JP2013222556A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery causing no deterioration in charge/discharge performance of a battery even when a negative electrode contains lithium, and improved in safety even during long-term use and an abnormal state by suppressing needle-like precipitation of lithium.SOLUTION: A battery includes: an ion conductor containing a low molecular gelator (a low molecular gelator having a perfluoroalkyl group, a coumarin type gelator, a gelator having an azo group, or the like) having a gelling ability in order to enhance an effect for suppressing needle-like precipitation of lithium; a negative electrode containing a lithium compound as a negative electrode active material; and a positive electrode. The battery can be also applied for a lithium-air battery.

Description

  The present invention relates to a battery.

  In recent years, there has been a demand for a reduction in the use of energy using fossil fuels and nuclear energy from the point of increasing awareness of environmental issues and emphasis on safety. Under such circumstances, not only energy creation represented by power generation but also innovation of energy technology from various viewpoints including energy saving and energy storage is required.

Lithium-ion batteries, which are typical energy storage materials, have a high capacity density and energy density among general-purpose storage batteries, so if they are currently only widely used in mobile devices such as mobile phones and laptop computers It is also used as a backup power source for electric tools and various devices. Furthermore, recently, adoption in in-vehicle and smart houses such as hybrid cars and electric cars has been examined, and further expansion of lithium ion batteries is expected and predicted.
However, high-capacity, high-power, and other high-performance batteries are required for automobile use and residential use as compared with conventional portable devices, and therefore there is an increasing demand for improved next-generation batteries.

As an example of such a next-generation battery, a battery containing lithium as a negative electrode active material, such as a lithium battery, a lithium-air battery, or a lithium-sulfur battery, has attracted attention as a next-generation large-capacity battery.
Lithium metal oxides such as lithium cobaltate are used as the positive electrode active material of the lithium ion battery, but a carbon material is generally used as the negative electrode active material. Therefore, if a material containing lithium is used for the negative electrode as the negative electrode active material, a higher capacity battery can be expected.
Here, the lithium-air battery includes a negative electrode capable of inserting and extracting lithium ions, a positive electrode including oxygen as a positive electrode active material and an oxygen redox catalyst, and an ion conductor interposed between the negative electrode and the positive electrode ( An electrolyte solution is known. The oxygen used for the positive electrode is obtained from the air, and since there is no need to enclose a solid active material in the battery, the capacity of the positive electrode is theoretically infinite, achieving a significantly higher capacity compared to lithium ion batteries. can do. However, in lithium-air batteries, there is a problem that the battery cannot be used for a long time because moisture mixed when taking air from the positive electrode deteriorates the battery or carbon dioxide reduces the performance of the electrolyte. Various improvements are being considered.
Patent Document 1 discloses a negative electrode that releases lithium ions, an air electrode current collector made of a porous material, a porous positive electrode containing a conductive material, and a space between the air electrode current collector and the porous positive electrode. There is disclosed a lithium-air battery having a diffusion layer made of a conductive material and a non-aqueous electrolyte arranged between the negative electrode and the porous positive electrode.
Patent Document 2 discloses an air electrode having an air electrode layer containing a conductive material and an air electrode current collector for collecting the air electrode layer, a negative electrode layer containing a negative electrode active material, and a collection of the negative electrode layer. A negative electrode having a negative electrode current collector that conducts electricity, a separator disposed between the air electrode layer and the negative electrode layer, a lithium salt that conducts lithium ions between the air electrode layer and the negative electrode layer, and An organic solvent electrolyte containing an organic solvent, wherein the organic solvent includes a reaction-resistant organic solvent having a high dielectric constant and resistance to discharge products. A lithium air battery is disclosed.

International Publication 2011/052440 JP 2011-146283 A

  However, in a battery containing lithium in the negative electrode as described in the above-mentioned patent document, metallic lithium gradually accumulates on the negative electrode in accompaniment with charge and discharge, and this causes a battery short circuit, so long-term use There are problems with the charge and discharge characteristics and safety at the time. Moreover, since such acicular lithium deposits in a short time in the event of an abnormality such as overcharging, battery control is required so that no abnormal charging occurs. Such acicular volume of lithium is highly reactive and can cause fire or runaway in abnormal situations.

  Therefore, the present invention has been made in view of the above circumstances, and even when lithium is contained in the negative electrode, the charge / discharge performance of the battery is not deteriorated, and the acicular precipitation of lithium is suppressed and used for a long time. An object is to provide a battery with improved safety even in the event of an abnormality.

  As a result of studying battery performance using various ion conductors in order to achieve the above object, the present inventors can achieve the above object by using an ion conductor containing a low-molecular gelling agent. The present invention was completed.

That is, the present invention is as follows.
[1]
A battery comprising an ionic conductor containing a low-molecular gelling agent, a negative electrode containing a lithium compound as a negative electrode active material, and a positive electrode.
[2]
The battery according to [1] above, wherein the lithium compound is lithium metal.
[3]
[1] or [2] above, wherein the low-molecular gelling agent comprises one or more compounds selected from the group consisting of compounds represented by the following general formulas (1), (2) and (3): The battery described.
^{Rf 1 -R 1 -X 1 -L 1} -R 2 (1)
Rf ¹ -R ¹ -X ¹ -L ¹ -R ³ -L ² -X ² -R ⁴ -Rf ² (2)
^{R 5 -O-Cy-X 3} -Cm (3)
(In the formulas (1) and (2), Rf ¹ and Rf ² each independently represents a perfluoroalkyl group having 2 to 20 carbon atoms, and R ¹ and R ⁴ each independently represent a single bond or 1 carbon atom. To 6 divalent saturated hydrocarbon groups, wherein X ¹ and X ² are each independently the following formulas (1a), (1b), (1c), (1d), (1e), (1f) and ( 1g) represents a divalent group selected from the group consisting of groups represented by 1g), L ¹ and L ² are each independently a single bond, an alkyl group or an oxyalkylene group optionally substituted with a halogen atom, an alkyl An oxycycloalkylene group which may be substituted with a group or a halogen atom, or a divalent oxyaromatic group which may be substituted with an alkyl group or a halogen atom, and R ² represents an alkyl group or a halogen atom ( However, A fluoroalkyl group, an aryl group or a fluoro group optionally substituted with an alkyl group having 1 to 20 carbon atoms, an alkyl group or a halogen atom (excluding a fluorine atom) which may be substituted with An aryl group, or a monovalent group in which one or more of these groups and one or more of divalent groups corresponding to these groups are bonded, R ³ represents oxygen and And / or a C1-C18 divalent saturated hydrocarbon group which may have one or more sulfur atoms and may be substituted with an alkyl group.

In formula (3), R ⁵ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms in the main chain, and Cy represents a substituted or unsubstituted divalent aromatic group having 5 to 30 nucleus atoms. It shows the family hydrocarbon group or an alicyclic hydrocarbon group, X ³ is represented by the following formula (3a), (3b), (3c), (3d), (3e), (3f) and (3 g) A divalent group selected from the group consisting of the following groups, or a divalent group in which two or more of these divalent groups are bonded, and Cm is a monovalent group represented by the following general formula (3z) In the following formula (3z), a plurality of R ^a each independently represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.

[4]
The battery according to [3] above, wherein X ¹ and X ² are each independently a divalent functional group represented by the formula (1a) or the formula (1d).
[5]
The battery according to [3] or [4] above, wherein both X ¹ and X ² are divalent functional groups represented by the formula (1d).
[6]
The battery according to any one of [1] to [5], wherein one or more phases of the ion conductor are in a gel form.
[7]
The battery according to any one of [1] to [6], wherein the battery is a lithium-air battery using oxygen as a positive electrode active material of the positive electrode.

  According to the present invention, a battery using a negative electrode containing a lithium compound as a negative electrode active material, which is safe by suppressing lithium needle-like precipitation during long-term use and abnormal conditions without reducing the charge / discharge performance of the battery A battery with improved properties can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail.
The battery in this embodiment includes an ionic conductor containing a low molecular gelling agent, a negative electrode containing a lithium compound as a negative electrode active material, and a positive electrode.

<Ionic conductor>
The ion conductor in this embodiment contains a low molecular gelling agent. As the ionic conductor, a known electrolytic solution containing an electrolyte can be used, and various media such as solid, gel, liquid, and slurry can be selected as long as they can carry ions. Two or more ionic conductors may be present. In that case, at least one phase of the ionic conductor includes a low-molecular gelling agent. In particular, since the suppression effect of acicular lithium deposition tends to be further improved, it is preferable to include a low molecular gelling agent in the ion conductor phase close to the negative electrode, and the low molecular weight in the ion conductor phase closest to the negative electrode More preferably, it contains a gelling agent. In addition, it is preferable to include a low-molecular gelling agent in a plurality of phases because the effect of improving safety tends to be further increased.

  The solvent contained in the electrolytic solution that is an ionic conductor is not particularly limited, and either water or a non-aqueous solvent can be used. However, one or more phases of the ionic conductor are preferably a non-aqueous solvent phase.

  The non-aqueous solvent is not particularly limited and various solvents can be used, but a non-aqueous solvent that is liquid at room temperature is generally used. Examples of such non-aqueous solvents include alcohols such as methanol, ethanol, isopropanol, butanol and octanol; methyl acetate, ethyl acetate, propyl acetate, butyl acetate and γ-butyrolactone, γ-valerolactone, ε-caprolactone and the like. Acid esters; ketones such as acetone, diethyl ketone, methyl ethyl ketone and 3-pentanone; hydrocarbons such as pentane, hexane, octane, cyclohexane, benzene, toluene, xylene, fluorobenzene and hexafluorobenzene; diethyl ether, dimethoxy Ethers such as methane, 1,2-dimethoxyethane, 1,4-dioxane, crown ethers, glymes, tetrahydrofuran and fluoroalkyl ether; N, N-dimethylacetate Amides such as amide, N, N-dimethylformamide and N-methylpyrrolidone (NMP); amines such as ethylenediamine and pyridine; imidazoles; propylene carbonate, ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate Carbonates such as ethyl methyl carbonate; nitriles such as acetonitrile, propionitrile, adiponitrile, methoxyacetonitrile; sulfones such as sulfolane; sulfoxides such as dimethyl sulfoxide; industrial oils such as silicon oil and petroleum; Is mentioned.

  Moreover, an ionic liquid can also be used as a non-aqueous solvent. An ionic liquid is a room temperature molten salt composed of ions obtained by combining an organic cation and an anion. Ionic liquids are flame retardant, have low explosive properties, little vapor pressure, high heat and ion conductivity, and physical property control design by selecting ionic species have.

Examples of the organic cation include imidazolium ions such as a dialkylimidazolium cation and a trialkylimidazolium cation, a tetraalkylammonium ion, an alkylpyridinium ion, a dialkylpyrrolidinium ion, and a dialkylpiperidinium ion. Examples of the anion serving as a counter for these organic cations include PF ₆ anion, PF ₃ (C ₂ F ₅ ) ₃ anion, PF ₃ (CF ₃ ) ₃ anion, BF ₄ anion, and BF ₂ (CF ₃ ) ₂ anion. BF ₃ (CF ₃ ) anion, bisoxalatoborate anion, Tf (trifluoromethanesulfonyl) anion, Nf (nonafluorobutanesulfonyl) anion, bis (fluorosulfonyl) imide anion, bis (trifluoromethanesulfonyl) imide anion, bis (Pentafluoroethanesulfonyl) imide anion, dicyanoamine anion, halide anion.

  These non-aqueous solvents are used alone or in combination of two or more.

  In order to increase the degree of ionization of the electrolyte that contributes to charge and discharge, the non-aqueous solvent preferably contains one or more solvents having a high dielectric constant. From the same viewpoint, the non-aqueous solvent more preferably contains one or more ethers such as cyclic carbonates typified by ethylene carbonate and propylene carbonate, nitriles typified by acetonitrile, dimethoxyethane, and glyme. High dielectric constant solvents have the advantage of helping the ionization of the electrolyte and increasing the gelling ability.

The electrolyte in the present embodiment is not particularly limited as long as it is used as an ordinary non-aqueous electrolyte in the electrolytic solution, and any electrolyte may be used. Is preferably used. Specific examples of the lithium salt include, for example, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li ₂ SiF ₆ , LiOSO ₂ C _k F _{2k + 1} [k is an integer of 1 to 8], LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k is an integer of 1-8], LiPF _n (C _k F _{2k + 1} ) _6-n [n is an integer of 1-5, k is an integer of 1-8], LiBF _n ((C _k F _{2k + 1} ) _4-n [n is an integer of 1 to 3, k is an integer of 1 to 8], lithium bis (oxalate) borate represented by LiB (C ₂ O ₄ ) ₂ , LiBF ₂ lithium difluoro oxalyl borate represented by (C ₂ O _2), include lithium trifluoromethane oxalyl phosphate represented by _{LiPF 3 (C 2 O 2)} .

Moreover, the lithium salt represented by the following general formula (3a), (3b) or (3c) can also be used as an electrolyte.
LiC (SO ₂ R ¹¹ ) (SO ₂ R ¹² ) (SO ₂ R ¹³ ) (3a)
LiN (SO ₂ OR ¹⁴ ) (SO ₂ OR ¹⁵ ) (3b)
LiN (SO ₂ R ¹⁶ ) (SO ₂ OR ¹⁷ ) (3c)
Here, in the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ may be the same or different from each other, and are a C 1-8 perfluoroalkyl group. Indicates.

These electrolytes are used singly or in combination of two or more. Among these electrolytes, LiPF ₆ , LiBF ₄ and LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k is an integer of 1 to 8] are used from the viewpoint of enhancing gelation ability in addition to battery characteristics and stability. preferable.

  The concentration of the electrolyte is not particularly limited as long as it does not hinder the achievement of the object of the present invention, but is preferably 0.1 to 3 mol / liter, more preferably 0.5 to 2 mol / liter in the electrolytic solution. Contained in concentration.

  When the ion conductor in this embodiment is two or more phases, the electrolyte contained in each phase may be common or different.

  The low molecular gelling agent is a general term for compounds having gelling ability other than a polymer (polymer) obtained by polymerizing monomers. Supramolecular gelling agents are also included in the low molecular weight gelling agents. The polymer gelling agent forms a three-dimensional network structure by cross-linking, and forms a gel in which the solvent is swollen by absorbing the solvent. On the other hand, low-molecular gelling agents self-assemble in one dimension in solution to form a pseudo polymer (supermolecular fiber), and further entangle them to hold the solvent and form a gel. . The molecular weight of the low molecular weight gelling agent is preferably 50 to 10,000, more preferably 100 to 5,000, as determined by gel permeation chromatography from the viewpoint of gelling ability and gel handling.

  The low molecular gelling agent in the present embodiment is not particularly limited. For example, a compound having one or more groups of an amide group, a urea group and a urethane group, an amino acid derivative, “Chem. Rev. Vol. 97, p3133 to p3159, published in 1997, compounds described in JP-A-10-175901, compounds described in International Publication No. 2006/82768, and JP-A-2007-506833 Compounds described in Japanese Patent Application Laid-Open No. 2009-155592, compounds described in “Chem. Mater. 11, p649-655, 1999”, and “J. Phys. Chem” .B 105, p12809-12815, published 2001 ”. It is.

  The low-molecular gelling agent may be a mixture of a plurality of gelling agents in order to develop target performance such as charge / discharge performance and safety.

  The low molecular gelling agent can gel the electrolytic solution with a smaller addition amount, and can lower the viscosity of the electrolytic solution at high temperatures. As the low-molecular gelling agent, a compound having chemical stability and stability against redox is preferably used, and examples of such a compound include the compounds described below.

The low molecular weight gelling agent in the present embodiment is composed of compounds represented by the following general formulas (1), (2) and (3) from the viewpoint of electrochemical stability and gelling ability with respect to the electrolyte solution. It is preferred to include one or more compounds selected from the group.
^{Rf 1 -R 1 -X 1 -L 1} -R 2 (1)
Rf ¹ -R ¹ -X ¹ -L ¹ -R ³ -L ² -X ² -R ⁴ -Rf ² (2)
^{R 5 -O-Cy-X 3} -Cm (3)

In the general formulas (1) and (2), Rf ¹ and Rf ² each independently represents a C 2-20 perfluoroalkyl group. When the number of carbon atoms is 2 to 20, it is easy to obtain raw materials and synthesize the compounds. From the viewpoints of the compounding of the compounds represented by the above general formulas (1) and (2) (hereinafter also referred to as “perfluoro compounds”) into the electrolyte, the electrochemical characteristics of the electrolyte, and the gelling ability. The carbon number is preferably 2-12. Examples of the perfluoroalkyl group include perfluoroethyl group, perfluoro n-propyl group, perfluoroisopropyl group, perfluoro n-butyl group, perfluoro t-butyl group, perfluoro n-hexyl group, perfluoro n. -An octyl group, a perfluoro n-decyl group, and a perfluoro n-dodecyl group are mentioned.

In the general formulas (1) and (2), R ¹ and R ⁴ each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms, and the carbon number is 2 to 5. It is preferable. When the divalent saturated hydrocarbon group has 3 or more carbon atoms, it may or may not be branched. Examples of such a divalent saturated hydrocarbon group include a methylidene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butene group.

X ¹ and X ² are each independently selected from the group consisting of groups represented by the following formulas (1a), (1b), (1c), (1d), (1e), (1f) and (1g). The divalent group selected is shown. Among these, from an electrochemical viewpoint, a divalent group selected from the group consisting of groups represented by the following formulas (1a), (1b) and (1d) is preferable, and the following formula (1a) or A divalent group represented by the formula (1d) is more preferable, and a divalent group represented by the following formula (1d) is more preferable.

L ¹ and L ² are each independently a single bond, an oxyalkylene group optionally substituted with an alkyl group or a halogen atom, an oxycycloalkylene group optionally substituted with an alkyl group or a halogen atom, or an alkyl group Or the divalent oxy aromatic group (-OAr-; Ar shows a bivalent aromatic group) which may be substituted by the halogen atom is shown. Examples of the oxyalkylene group include an oxyalkylene group having 2 to 10 carbon atoms, more specifically, an oxyethylene group (—C ₂ H ₄ O—) and an oxypropylene group (—C ₃ H ₆ O—). Can be mentioned. Examples of the oxycycloalkylene group include an oxycycloalkylene group having 5 to 12 carbon atoms, and more specifically, an oxycyclopentylene group, an oxycyclohexylene group, and an oxydicyclohexylene group.

  Among these, a divalent oxyaromatic group which may be substituted with an alkyl group or a halogen atom is preferable from the viewpoint of gelling ability and safety improvement of the electrolytic solution. The divalent aromatic group in the divalent oxyaromatic group which may be substituted with an alkyl group or a halogen atom is a cyclic divalent group exhibiting so-called “aromaticity”. This divalent aromatic group may be a monocyclic group or a heterocyclic group.

  The monocyclic group has 6 to 30 nuclear atoms and may be substituted with an alkyl group or a halogen atom. Specific examples thereof include a divalent group having a nucleus represented by a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, a chrysenylene group, and a fluoranthenylene group. It is done. The heterocyclic group has 5 to 30 nucleus atoms and may be substituted with an alkyl group or a halogen atom. Specific examples thereof include a divalent group having a nucleus represented by a pyrrolene group, a furylene group, a thiophenylene group, a triazolen group, an oxadiazolene group, a pyridylene group, and a pyrimidylene group. Among these, the divalent aromatic group is preferably a phenylene group, a biphenylene group, or a naphthylene group.

  Moreover, examples of the alkyl group as a substituent include alkyl groups such as a methyl group and an ethyl group, and examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

  The oxycycloalkylene group and the oxyaromatic group include those in which a plurality of rings are connected, and examples of such a group include an oxybiphenylene group, an oxyterphenylene group, and an oxycycloalkylphenylene group.

R ² in the general formula (1) is an alkyl group having 1 to 20 carbon atoms, an alkyl group, or a halogen atom (provided that it may be substituted with an alkyl group or a halogen atom (excluding a fluorine atom)). A fluoroalkyl group, an aryl group or a fluoroaryl group optionally substituted with a fluorine atom, or one or more of these groups and a divalent group corresponding to these groups (for example, alkyl A monovalent group (for example, an aralkyl group in which an alkylene group and an aryl group are bonded) bonded to one or more of an alkylene group corresponding to a group and an arylene group corresponding to an aryl group. More specifically, R ² is methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n-decyl. C1-C12 alkyl groups represented by group are mentioned. These alkyl groups may be further substituted with an alkyl group or a halogen atom (excluding a fluorine atom).

  As a fluoroalkyl group, a C1-C12 fluoroalkyl group (however, except a perfluoroalkyl group) or a C1-C12 perfluoroalkyl group is preferable. Specific examples of the fluoroalkyl group having 1 to 12 carbon atoms (excluding the perfluoroalkyl group) and the perfluoroalkyl group having 1 to 12 carbon atoms include a trifluoromethyl group, 1,1,1, 2,2-pentafluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 1,1,1,2,2,3,3-heptafluoron-butyl group, 1,1,2,2 , 3,3,4,4,5,5,6,6-dodecafluoro n-hexyl group and 1,1,1,2,2,3,3,4,4,5,5,6,6- A tridecafluoro n-decyl group is mentioned. The fluoroalkyl group having 1 to 12 carbon atoms may be further substituted with an alkyl group or a halogen atom (excluding a fluorine atom).

  As an aryl group, for example, an aryl group having 6 to 12 nuclear atoms represented by a phenyl group, a biphenyl group, and a naphthyl group, and a fluoroaryl group, for example, a monofluorophenyl group, a difluorophenyl group, a tetrafluorophenyl Examples thereof include a fluoroaryl group having 6 to 12 nuclear atoms represented by the group.

R ² represents one or more of the aforementioned alkyl group, fluoroalkyl group, aryl group and fluoroaryl group, and a divalent group corresponding to these groups, that is, an alkylene group, a fluoroalkylene group, an arylene group. A monovalent group in which one or more of a group and a fluoroarylene group are bonded may be used. Examples of such a group include a group in which an alkylene group and a perfluoroalkyl group are bonded (however, this group is also a kind of fluoroalkyl group), a group in which an alkylene group and an aryl group are bonded (aralkyl). Group), a group in which a fluoroalkyl group and a fluoroarylene group are bonded to each other.

R ² is preferably an alkyl group or a fluoroalkyl group from the viewpoint of more effectively and reliably achieving the effects of the present invention, and is an alkyl group having 1 to 12 carbon atoms or a fluoroalkyl group having 1 to 12 carbon atoms (provided that Or a perfluoroalkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms or a fluoroalkyl group having 2 to 10 carbon atoms (provided that perfluoro More preferably, the alkyl group is excluded.

R ³ in the general formula (2) may have one or more oxygen and / or sulfur atoms in the main chain, and may be substituted with an alkyl group. Represents a saturated saturated hydrocarbon group. The carbon number is preferably 1 to 16, and more preferably 2 to 14. The gelling ability can also be controlled by the number of carbon atoms in R ³ . Moreover, it is preferable that it is carbon number of the said range from a viewpoint of a synthesis | combination and raw material acquisition.

Examples of the gelling agent having a perfluoroalkyl group represented by the general formula (1) or (2) include Rf ¹ -R ¹ —O—R ² and Rf ¹ —R ¹ —S—R ^2. Rf ¹ -R ¹ -SO ₂ -R ² , Rf ¹ -R ¹ -OCO-R ² , Rf ¹ -R ¹ -O-Ar-O-R ² (where Ar is a divalent aromatic group) are shown. ^{Similarly.), Rf 1 -R 1 -SO} 2 -Ar-O-R 2, Rf 1 -R 1 -SO 2 -Ar-O-Rf 4, Rf 1 -R 1 -SO 2 -Ar —O—Rf ³ —Rf ⁴ (where Rf ³ represents a fluoroalkylene group and Rf ⁴ represents a fluoroalkyl group), Rf ¹ —R ¹ —SO—Ar—O—R ² , Rf ¹ —R ¹ —S—Ar—O—R ² , Rf ¹ —R ¹ —O—R ⁵ —O—R ² (wherein R ⁵ represents an alkylene group), Rf ¹ —R ¹ —CONH—R ² , Rf ¹ -R ^1— SO ₂ —Ar ¹ —O—R ³ —O—Ar ² —SO ₂ —R ⁴ —Rf ² (wherein Ar ¹ and Ar ² each independently represent a divalent aromatic group. . ^{Similarly), Rf 1 -R 1 -O-} Ar 1 -O-R 3 -O-Ar 2 -O-R 4 -Rf 2, Rf 1 -R 1 -SO 2 -Ar 1 -O-R 6 - Examples include compounds represented by the general formula: O—R ⁷ —O—Ar ² —O—R ⁴ —Rf ² (wherein R ⁶ and R ⁷ each independently represents an alkylene group; the same shall apply hereinafter). It is done. More specifically, Rf ¹ and Rf ² are each independently a perfluoroalkyl group having 2 to 10 carbon atoms, R ¹ is an alkylene group having 2 to 4 carbon atoms, Ar is (or Ar ¹ and Ar ² are each Independently, a p-phenylene group or a p-biphenylene group, a compound represented by each of the above general formulas wherein R ² is an alkyl group having 4 to 8 carbon atoms, and a dimer structure thereof, for example, Rf ¹ -R ^1- O—Ar—O—R ² , Rf ¹ —R ¹ —SO ₂ —Ar—O—R ² , Rf ¹ —R ¹ —O—Ar ¹ —O—R ³ —O—Ar ² —O— R ⁴ —Rf ² , Rf ¹ —R ¹ —SO ₂ —Ar ¹ —O—R ⁶ —O—R ⁷ —O—Ar ² —O—R ⁴ —Rf ² are exemplified. It is done.

  In the general formula (3), Cy represents a substituted or unsubstituted divalent aromatic hydrocarbon group or alicyclic hydrocarbon group having 5 to 30 nuclear atoms. The divalent aromatic hydrocarbon group is a cyclic divalent group exhibiting so-called “aromaticity”. The divalent aromatic hydrocarbon group may be a monocyclic group or a heterocyclic group. These divalent aromatic hydrocarbon groups may be substituted with a substituent or may be an unsubstituted one that is not substituted. The substituent of the divalent aromatic hydrocarbon group can be selected from the viewpoint of synthesis and availability of raw materials. Alternatively, the substituent of the divalent aromatic hydrocarbon group can be selected from the viewpoint of the melting temperature and gelling ability of the gelling agent. The monocyclic group has 6 to 30 nuclear atoms, may be substituted with a substituent, or may be unsubstituted or unsubstituted. Specific examples thereof include divalent groups having a nucleus represented by a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, a chrysenylene group, and a fluoranthenylene group. It is done. The heterocyclic group has 5 to 30 nuclear atoms, may be substituted with a substituent, or may be unsubstituted. Specific examples thereof include a divalent group having a nucleus represented by a pyrrolene group, a furylene group, a thiophenylene group, a triazolen group, an oxadiazolene group, a pyridylene group, and a pyrimidylene group.

  The aromatic hydrocarbon group is a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 nuclear atoms from the viewpoints of availability of raw materials and ease of synthesis and gelation ability in the electrolytic solution. It is preferably a group selected from the group consisting of a phenylene group, a biphenylene group, a naphthylene group, a terphenylene group and an anthranylene group.

  The alicyclic hydrocarbon group has 5 to 30 nuclear atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

  An aromatic hydrocarbon group or an alicyclic hydrocarbon group has a combination of a plurality of groups as long as the number of core atoms is within the above range, or has both a simple ring and a heterocyclic ring, or an aromatic group And an alicyclic group. In addition, examples of the substituent of the aromatic hydrocarbon group or the alicyclic hydrocarbon include an alkyl group typified by a methyl group and an ethyl group, and a halogen atom.

In the general formula (3), R ⁵ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms in the main chain, and may be saturated or unsaturated. R ⁵ may be an aliphatic hydrocarbon group and may further have an aromatic hydrocarbon group. A part or all of the hydrocarbon groups in the aliphatic hydrocarbon group and aromatic hydrocarbon group may be substituted with a halogen atom. When the monovalent hydrocarbon group is a monovalent aliphatic hydrocarbon group, it may be branched or unbranched, and part or all of the branched chain may be substituted with a halogen atom. Moreover, this hydrocarbon group may have an oxygen atom and / or a sulfur atom in its chain. Furthermore, when the monovalent hydrocarbon group has an aromatic hydrocarbon group, the aromatic hydrocarbon group may further have a substituent. However, the monovalent hydrocarbon group is obtained by dissolving the compound represented by the general formula (3) (hereinafter also referred to as “compound (3)”) in a solvent, Therefore, it is preferably a hydrocarbon group that makes the compound (3) easily soluble in a solvent, such as an aralkyl group typified by a benzyl group. Moreover, when the carbon number of the monovalent hydrocarbon group is 21 or more, it tends to be difficult to obtain raw materials. The monovalent hydrocarbon group represented by R ⁵ is preferably an alkyl group having 4 to 18 carbon atoms, more preferably an alkyl group having 4 to 14 carbon atoms, from the viewpoint of more effectively and reliably achieving the effects of the present invention. More preferably. R ⁵ is preferably a linear alkyl group from the viewpoints of gelling ability and handling properties.

In the general formula (3), X ³ represents the following formulas (3a), (3b), (3c), (3d), (3e), (3f) and (3g) (hereinafter, (3a) to (3g) Or a divalent group in which two or more of the groups represented by the following formulas (3a) to (3g) are bonded to each other. Show. Among these, from the viewpoint of gelling ability, charge / discharge characteristics of the battery, and long-term stability, any group selected from the group consisting of groups represented by the following formulas (3a), (3e) and (3g) Preferably there is.

In the general formula (3), X ³ is preferably selected from the viewpoint of long-term stability and gelling ability when the compound (3) is used as a gelling agent contained in a battery. When X ³ is a group represented by the above formula (3a), the composition containing the gelling agent tends to be a very stable gel. When X ³ is a group represented by the above formula (3e), the composition containing the gelling agent can be used in that the gel-sol transition can be induced not only by temperature adjustment but also by light irradiation. It leads to expansion.

In the general formula (3), Cm represents a monovalent group (coumarin moiety) represented by the following general formula (3z). In the following formula (3z), a plurality of R ^a are each independently a hydrogen atom. Represents an alkyl group, an alkoxy group or a halogen atom. When R ^a is an alkyl group, the carbon number is preferably 1 to 6, and when it is an alkoxy group, the carbon number is preferably 1 to 8.

  The low molecular gelling agent mentioned above is used individually by 1 type or in combination of 2 or more types.

  The low molecular weight gelling agent in this embodiment may be synthesized by a conventional method, or a commercially available product may be obtained. Examples of the low-molecular gelling agent having a perfluoroalkyl group include International Publication No. 2007/083843, Japanese Unexamined Patent Publication No. 2007-191626, Japanese Unexamined Patent Publication No. 2007-191627, Japanese Unexamined Patent Publication No. 2007-191661, and International Publication No. It can manufacture with reference to the method of 2009/78268.

Moreover, the low molecular gelling agent which has a perfluoroalkyl group is compoundable with the following scheme, for example. First, a thiol compound represented by the following general formula (11a) is sulfided with a compound represented by the following general formula (11b) in the presence of a base such as triethylamine in a solvent such as dry THF. The compound represented by (11c) is obtained.
HS-Ar-OH (11a)
C _m F _{2m + 1} C _p H _2p X ¹ (11b)
_{C m F 2m + 1 C p} H 2p -S-Ar-OH (11c)

Next, the compound represented by the general formula (11c) is etherified with a compound represented by the following general formula (11d) in the presence of an alkali metal compound such as K ₂ CO _{3 in} a solvent such as 3-pentanone. To obtain a compound represented by the following general formula (11e).
R ¹ X ² (11d)
_{C m F 2m + 1 C p} H 2p -S-Ar-O-R 1 (11e)

Then, the perfluoro compound represented by the following general formula (11j) is obtained by oxidizing the compound represented by the general formula (11e) with an oxidizing agent such as hydrogen peroxide in the presence of a catalyst such as acetic acid. Is obtained.
_{C m F 2m + 1 C p} H 2p -SO 2 -Ar-O-R 1 (11j)
Here, as long as in the production scheme of the perfluoro compound represented by the general formula (11j), Ar represents a substituted or unsubstituted divalent aromatic group having 8 to 30 nuclear atoms, and R ¹ is saturated or Represents an unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms, m represents a natural number of 2 to 16, p represents an integer of 0 to 6, and X ¹ represents a halogen atom such as an iodine atom, for example. X ² represents a halogen atom such as a bromine atom.

  As such a synthesis method, for example, the synthesis method described in International Publication No. 2009/78268 pamphlet can be referred to.

Further, when Ar is a group in which a plurality of aromatic rings such as a biphenylene group or a terphenylene group are bonded by a single bond, a perfluoro compound represented by the above general formula (11j) is obtained by the following synthesis method, for example. Can do. First, a thiol compound represented by the following general formula (11f) is sulfided with a compound represented by the above general formula (11b) in the presence of a base such as triethylamine in a solvent such as dry THF. A compound represented by (11 g) is obtained. Here, in the formulas (11f) and (11g), m and p are as defined in the formula (11j), X ³ represents a halogen atom such as a bromine atom, and Ar ² represents the above formula (11j). ) Represents a part of the divalent aromatic hydrocarbon group constituting Ar.
^{HS-Ar 2 -X 3 (11f} )
_{C m F 2m + 1 C p} H 2p -S-Ar 2 -X 3 (11g)

Next, the following compound (11h) is obtained by oxidizing the compound represented by the general formula (11g) with an oxidizing agent such as hydrogen peroxide in the presence of a catalyst such as acetic acid. Here, in the formula (11h), Ar ² , X ³ , m and p are as defined in the formula (11g).
_{C m F 2m + 1 C p} H 2p -SO 2 -Ar 2 -X 3 (11h)

Then, from the compound represented by the above general formula (11h) and the compound represented by the following general formula (11i), in the presence of a palladium catalyst in a basic aqueous solution such as K ₂ CO ₃ , Suzuki-Miyaura coupling To obtain the perfluoro compound represented by the general formula (11j). Here, in the formula (11i), R ¹ has the same meaning as in the formula (11j), Ar ³ is Ar ² a divalent aromatic hydrocarbon group constituting Ar in the formula (11j) A part different from is shown, and Ar ² and Ar ³ bonded by a single bond is Ar.
R ¹ —O—Ar ³ —B (OH) ₂ (11i)

Moreover, the gelling agent which has a perfluoroalkyl group in this embodiment is compoundable with the following scheme, for example. That is, from the compound represented by the following general formula (Ia) and the compound represented by the following general formula (IIa), dehydration condensation such as Mitsunobu reaction is a kind of gelling agent having a perfluoroalkyl group. A compound represented by the general formula (IIIa) can be synthesized. Here, in the formula, Y ¹ and Y ² each independently represent a sulfur atom or an oxygen atom.
^{Rf 1 -R 1 -Y 1 -Z-} Y 2 H (Ia)
Rf ² R ² OH (IIa)
^{Rf 1 -R 1 -Y 1 -Z-} Y 2 -R 2 -Rf 2 (IIIa)

Further, in the compound represented by the above general formula (IIIa), when Y ¹ and / or Y ² is a sulfur atom, the sulfur atom is further sulfonylated or sulfoxidized to have a perfluoroalkyl group. A compound represented by the following general formula (IVa), which is another kind of gelling agent, can be synthesized. Here, at least one of Y ³ and Y ⁴ is an SO group or SO ₂ group, and when one of Y ³ and Y ⁴ is an SO group or SO ₂ group, the other is a sulfur atom or an oxygen atom.
^{Rf 1 -R 1 -Y 3 -Z-} Y 4 -R 2 -Rf 2 (IVa)

The compound represented by the general formula (Ia) is, for example, a perfluoroalkane halide (thiol group or a hydrogen atom of a hydroxyl group) of a compound represented by the following formula (Va) under alkaline conditions ( For example, it can be synthesized by substitution with a perfluoroalkyl group of iodide.
HY ¹ -ZY ² H (Va)

  The compound represented by the above formula (IIa) can be synthesized by further reducing the halide of alkanol obtained by the addition reaction of perfluoroalkane halide (for example, iodide) to alkenol.

Here, as long as in the production scheme of the perfluoro compound (gelator) represented by the above general formula (IIIa) or (IVa), Rf ¹ and Rf ² are each independently of 2 to 18 carbon atoms in the main chain. A substituted or unsubstituted perfluoroalkyl group, R ¹ and R ² each independently represents a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms in the main chain; A substituted or unsubstituted divalent aromatic hydrocarbon group or alicyclic hydrocarbon group having 5 to 30 nuclear atoms is shown.

  However, the synthesis method of the gelling agent having a perfluoroalkyl group in the present embodiment is not limited to the above method.

  In addition, the compound (3) in the present embodiment is a coumarin-type gelling agent, and for example, the compound described in the liquid crystal discussion conference proceedings collection p44 (2007) can be used as the compound (3).

The compound (3) having an azo group, that is, the compound (3) in which X ³ is represented by the above formula (3e) can be synthesized, for example, by the following reaction pathway.

  Examples of the compound (3) having an azo group synthesized in this way include a compound represented by the following formula (3I) (hereinafter also referred to as “compound (3I)”) and the following formula (3II). And a compound represented by the following (hereinafter also referred to as “compound (3II)”).

Hereinafter, a method for synthesizing the compounds (3I) and (3II) will be described in detail.
[Method for Synthesizing Compound (3I)]
(Step 1: Synthesis of Compound (a))

  Add a mixed solution of concentrated nitric acid and concentrated sulfuric acid to the eggplant flask. While cooling the eggplant flask in an ice bath, coumarin is gradually added so that the temperature of the mixed solution does not exceed 20 ° C. When all the coumarin has been added, remove the ice bath and stir at room temperature for 1 hour to react. The reaction solution is poured into water, and the precipitated solid is collected by filtration. The solid collected by filtration is recrystallized from toluene to obtain a light yellow solid compound (a).

(Step 2: Synthesis of Compound (b))

  In an eggplant flask, the compound (a) is dissolved in a mixed solution of ethanol and toluene, and a hydrogenation reaction is performed in the presence of Pd / C. After the hydrogenation reaction, Pd / C is collected by filtration, and the filtrate is concentrated by an evaporator. The precipitated solid is recrystallized from toluene to obtain a yellow solid compound (b).

(Step 3: Synthesis of Compound (c))

A 12N aqueous hydrochloric acid solution is prepared in an eggplant flask under ice cooling at 5 ° C. Compound (b) and sodium nitrite (NaNO ₂ ) are added to the aqueous solution and stirred for 20 minutes. Further, a mixed solution of phenol, sodium hydroxide and water is added and stirred. The precipitated solid is recrystallized from toluene to obtain compound (c).

(Step 4: Synthesis of Compound (3I))

  In an eggplant flask, compound (c) is dissolved in 3-pentanone. 1-Bromooctane and potassium carbonate are added to the obtained solution and refluxed for 15 hours. The obtained solid is recrystallized from toluene and purified by column chromatography to obtain compound (4I). In the column chromatography, silica gel is used as a filler and chloroform is used as a developing solvent.

  [Method for Synthesizing Compound (3II)]

  In an eggplant flask, compound (c) is dissolved in 3-pentanone. 1-Bromohexane and potassium carbonate are added to the obtained solution and refluxed for 15 hours. The obtained solid is recrystallized from toluene and purified by column chromatography to obtain compound (3II). In the column chromatography, silica gel is used as a filler and chloroform is used as a developing solvent.

  However, the manufacturing method of a compound (3) is not limited to the said method.

  The content of the low molecular gelling agent in the ion conductor in the present embodiment is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte. More preferably, it is part by mass. The content of the low molecular gelling agent is preferably 0.0005 to 18 parts by mass, and more preferably 0.005 to 8 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte.

  When there are two or more ionic conductors in the present embodiment, there may be at least one phase containing a low molecular gelling agent. In particular, it is preferable that the ionic conductor phase in the vicinity of the negative electrode contains a low molecular gelling agent because the effect of improving safety tends to become more remarkable.

  The ion conductor in this embodiment can further contain an additive as necessary. Examples of the additive include a heat stabilizer, a flame retardant, a thermal runaway inhibitor, an overcharge suppression additive, a thickener, an emulsifier, a reinforcing agent, and an additive for forming an electrode protective film. These additives may be solid (bulk), powder, or liquid, and may be dissolved or not dissolved in the electrolytic solution.

  The content of the additive is selected within a range that does not hinder the achievement of the object of the present invention and can achieve the purpose of use of the additive, but achieves both good battery characteristics and the effect of the additive. From this viewpoint, the content of the additive is preferably 0.5 part by mass to 20 parts by mass, and preferably 1 part by mass to 10 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte. More preferred.

  The mixing ratio of the solvent, the electrolyte, and the low-molecular gelling agent can be selected according to the purpose, but both the concentration of the electrolyte and the content of the gelling agent are within the above-mentioned preferable range, and further more preferable range. desirable. By preparing the electrolytic solution with such a composition, all of battery characteristics, handleability and safety can be further improved.

  The ionic conductor injected into the battery may be in a liquid form in which an electrolyte and a low molecular gelling agent are dissolved in a solvent, or in a gel form containing a solvent, an electrolyte and a low molecular gelling agent, Furthermore, it may be in the form of a slurry in which an electrolyte is dissolved in a solvent and a low molecular gelling agent is dispersed, or may be in a solid form. It is preferable that the ionic conductor is in the form of a liquid or a slurry because it tends to be easily injected into the battery and impregnated into the battery structure. On the other hand, the gel or solid form is preferable because safety tends to be further improved. The “slurry” refers to a muddy state in which a solid (low molecular gelling agent) is dispersed in a liquid (electrolytic solution), that is, a solid in which a solid that does not dissolve in the liquid exists. This refers to a fluid that is in a two-phase system of liquid (a state in which no solid is precipitated) and is in a muddy state due to the presence of some solids. Moreover, when an ionic conductor is two or more phases, it is preferable that the one or more phases are gelatinous.

The preparation method of the ion conductor in this embodiment will not be specifically limited if it is the method of mixing each component contained there, The order which mixes each component is not ask | required. Specifically, an ion conductor is prepared by mixing a predetermined amount of electrolyte and a solvent to prepare a preliminary electrolyte solution-containing liquid, and then mixing a low-molecular gelling agent with the preliminary electrolyte solution-containing solution. Can be obtained. Alternatively, it is possible to obtain an ionic conductor by mixing all the components in a predetermined amount simultaneously. In addition, in the preparation method of an ion conductor, the mixture containing a low molecular weight gelatinizer can be once heated, and it can cool to room temperature in the state in which each component in a mixture became uniform.
In addition, an ion conductor prepared in advance can be injected into the battery structure, or an ion conductor component can be mixed and prepared in the battery structure.

<Negative electrode>
The negative electrode in the present invention contains a lithium compound as a negative electrode active material. Specific examples of the lithium compound include lithium metal, an alloy having a lithium element, or a metal oxide or metal nitride having a lithium element. As the lithium compound, lithium metal is preferably used from the viewpoint of battery characteristics.

  Examples of the alloy having a lithium element include a lithium aluminum alloy, a lithium tin alloy, a lithium lead alloy, and a lithium silicon alloy. Moreover, as a metal oxide which has a lithium element, lithium titanium oxide etc. can be mentioned, for example. Examples of the metal nitride having a lithium element include lithium cobalt nitride, lithium iron nitride, and lithium manganese nitride.

  A negative electrode active material is used individually by 1 type or in combination of 2 or more types.

  The negative electrode in this embodiment may have only a negative electrode active material, and may contain at least one of a conductive material, a binder, and a catalyst in addition to the negative electrode active material. For example, when the negative electrode active material is in the form of a foil, a negative electrode containing only the negative electrode active material can be obtained. On the other hand, when the negative electrode active material is in a powder form, a negative electrode containing a negative electrode active material and a binder can be obtained. As the binder used at this time, one that functions to bind the active material particles and the conductive particles can be used. For example, fluorine-containing resins such as polytetrafluoroethylene, polyvinylidene fluoride, and fluororubber; polyethylene Polyolefin such as polypropylene, synthetic rubber, latex, cellulose and the like can be used. As the catalyst, for example, inorganic ceramics or organic complexes can be used.

  Examples of the solvent in which the negative electrode active material, the conductive material, the binder, and the catalyst are dispersed include, for example, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, 2-butanol, cyclohexanone, carbonate ester Organic solvents such as acrylic acid esters can be used. A binder such as styrene butadiene rubber and cellulose can be used in a slurry dispersed in water. In that case, it is preferable to use a cellulose-based thickener (such as carboxymethyl cellulose) or a dispersant.

  The negative electrode current collector is not particularly limited as long as it has conductivity, and examples thereof include copper, stainless steel, nickel, and carbon. Examples of the shape of the current collector include a foil shape, a plate shape, and a grid. Or the battery exterior body may have the function of a negative electrode electrical power collector.

<Positive electrode>
A positive electrode will not be specifically limited if it acts as a positive electrode of a battery, A well-known thing may be used. Examples of the positive electrode active material included in the positive electrode include composite oxides represented by the following general formulas (6a) and (6b), metal chalcogenides and metal oxides having a tunnel structure and a layered structure, and olivine-type phosphate compounds. Can be mentioned.
Li _x MO ₂ (6a)
Li _y M ₂ O ₄ (6b)
Here, in the formula, M represents one or more metals selected from transition metals, x represents a number from 0 to 1, and y represents a number from 0 to 2.

More specifically, as the positive electrode active material, for example, lithium cobalt oxide typified by LiCoO ₂ ; lithium manganese oxide typified by LiMnO ₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O ₄ ; LiNiO ₂ Li _z MO ₂ (M represents two or more elements selected from the group consisting of Ni, Mn, Co, Al, and Mg, and z is more than 0.9 and less than 1.2. And a lithium-containing composite metal oxide represented by LiFePO ₄ and an iron phosphate olivine represented by LiFePO ₄ . Further, as the positive electrode active material, for example, a metal other than lithium represented by S, MnO ₂ , FeO ₂ , FeS ₂ , V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , TiS ₂ , MoS ₂ and NbSe ₂ is used. Oxides are also included. Furthermore, conductive polymers typified by polyaniline, polythiophene, polyacetylene, and polypyrrole are also exemplified as the positive electrode active material.

Further, it is preferable to use a lithium-containing compound as the positive electrode active material because a high voltage and a high energy density tend to be obtained. As such a lithium-containing compound, any compound containing lithium may be used. For example, a composite oxide containing lithium and a transition metal element, a phosphate compound containing lithium and a transition metal element, and lithium and a transition metal element (For example, Li _{t Mu} SiO ₄ , where M is as defined in the above formula (6a), t is a number from 0 to 1, and u is a number from 0 to 2). . From the viewpoint of obtaining a higher voltage, lithium, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), chromium (Cr), vanadium ( V) and composite oxides containing at least one transition metal element selected from the group consisting of titanium (Ti) and phosphate compounds are preferred.

  A positive electrode active material is used individually by 1 type or in combination of 2 or more types.

  The battery in this embodiment may be a lithium-air battery using oxygen as the positive electrode active material. A lithium-air battery includes an air electrode as a positive electrode. The air electrode contains at least a conductive material, and may contain at least one of a catalyst and a binder as necessary.

  The conductive material used for the air electrode is not particularly limited as long as it shows conductivity. For example, the material exemplified for the negative electrode can be used.

  Examples of the catalyst used for the air electrode include inorganic ceramics such as manganese dioxide and cerium dioxide, organic complexes such as metal phthalocyanine, and composite materials thereof. When a catalyst is supported on the conductive material, the electrode reaction tends to proceed more rapidly. The catalyst content in the air electrode is preferably 1% by mass to 30% by mass and more preferably 5% by mass to 20% by mass with respect to the mass of the entire air electrode. When the content of the catalyst is within the above range, the catalyst function and the battery capacity tend to be efficiently compatible.

  A binder for fixing the conductive material can be used for the air electrode. As a binder, the same thing as what was illustrated by the negative electrode can also be used, and a different thing can also be used.

  The air electrode current collector is not particularly limited as long as it has conductivity, and examples thereof include stainless steel, nickel, aluminum, iron, titanium, carbon, and copper. Further, the surface of the current collector may be coated with a metal or alloy having oxidation resistance and corrosion resistance in order to suppress oxidation and corrosion. Examples of the shape of the current collector include a foil shape, a plate shape, a grid, a sponge shape, a punched metal, an expanded metal, and the like, and preferably have porosity from the viewpoint of current collection efficiency. Particularly preferred is a grid. Furthermore, you may have another electrical power collector which collects the electric charge collected by the grid. Or the battery exterior body may have the function of an air electrode current collector.

  The positive electrode can be formed, for example, by mixing a conductive material, a binder, and, if necessary, a catalyst, rolling the mixture into a film, forming a film, and drying. Alternatively, it can be formed by mixing a conductive material, a binder and, if necessary, a catalyst in a solvent, applying the mixture to a current collector and drying.

<Separator>
The separator in the present embodiment can be provided between the positive electrode and the negative electrode in order to provide safety such as prevention of short circuit between the positive and negative electrodes. As the separator, an insulating thin film having high ion permeability and excellent mechanical strength is preferable.

  Examples of the material of the separator in the present embodiment include ceramic, glass, resin, and cellulose. The resin may be a synthetic resin or a natural resin (natural polymer), and may be an organic resin or an inorganic resin. From the viewpoint of excellent performance as a separator, An organic resin is preferred. Examples of the organic resin include polyolefin, polyester, polyamide, and heat resistant resins such as liquid crystal polyester and aramid. The material other than the low-molecular gelling agent for the separator is preferably ceramic and glass from the viewpoint of heat resistance, and polyester, polyamide, liquid crystal polyester, aramid, and cellulose are preferable from the viewpoint of handling properties and heat resistance. The material other than the low-molecular gelling agent for the separator is preferably polyolefin from the viewpoint of cost and processability. Among these materials, when a resin is employed, it may be a homopolymer or a copolymer, and a mixture of a plurality of types of resins and an alloy may be used.

  Further, the separator may be a laminated body in which films made of a plurality of materials are laminated. When the separator is a laminate, the material of each layer may be the same or different. In the case of manufacturing a separator of a laminated body, it may be manufactured by sequentially stacking a certain layer on another layer, that is, by sequentially multilayering, and a plurality of separate films may be bonded together. Thus, a laminate may be produced.

  As the form of the separator in the present embodiment, for example, a synthetic resin microporous film produced by forming a synthetic resin film, a fiber spun from a synthetic resin or a natural polymer, a woven fabric processed from glass fiber or ceramic fiber, Nonwoven fabrics, knitted fabrics, papermaking, and films prepared by arranging synthetic resin, ceramic particles, and glass fine particles are listed.

  The separator may be produced by stacking a plurality of films produced by a plurality of production methods, or may be produced by sequentially multilayering films produced by a plurality of production methods.

  The separator in the present embodiment is a component other than the above, for example, an organic filler, an inorganic filler, an organic particle, and an inorganic particle on the surface and / or inside of the separator from the viewpoints of membrane reinforcement, charge / discharge assist, heat resistance improvement, and the like. May be included.

  As the separator in the present embodiment, it is preferable to use a separator excellent in water vapor barrier property and oxygen permeability.

<Battery>

A method for manufacturing the battery in the present embodiment is not particularly limited as long as a general method is used. For example, the following method can be selected.
First, a battery structure manufactured using a positive electrode, a negative electrode, and a separator is accommodated in a battery case (exterior). And it can produce by inject | pouring another member and an ion conductor in it.

  The battery structure is, for example, first formed by winding a positive electrode and a negative electrode in a laminated state with a separator interposed therebetween to form a laminated body of a wound structure, or bending them or laminating a plurality of layers. It can be produced by forming into a laminate in which separators are interposed between a plurality of positive electrodes and negative electrodes alternately stacked.

  In the battery manufacturing method of the present embodiment, when an ion conductor is injected into the battery case, the ion conductor can be injected in a liquid state in which an electrolyte and a low-molecular gelling agent are dissolved in a solvent. Moreover, it can also inject | pour in the gel state containing a solvent, electrolyte, and a low molecular gelatinizer.

  In addition, an ion conductor or an ion conductor-containing liquid is applied in advance to one or more members selected from the group consisting of a positive electrode, a negative electrode, and a separator, and then a battery structure is produced using them and accommodated in a battery case. It can also be manufactured.

  In order to improve the affinity between the ion conductor containing the low-molecular gelling agent and other members, it is preferable to include a step of heating after the battery preparation. In the heating step, the heating means is not particularly limited, and for example, a dryer (oven), a vacuum dryer, an inert gas flow dryer, a dry gas flow dryer, an electric heating plate, and a block heater can be used. The heating temperature is preferably 40 ° C. or higher and 200 ° C. or lower, more preferably 50 ° C. or higher and 150 ° C. or lower, and still more preferably 50 ° C. or higher and 120 ° C. or lower. Further, the heating time is preferably 15 seconds or more and 25 hours or less, and the impregnation property to the battery structure tends to be improved by heating within the range. In addition, it is also possible to raise / lower temperature as needed during the process to heat. The battery that has undergone the heating step may be cooled to room temperature, and the cooling rate can be arbitrarily selected.

  In manufacturing the battery in the present embodiment, a process of pressurizing or depressurizing the inside of the battery can be included. The method of pressurization or decompression is not particularly limited, and the heating and the decompression or pressurization may be performed simultaneously or separately. By passing through these steps, the impregnation property of the electrolytic solution into the electrode and separator of the battery structure can be improved.

  After passing through the above steps, if necessary, the remaining members are incorporated into the battery structure, and if the battery case (exterior) is not completely sealed (sealed), the battery is sealed. Can be obtained. If necessary, after passing through the above-described steps, the shape may be adjusted, for example, the excess portion of the battery may be removed, or the battery may be retightened or resealed.

  The shape of the battery in the present embodiment is not particularly limited, and for example, a cylindrical shape, an elliptical shape, a rectangular tube shape, a button shape, a coin shape, a flat shape, and a laminate shape are suitably employed. Among them, a coin type, a cylindrical type, a rectangular tube type, a flat type and a laminate type are more preferably used, and a coin type and a laminate type are more preferably used. The battery having such a shape can further enhance the affinity between the ion conductor and the battery structure, expresses various performances possessed by the ion conductor in the present embodiment, and also produces the battery. It is relatively easy. Also, the size of the battery is not particularly limited, and a structure in which a plurality of batteries are stacked or arranged can be used in combination with many kinds of batteries. Also, among laminated batteries, the battery case (exterior) is constructed by laminating an aluminum film and a resin like an aluminum laminate material from the viewpoint of lightness, durability, handleability, and cost. More preferably.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said embodiment. The present invention can be variously modified without departing from the gist thereof.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples, A various deformation | transformation is possible in the range which does not deviate from the summary. Various characteristics of the battery were measured and evaluated as follows.

(I) Battery performance test Measurement was performed using a charge / discharge device ACD-01 (trade name) manufactured by Asuka Electronics Co., Ltd. and a thermostat PLM-63S (trade name) manufactured by Futaba Kagaku. First, the battery was charged with a constant current of 0.2 C at a constant temperature of 25 ° C., and after reaching 4.2 V, charging was performed at a constant voltage of 4.2 V for a total of 8 hours. Then, it discharged to 2.75V with the constant current of 0.2C. Subsequently, the battery was charged with a constant current of 1 C at a constant temperature of 50 ° C., and after reaching 4.2 V, charging was performed at a constant voltage of 4.2 V for a total of 8 hours. Then, it discharged to 2.75V with the constant current of 1C. This charging / discharging at 50 ° C. was counted as one cycle, and subsequently, charging / discharging was performed up to 10 cycles at 50 ° C. A battery that was able to be charged and discharged for 10 cycles was judged as an acceptable battery, and a battery that failed in the middle was judged as an unacceptable battery.

(Ii) Overcharge test of lithium battery Measurement was performed using a charge / discharge device ACD-01 (trade name) manufactured by Asuka Electronics Co., Ltd. and a thermostat PLM-63S (trade name) manufactured by Futaba Kagaku. After charging at a constant current of 0.2 C and reaching 4.2 V, charging was performed at a constant voltage of 4.2 V for a total of 8 hours. Thereafter, overcharging was performed at a predetermined current to a predetermined charging rate. The overcharged battery was disassembled, the cross section and the surface of the negative electrode were observed with a microscope, the lithium dendrite precipitation form was evaluated, and the following determination was made.
○: Lithium is deposited smoothly.
X: Lithium precipitates in a dendritic shape. Or, charging failure occurs.

(Preparation Example 1)
Ethylene carbonate and methyl ethyl carbonate are mixed so that the volume ratio is 1: 2, and LiPF ₆ is added to the mixed solution so as to have a concentration of 1 mol / L. Was prepared. 3 parts by mass of a compound represented by the following formula (A) as a gelling agent was added to 100 parts by mass of the mother electrolyte, heated to 110 ° C., and mixed uniformly. The obtained mixed solution was cooled to 25 ° C. to obtain a gel electrolyte solution (a).
The compound represented by the formula (A) was produced according to the production method described in JP2011-184436A.

(Preparation Example 2)
A non-gelled mother electrolyte (ii) was prepared by adding LiN (CF ₃ SO ₂ ) ₂ at 1 mol / L to propylene carbonate. 3 parts by mass of the compound represented by the above formula (A) as a gelling agent was added to 100 parts by mass of the mother electrolyte, and the mixture was heated to 110 ° C. and uniformly mixed. The obtained mixed solution was cooled to 25 ° C. to obtain a gel electrolyte solution (b).

(Preparation Example 3)
A non-gelled mother electrolyte (iii) was prepared by adding LiBF ₄ to acetonitrile at 1.5 mol / L. 3 parts by mass of the compound represented by the above formula (A) as a gelling agent was added to 100 parts by mass of the mother electrolyte, and the mixture was heated to 110 ° C. and uniformly mixed. The obtained mixed solution was cooled to 25 ° C. to obtain a gel electrolyte solution (c).

(Preparation Example 4)
3 parts by mass of a compound represented by the following formula (B) as a gelling agent is added to 100 parts by mass of the mother electrolyte with respect to the mother electrolyte (i) prepared in Preparation Example 1, and heated to 95 ° C. And mixed uniformly. The obtained mixed solution was cooled to 25 ° C. to obtain a gel electrolyte solution (d).
The compound represented by the formula (B) was produced according to the production method described in JP2011-184436A.

Example 1
Manganese dioxide, ketjen black and polytetrafluoroethylene powder were mixed at a weight ratio of 25: 100: 5, and the mixture was kneaded in an agate mortar to prepare a mixture. The prepared mixture was pressure-bonded to a nickel mesh to obtain a positive electrode (air electrode).
A lithium metal foil (sheet having a thickness of 200 μm) was used as the negative electrode, and a polyethylene microporous film (film thickness: 25 μm) (Hypore manufactured by Asahi Kasei E-Materials Co., Ltd.) was used as the separator.
At this time, the battery was prepared so that 1C = 45.0 mAh.
Using the positive electrode, the negative electrode, and the separator, a positive electrode, a separator, and a negative electrode were stacked in this order, and the battery was covered with the separator to produce a battery structure.
Subsequently, a battery structure composed of a positive electrode, a separator, and a negative electrode was placed on a battery outer body in which aluminum and resin sealed in three directions were laminated, and the gel electrolyte solution prepared in Preparation Example 1 ( 0.5 g of a) was introduced to seal all directions of the battery outer package.
Thereafter, the battery structure containing the electrolytic solution was sandwiched between two stainless steel plates heated to 110 ° C. for 10 minutes, whereby the entire battery structure was sufficiently impregnated with the electrolytic solution. Next, an extra portion of the battery outer package was cut and resealed to obtain a single-layer laminated battery (a).

  The battery obtained was subjected to “(i) battery performance test” and “(ii) lithium battery overcharge test”. The results are shown in Table 1.

(Examples 2 to 4, Comparative Examples 1 to 3)
A single-layer laminate type battery with 1C = 45.0 mAh was produced by the same method as in Example 1 except that the electrolyte shown in Table 1 was used, and the tests (i) and (ii) were conducted. did. The results are shown in Table 1.

  From the above test results, the batteries (Examples 1 to 4) in this embodiment are batteries using a negative electrode containing a lithium compound as a negative electrode active material, without reducing the charge / discharge performance of the battery, It was possible to remarkably suppress lithium needle-like precipitation at the time of abnormality.

  The battery of the present invention has industrial applicability as, for example, a rechargeable battery for a vehicle such as a hybrid vehicle, a plug-in hybrid vehicle, and an electric vehicle, a stationary power source, or a household power source.

Claims (7)

  A battery comprising an ionic conductor containing a low-molecular gelling agent, a negative electrode containing a lithium compound as a negative electrode active material, and a positive electrode.   The battery according to claim 1, wherein the lithium compound is lithium metal. The battery according to claim 1 or 2, wherein the low-molecular gelling agent comprises one or more compounds selected from the group consisting of compounds represented by the following general formulas (1), (2) and (3). .
^{Rf 1 -R 1 -X 1 -L 1} -R 2 (1)
Rf ¹ -R ¹ -X ¹ -L ¹ -R ³ -L ² -X ² -R ⁴ -Rf ² (2)
^{R 5 -O-Cy-X 3} -Cm (3)
(In the formulas (1) and (2), Rf ¹ and Rf ² each independently represents a perfluoroalkyl group having 2 to 20 carbon atoms, and R ¹ and R ⁴ each independently represent a single bond or 1 carbon atom. To 6 divalent saturated hydrocarbon groups, wherein X ¹ and X ² are each independently the following formulas (1a), (1b), (1c), (1d), (1e), (1f) and ( 1g) represents a divalent group selected from the group consisting of groups represented by 1g), L ¹ and L ² are each independently a single bond, an alkyl group or an oxyalkylene group optionally substituted with a halogen atom, an alkyl An oxycycloalkylene group which may be substituted with a group or a halogen atom, or a divalent oxyaromatic group which may be substituted with an alkyl group or a halogen atom, and R ² represents an alkyl group or a halogen atom ( However, A fluoroalkyl group, an aryl group or a fluoro group optionally substituted with an alkyl group having 1 to 20 carbon atoms, an alkyl group or a halogen atom (excluding a fluorine atom) which may be substituted with An aryl group, or a monovalent group in which one or more of these groups and one or more of divalent groups corresponding to these groups are bonded, R ³ represents oxygen and And / or a C1-C18 divalent saturated hydrocarbon group which may have one or more sulfur atoms and may be substituted with an alkyl group.
In formula (3), R ⁵ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms in the main chain, and Cy represents a substituted or unsubstituted divalent aromatic group having 5 to 30 nucleus atoms. It shows the family hydrocarbon group or an alicyclic hydrocarbon group, X ³ is represented by the following formula (3a), (3b), (3c), (3d), (3e), (3f) and (3 g) A divalent group selected from the group consisting of the following groups, or a divalent group in which two or more of these divalent groups are bonded, and Cm is a monovalent group represented by the following general formula (3z) In the following formula (3z), a plurality of R ^a each independently represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.
The battery according to claim 3, wherein X ¹ and X ² are each independently a divalent functional group represented by the formula (1a) or the formula (1d). 5. The battery according to claim 3, wherein both of X ¹ and X ² are a divalent functional group represented by the formula (1d).   The battery according to claim 1, wherein one or more phases of the ion conductor are in a gel form.   The battery according to claim 1, wherein the battery is a lithium-air battery using oxygen as a positive electrode active material of the positive electrode.