JP2019091577A - Carbonic acid gas generating agent and nonaqueous electrolyte storage battery using the same - Google Patents

Abstract

To provide a carbonic acid gas generating agent which enables a large amount of generation of carbonic acid gas and enables enhanced safety of a battery, and which can suppress a thermal runaway by rapidly generating a high capacity of carbonic acid gas in the event of overcharge in the case of being used for a nonaqueous electrolyte storage battery.SOLUTION: A carbonic acid gas generating agent comprises a reaction product of a mixture including an amine-based polymer having an amino group in its repeating unit and an alcohol compound, and carbon dioxide.SELECTED DRAWING: None

Description

  The present invention relates to a non-aqueous electrolyte storage battery comprising a carbon dioxide gas generating agent and the carbon dioxide gas generating agent.

  Nonaqueous electrolyte storage batteries such as lithium ion secondary batteries have a high energy density, and are widely used in portable devices, notebook computers, and the like. Further, in recent years, with the increase of carbon dioxide, the interest in electric vehicles is increasing from the viewpoint of global warming prevention, and the use of nonaqueous electrolyte storage batteries is also promoted as a power source.

  With the progress of applications in this way, improvement in the safety of non-aqueous electrolyte batteries is still required, and in particular, safety during overheat and overcharge has become an issue. For example, if the lithium ion secondary battery is overcharged, the thermal stability of the electrode material may be reduced, which may lead to a decrease in battery safety. Therefore, conventionally, in non-aqueous electrolyte storage batteries, measures against overheat and overcharge by cooling measures have been taken.

  As a safety measure at the time of overcharge, for example, in Patent Document 1, an aromatic compound having a specific structure is added to the non-aqueous electrolyte solution, and the pressure relief valve inside the battery is operated by hydrogen gas generated at the time of overcharge. Technology is disclosed. Further, Patent Document 2 discloses a technique of mixing lithium carbonate in a positive electrode to improve the stability during overcharge. Specifically, in this technology, the internal pressure of the battery is raised by carbon dioxide gas generated by decomposition of lithium carbonate during overcharge, and overcharge is avoided by operating the current shutoff valve.

JP 2004-349131 A JP 2008-277106 A

  However, when an aromatic compound as disclosed in Patent Document 1 is added to the electrolytic solution, it is necessary to add a large amount of the aromatic compound in order to maintain the stability of the overcharge sufficiently. There is a problem that the concentration is significantly reduced and the battery performance itself is reduced. Also, the reaction potential of lithium carbonate is 4.8 V to 5.0 V vs. It was high as Li / Li +, the reaction started at the end of overcharging, and there was a risk that the battery could run away due to heat generation before lithium carbonate was decomposed. For this reason, in order to improve safety against overcharge and thermal runaway, there is a need for a technology that can simultaneously achieve quick operation of the current shutoff valve and battery performance.

  Therefore, the present invention can realize a high generation amount of carbon dioxide gas, and when used for a non-aqueous electrolyte storage battery, suppresses the thermal runaway by generating a high capacity carbon dioxide gas quickly at the time of overcharge, It is an object of the present invention to provide a carbon dioxide gas generating agent capable of improving the safety of

The present inventors arrived at the present invention as a result of earnestly examining in order to solve the above-mentioned subject. That is, the present invention includes the following preferred embodiments.
[1] A carbon dioxide gas generating agent comprising a reaction product of carbon dioxide and a mixture containing an amine polymer having an amino group in a repeating unit and an alcohol compound.
[2] The carbon dioxide gas generator according to the above [1], wherein the carbon dioxide gas emission temperature is 60 ° C. or more and 200 ° C. or less.
[3] The amine polymer is selected from the group consisting of polyethyleneimine, polyallylamine, polyacrylamide, polytetramethyleneimine, polyvinylamine, dicyandiamide-formalin condensate and dicyandiamide-alkylene (polyamine) condensate. ] Or the carbon dioxide gas generating agent as described in [2].
[4] The carbon dioxide gas according to any one of the above [1] to [3], wherein the alcohol compound is selected from the group consisting of monosaccharides, oligosaccharides, polysaccharides, polyvinyl alcohol and derivatives thereof and polyphenols and derivatives thereof Generator.
[5] The carbon dioxide gas generating agent according to any one of the above [1] to [4], which is in the form of a film, a film, a sheet, a fiber or a powder.
[6] A positive electrode capable of storing and releasing electrolyte ions, a negative electrode capable of storing and releasing electrolyte ions, a separator disposed between the positive electrode and the negative electrode, an electrolytic solution, and any one of the above [1] to [5] Nonaqueous electrolyte storage battery provided with the carbon dioxide generating agent as described in-.
[7] The nonaqueous electrolyte storage battery according to the above [6], wherein the carbon dioxide gas generating agent is contained in the positive electrode.

  According to the present invention, a high generation amount of carbon dioxide gas can be realized, and when used for a non-aqueous electrolyte storage battery, a high capacity carbon dioxide gas is promptly generated at the time of overcharge, thereby suppressing thermal runaway. It is possible to provide a carbon dioxide gas generating agent capable of improving the safety of

  Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the present invention.

<CO2 gas generator>
The carbon dioxide gas generating agent of the present invention is an organic carbon dioxide gas generating agent comprising a reaction product of carbon dioxide and a mixture containing an amine polymer having an amino group in a repeating unit and an alcohol compound. The carbon dioxide gas generating agent of the present invention is a reaction product obtained by bringing carbon dioxide into contact with a mixture containing an amine polymer and an alcohol compound, which contains carbon dioxide in the form of a carbonate, Carbon dioxide gas (carbon dioxide) is generated under the carbon dioxide gas discharge temperature of the gas generating agent. Since the carbon dioxide gas generating agent of the present invention is an organic carbon dioxide gas generating agent, it can be easily formed into a film or powder as compared with an inorganic carbon dioxide gas generating agent, and thus has a high degree of morphological freedom. Even when one electrode is touched, there is an advantage such as little damage to the electrode.

  In the present invention, the amine-based polymer contained in the mixture to be reacted with carbon dioxide means at least a nitrogen atom to be a primary amine, a secondary amine or a tertiary amine in the main chain and / or side chain of the polymer. It refers to a polymer that has one or more. In the present invention, the amine-based polymer constituting the mixture to be reacted with carbon dioxide is not particularly limited, and any conventionally known amine-based polymer can be used. When the carbon dioxide gas generating agent of the present invention is used in a non-aqueous electrolyte storage battery, the battery performance of the non-aqueous electrolyte storage battery is unlikely to deteriorate and can be easily installed in the battery. Preferred are those that can form a mixture. By selecting an amine species, it is possible to control the release temperature of the resulting carbon dioxide gas generating agent.

  Such an amine polymer is synthesized using, for example, ethyleneimine, vinylamine, allylamine, amino acid, primary amine such as aniline, pyrrole or melamine, secondary amine, tertiary amine compound as a monomer Besides synthetic polymer compounds, naturally occurring polymer compounds such as secondary products of microorganisms may also be used.

  In the present invention, the amine-based polymer is a polymer having at least one selected from a primary amino group, a secondary amino group and a tertiary amino group in the repeating unit. Such a polymer may be a polymer having at least one selected from a primary amino group, a secondary amino group and a tertiary amino group in one repeating unit, and such one The above repeating unit may be a random, graft or block copolymerized polymer.

  Specific examples of the amine-based polymer that can be used as a carbon dioxide gas generating agent in the present invention include, for example, polyethyleneimine, polypropyleneimine, alkyleneimine polymers such as polytetramethyleneimine, polyallylamine, polyvinylamine, polyacrylamide And amino group-containing polymers such as dicyandiamide-formalin condensate, dicyandiamide-alkylene (polyamine) condensate, polyaniline, polypyrrole, melamine resin, modified melamine resin and the like. Among them, from the viewpoint of the stability of the salt obtained by the reaction with carbon dioxide, polyethyleneimine, polyallylamine, polyacrylamide, polytetramethyleneimine, dicyandiamide-formalin condensate, dicyandiamide-alkylene (polyamine) condensate and polyvinylamine melamine Amine polymers selected from the group consisting of resins are preferred, and amines selected from the group consisting of polyethylenimine, polyallylamine, polyacrylamide, polytetramethyleneimine, dicyandiamide-formalin condensate and dicyandiamide-alkylene (polyamine) condensate Amine-based polymers selected from polyethylenimine and polyallylamine are preferred because they are more preferred, are readily available, and have good carbonate stability. Preferred in La. These may be used alone or in combination of two or more.

  In the present invention, the amine-based polymer preferably contains a primary amino group, and more preferably contains a primary amino group, a secondary amino group and a tertiary amino group. By containing a primary amino group, the amount of carbon dioxide absorption can be increased, and by containing a primary amino group, a secondary amino group and a tertiary amino group, the generation of carbon dioxide gas It becomes easy to adjust (as generation of carbon dioxide gas occurs at a desired temperature). In the case where the amine polymer contains a secondary amino group and / or a tertiary amino group in addition to the primary amino group, the ratio of the primary amino group contained in the amine polymer is the total of the amine polymer The content is preferably 25% or more, more preferably 30% or more, and still more preferably 35% or more based on the amino group. The salt obtained by reaction with a carbon dioxide as the ratio of a primary amino group is more than the said lower limit stabilizes, and it can suppress generation | occurrence | production of rapid carbon dioxide gas. Further, from the viewpoint of suppressing battery thermal runaway at an early stage, the ratio of primary amino groups is preferably 60% or less with respect to all the amino groups of the amine polymer.

  Also, in the present invention, the amine-based polymer may be a polymer mixture, and in this case, a polymer containing a primary amine and a polymer containing a secondary amine and a polymer containing a tertiary amine are mixed. Is preferred. Even when two or more types of polymers are combined, it is preferable that the ratio of the primary amino group to the total amino groups in all the amine polymers is in the same range as above.

  In the present invention, the weight average molecular weight of the amine-based polymer is preferably 2000 or more, more preferably 5000 or more, still more preferably 10000 or more, preferably 100000 or less, more preferably 80000 or less More preferably, it is 70000 or less. When the carbon dioxide gas generating agent is used in the non-aqueous electrolyte storage battery when the weight average molecular weight of the amine polymer is equal to or more than the above lower limit value, it is easy to suppress the elution of the carbon dioxide gas generating agent into the electrolyte. This facilitates the processing to the desired form. The weight average molecular weight of the amine polymer can be determined, for example, using gel permeation chromatography (GPC).

  In the present invention, the alcohol compound is a compound having at least one hydroxyl group. In the present invention, it is preferable to select an alcohol compound which is solid at normal temperature so that a mixture containing an amine polymer and an alcohol compound is solid. Such alcohol compounds include, for example, monosaccharides, oligosaccharides, polysaccharides, polyvinyl alcohol and derivatives thereof, and polyphenols and derivatives thereof. These alcohol compounds may be used alone or in combination of two or more.

  Specific examples of the monosaccharides include glucose, fructose, galactose and the like. Examples of the oligosaccharides include sucrose, sorbitol, xylitol and the like. Moreover, as said polysaccharide, starch and its derivative (s), cellulose, its derivative, etc. are mentioned, for example.

  As said starch and its derivative, for example, corn starch (corn starch); wheat starch; potato starch; tapioca starch; rice starch; dextrin; amylose; amylopectin; pullulan; high amylose corn starch; hydroxyalkyl starch such as hydroxypropyl starch; Examples thereof include dihydroxyalkyl starches such as propyl starch; dihydroxyalkyl pullulan such as dihydroxypropyl pullulan and the like.

  Further, examples of the cellulose and derivatives thereof include regenerated cellulose; powdered cellulose; microcrystalline cellulose; hydroxyalkyl cellulose such as hydroxyethyl cellulose and hydroxypropyl cellulose; and dihydroxyalkyl cellulose such as dihydroxypropyl cellulose.

  In the present invention, when a polysaccharide is used as the alcohol compound, its molecular weight varies depending on the number and type of repeating units of the polysaccharide, and is not limited, but it is 5000 to 1000000 in weight average molecular weight Preferably, it is more preferably 10,000 to 200,000. The weight average molecular weight can be determined, for example, using gel permeation chromatography (GPC).

  By using polyvinyl alcohol and / or a derivative thereof as the alcohol compound, the molecular weight can be stabilized, and the inclusion of impurities such as metal can be suppressed. Therefore, in the present invention, the alcohol compound is preferably polyvinyl alcohol and derivatives thereof .

  In the present invention, when polyvinyl alcohol is contained as the alcohol compound, the average degree of polymerization is preferably 100 to 10,000, more preferably 200 to 5,000, and still more preferably 300 to 4,000. . When the average degree of polymerization of polyvinyl alcohol is in the above range, when the carbon dioxide gas generating agent is used for a non-aqueous electrolyte storage battery, it is easy to suppress the elution of the carbon dioxide gas generating agent into the electrolyte and to easily ensure formability. Also, the saponification degree of polyvinyl alcohol may be, for example, 96 mol% or more, preferably 98 mol% or more, and more preferably 99 mol% or more. When the saponification degree of polyvinyl alcohol is in the above range, the amount of carbon dioxide per polyvinyl alcohol in the carbon dioxide gas generating agent can be sufficiently secured.

  In the present invention, polyvinyl alcohol may be a copolymer with an ethylenic carboxylic acid such as acrylic acid, methacrylic acid or maleic anhydride, or an olefin such as ethylene or propylene, and polyvinyl alcohol and modified polyvinyl alcohol may be used. You may mix and use. Although the amount of modification is not particularly limited, it is preferably 0.01 to 20 mol%, and preferably 0.1 to 10 mol% in consideration of the amount of alcohol per weight of polyvinyl alcohol.

  The mixing ratio of the amine-based polymer to the alcohol compound in the mixture used for the carbon dioxide gas generating agent is preferably 1:10 to 10: 1 in terms of the molar amount of amine in the amine-based polymer and the molar amount of alcohol in the alcohol compound, The ratio is more preferably 5 to 5: 1, and still more preferably 1: 2 to 2: 1. When the mixing ratio of the amine polymer and the alcohol compound constituting the mixture is within the above range, the amount of carbonate formed can be increased in the reaction with carbon dioxide, and a high carbon dioxide gas emission can be secured.

  In the present invention, the above-mentioned mixture used for the carbon dioxide gas generating agent may contain components other than the amine polymer and the alcohol compound. As such components, for example, plasticizers, dispersion stabilizers, viscosity modifiers, molding assistants and the like can be mentioned. Specific examples include plasticizer components such as polyethylene glycol.

  When the mixture used for the carbon dioxide gas generating agent of the present invention contains components other than the amine polymer and the alcohol compound, the total amount of the amine polymer and the alcohol compound is 90% by mass or more as solid content based on the total mass of the mixture Is preferable, 95% by mass or more is more preferable, and 98% by mass or more is more preferable. In addition, solid content here means the component except the quantity of solvent, such as water, from the mixture which comprises a carbon dioxide gas absorber.

  The carbon dioxide gas generating agent of the present invention comprises a reaction product obtained by bringing carbon dioxide into contact with a mixture containing the above amine polymer and alcohol compound, and reacting the mixture with carbon dioxide, wherein carbon dioxide is an amine type It is absorbed / adsorbed in the form of a carbonate formed by the reaction with a polymer, and is contained in a carbon dioxide gas generating agent.

  Specifically as the carbon dioxide gas generating agent of the present invention, for example, polyvinyl alcohol-polyethyleneimine mixture, polyvinyl alcohol-ethylene copolymer-polyethyleneimine mixture, polyvinyl alcohol butyl acetal-polyethyleneimine mixture, polyvinyl alcohol-polyallylamine mixture, Polyvinyl alcohol-ethylene copolymer-polyallylamine mixture, polyvinyl alcohol butyl acetal-polyallylamine mixture, polyvinyl alcohol-polymelamine mixture, polyvinyl alcohol-ethylene copolymer-polymelamine mixture, polyvinyl alcohol butyl acetal-polymelamine mixture, starch-polyethylene Imine mixture, starch-polyallylamine mixture, starch-polymelamine mixture, glucose Li ethyleneimine mixture Glucose - polyallylamine mixture, glucose - poly melamine mixture, fructose - polyethyleneimine mixture, fructose - polyallylamine mixture, fructose - carbon dioxide complex of poly melamine mixtures, and combinations thereof.

  The form of the carbon dioxide gas generating agent of the present invention is not particularly limited, but it can be used in an environment which is easy to handle and in which there is a need to reduce the water content or the absence of water. Therefore, it is preferable to be solid. For this reason, in the present invention, the water content of the carbon dioxide gas generating agent is preferably less than 10% by mass, preferably 5% by mass or less, and 1% by mass or less based on the total mass of the carbon dioxide gas generating agent. Is more preferably 0.5% by mass or less, and the water content may be 0% by mass. When the water content is less than 10% by mass, the carbon dioxide gas generating agent can be maintained in a solid form. When a carbon dioxide gas generating agent is used for a non-aqueous electrolyte storage battery, the water content of the carbon dioxide gas generating agent is preferably as low as possible, more preferably 500 ppm or less, still more preferably 300 ppm, from the viewpoint of preventing the performance deterioration of the non-aqueous electrolyte storage battery. The lower limit is particularly preferably 200 ppm or less, ideally 0 ppm, but the lower limit is usually 100 ppm or more from the viewpoint of production efficiency and the like.

  The water content of the carbon dioxide gas generating agent of the present invention is controlled by controlling the water content in a mixture containing an amine polymer and an alcohol compound, heating conditions at the time of preparing (forming etc.) the carbon dioxide gas generating agent from the mixture, and drying conditions It can adjust by controlling etc. Moreover, the moisture content of the carbon dioxide gas generating agent can be maintained in an appropriate range by limiting storage conditions such as storage under a specific humidity.

  The carbon dioxide gas emission temperature of the carbon dioxide gas generating agent of the present invention is preferably 60 ° C. or more, more preferably 80 ° C. or more, preferably 200 ° C. or less, more preferably 160 ° C. or less, still more preferably 120 ° C. or less . When the carbon dioxide gas discharge temperature is within the upper limit and the lower limit value, carbon dioxide gas can be released at an early stage of heat generation caused by overcharge, and high capacity carbon dioxide gas can be generated promptly. It becomes a carbon dioxide gas generating agent capable of suppressing thermal runaway and improving battery safety.

  The carbon dioxide gas discharge temperature of the carbon dioxide gas generating agent can be controlled, for example, by selecting the type, combination, mixing ratio, water content, shape, and the like of the amine polymer and alcohol compound to be used. For example, in order to increase the carbon dioxide gas release temperature, the ratio of primary amines may be increased, and the surface area during molding may be reduced. On the other hand, in order to lower the carbon dioxide gas release temperature, to increase the moisture content, to increase the proportion of the total of secondary and tertiary amino groups in the amine polymer, to reduce the particle shape at the time of molding Etc.

  The carbon dioxide gas generating agent of the present invention can be used in various forms such as a film, a film, a sheet, a fiber, a powder, a granule, and a gel according to a desired use environment and a use. It is preferably in the form of a film, a film, a sheet, a fiber and a powder, because it is easy to handle and easy to use for various applications. In the present invention, when the shape of the carbon dioxide gas generating agent is a film, film or sheet, its thickness can be appropriately determined according to the environment and application to be used, and is, for example, 0.1 to 500 μm. And preferably 1 to 100 μm.

  The carbon dioxide gas generating agent of the present invention is, for example, a mixture obtained after a mixture containing an amine polymer and an alcohol compound is obtained by stirring and mixing an amine polymer and an alcohol compound, and if necessary, other components. The carbon dioxide can be brought into contact with carbon dioxide, and the mixture can be absorbed / adsorbed in the form of a carbonate in the form of a carbonate, followed by shaping or the like to obtain a desired shape. In addition, after obtaining a mixture containing an amine polymer and an alcohol compound, it is molded into a desired shape, and after molding, it is made to contact with carbon dioxide to absorb / adsorb carbon dioxide in the form of carbonate. It can also be done.

  When preparing a mixture of an amine polymer and an alcohol compound, the mixture is easily handled by appropriately dissolving the amine polymer and / or the alcohol compound in a solvent such as water and mixing as an aqueous solution. The solvent may be appropriately selected depending on the type and amount of the amine polymer or alcohol compound to be used. Examples of the solvent include water, alcohol solvents and the like.

  The stirring and mixing conditions (temperature, time, stirring speed, etc.) at the time of mixing the amine polymer and the alcohol compound may be appropriately determined according to the type and amount of the amine polymer and alcohol compound to be used.

  The contact of a mixture containing an amine polymer and an alcohol compound with carbon dioxide may be carried out by passing carbon dioxide through a solution obtained by dissolving a mixture containing an amine polymer and an alcohol compound in a solvent such as water. After forming a mixture containing an amine polymer and an alcohol compound into a desired solid form, the mixture may be contacted with carbon dioxide to perform gas-solid reaction.

  In the present invention, the method of contacting carbon dioxide in contact with a mixture containing an amine polymer and an alcohol compound is, for example, dissolving carbon dioxide in gas-solid contact of carbon dioxide and the mixture, an organic solvent which does not dissolve the mixture, etc. Any method such as liquid-solid contact may be used. Moreover, it is preferable to carry out the contact temperature of a mixture and a carbon dioxide lower than the carbon dioxide discharge temperature of a carbon dioxide gas generating agent, and make it contact at about 50-80 degreeC lower temperature than the carbon dioxide discharge temperature of a carbon dioxide generator Is more preferred.

  For forming into a film, film or sheet, for example, a mixture containing an amine polymer and an alcohol compound or a reaction product obtained by reacting carbon dioxide with the mixture is coated on a substrate and dried. It can be carried out by peeling off the substrate after removing the solvent. It does not specifically limit as a base material, For example, a PET film, a Teflon sheet, etc. can be used. The drying method may, for example, be a natural drying method, a ventilation drying method, a heating drying or a reduced pressure drying method, but since the solvent contained in the mixture can be efficiently removed, it is preferable to heat drying. The heating temperature is not particularly limited, and may be, for example, 40 to 150 ° C., and preferably 80 to 120 ° C. The drying time may be appropriately adjusted depending on the heating temperature and the like, and may be, for example, 0.1 to 30 hours, and preferably 1 to 10 hours.

  The fibrous carbon dioxide gas generating agent prevents a mixture of (an aqueous solution of) an amine polymer and (an aqueous solution of) an alcohol compound as an aqueous solution while desolvating like electrospinning or after desolvating at about 200 ° C. It can be produced by drawing at a temperature of 50%, reacting with carbon dioxide and carbonation. In addition, a mixture of an amine polymer (an aqueous solution) and an alcohol compound (an aqueous solution) is freeze-dried as it is an aqueous solution, pulverized or desolventized, then pulverized, reacted with carbon dioxide, carbonated, or in solution A powdery carbon dioxide gas generating agent can be produced by pre-carbonation using carbon dioxide, and then freeze-dried or desolvated and then ground.

  Since the carbon dioxide gas generating agent of the present invention is a substance having a high concentration of carbon dioxide gas in a solid, a large amount of carbon dioxide gas can be generated. Therefore, the carbon dioxide gas emission amount of the carbon dioxide gas generating agent of the present invention is preferably 0.01 to 1 (g / g carbon dioxide gas generating agent), more preferably 0.05 to 0.5 (g / carbon dioxide gas generating agent) 1g).

  The carbon dioxide gas generating agent of the present invention is suitable for use in an environment where it is necessary to reduce the water content or an environment where it is preferable that there is no water, and can be used, for example, as a foaming agent or a fire extinguisher. In particular, since the carbon dioxide gas can be released at a relatively low temperature with a high carbon dioxide gas emission amount, it is suitable as a carbon dioxide gas generator for preventing thermal runaway at the time of overcharging in a non-aqueous electrolyte storage battery.

<Non-aqueous electrolyte storage battery>
The non-aqueous electrolyte storage battery of the present invention comprises a positive electrode capable of storing and releasing electrolyte ions, a negative electrode capable of storing and releasing electrolyte ions, a separator disposed between the positive electrode and the negative electrode, an electrolyte and a carbon dioxide gas generating agent . The nonaqueous electrolyte storage battery of the present invention is, for example, in the form of a lithium ion secondary battery, a sodium ion secondary battery, a nonaqueous electrolyte secondary battery such as a lithium-sulfur secondary battery, an electric double layer capacitor, a lithium ion capacitor, etc. May be there.

  The non-aqueous electrolyte storage battery of the present invention includes the carbon dioxide gas generating agent of the present invention, and the temperature inside the storage battery rises during overcharge, and carbon dioxide gas is released when the carbon dioxide gas discharge temperature of the carbon dioxide gas generating agent is reached. By operating the pressure relief valve inside the battery by the released carbon dioxide gas, thermal runaway of the storage battery can be suppressed. By using the carbon dioxide gas generating agent of the present invention as the carbon dioxide gas generating agent, it can be used for storage batteries in various forms such as film or powder, and damage to the electrode is small even if the electrode is touched. can do. In addition, it is possible to obtain the advantage that individual raw materials are easily available, the carbon dioxide content in the carbon dioxide gas generating agent can be increased, and the carbon dioxide emission temperature can be easily controlled by the selection of the amine species.

A non-aqueous electrolyte secondary battery generally comprises a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte. In the present invention, the non-aqueous electrolyte secondary battery can be manufactured using known materials and techniques. For example, when the non-aqueous electrolyte secondary battery is a lithium secondary battery, as a positive electrode material, for example, TiS ₂ , TiS ₃ , amorphous MoS ₃ , Cu ₂ V ₂ O ₃ , amorphous V ₂ O-P ₂ Transition metal oxides such as O ₅ , MoO ₃ , V ₂ O ₅ and V ₆ O ₁₃ and lithium-containing composite metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ can be used.

  Water or organic dispersion medium: positive electrode material, conductive additive such as metal powder, conductive polymer, acetylene black, carbon black, and binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, etc. Etc. to prepare a slurry for the positive electrode, for example, it can be applied to a positive electrode current collector such as aluminum, and the solvent can be dried to form a positive electrode.

As the negative electrode material, for example, conductive materials such as amorphous carbon, graphite, natural graphite, meso carbon micro beads (MCMB), pitch carbon fiber, carbon black, activated carbon, carbon fiber, hard carbon, soft carbon, mesoporous carbon, polyacene, etc. Carbonaceous materials such as polymers, complex metal oxides represented by SiO _x , SnO _x , LiTiO _x and other metal oxides, lithium metals, lithium metals such as lithium alloys, metals such as TiS ₂ , LiTiS ₂ A compound and a composite material of a metal oxide and a carbonaceous material can be used.

  A slurry for the negative electrode is prepared by mixing the negative electrode material and the same conductive aid and binder as the positive electrode in water, an organic dispersion medium, etc., for example, applying it to a negative electrode current collector such as copper and drying the solvent. Can be used as a negative electrode.

The electrolytic solution may be liquid or gel as long as it is used for a normal non-aqueous electrolyte secondary battery, and an electrolyte that exhibits the function as a battery may be appropriately selected according to the type of the negative electrode material and the positive electrode material. Good. As the electrolyte, any known lithium salt can be used, for _{example, LiClO 4, LiBF 6, LiPF} 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10, LiAlCl 4, LiCl , LiBr, LiB (C ₂ H ₅ ) ₄ , CF ₃ SO ₃ Li, CH ₃ SO ₃ Li, LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, lower aliphatic carboxylic acids And lithium acid.

  The solvent (electrolyte solution solvent) for dissolving such an electrolyte is not particularly limited. Specific examples thereof include carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate and vinylene carbonate; lactones such as γ-butyrolactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether, 2- Ethers such as ethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran; sulfoxides such as dimethylsulfoxide; oxolanes such as 1,3-dioxolane, 4-methyl-1,3-dioxolane; nitrogen-containing compounds such as acetonitrile and nitromethane Organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate and ethyl propionate; triethyl phosphate, dimethyl carbonate, carbonic acid Inorganic acid esters such as ethyl; diglymes; triglymes; sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propane sultone, 1,4-butane sultone and naphtha sultone These can be used alone or in combination of two or more. When a gel electrolyte solution is used, a nitrile polymer, an acrylic polymer, a fluorine polymer, an alkylene oxide polymer and the like can be added as a gelling agent.

  For example, a non-aqueous electrolyte secondary battery is obtained by stacking the negative electrode and the positive electrode through a separator such as a polypropylene porous film, winding it according to the battery shape, folding it, etc. It can be manufactured by sealing. The shape of the battery may be any of known coin type, button type, sheet type, cylindrical type, square type, flat type and the like.

  For example, when the carbon dioxide gas generating agent is in the form of a film, a film or a sheet, the carbon dioxide gas generating agent may be placed on the non-aqueous electrolyte secondary battery in a laminated manner with the electrode and the separator. Alternatively, in the case of powder or the like, it may be mixed with an electrode material or a separator material, and may be disposed in the battery as a part of a component of the electrode or the separator.

  It is preferable that the carbon dioxide gas generating agent is contained in the positive electrode from the viewpoint of directly receiving heat runaway due to an overcurrent and generating carbon dioxide gas promptly. For example, the carbon dioxide gas generating agent can be contained in the positive electrode by mixing the carbon dioxide gas generating agent formed into a powder or the like with the positive electrode material.

  In general, an electric double layer capacitor mainly has a polarizable electrode, an electrolytic solution, and a separator, and has a structure in which a separator is disposed between a pair of electrodes. The electric double layer capacitor of the present invention can be manufactured using known materials and techniques. As the polarizable electrode material, for example, it is preferable to use activated carbon in terms of capacitance. The carbon material used as the raw material of activated carbon is not particularly limited, and examples thereof include coal, coal pitch, petroleum pitch, thermosetting resin such as phenol, coconut shell and the like.

  For the production of the polarizable electrode, known methods can be applied. For example, a commercially available substance known as a binder such as polyvinylidene fluoride or polytetrafluoroethylene or a conductive material such as carbon black may be added to the polarizable electrode material up to about several percent, if necessary. After well-kneaded, it can be molded into an electrode by punching into a required shape after being put into a mold and press-molded or rolled into a sheet. In addition, the kneaded material may be applied to a current collector to form a coated electrode. At the time of electrode formation, if necessary, solvents such as alcohols and organic compounds such as N-methyl pyrrolidone, water, etc., dispersants, and various additives may be used. Moreover, it is also possible to add heat in the range which does not impair the effect of this invention.

  As the separator, glass filter paper, non-woven fabric such as polypropylene or nylon, or porous film such as polytetrafluoroethylene can be used.

  As the electrolyte, tetraethylammonium tetrafluoroborate, tetramethylammonium tetrafluoroborate or the like can be used. As a solvent for dissolving the electrolyte and forming an electrolyte solution, carbonates such as ethylene carbonate, dimethyl carbonate, diethyl carbonate and propylene carbonate, nitriles such as acetonitrile, lactones such as γ-butyrolactone and α-methyl-γ-butyrolactone, Sulfoxides such as dimethylsulfoxide and amides such as dimethylformamide are used.

  Each component constituting the electric double layer capacitor can have the same structure as a known electric double layer capacitor except that a carbon dioxide gas generating agent is used, and for example, a current collector made of aluminum or the like, polarizable A case made of a material such as an electrode, a separator, a gasket made of polypropylene, polyethylene, polyamide, polyamide imide, polybutylene or the like, stainless steel or the like is used.

  For example, when the carbon dioxide gas generating agent is in the form of a film, film or sheet, the carbon dioxide gas generating agent may be disposed in a laminated manner with the polarizable electrode and the separator. Alternatively, in the case of powder or the like, it can be disposed in the battery as a part of constituent members of the polarizable electrode or separator.

  In the non-aqueous electrolyte storage battery of the present invention, the carbon dioxide gas generating agent thermally decomposes and releases the carbon dioxide gas, whereby the non-aqueous electrolyte storage battery is operated by pressure burst or a spring etc. A device for interrupting the current between the positive electrode collector electrode and the electrode for transferring the current when the safety valve is operated to reduce the pressure of the valve.

  The non-aqueous electrolyte storage battery of the present invention has a high carbon dioxide gas emission amount and is provided with a carbon dioxide gas generating agent capable of releasing carbon dioxide gas at a relatively low temperature, thereby preventing thermal runaway during overcharge at an early stage. Storage battery that can be

  Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

1. Example 1
(1) Preparation of a carbon dioxide gas generating agent 1000 g of a 10% by mass aqueous solution of polyvinyl alcohol (made by Kuraray, PVA-117, average degree of polymerization: 1700, degree of saponification 98-99%) was added to a 5 L flask and stirred with a mechanical stirrer. . Subsequently, 100 g of polyethyleneimine (made by Showa Chemical Co., Ltd., undiluted solution, weight average molecular weight Mw 10000, amine ratio primary: secondary: tertiary = 35: 35:30) is added, and stirring is continued at 25 ° C for 3 hours for 18 mass% A mixed solution of The resulting mixture was coated on a 100 μm polyethylene terephthalate (PET) film to a thickness of 500 μm, and then dried in an oven at 80 ° C. for 30 minutes. The polyvinyl alcohol-polyethyleneimine mixed film was peeled off from the PET film to obtain a film-like composite. The film thickness of the mixed film was 60 μm. The obtained film-like composite was placed in a desiccator, the inside of the desiccator was depressurized in vacuo, carbon dioxide was returned to atmospheric pressure, and carbon dioxide was supplied while the carbon dioxide was continuously consumed by the film-like composite. The amount of carbon dioxide supplied was 140 ml per 500 mg of the film-like composite.

(2) Measurement of moisture content The moisture content of the obtained carbon dioxide gas generating agent was measured according to the following method.
After vacuum-drying 10 g of the sample for moisture content measurement at 105 ° C. for 6 hours and 140 ° C. for 3 hours, 1 g of the sample is weighed in a glove box in an inert atmosphere, and Karl Fischer (Mitsubishi Chemical Analytech Co., Ltd. C.), and the amount of moisture absorption was measured under a nitrogen stream. The moisture content of the film-like carbon dioxide gas generating agent obtained in the above (1) was 112 ppm.

(3) Measurement of carbon dioxide emission temperature 1 g of the film-like carbon dioxide gas generating agent obtained in the above (1) is put in a desiccator, 10 g of carbon dioxide is put in it, and stored at 25 ° C. for 1 hour. The thermogravimetry simultaneous measurement device: TG-DTA, manufactured by Seiko Instruments Inc.) was used to measure the carbon dioxide emission temperature of the carbon dioxide gas generating agent. The carbon dioxide emission temperature of the carbon dioxide gas generating agent obtained in the above (1) was 120.degree.

(4) Measurement of Carbon Dioxide Generation Amount The carbon dioxide generation amount of the carbon dioxide gas generating agent was measured according to the following method.
Take 48 mg of the carbon dioxide gas generating agent obtained in Example 1 and raise the temperature at 10 ° C./min in a nitrogen stream with a TG / DTA (manufactured by Seiko Instruments Inc.) device, and heat to 280 ° C. to reduce weight It was measured. Furthermore, the decomposition product up to 280 ° C is detected with a multi-shot pyrolyzer (EGA / PY-3030D manufactured by Nippon Denshi Co., Ltd.), and it is confirmed that the product under this temperature is carbon dioxide (carbon dioxide gas) did.
The carbon dioxide gas generation amount of the film-like carbon dioxide gas generating agent obtained in the above (1) was 0.27 g / g of carbon dioxide gas generating agent.

(5) Preparation of coin-type lithium secondary battery The slurry for the electrode is prepared by using a solid solution of 10 wt% SBR aqueous solution as the binder for the negative electrode with respect to 100 parts by weight of natural graphite (DMGS, BYD made) as the active material for the negative electrode As a solid content, 6.452 parts by weight of Super-P (manufactured by Timcal) as a conductive aid (conductive agent) and 1.075 parts by weight of the solid content are charged into a dedicated container, and a planetary stirrer (ARE-250, It knead | mixed using the product made in Shinky. In order to adjust the slurry viscosity, water was added at the time of kneading and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active material to the binder in the slurry is, as a solid content, graphite powder: conductive auxiliary agent: binder composition = 100: 1.075: 6.452.

  Using a bar coater (T101, manufactured by Matsuo Sangyo), coat the obtained slurry on copper foil (C1100H, manufactured by UACJ) as a current collector, and use a hot air dryer (manufactured by Yamato Scientific Co., Ltd.) for 30 minutes at 80 ° C. After primary drying, rolling treatment was carried out using a roll press (manufactured by Takasen). Thereafter, after punching out as a battery electrode (φ 14 mm), a coated electrode for a coin battery was produced by secondary drying at 120 ° C. for 3 hours under reduced pressure conditions.

The coated electrode for a battery obtained above was transferred to a glove box (manufactured by Miwa Seisakusho) under an argon gas atmosphere. A metal lithium foil (thickness 0.2 mm, φ16 mm) was used as the positive electrode. In addition, a polypropylene-based (Celgard # 2400, manufactured by Polypore) was used as a separator. The carbon dioxide gas generator, the coated electrode, the separator, and the positive electrode were laminated in this order in the SUS case. Mixed solvent system (1M-LiPF ₆ , EC / EMC = 3) in which vinylene carbonate (VC) is added to ethylene carbonate (EC) of lithium hexafluorophosphate (LiPF ₆ ) and ethyl methyl carbonate (EMC) as an electrolytic solution It injected using / 7vol%, VC2 wt%), and produced the coin battery (2032 type).

(6) Evaluation of charge and discharge performance The charge and discharge test of the manufactured coin battery was carried out using a charge and discharge tester (TOSCAT 3100, manufactured by Toyo System Co., Ltd.). Place the coin battery in a 25 ° C thermostatic bath, perform constant current charge of 0.1 C (about 0.5 mA / cm ² ) to the mass of the active material until it becomes 0 V with respect to lithium potential, and further lithium potential Constant voltage charging at 0 V to a current of 0.02 mA. Next, in an 80 ° C. constant temperature bath, constant current charging of 0.1 C (about 0.5 mA / cm ² ) is performed on the active material mass until it reaches 0 V with respect to the lithium potential, and further 0 A constant voltage charge of 0 V was performed to a current of .02 mA. After reaching 0 V in constant current charging, low voltage charging could not be performed due to the increase in internal resistance.

2. Example 2
(1) Preparation of a carbon dioxide gas generating agent 1000 g of a 10% by mass aqueous solution of polyvinyl alcohol (made by Kuraray, PVA-117, average degree of polymerization: 1700, degree of saponification 98-99%) was added to a 5 L flask and stirred with a mechanical stirrer. . Subsequently, 100 g of polyethyleneimine (made by Showa Chemical Co., Ltd., undiluted solution, weight average molecular weight Mw 10000, amine ratio primary: secondary: tertiary = 35: 35:30) is added, and stirring is continued at 25 ° C for 3 hours for 18 mass% A mixed solution of The obtained mixture was dried at 80 ° C. for 120 minutes in a drier, and further dried at 80 ° C. under vacuum for 12 hours, and then a ball mill was used to obtain a powder composite having an average particle diameter of 20 μm. The resulting composite was placed in a desiccator, the pressure in the desiccator was reduced to a vacuum, the pressure was returned to atmospheric pressure with carbon dioxide, and carbon dioxide was supplied only as the carbon dioxide continued to be consumed by the powder composite. The amount of carbon dioxide supplied was 151 ml per 500 mg of the powder composite. The water content and the carbon dioxide emission temperature of the obtained carbon dioxide gas generating agent were measured in the same manner as in Example 1. As a result, the water content was 155 ppm, the carbon dioxide emission temperature was 120 ° C., and the carbon dioxide generation amount was 0.23 g / g of carbon dioxide gas generating agent.

(2) Preparation of coin-type lithium secondary battery The slurry for the electrode was prepared by using a solid solution of 10 w% aqueous solution of SBR as the binder for the negative electrode with respect to 100 parts by weight of natural graphite (DMGS, BYD made) as the active material for the negative electrode. As a solid content, 6.452 parts by weight of Super-P (manufactured by Timcal) as a conductive aid (conductive agent) and 1.075 parts by weight of the solid content are charged into a dedicated container, and a planetary stirrer (ARE-250, It knead | mixed using the product made in Shinky. In order to adjust the slurry viscosity, water was added at the time of kneading and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active material to the binder in the slurry is, as a solid content, graphite powder: conductive auxiliary agent: binder composition = 100: 1.075: 6.452.

  Using a bar coater (T101, manufactured by Matsuo Sangyo), coat the obtained slurry on copper foil (C1100H, manufactured by UACJ) as a current collector, and use a hot air dryer (manufactured by Yamato Scientific Co., Ltd.) for 30 minutes at 80 ° C. After primary drying, rolling treatment was carried out using a roll press (manufactured by Takasen). Thereafter, after punching out as a battery electrode (φ 14 mm), a coin battery electrode was manufactured by secondary drying at 120 ° C. for 3 hours under reduced pressure conditions.

The coated electrode for a battery obtained above was transferred to a glove box (manufactured by Miwa Seisakusho) under an argon gas atmosphere. As the positive electrode, an NCM ternary positive electrode foil manufactured by Yayama Co., Ltd. was used, and the positive electrode / negative electrode ratio was 1. In addition, a polypropylene-based (Celgard # 2400, manufactured by Polypore) was used as a separator. The carbon dioxide gas generator, the coated electrode, the separator, and the positive electrode were laminated in this order in the SUS case. Mixed solvent system (1M-LiPF ₆ , EC / EMC = 3) in which vinylene carbonate (VC) is added to ethylene carbonate (EC) of lithium hexafluorophosphate (LiPF ₆ ) and ethyl methyl carbonate (EMC) as an electrolytic solution It injected using / 7vol%, VC2 wt%), and produced the coin battery (2032 type).

(3) Evaluation of charge and discharge performance The charge and discharge test of the manufactured coin battery was carried out using a charge and discharge tester (TOSCAT 3100, manufactured by Toyo System Co., Ltd.). A coin battery was subjected to constant current charging of 100% of battery design capacity (equivalent to a negative electrode capacity of 365 mAh / g) in a constant temperature bath at 80 ° C., and constant voltage charging of 0 V was performed to a current of 0.02 mA with respect to lithium potential. . After reaching the design capacity charge, low voltage charge could not be implemented due to the increase of internal resistance.

3. Comparative Example 1
A coin-type lithium secondary battery was produced in the same manner as in Example 2 except that the carbon dioxide gas generating agent was not used, and charging was performed in the same manner as in Example 2. Immediately after the start of constant voltage charging, the internal pressure of the battery increased, and the electrolyte leaked from the coin cell, and the charging was stopped.

Claims (7)

  A carbon dioxide gas generating agent comprising a reaction product of carbon dioxide and a mixture containing an amine polymer having an amino group in a repeating unit and an alcohol compound.   The carbon dioxide gas generating agent according to claim 1, wherein the carbon dioxide gas emission temperature is 60 ° C. or more and 200 ° C. or less.   The amine-based polymer is selected from the group consisting of polyethyleneimine, polyallylamine, polyacrylamide, polytetramethyleneimine, polyvinylamine, dicyandiamide-formalin condensate and dicyandiamide-alkylene (polyamine) condensate. Description carbon dioxide gas generating agent.   The carbon dioxide gas generating agent according to any one of claims 1 to 3, wherein the alcohol compound is selected from the group consisting of monosaccharides, oligosaccharides, polysaccharides, polyvinyl alcohol and derivatives thereof and polyphenol and derivatives thereof.   The carbon dioxide gas generating agent according to any one of claims 1 to 4, which is in the form of a film, a film, a sheet, a fiber or a powder.   A positive electrode capable of absorbing and desorbing electrolyte ions, a negative electrode capable of absorbing and desorbing electrolytic ions, a separator disposed between the positive electrode and the negative electrode, an electrolytic solution, and carbon dioxide gas generation according to any one of claims 1 to 5. Non-aqueous electrolyte storage battery with an agent.   The non-aqueous electrolyte storage battery according to claim 6, wherein a carbon dioxide gas generating agent is contained in the positive electrode.