C., the pressure was reduced to 0.05 MPa while nitrogen bubbling was performed at a flow rate of 20 ml / min, dehydration was performed, and 1657.7 g (37. 7 mol) to feed ethylene oxide.

After cooling to 80 ° C. and adjusting the pH to 7 by adding acetic acid, pure water was added at 10% to the total amount of polyethyleneimine polyethoxylate, and 20 ml / m 2 was added.
0.005MPa while bubbling nitrogen with flow rate of in
, And degassed for 5 hours to remove light impurities to obtain the desired compound (I). The compound (I)
The content of the polyethoxylate group therein was 98.5% by mass.

<Synthesis Example 2: Compound (II)> Polyethyleneimine (Epomin SP-003 manufactured by Nippon Shokubai Co., Ltd.) 3
0.0 g (0.1 mol) was charged into a 10 L autoclave and heated to 150 ° C. Thereafter, ethylene oxide was added by feeding 25.9 g (0.59 mol) of ethylene oxide. Next, the temperature is lowered to 80 ° C. to 49% K
After charging 2.5 g (0.05 mol) of OH, the temperature was raised to 165 ° C., the pressure was reduced to 0.05 MPa while bubbling with nitrogen at a flow rate of 20 ml / min, and after dehydration, 5024.9 g of ethylene oxide (114. 2 mol) to feed ethylene oxide.

After cooling to 80 ° C. and adjusting the pH to 7 by adding acetic acid, pure water was added at 10% with respect to the total amount of polyethyleneimine polyethoxylate, and 20 ml / m 2.
0.005MPa while bubbling nitrogen with flow rate of in
And degassed for 5 hours to remove light impurities to obtain the desired compound (II). The compound (II)
The content of the polyethoxylate group therein was 99.5% by mass.

<Synthesis Example 3: Compound (III)> Polyethyleneimine (Epomin SP-006 manufactured by Nippon Shokubai Co., Ltd.)
60.0 g (0.1 mol) was charged into a 5 L autoclave and heated to 150 ° C. Thereafter, 48.1 g (1.1 mol) of ethylene oxide was fed to add ethylene oxide. Next, the temperature was lowered to 80 ° C.
After charging 2.5 g (0.05 mol) of H, the temperature was raised to 165 ° C., the pressure was reduced to 0.05 MPa while bubbling with nitrogen at a flow rate of 20 ml / min, and after dehydration, 3078.6 g (70. 0 mol) to feed ethylene oxide.

After cooling to 80 ° C. and adjusting the pH to 7 by adding acetic acid, pure water was added at 10% to the total amount of polyethyleneimine polyethoxylate, and 20 ml / m 2 was added.
0.005MPa while bubbling nitrogen with flow rate of in
And degassed for 5 hours to remove light impurities to obtain the desired compound (III). The compound (II
Polyethoxylate group content in I) is 98.5% by mass.
It is.

<Synthesis Example 4: Compound (IV)> Polyethyleneimine (Epomin SP-006 manufactured by Nippon Shokubai Co., Ltd.) 6
0.0 g (0.1 mol) was charged into a 10 L autoclave and heated to 150 ° C. Thereafter, 48.1 g (1.1 mol) of ethylene oxide was fed to add ethylene oxide. Next, the temperature was lowered to 80 ° C.
After adding 2.5 g (0.05 mol) of H, the temperature was raised to 165 ° C., the pressure was reduced to 0.05 MPa while nitrogen bubbling was performed at a flow rate of 20 ml / min, and after dehydration, 4521.6 g of ethylene oxide (102. 8 mol) to feed ethylene oxide.

After cooling to 80 ° C. and adjusting the pH to 7 by adding acetic acid, pure water was added at 10% with respect to the total amount of polyethyleneimine polyethoxylate, and 20 ml / m 2
0.005MPa while bubbling nitrogen with flow rate of in
, And degassed for 5 hours to remove light impurities to obtain the desired compound (IV). The compound (IV)
The weight% of the polyethoxylate groups in the composition is 99.0%.

<Examples 1-4> At the compounding ratios shown in Table 1,
Compounds (I) to (IV) and a LiTFSI salt (lithium bistrifluoromethylsulfonylimide) are stirred and mixed in 20 g of dehydrated acetonitrile to obtain a uniform solution, and then the solid polymer electrolyte is removed by removing acetonitrile under reduced pressure. I got

[0058]

[Table 1]

The ion conductivity of each polymer solid electrolyte and the stability to metallic lithium were evaluated. Table 2 shows the results.

[0060]

[Table 2]

The evaluation of ion conductivity was performed by a complex impedance method using an SUS electrode and an impedance analyzer HP4294A. The evaluation of the stability test for lithium metal was performed by preparing a cell in which a polymer electrolyte was sandwiched between two pieces of lithium metal and using a charge / discharge tester BS25.
It was performed by passing a constant current density of 0.1 mA / hcm ² in 00-05R1.

As shown in Table 2, it was shown that the solid polymer electrolyte according to the present invention was excellent in ionic conductivity and stability against metallic lithium.

[0063]

According to the present invention, a polymer compound in which an alkylene oxide is added to a polyalkyleneimine having a branched structure is used as the polymer compound constituting the polymer solid electrolyte, so that the ion conductivity of the polymer solid electrolyte and the metal lithium are improved. Stability can be improved. Therefore, a battery, an electrochromic device, a capacitor, and a sensor to which the polymer solid electrolyte according to the present invention is applied have low power consumption and excellent durability.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor, Satoshi Inaoka 14-1, Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term (reference) 4J043 QA03 RA08 SA32 SA33 SB01 UA331 XB13 YB08 YB21 ZA44 ZB49 5G301 CA30 CD01 5H029 AJ02 AJ07 AK03 AL06 AL12 AM16 DJ09 EJ12 HJ01

Claims (2)

[Claims] 1. A polymer solid electrolyte comprising a polyamine polyether polyol in which an alkylene oxide is added to an NH bonding site of a polyalkylenimine, wherein the polyalkylenimine has a branched structure. Polymer solid electrolyte. 2. The ratio of a primary amine, a secondary amine and a tertiary amine contained in the polyalkyleneimine is as follows: primary amine: secondary amine: tertiary amine = 10-60: 20-
The polymer solid electrolyte according to claim 1, wherein the ratio is 70: 5 to 50.