Ion-conductive polymer film, electrode composite, battery, and solution containing polymer

Abstract

To provide an ion-conductive polymer film suitable for use in a lithium-air battery having superior battery life and capacity.SOLUTION: An ion-conductive polymer film comprises a polymer comprising at least one kind selected from a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an ion-conductive polymer film, an electrode composite, a battery, and a solution containing a polymer.

Background Art

[0002] In recent years, for the purpose of reducing the weight and increasing the energy density of batteries, metal Li negative electrode batteries, batteries, air batteries, etc. have been actively studied, and the design of positive electrodes, negative electrodes, separators, electrolytes, etc. has been advanced towards practical application. Among them, lithium-air batteries have the highest theoretical capacity and are expected as ultimate secondary batteries (Patent Document 1). In addition, ion-conductive polymer films have been actively studied as separators and electrolytes from the viewpoint of processability. (Patent Documents 2 to 4)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the separator used in Patent Document 1 is an inorganic solid electrolyte, which has problems in processability. In addition, in order for the ion-conductive polymer films of Patent Documents 2 to 4 to achieve practical levels of battery life and capacity of a lithium-air battery, further improvement in the conductivity of ions contributing to battery operation, such as lithium ions, and the performance of blocking the permeation of substances other than those ions is required. Therefore, in view of the above circumstances, an object of the present invention is to provide an ion-conductive polymer film for a lithium-air battery excellent in battery life and capacity.

Means for Solving the Problems

[0005] In order to solve the above problems, the present invention has the following features. [I] In NanoESI (Nano Electrospray Ionization)-MS (Mass spectrometry) analysis, an ion-conductive polymer film containing a polymer having a unit in which the association strength ratio to the ion intensity is 0.6 or more. 4 [II] The ion-conductive polymer film according to [I], containing a polymer having a unit in which the irradiation energy at which the Li association peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 is greater than 0 eV and 2.0 eV or less.

[0006] [III] An ion-conductive polymer film containing a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group. [IV] The ion-conductive polymer film according to any one of [I] to [III], having a non-porous region. [V] The ion-conductive polymer film according to any one of [I] to [IV], wherein the polymer has an aromatic structure in the main chain. [VI] ​The ion-conductive polymer film according to any one of [I] to [V], wherein the glass transition temperature of the polymer is 51°C or higher and 400°C or lower. [VII] The ion-conductive polymer film according to any one of [I] to [VI], wherein the cation concentration is 1 μmol / g or higher and 50,000 μmol / g or lower. [VIII] The ion-conductive polymer film according to any one of [I] to [VII], wherein the lithium ion concentration is 1 μmol / g or higher and 50,000 μmol / g or lower. [IX] The ion-conductive polymer film according to any one of [I] to [VIII], wherein the ionic conductivity is 1.0×10 -7 S / cm or higher and 1.0×10 S / cm or lower. [X] The ion-conductive polymer film according to any one of [I] to [IX], wherein the cation transference number is 0.5 or higher and 1.0 or lower. [XI] The ion-conductive polymer film according to any one of [I] to [X], wherein the haze is 0% or higher and 30% or lower. [XII] The ion-conductive polymer film according to any one of [I] to [XI], wherein the film contains at least one of bis(trifluoromethanesulfonamide) ion, bis(fluorosulfonamide) ion, trifluoromethanesulfonic acid ion, PF 6 ion, ClO 4 ion, BF 4 ion. [XIII] The ion-conductive polymer film according to any one of [I] to [XII], wherein the lithium salt weight concentration is 0 wt% or higher and 80 wt% or lower. [XIV] The ion-conductive polymer film according to any one of [I] to [XIII], which contains an anion having an association constant with the polymer of 1.0 M -1 or higher and 1.0×10 10 M -1 or lower. [XV] An electrode complex having an ion-conductive polymer film according to any one of [I] to [XIV] and an electrode in proximity thereto. [XVI] A battery comprising an ion-conductive polymer film according to any one of [I] to [XVI]. [XVII] The battery according to [XVI], wherein the weight ratio of the electrolytic solution to the film is 0 or more and 5 or less. [XVIII] A vehicle, unmanned transporter, electronic device, unmanned aerial vehicle, or stationary power source comprising the battery according to [XVI] or [XVII]. [XIX] In NanoESI-MS analysis, ClO 4 A polymer having a unit in which the association strength ratio to the ionic strength is 0.6 or more. Solution . [XX] The polymer according to [XIX], comprising a unit in which the irradiation energy at which the Li association peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 is greater than 0 eV and 2.0 eV or less. Solution . [XXI] A solution comprising a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group. [Advantages of the Invention]

[0007] According to the present invention, it is possible to provide an ion-conductive polymer film excellent in ion conductivity, cation transference number, and liquid separation property, and a battery excellent in discharge capacity and cycle life. [Brief Description of the Drawings]

[0008]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0009] The present invention will be described in detail below.

[0010] As one aspect of the present invention, there is provided an ion-conductive polymer film excellent in ion conductivity, cation transport rate, and liquid separation property. Further, as one aspect of the present invention, there is provided a solution containing a polymer used for an ion-conductive polymer film excellent in ion conductivity, cation transport rate, and liquid separation property.

[0011] The ion-conductive polymer film (hereinafter sometimes referred to as "polymer film") used in the embodiments of the present invention is a film made of a polymer that enables ion conduction between a positive electrode and a negative electrode when used as a battery. Specifically, the ion-conductive polymer film has an ion conductivity of 10 -9 S / cm or more. The ion conductivity referred to here means a value measured by the measurement method described later in an environment at 25°C. The upper limit value of the ion conductivity is not particularly limited, but is substantially 1.0×10 S / cm or less. The ion conductivity is preferably 1.0×10 -7 S / cm or more and 1.0×10 S / cm or less, preferably 1.0×10 -6 S / cm or more and 1.0×10 S / cm or less, more preferably 1.0×10 -5 S / cm or more and 1.0×10 S / cm or less, more preferably 1.0×10 -4 S / cm or more and 1.0×10 S / cm or less, more preferably 2.0×10 -4 S / cm or more and 1.0×10 S / cm or less, more preferably 5.0×10 -4It is more preferably 1.0×10 S / cm or more and 1.0×10 S / cm or less. By setting the ionic conductivity within the above range, the ionic permeability inside the battery is high, and excellent output characteristics and cycle characteristics can be obtained. When the ionic conductivity is less than 1.0×10 -5 S / cm, the ionic permeability is low, the output characteristics deteriorate, and the capacity degradation becomes large when repeatedly used. In order to set the ionic conductivity within such a range, it is preferable to form a polymer film using the polymer described later. In the embodiment of the present invention, by including this ion-conductive polymer film, ions can be conducted uniformly. Furthermore, since it is possible to prevent cracks and defects in each layer due to the impact during battery use, which is unique to the polymer film, it is possible to suppress short circuits and ignition due to dendrite generation. Due to the above two points, the capacity maintainability of the battery is improved. Moreover, the interface between the electrode binder layer and the electrolyte layer becomes smooth and the adhesion improves, so that the interfacial resistance value becomes small and the battery characteristics also improve.

[0012] As one aspect of the ion-conductive polymer film of the present invention, in NanoESI-MS analysis, ClO 4 An ion-conductive polymer film containing a polymer having a unit in which the aggregate strength ratio to the ion strength is 0.6 or more can be mentioned. In NanoESI-MS analysis, ClO 4 The aggregate strength ratio to the ion strength can be measured by the method described later, and the stronger the interaction between the polymer and ClO 4 ions, the higher the value. By being within the above range, the polymer and the anions in the ion-conductive polymer film interact strongly, so that the cation transference number, especially the Li transference number, is improved and side reactions of the battery are suppressed, and a battery excellent in discharge capacity and cycle life can be obtained. In NanoESI-MS analysis, ClO 4 The aggregate strength ratio to the ion strength is preferably 1 or more, more preferably 2 or more, further preferably 10 or more, and particularly preferably 100 or more. The upper limit is not particularly limited, but it is preferably 10000 or less. In NanoESI-MS analysis, ClO 4The method for making the complex strength ratio with respect to the ionic strength within the above range is not particularly limited, but a proton-donating functional group may be included in the unit. Specific functional groups include a thiourea group, a urea group, an amino group, a phenol group, and an alcohol group. A thiourea group, a urea group, and an amino group are more preferable, a thiourea group and a urea group are further preferable, and a thiourea group is particularly preferable. Here, the unit is a chemical structure having a molecular weight of 1 or more and 750 or less.

[0013] The polymer in the ion-conductive polymer film according to an embodiment of the present invention, in NanoESI-MS analysis, ClO 4 Preferably, 50 mol% or more of the units having a complex strength ratio with respect to the ionic strength of 0.6 or more, more preferably 65 mol% or more, still more preferably 80 mol% or more, and particularly preferably 95 mol% or more. By being within the above range, the polymer and the anions in the ion-conductive polymer film strongly interact with each other, so that the cation transport rate, particularly the Li transport rate, is improved, side reactions of the battery are suppressed, and a battery excellent in discharge capacity and cycle life can be obtained. For the same reason, the polymer in the ion-conductive polymer film according to an embodiment of the present invention, in NanoESI-MS analysis, ClO 4 Preferably, the units having a complex strength ratio with respect to the ionic strength of 0.6 or more are included in the repeating structure.

[0014] The ion-conductive polymer film according to an embodiment of the present invention preferably contains a polymer having a unit in which the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 is greater than 0 eV and not more than 2.0 eV. The irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 can be measured by the method described later, and the stronger the interaction between the polymer and Li ions, the higher the value. By being within the above range, the polymer interacts weakly with lithium ions in the ion-conductive polymer film, so that the Li transport rate is improved, side reactions of the battery are suppressed, and a battery excellent in discharge capacity and cycle life can be obtained. The irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 is more preferably greater than 0 eV and not more than 1.5 eV, still more preferably 0 eV or more and not more than 1.2 eV, and particularly preferably greater than 0.5 eV and not more than 1.2 eV. The method for setting the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 within the above range is not particularly limited, but an electron-donating functional group may be included in the unit. Specific functional groups include a thiourea group, a thioamide group, a thiourethane group, a cyano group, an ether group, and a fluoro group. The thiourea group, the thioamide group, the thiourethane group, the cyano group, and the ether group are preferable, the thiourea group, the thioamide group, and the thiourethane group are more preferable, and the thiourea group is particularly preferable.

[0015] In the polymer in the ion-conductive polymer film according to an embodiment of the present invention, the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis is 0.5 is greater than 0 eV and 2.0 eV or less, and it is preferable that the unit is 50 mol% or more, more preferably 65 mol% or more, still more preferably 80 mol% or more, and particularly preferably 95 mol% or more. By being within the above range, the polymer interacts weakly with lithium ions in the ion-conductive polymer film, improving the Li transport rate, suppressing side reactions of the battery, and obtaining a battery excellent in discharge capacity and cycle life. Also, for the same reason, in the polymer in the ion-conductive polymer film according to an embodiment of the present invention, the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis is 0.5 is greater than 0 eV and 2.0 eV or less, and it is preferable that the unit is included in the repeating structure.

[0016] As an aspect of the ion-conductive polymer film of the present invention, an ion-conductive polymer film containing a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group can be mentioned. By containing the above polymer, the ion-conductive polymer film can achieve both ion conductivity and the performance of blocking the permeation of substances other than the ions. This effect is considered to be because by containing the above polymer, only cations that contribute to battery operation, such as lithium ions, can be selectively permeated. In particular, it is preferable to contain at least one of a thiourea group, a thioamide group, and a thiourethane group, more preferably to contain at least one of a thiourea group and a thioamide group from the viewpoint of the stability of the chemical structure, and particularly preferably to contain a thiourea group from the viewpoint of lithium ion selective permeability. The method for obtaining the above ion-conductive polymer film is not particularly limited, but for example, it is possible by setting the concentration of the solution for forming the polymer film within the range described below.

[0017] The permeation rate of the ion-conductive polymer film according to an embodiment of the present invention is 0 or more and 2.0×10 -3It is preferably 100 cc / second or less per second. Preferably 0 or more and 5.0×10 -3 It is 100 cc / second or less per second, more preferably 0 or more and 1.0×10 -4 It is 100 cc / second or less per second. When the air permeability is 2.0×10 -3 By setting it to 100 cc / second or less per second, there are few physical through-holes, and the effect of blocking the penetration of dendrites and the like can be obtained. In order to set the air permeability within such a range, it is preferable to form a polymer film using the polymer described later.

[0018] The ion-conductive polymer film of the present invention preferably has a non-porous region. The non-porous region refers to a region where, in a cross-sectional image of the polymer film obtained by field emission scanning electron microscope measurement (FE-SEM) in the measurement method described later, a straight line perpendicular to the interface is drawn from one interface toward the other interface, and the number of voids of 50 nm or more intersecting the straight line is determined, and the number of voids is 10 or less. In the present invention, having a non-porous region means that the thickness of the non-porous region is 0.5 μm or more. When the ion-conductive polymer film is a composite film composed of a non-porous region and a microporous membrane, the point where the distribution and size of voids in the thickness direction start to change is regarded as the interface. By having a non-porous region, the performance of blocking the permeation of substances other than ions contributing to battery operation is improved, and the battery capacity and life can be increased.

[0019] The ion-conductive polymer film of the present invention preferably has a non-porous region thickness of 0.5 μm or more and less than 20 μm. By setting the thickness of the non-porous region below the above upper limit, it is possible to suppress the resistance of the polymer film from becoming too large in battery characteristics, and also to reduce the weight, so it can be suitably used as a battery for a flying object that requires weight reduction. The thickness of the non-porous region is preferably 15 μm or less, more preferably 10 μm or less, and most preferably 5 μm or less. Also, if the thickness of the non-porous region is too small, the cycle life of the battery will decrease, so it is preferably 0.6 μm or more, more preferably 0.8 μm or more, and most preferably 1.0 μm or more. The method for setting the thickness of the non-porous region within the above range is not particularly limited. For example, it can be achieved by setting the concentration of the solution for forming the polymer film within the range described later.

[0020] From the perspective of improving ionic conductivity, the polymer ion-conducting membrane of the present invention preferably has a cation concentration of 1 μmol / g or more. The cation is preferably one or more metal element ions selected from the group consisting of lithium ions, sodium ions, magnesium ions, zinc ions, and aluminum ions. By including one or more metal elements selected from the group consisting of lithium, sodium, magnesium, zinc, and aluminum in the ion-conducting polymer film, the ion mobility increases and the performance of a practical battery can be obtained. The cation concentration is more preferably 30 μmol / g or more, still more preferably 50 μmol / g or more, particularly preferably 100 μmol / g or more, extremely preferably 500 μmol / g or more, and most preferably 1000 μmol / g or more. When the cation concentration is in the above range and the content of one or more metal elements selected from lithium, sodium, magnesium, zinc, and aluminum is less than 30 μmol / g, sufficient ionic conductivity cannot be obtained when used in a secondary battery, and the battery characteristics may be inferior. Although the upper limit of such a content is not particularly defined, if it is too large, the handleability will decrease due to moisture absorption, so it is preferably 50000 μmol / g or less, and more preferably 10000 μmol / g or less. That is, per 1 g of the polymer constituting the polymer ion-conducting membrane, the content of one or more metal elements selected from the group consisting of lithium, sodium, magnesium, zinc, and aluminum is preferably 1 μmol / g or more and 50000 μmol / g or less. Note that the above means that the polymer ion-conducting membrane contains one or more metal elements selected from the group consisting of lithium, sodium, magnesium, zinc, and aluminum, and the content of at least one of the metal elements is within the above range. Alternatively, there may be two or more metal elements among the one or more metal elements selected from the group consisting of lithium, sodium, magnesium, zinc, and aluminum whose contents are within the above range. Further, the cation concentration can be evaluated using known methods such as atomic absorption spectrometry and ICP emission analysis. The method for setting the cation concentration within the above range is not particularly limited, and examples include the method of adding a metal salt described later.

[0021] In the polymer ion-conducting membrane according to an embodiment of the present invention, from the viewpoint of improving ion conductivity, the lithium ion concentration is preferably 1 μmol / g or more. By including a lithium element having a relatively small atomic weight in the polymer ion-conducting membrane, particularly when lithium ions are used as a mobile medium, the ion mobility increases and practical battery performance can be obtained. The lithium ion concentration is more preferably 30 μmol / g or more, still more preferably 50 μmol / g or more, particularly preferably 100 μmol / g or more, extremely preferably 500 μmol / g or more, and most preferably 1000 μmol / g or more. When the content of the lithium element is less than 30 μmol / g, sufficient ion conductivity may not be obtained when used in a secondary battery, and the battery characteristics may be inferior. Although the upper limit of such content is not particularly defined, if it is too large, the handleability may decrease due to moisture absorption, so it is preferably 50000 μmol / g or less, and more preferably 10000 μmol / g or less. That is, the lithium concentration of the polymer ion-conducting membrane is preferably 1 μmol / g or more and 50000 μmol / g or less. The content of the lithium element can be evaluated using known methods such as atomic absorption spectrometry and ICP emission analysis. The method for setting the lithium ion concentration within the above range is not particularly limited, and examples thereof include a method of adding a metal salt described later.

[0022] The lithium element contained in the polymer ion-conducting film in the embodiment of the present invention may be added into the polymer film in the state of a lithium salt (Li salt) as an electrolyte. From the viewpoints of thermal and electrochemical stability, the lithium salt is preferably LiPF 6 、LiAsF 6 、LiClO 4 、LiBF 4 、LiBr, lithium trifluoromethanesulfonate, lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(pentafluoroethanesulfonyl)imide, etc., and LiPF 6 、LiClO 4 、LiBF 4, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, etc. are particularly preferred. These lithium salts may be used alone or in combination of two or more. Similarly, one or more metal elements selected from the group consisting of sodium, magnesium, zinc, and aluminum contained in the polymer ion conductive membrane in the embodiment of the present invention may also be added into the polymer film in the form of a salt as an electrolyte.

[0023] The ion-conductive polymer film in the embodiment of the present invention preferably contains at least one of bis(trifluoromethanesulfonamide) ion, bis(fluorosulfonamide) ion, trifluoromethanesulfonate ion, PF 6 ion, ClO 4 ion, BF 4 ion. By containing the above ions, the number of dissociated cations in the film is improved, and the ion-conductive polymer film exhibits good ionic conductivity.

[0024] The anion in the ion-conductive polymer film according to the embodiment of the present invention preferably has an association constant with the polymer of 1.0 M -1 or more and 1.0×10 10 M -1 or less, more preferably 5.0 M -1 or more and 1.0×10 10 M -1 or more and 1.0×10 1 M -1 or more and 1.0×10 10 M -1 or more and 1.0×10 2 M -1 or more and 1.0×10 10 M -1It is particularly preferable that it is within the above range. By being within the above range, dissociation of the electrolyte salt contained in the polymer is promoted, and at the same time, the cation transport rate is improved, thereby improving the battery life and capacity. The above association constant represents the strength of the interaction between the polymer and the anion. In the combination of a polymer and an anion with a high binding constant, conduction of the anion, which is a factor in battery side reactions, is inhibited. The association constant with the polymer can be measured by NMR described later. The method for setting the association constant with the polymer within the above range is not particularly limited. For example, it is preferable to form a polymer film using the polymer and the Li salt described later.

[0025] The weight concentration of the Li salt contained in the polymer ion conductive film in the embodiment of the present invention is preferably 0 wt% or more and 80 mass% or less, more preferably 10 wt% or more and 60 mass% or less, and particularly preferably 20 wt% or more and 40 mass% or less. By being 0 wt% or more, the ionic conductivity is improved. On the other hand, by being 80 wt% or less, the film strength is good. The method for setting the Li salt weight concentration within the above range is not particularly limited. For example, the metal salt concentration can be changed by the method for forming the polymer ion conductive film described later.

[0026] The haze of the ion conductive polymer film of the present invention is preferably 0% or more and 30% or less, more preferably 0% or more and 10% or less, still more preferably 0% or more and 5% or less, and particularly preferably 0% or more and 1% or less. By being within the above range, a uniform film can be obtained, and good ionic conductivity and electrolyte blocking performance are exhibited. The method for setting the haze within the above range is not particularly limited. For example, it is preferable to form a polymer film using the polymer described later.

[0027] In the polymer ion-conducting membrane according to the embodiment of the present invention, the cation transport rate is preferably 0.5 or more and 1.0 or less, more preferably 0.6 or more and 1.0 or less, still more preferably 0.7 or more and 1.0 or less, and even more preferably 0.8 or more and 1.0 or less. By the cation transport rate being within the above range, side reactions in the battery and a decrease in liquid separation properties can be suppressed, and good battery characteristics can be exhibited. The cation transport rate can be evaluated using known methods using an alternating current impedance method and a direct current method.

[0028] The polymers that can be used in the embodiment of the ion-conducting polymer film of the present invention include polymers containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group. In particular, polymers having an aromatic ring on the main chain can be preferably used. Examples of the polymers having an aromatic ring on the main chain include aromatic polythioketones, aromatic polythioureas, aromatic polythioamides, aromatic polythiourethanes, semi-aromatic polythioketones, semi-aromatic polythioureas, semi-aromatic polythioamides, and semi-aromatic polythiourethanes. A blend of a plurality of polymers may also be used. Among them, aromatic polythioureas, aromatic polythioamides, aromatic polythiourethanes, and semi-aromatic polythioureas are more preferable, and aromatic polythiourea is particularly preferable because it is easy to maintain high strength when thinned. That is, it is preferable that the ion-conducting polymer according to the embodiment of the present invention contains aromatic polythiourea.

[0029] Examples of the aromatic polythiourea and semi-aromatic polythiourea that can be preferably used in the present invention include those having a repeating unit represented by the following chemical formula (1), chemical formula (2), and / or chemical formula (3). Ar in chemical formula (1) 1 , Ar in chemical formula (2) 2 , and Ar 3、 Ar in chemical formula (3) 4is a group containing an aromatic group, and each may be a single group or a multi-component copolymer composed of a plurality of groups. R in Chemical Formula (3) is a non-aromatic structure that does not contain an aromatic ring. By using the above aromatic polythiourea and semi-aromatic polythiourea, the performance of blocking the permeation of substances other than ions contributing to battery operation is improved. Among the following Chemical Formulas (1), (2) and / or (3), Chemical Formulas (1) and (2) are more preferred. Also, the bonds constituting the main chain on the aromatic ring may be either meta-oriented or para-oriented. Further, a part of the hydrogen atoms on the aromatic ring may be substituted with any group.

[0030]

Chem.

[0031]

Chem.

[0032]

Chem.

[0033] Specific examples of the aromatic diamines that constitute aromatic polythioureas, aromatic polythioamides, and aromatic polythiourethanes include paraphenylenediamine, metaphenylenediamine, orthophenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis(trichloromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 2-chloro-1,4-phenylenediamine, 2-trifluoromethyl-1,4-phenylenediamine, 5-trifluoromethyl-1,3-phenylenediamine, 4,'-oxybis(3-trifluoromethyl)aniline, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,5'-naphthalenediamine, 4,4'-diaminodiphenyl sulfone, etc., but are not limited thereto.

[0034] Specific examples of the non-aromatic diamines include ethylenediamine, propanediamine, butanediamine, pentanediamine, hexamethylenediamine, etc., but are not limited thereto.

[0035] For the confirmation of each constituent component and its content of the ion-conductive polymer film according to the embodiment of the present invention, although it is not limited to a specific method, proton nuclear magnetic resonance spectroscopy ( 1 1H-NMR) and Fourier transform infrared spectroscopy (FT-IR) can be used. Also, if necessary, a plurality of methods can be combined for confirmation.

[0036] The electrodes in the battery according to the embodiment of the present invention may contain the same polymer as the ion-conductive polymer film. By the electrodes containing the same ion-conductive polymer, the interfacial resistance between the layers can be reduced, and the ion conductivity and cycle characteristics can be improved dramatically, thereby enhancing the battery characteristics.

[0037] The ion-conductive polymer film of the present invention may contain other components that serve as ion-conduction aids as long as the effects of the present invention are not inhibited. Examples thereof include inorganic solid electrolytes, ionic liquids, and lithium salts.

[0038] The ion-conductive polymer film of the present invention preferably has a film thickness change rate (T0 / T1) measured under the conditions described below of 0.3 or more and less than 1.0.

[0039] (Measurement conditions for film thickness change rate) The polymer film is immersed in a non-aqueous electrolyte (1M LiTFSI EC / DEC = 1 / 1, manufactured by Mitsui Chemicals, Inc.) at 25°C for 24 hours, and the thickness of the polymer film before and after immersion is measured with a high-precision digital length measuring instrument (manufactured by Mitutoyo Corporation, model number: VL-50), and substituted into equation (1) for calculation. Film thickness change rate = (T0 / T1) (1) T0: Thickness of the polymer film before immersion in the non-aqueous electrolyte (cm) T1: Thickness of the polymer film after immersion in the non-aqueous electrolyte (cm).

[0040] When the film thickness change rate is 0.3 or more, it is possible to suppress a decrease in the strength of the polymer film inside the battery, and it is excellent in dendrite resistance. Further, when it is less than 1.0, it is excellent in ion conductivity of the polymer film inside the battery. More preferably, it is 0.3 or more and 0.9 or less. In order to set the film thickness change rate within such a range, examples of the polymer constituting the ion-conductive polymer film include the polymers described below.

[0041] The ion-conductive polymer film of the present invention preferably has a non-porous region and a microporous film, and particularly preferably is a composite film having a non-porous region and a microporous film. The method for forming the composite film is not particularly limited, but an example is a method of applying an ion-conductive polymer to at least one surface of the microporous film by the method described below. Examples of the microporous film include a porous film having pores inside, a non-woven fabric, or a porous film sheet made of a fibrous material. The material constituting the microporous film is preferably composed of a resin that is electrically insulating, electrically stable, and stable in a non-aqueous electrolyte. Further, from the viewpoint of imparting a shutdown function, the resin used is preferably a thermoplastic resin having a melting point of 200°C or lower. The shutdown function here refers to a function of closing the porous structure by melting with heat when the lithium-ion battery generates abnormal heat, stopping ion movement, and stopping power generation.

[0042] Examples of the thermoplastic resin include polyolefin-based resins. The microporous film is preferably a polyolefin-based microporous film, and more preferably has a melting point of 200°C or lower. Specific examples of the polyolefin-based resin used for the microporous film include polyethylene, polypropylene, copolymers thereof, and mixtures thereof. Examples include a single-layer microporous film containing 90% by mass or more of polyethylene, and a multi-layer microporous film composed of polyethylene and polypropylene.

[0043] The ion-conductive polymer film of the present invention preferably has a heat shrinkage rate of 10% or less at 150 °C determined by the method described below. Further, it is preferable that both the longitudinal direction (MD) and the width direction (TD) of the polymer film are 10% or less, more preferably 8% or less, and most preferably 5% or less. The lower limit is not particularly limited, but is -1% or more. By setting the heat shrinkage rate of either MD or TD within the above range, it is possible to suppress a short circuit from occurring at the battery end due to dimensional changes of the polymer film during battery heating, and a battery with excellent heat resistance can be obtained. In order to keep the heat shrinkage rate within the above range, it is preferable to use a polymer having the above-described molecular structure and set the production conditions of the polymer film within the range described below.

[0044] It is preferable that at least one of the positive electrode and the negative electrode of the present invention and the ion-conductive polymer film are in proximity. The ion-conductive polymer of the present invention is a polymer that enables ion conduction between the positive electrode and the negative electrode. When at least one of the positive electrode and the negative electrode and the polymer layer are in proximity, the ion conductivity between the layers is improved, and when in proximity to at least one of the electrodes, short circuits and ignition due to dendrite generation during battery use can be suppressed. Here, being in proximity means being within 1 μm, and it may be in direct contact or via other layers.

[0045] A method for obtaining a polymer that can be used as the ion-conductive polymer according to the embodiment of the present invention will be described by taking aromatic polythiourea and semi-aromatic polythiourea as examples, but the polymer that can be used and its polymerization method are not limited thereto.

[0046] Although various methods are available for obtaining aromatic polythiourea, for example, when using the low-temperature solution polymerization method with dithioisocyanate and diamine, thiophosgene and diamine, or 1,1'-thiocarbonyldiimidazole and diamine as respective raw materials, it is synthesized in an aprotic organic polar solvent such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide. In the case of solution polymerization, in order to obtain a polymer with a high molecular weight, it is preferable that the water content of the solvent used for polymerization is 500 ppm or less (mass basis, the same hereinafter), and more preferably 200 ppm or less. Further, a metal salt may be added for the purpose of promoting the dissolution of the polymer. As this metal salt, a halide of an alkali metal or alkaline earth metal that dissolves in an aprotic organic polar solvent is preferable, and examples thereof include lithium chloride, lithium bromide, sodium chloride, sodium bromide, potassium chloride, and potassium bromide. Since the use of equal amounts of both the dithioisocyanate and diamine used may produce an ultra-high molecular weight polymer, it is preferable to adjust the molar ratio so that one is 95.0 to 100.0 mol% of the other. In the case of the reaction between dithioisocyanate and diamine, a basic compound may be added to increase the degree of polymerization, and examples thereof include imidazole, triethylamine, and pyridine.

[0047] The reduced viscosity ηinh of the polymer is preferably 0.3 to 7.0 dl / g. By setting the viscosity within the above range, a polymer excellent in toughness and strength and having good ionic conductivity can be obtained. The reduced viscosity ηinh can be measured, for example, by the method described later.

[0048] The glass transition temperature of the polymer contained in the ion-conductive polymer film of the present invention is preferably 51°C or higher and 400°C or lower, more preferably 100°C or higher and 400°C or lower, still more preferably 150°C or higher and 400°C or lower, and particularly preferably 180°C or higher and 400°C or lower. By being within the above range, the diffusion of the solvent in the electrolyte is suppressed, the decomposition of the electrolyte on the electrode surface and the crossover of decomposition products between the positive and negative electrodes are reduced, and the battery life is improved. The glass transition temperature can be measured by the method using DMA (N,N-dimethylacetamide) described later. The method for setting the glass transition temperature of the polymer within the above range is not particularly limited, and examples thereof include using the polymer described above.

[0049] Next, the film-forming stock solution (hereinafter referred to as the film-forming stock solution) used when manufacturing the electrode mixture layer and the electrolyte layer according to the embodiment of the present invention will be described.

[0050] As one aspect of the battery according to the embodiment of the present invention, a current collector layer on the positive electrode side, an electrode mixture layer containing a positive electrode active material (sometimes referred to as a positive electrode layer), an electrolyte layer, an electrode mixture layer containing a negative electrode active material (sometimes referred to as a negative electrode layer), and a current collector layer on the negative electrode side are laminated in this order or in the reverse order. In addition, a battery can be assembled using known battery components.

[0051] The polymer of the present invention is not only used as the electrolyte layer in the above-described battery as a polymer film, but may also be contained in either the electrode mixture layer of the positive electrode layer or the negative electrode layer, or may be contained in both layers. Further, an ion-conductive polymer may be applied to the surface of the positive electrode layer or the negative electrode layer to serve as both a protective film on the electrode surface and the function of the electrolyte layer.

[0052] As one aspect of the present invention, in NanoESI-MS analysis, a polymer having a unit in which the association strength ratio to the ion intensity is 0.6 or more is included 4 SolutionExamples include the following. By forming an ion-conductive polymer film using a polymer solution containing the above polymer, the polymer strongly interacts with anions in the ion-conductive polymer film, thereby improving the cation transport rate, particularly the Li transport rate, suppressing side reactions of the battery, and obtaining a battery excellent in discharge capacity and cycle life. Further, by forming an ion-conductive polymer film using a solution containing a polymer having a unit in which the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis becomes 0.5 is greater than 0 eV and not more than 2.0 eV, the polymer weakly interacts with lithium ions in the ion-conductive polymer film, thereby improving the Li transport rate, suppressing side reactions of the battery, and obtaining a battery excellent in discharge capacity and cycle life.

[0053] Further, as one aspect of the present invention, a solution containing a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group is exemplified. By forming an ion-conductive polymer film using the polymer solution containing the above polymer, an ion-conductive polymer film excellent in ion conductivity and in the performance of blocking the permeation of substances other than the ions can be obtained.

[0054] The polymer solution after polymerization may be used as it is for the film-forming stock solution, but from the viewpoint of improving the ionic conductivity, it is preferable to add a Li salt to the polymerization solution. When a large amount of unnecessary substances such as neutralization salts are contained, it is preferable to isolate the polymer once and then redissolve it in an organic solvent such as the above-mentioned aprotic organic polar solvent for use. The method for isolating the polymer is not particularly limited, and examples include a method in which the polymer solution after polymerization is poured into a large amount of water or alcohol to extract the solvent and the neutralization salt into water, separating only the precipitated polymer, and then drying it.

[0055] In the manufacturing process of the electrode binder layer and the electrolyte layer according to the embodiment of the present invention, it is preferable to add an active material, an inorganic solid electrolyte, a conductive auxiliary, a lithium salt, etc. to the ion-conductive polymer. There is no limitation on the timing of adding these materials, and it may be any of the polymer polymerization process, the casting solution preparation process, and the casting process. However, it is preferable to add them in the casting solution preparation process because they can be uniformly dispersed with the polymer. Also, it is possible to add them in a plurality of steps, or to add them in multiple portions in the same step.

[0056] The concentration of the polymer in the casting solution is preferably 3 to 30% by mass, more preferably 4 to 20% by mass. Inorganic particles or organic particles may be added to the casting solution within a range that does not inhibit the effects of the present invention for the purpose of improving the strength, heat resistance, ion permeability, and reducing the coefficient of static friction of the resulting polymer film. Examples of the inorganic particles include wet and dry silica, colloidal silica, aluminum silicate, titanium oxide, calcium carbonate, calcium phosphate, barium sulfate, alumina, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, zinc carbonate, titanium oxide, zinc oxide (zinc white), antimony oxide, cerium oxide, zirconium oxide, tin oxide, lanthanum oxide, magnesium oxide, barium carbonate, zinc carbonate, basic lead carbonate (white lead), barium sulfate, calcium sulfate, lead sulfate, zinc sulfide, mica, mica titanium, talc, clay, kaolin, lithium fluoride, and calcium fluoride. Examples of the organic particles include particles crosslinked using a polymer compound as a crosslinking agent. Examples of such crosslinked particles include crosslinked particles of a polymethoxysilane-based compound, a polystyrene-based compound, an acrylic-based compound, a polyurethane-based compound, a polyester-based compound, a fluorine-based compound, or a mixture thereof.

[0057] Next, a method for forming the ion-conductive polymer film of the present invention will be described. The casting solution prepared as described above can be cast by a so-called solution casting method. The solution casting method includes a dry-wet method, a dry method, a wet method, etc., and any method can be used for casting. Here, the dry-wet method will be described as an example.

[0058] When forming a film by the dry-wet method, the film-forming stock solution is extruded from a die onto a support such as a drum, endless belt, film, etc. to form a film-like material, and then the film-like material is dried until it has self-supporting properties. The drying conditions can be carried out, for example, in the range of 60 to 220°C for within 60 minutes. However, the film after the dry process is peeled off from the support and introduced into the wet process, where desalting, solvent removal, etc. are carried out, and stretching, drying, and heat treatment are carried out as necessary.

[0059] When stretching, the stretching ratio is preferably in the range of 0.8 to 8.0 times in terms of area ratio (the area ratio is defined as the value obtained by dividing the film area after stretching by the film area before stretching. A value of 1 or less means relaxation), and more preferably 1.0 to 5.0 times. Also, when heat-treating, heat treatment is carried out at a temperature of 80°C to 500°C, preferably 130°C to 400°C, for several seconds to several tens of minutes. The ion-conductive polymer film of the present invention obtained by the above production method can be used as an electrolyte membrane by simply inserting it between the positive and negative electrodes.

[0060] When the ion-conductive polymer film of the present invention is made into a composite membrane having a non-porous region and a microporous membrane, the polymer film and the microporous membrane obtained by the above film-forming method may be used by overlapping them, or they may be laminated. Also, a method of applying and laminating the film-forming stock solution polymerized above on the microporous membrane is also preferable. As a form of applying the stock solution on the microporous membrane, any coating form such as a roll coater, slit coater, dip coater, etc. can be used.

[0061] The thickness of the ion-conductive polymer film according to the embodiment of the present invention is not particularly limited, but is preferably 0.03 to 30 μm, more preferably 0.10 to 20 μm, and even more preferably 0.20 to 15 μm. Further, when the ion-conductive polymer film of the present invention is a composite film of a polymer film and a microporous membrane, the thickness ratio of the polymer film to the microporous membrane is preferably 0.001 or more and 5 or less, and more preferably 0.01 or more and 1 or less. By setting the thickness within the above range, the strength of the polymer film is sufficient, there is no increase in resistance due to the film thickness, and it can be suitably used. The thickness of the ion-conductive polymer film can be controlled by various conditions such as the concentration of the film-forming stock solution, the viscosity of the film-forming stock solution, the type and concentration of additives in the film-forming stock solution, the casting thickness of the polymer film, the heat treatment temperature, and the stretching conditions.

[0062] The battery according to the embodiment of the present invention preferably includes the ion-conductive polymer film of the present invention. As one aspect of the battery of the present invention, there is an example in which an ion-conductive polymer film obtained by the above-described film-forming method is disposed between a positive electrode and a negative electrode to form a battery. Further, any method can be used as the method for manufacturing the battery. By including the ion-conductive polymer film, the crossover of side reaction products generated at the electrodes between the electrodes and the generation of dendrites at the negative electrode are suppressed, and the life and capacity of the battery are improved.

[0063] The battery according to the embodiment of the present invention is preferably a metal Li negative electrode battery, a silicon negative electrode battery, a clay battery, a sulfur battery, or an air battery from the viewpoint of energy density. Among sulfur batteries, a lithium-sulfur battery is more preferable. Among air batteries, an aluminum air battery, a zinc air battery, a hydrogen air battery, and a lithium air battery are more preferable, and a lithium air battery is particularly preferable.

[0064] The battery according to an embodiment of the present invention has a positive electrode, an electrolyte, an ion-conductive polymer film, an electrolyte, and a negative electrode in this order, and is preferably composed of electrolytes with different compositions on the positive electrode side and the negative electrode side through the ion-conductive polymer film. With the above configuration, decomposition of the electrolyte can be suppressed, leading to an increase in the battery capacity and a longer battery life. Further, in the above battery configuration, it is preferable that at least one of the electrolytes on the electrode side contains water. In particular, when the positive electrode is an air electrode, it is preferable that the electrolyte on the positive electrode side contains water. It is possible to suppress the precipitation of lithium oxide on the positive electrode surface and improve the battery life.

[0065] The positive electrode of the battery according to an embodiment of the present invention includes a known positive electrode active material such as a lithium metal oxide containing at least one transition metal selected from manganese, cobalt, nickel, and titanium and lithium as the positive electrode active material (such as lithium cobaltate and lithium manganate). Further, an air electrode may be used as the positive electrode. From the perspective of energy density, it is preferable to use an air electrode.

[0066] The negative electrode of the present invention is not particularly limited as long as it is a material capable of occluding and releasing metal ions or the like as an active material. For example, known negative electrode active materials such as Li, Sn, Si, In, lithium alloy particles (lithium alloy particles of lithium and titanium, magnesium, aluminum, etc.), and carbon-based materials (carbon, hard carbon, soft carbon, and graphite, etc.) can be appropriately used. Among these, using metallic lithium is preferable from the perspective of increasing the energy density of the battery. Further, the lithium-equivalent concentration of the negative electrode is preferably 1.0 mol / l or more based on the entire negative electrode. If the lithium-equivalent concentration is 1.0 mol / l or more, the battery capacity can be increased. The upper limit is not particularly limited, but is substantially 100 mol / l or less.

[0067] The non-aqueous electrolyte of the present invention can use an organic solvent that is not particularly limited and is used in conventional lithium-ion batteries. Further, the electrolyte to which the present invention is applied may be solid or liquid, but it is preferable to use an electrolytic solution in order to increase the contact area with the electrode. As the solvent of the above electrolytic solution, cyclic esters, chain esters, cyclic ethers, chain ethers, etc. are used. Specifically, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane (DME), 1,2-ethoxyethane, diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, dipropyl carbonate, methyl butyl carbonate, methyl propyl carbonate, ethyl butyl carbonate, ethyl propyl carbonate, butyl propyl carbonate, alkyl propionate, dialkyl malonate, alkyl acetate, tetrahydrofuran (THF), alkyl tetrahydrofuran, dialkyl alkyl tetrahydrofuran, alkoxy tetrahydrofuran, dialkoxy tetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, 1,4-dioxolane, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, methyl propionate, ethyl propionate, triester phosphate, N-methyl-2-pyrrolidone, sulfolane and other organic solvents, water and their derivatives and mixtures, etc. are preferably used.

[0068] As the electrolyte contained in the non-aqueous electrolyte solution, halides, perchlorates, thiocyanates, borofluorides, phosphofluorides, arsenofluorides, aluminum fluorides, trifluoromethyl sulfates, etc. of alkali metals, particularly lithium, are preferably used. For example, lithium perchlorate (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium bis(trifluoromethylsulfonyl)imide [LiN(CF 3 SO 2 ) 2 , lithium bromide (LiBr), lithium bis(oxalate)borate, lithium difluoro(oxalate)borate, lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium bis(pentafluoroethanesulfonyl)imide, etc. One or more salts such as lithium salts (electrolytes) can be used, but lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide (LiFSI) are preferred.

[0069] The non-aqueous electrolyte of the battery according to the embodiment of the present invention contains at least one type of metal ion, and the metal ion concentration is preferably 0.5 mol / l or more and 7.0 mol / l or less. The above metal ion is preferably a metal ion that moves between the positive electrode and the negative electrode when the battery is charged and discharged. Specifically, in the case of a lithium-ion battery, it is a lithium ion, and in the case of a sodium battery, it is a sodium ion. The above metal ion concentration is preferably 0.5 mol / l or more and 5.0 mol / l or less, more preferably 1.0 mol / l or more and 5.0 mol / l or less. By being within the above range, the battery exhibits good battery characteristics. From the viewpoint of the operability of the battery, the above metal ions are preferably lithium ions, sodium ions, magnesium ions, potassium ions, calcium ions, more preferably lithium ions, sodium ions, magnesium ions, and particularly preferably lithium ions. Further, additives may be used in the non-aqueous electrolyte as needed. Examples of the additive include vinylene carbonate, fluoroethylene carbonate, ethylene sulfite, 1,4-butane sultone, propane sultone, 2,4-difluoroanisole, biphenyl, cyclohexylbenzene, etc., and one or more of these may be used.

[0070] For the battery according to the embodiment of the present invention, the weight ratio of the electrolytic solution to the above film contained in the battery (weight of the electrolytic solution / weight of the film) is preferably 0 or more and 5 or less, more preferably 0 or more and 1 or less, still more preferably 0 or more and 0.5 or less, and particularly preferably 0 or more and 0.2 or less. By setting the weight ratio of the electrolytic solution to the film within the above range, the weight energy density of the battery can be improved.

[0071] Next, the manufacturing method of the battery according to the embodiment of the present invention will be described below.

[0072] The material used as the current collector layer in the battery according to the embodiment of the present invention is not particularly limited. For example, metal foils made of gold, silver, aluminum, copper, stainless steel, nickel, titanium, alloys thereof, carbon-based materials, etc. can be used.

[0073] The electrode mixture layer of the positive electrode of the battery according to the embodiment of the present invention may be a single substance or may contain other components. As other components, known positive electrode active materials such as at least one transition metal selected from manganese, cobalt, nickel, and titanium and lithium metal oxides containing lithium (such as lithium cobaltate and lithium manganate) can be appropriately used. Also, for the electrode mixture layer of the negative electrode, the active material is not particularly limited as long as it is a material capable of occluding and releasing metal ions, etc. For example, known negative electrode active materials such as Li, Sn, Si, In, lithium alloy particles (lithium alloy particles of lithium and titanium, magnesium, aluminum, etc.), and carbon-based materials (carbon, hard carbon, soft carbon, graphite, etc.) can be appropriately used.

[0074] The electrode composite according to the embodiment of the present invention preferably has the above film and the electrode in proximity. The above film of the present invention is a polymer that enables ion conduction between the positive electrode and the negative electrode. When at least one of the positive electrode and the negative electrode is in proximity to the polymer layer, the ion conductivity between the layers is improved, and when in proximity to at least one of the electrodes, short circuits and ignition due to dendrite generation during battery use can be suppressed. Here, having in proximity means having within 1 μm, and it may be in direct contact or via other layers. As a method of bringing the electrode and the ion-conductive polymer film into proximity, a method using roll pressing or a method of applying a solution containing the ion-conductive polymer film to the electrode and drying it can be mentioned.

[0075] The battery according to the embodiment of the present invention can be suitably used as a power source for electronic devices such as mobile phones and watches, vehicles such as electric vehicles (EVs), hybrid vehicles (HEVs), plug-in hybrid vehicles (PHEVs), airplanes, UAMs, unmanned transporters such as drones, unmanned aircraft such as HAPS, and large industrial equipment such as industrial cranes. It can also be suitably used for power leveling in solar cells, wind power generation devices, etc., energy storage devices for smart grids, and stationary power sources. Furthermore, it can be suitably used for batteries used in special environments such as space.

Example

[0076] The present invention will be described in more detail with the following examples. The physical properties of the examples were measured by the following methods.

[0077] (1) Inherent viscosity ηinh The polymer is dissolved in N-methylpyrrolidone (NMP) with 2.5 mass% lithium bromide (LiBr) added at a concentration of 0.5 g / dl, and the flow-down time is measured at 30 °C using an Ubbelohde viscometer. The flow-down time of the blank LiBr 2.5 mass% / NMP without dissolving the polymer is also measured in the same way, and the inherent viscosity ηinh (dl / g) can be obtained by calculating using the following formula.

[0078] Inherent viscosity ηinh (dl / g) = [ln(t / t0)] / 0.5 t0: Flow-down time of the blank (seconds) t: Flow-down time of the sample (seconds).

[0079] (2) Permeation rate Measurement was carried out using a Wangyan permeability meter (manufactured by Asahi Seiko Co., Ltd., EGO-1T) with an air volume setting of 100 cc. The measurement upper limit of the device is 10,000 seconds / 100 cc. The polymer film was fixed so as not to wrinkle, and the measurement was carried out in accordance with JIS P8117:2009. The measurement points were set at 3 equally spaced points in the TD direction, and the reciprocal of the average value of the permeability was used as the permeation rate (100 cc / second).

[0080] (3) Cross-sectional structure (thickness of polymer film, thickness of non-porous region) The polymer film obtained in the example was subjected to cross-sectional cutting using a cross-section polisher (SM-9010 manufactured by JEOL Ltd.), and a platinum coating was applied to the cross-section in the thickness direction in the width direction to obtain an observation sample. Next, using a field emission scanning electron microscope (FE-SEM) (JSM 6701F manufactured by JEOL Ltd.), the cross-section of the sample was photographed at an arbitrary magnification, and the thickness of the polymer film was determined. The acceleration voltage during observation was set to 2.0 kV. When the polymer film was a composite film, the interface between the non-porous layer and the microporous layer was determined from the difference in cross-sectional structure or image contrast, and the respective thicknesses were determined. Next, from the image taken at 10,000 times magnification, the thickness of the non-porous region was determined by the following method. A straight line perpendicular to the interface was drawn from one interface of the polymer film to the other interface, and the number of voids of 50 nm or more intersecting the straight line was determined. If the number of voids was 10 or less, it was determined as the non-porous region, and the thickness was determined. When the polymer film was a composite film composed of a non-porous region and a microporous film, the point where the distribution and size of the voids in the thickness direction began to change was regarded as the interface.

[0081] (4) Glass transition temperature Using DMA, DMS6100 (manufactured by Seiko Instruments Inc.), measurements were performed in the MD direction of the film of the polymer alone under the following conditions, and the maximum value of tan δ was taken as the glass transition temperature.

[0082] Frequency: 1 Hz Measurement temperature: 25°C to 420°C Heating rate: 5°C / min Strain amplitude: 10 μm Minimum tension: 200 mN Initial value of force amplitude: 400 mN.

[0083] (5) Cation concentration Using an atomic absorption spectrometer, the cation concentration in the ion-conductive polymer film was determined. 0.1 g of the sample was weighed, sulfuric acid was added, and after heating and carbonizing, it was heated and ashed. The ash was decomposed by heating with sulfuric acid and hydrofluoric acid, and dissolved by warming with dilute nitric acid to make a constant volume. The cation element in this solution was measured by atomic absorption spectrometry, the content in the sample was determined, and it was converted to the cation element content per 1 g of the separator. When the sample was a laminate, only the electrolyte layer was peeled off and measured.

[0084] Apparatus: Atomic absorption spectrometer (Z-2300 manufactured by Hitachi High-Technologies Corporation).

[0085] (6) Ionic conductivity The polymer film was immersed in a non-aqueous electrolyte (1 M LiTFSI ethylene carbonate (EC) / diethyl carbonate (DEC) = 1 / 1) for 24 hours, then placed on a SUS304 electrode so as to cover the electrode part, and after dropping the non-aqueous electrolyte, it was sandwiched with another SUS electrode to prepare a laminate of electrode / polymer film / electrode. An evaluation cell was prepared by fixing it with a silicon plate so that the laminate did not shift.

[0086] For the prepared cell, the alternating current impedance was measured at 25 °C with an electrochemical test apparatus (manufactured by Biologic, model number: SP-150) under the conditions of an amplitude of 10 mV and a frequency of 1 MHz - 10 mHz, the resistance value was read from the graph plotted on the complex plane, substituted into equation (2), and the ionic conductivity was calculated. It was measured 5 times, and the calculated average value was taken as the ionic conductivity. σ = T0 / AR (2) σ: Ionic conductivity (S / cm) T0: Thickness of the polymer film (cm) A: Area of the electrode (cm 2 ) R: Resistance value (Ω).

[0087] (7) Cation transference number Using an HS cell (manufactured by Takizawa Co., Ltd.), metallic Li, an ion-conductive polymer film for testing, and metallic Li were laminated under an argon atmosphere (oxygen concentration of 0.1 ppm or less, dew point of -75°C or less), and 300 μL of 1 M LiTFSI EC / DEC = 1 / 1 (volume ratio) was injected and sealed. For the fabricated cell, AC impedance was measured at 25°C using an electrochemical test apparatus (manufactured by Biologic, model number: SP-150) under the conditions of an amplitude of 10 mV and a frequency of 1 MHz - 100 mHz, and the interfacial resistance (R 0 ) was calculated from the second arc in the Nyquist plot. Next, the DC resistance of the electrode interface was measured by applying a DC voltage (V) and measuring the current values of the initial current value (I 0 ) and the steady-state (I 1 ). Finally, AC impedance was measured at 25°C using an electrochemical test apparatus (manufactured by Biologic, model number: SP-150) under the conditions of an amplitude of 10 mV and a frequency of 1 MHz - 100 mHz, and the interfacial resistance (R 1 ) was calculated from the second arc in the Nyquist plot. The lithium transference number (τ) was calculated from each of the obtained values using the following equation.

[0088]

Equation

[0089] (8) Haze Measured using the following measuring instrument.

[0090] Apparatus: Direct-reading haze meter HGM-2DP (for C light source) (manufactured by Suga Test Instruments Co., Ltd.) Light source: Halogen lamp 12V, 50W Light reception characteristics: 395 - 745 nm Optical conditions: Conforming to JIS-K7136:2000 (9) Association constant The polymer concentrations were 0.50 mass% and 0.25 mass%, and 8-point weighted DMSO (dimethyl sulfoxide) solutions with Li salt concentrations of the target anions of 0 mass%, 0.01 mass%, 0.10 mass%, and 0.50 mass% were used for 1 1H-NMR measurement. 1All the measuring devices for 1H-NMR measurement used were JNM-EZ400R (manufactured by JEOL Ltd.). Incidentally, 1 The measurement conditions for 1H-NMR measurement were set as follows: the number of integrations was 32, and the relaxation time was 5 seconds. Next, the concentrations of the thiourea group, thioamide group, and thiourethane group of the polymer contained in the solution, the salt concentration, and the chemical shift change values corresponding to the N-H groups of each functional group were used as variables and substituted into the program "COMPLEX2MULTIFIT" for calculation, and the association constants between each functional group and the salt were determined. The average association constant weighted by the molar ratio of the association constants between each functional group and the salt was defined as the association constant.

[0091] (10) NanoESI-MS analysis A DMF solution in which the compound with phenyl groups at both ends of the target unit structure and LiClO 4 were each 10 mmol / L was prepared, and NanoESI-MS analysis was performed under the following conditions to obtain an MS spectrum with the molecular weight and intensity on the horizontal axis and vertical axis, respectively. The peak intensity I 4 corresponding to the molecular weight of ClO 1 in the obtained MS spectrum and the peak intensity I 4 corresponding to the molecular weight corresponding to the sum of the above compound and ClO 2 were used. When I 2 / I 1 × 1000 was defined as the complex strength ratio with respect to the ClO 4 ion strength of the above unit structure.

[0092] Mass spectrometer: Q Exactive Plus [Thermo Fisher Scientific] Ionization method: nano electrospray ionization (nanoESI) TriVersa NanoMate Mass range: Full scan (positive / negative m / z 50 - 750) Product ion scan Gas pressure: N 2 0.3 psi Voltage: 1.8 kV (11) NanoESI-MS / MS analysis A compound in which both ends of the target unit structure are phenyl groups and LiClO 4 were each prepared into a DMF solution at 10 mmol / L, and NanoESI-MS analysis was performed under the following conditions. A detection compound corresponding to the molecular weight equivalent to the sum of the above compound and Li was isolated, and CID (collision-induced dissociation)-MS analysis was performed. During CID-MS analysis, the collision energy was changed from 0.3 eV to 10 eV, and MS spectra at each collision energy were obtained. In each of the obtained spectra, the peak intensity corresponding to the molecular weight equivalent to the sum of the above compound and Li and the sum of the overall peak intensities were defined as I 3 and I 4 respectively. When I 3 / I 4 = 0.5, the collision energy (E oc ) was taken as the irradiation energy at which the Li aggregate peak intensity ratio measured by NanoESI-MS / MS analysis became 0.5.

[0093] Mass spectrometer: Q Exactive Plus [Thermo Fisher Scientific] Ionization method: nano electrospray ionization (nanoESI) TriVersa NanoMate Mass range: Full scan (positive / negative m / z 50~750) Product ion scan Gas pressure: N 2 0.3 psi Voltage: 1.8 kV.

[0094] (12) Liquid separability In an argon atmosphere, after separating two chambers with an ion-conducting polymer film using a two-chamber cell (SB-100B manufactured by ESI Frontier), 1.5 mL of an organic electrolyte (4.5 M LiFSI in diethoxyethane) was injected into one chamber. Then, 1.5 mL of an aqueous electrolyte (1 M LiCl in 10 LiCl aqueous solution) was injected into the other chamber under a dry room atmosphere to prepare an evaluation cell. Twenty-four hours after cell preparation, 200 μL of the organic electrolyte was collected, and its water content was measured with a Karl Fischer moisture meter.

[0095] ◎: 1.0% or less and 0% or more ○: Less than 3.0% and 1.0% or more △: Less than 5.0% and 3.0% or more ×: 5.0% or more.

[0096] (Example 1) Polymer solution P1 4,4'-Diaminodiphenyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) as a diamine was dissolved in dehydrated NMP (N-methyl-2-pyrrolidone, manufactured by Mitsubishi Chemical Corporation) under a nitrogen stream. Then, 1,4-phenylenedithioisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) corresponding to 100 mol% of the total amount of diamine was added thereto over 5 min under a nitrogen stream in the system. After the addition of the total amount, stirring was performed for about 7 hours to polymerize an aromatic polythiourea (polymer p-1). The inherent viscosity ηinh of the obtained polymer was 1.1 dl / g. Next, this polymer solution was poured into ethanol at a mass ratio of 10 times or more, and the solvent and unreacted substances were extracted into ethanol. After separating only the precipitated polymer, it was vacuum dried at 60 °C for 10 hours to obtain a polymer powder. Then, the ratio of the polymer powder to the lithium salt LiTFSI (lithium bis(trifluoromethanesulfonyl)imide) was 70:30 in mass ratio, and it was redissolved in dehydrated DMSO (manufactured by Fujifilm Wako Pure Chemical Corporation) so that the polymer concentration became 12 mass% to obtain a polymer solution P1.

[0097] (Example 2) Polymer solution P2 Using hexamethylenediamine (manufactured by Fujifilm Wako Pure Chemical Corporation) instead of 4,4'-diaminodiphenyl ether, polymerizing semi-aromatic polythiourea (polymer p-2), and using DMAc (dimethylacetamide) (manufactured by Fujifilm Wako Pure Chemical Corporation) instead of DMSO as the solvent, a polymer solution P2 was obtained in the same manner as in Example 1 except for these changes.

[0098] (Example 3) Polymer solution P3 Using LiClO (manufactured by Fujifilm Wako Pure Chemical Corporation) instead of LiTFSI as the lithium salt, a polymer solution P3 was obtained in the same manner as in Example 1 except for this change. 4 (Example 4) Polymer solution P4

[0099] (Example 4) Polymer solution P4 A polymer solution P4 was obtained in the same manner as in Example 3 except that the mass ratio of the polymer powder to the lithium salt was 85:15.

[0100] (Example 5) Polymer solution P5 Using LiBr (manufactured by Fujifilm Wako Pure Chemical Corporation) instead of LiTFSI as the lithium salt, a polymer solution P5 was obtained in the same manner as in Example 1 except for this change.

[0101] (Example 6) Polymer solution P6 Using hexamethylenediamine instead of 4,4'-diaminodiphenyl ether and 1,1'-thiocarbonyldiimidazole instead of 1,4-phenylenedithioisocyanate, a polymer solution P6 was obtained in the same manner as in Example 1 except for obtaining an aliphatic polythiourea (polymer p-3).

[0102] (Comparative Example 1) Polymer solution P7 To dehydrated NMP (N-methyl-2-pyrrolidone, manufactured by Mitsubishi Chemical Corporation), 4,4'-diaminodiphenyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) as a diamine was dissolved under a nitrogen stream and cooled to 30°C or lower. Thereto, while maintaining the system under a nitrogen stream at 30°C or lower, 2-chloroterephthaloyl chloride (manufactured by Nippon Light Metal Co., Ltd.) corresponding to 99 mol% based on the total amount of diamine was added over 30 min. After the addition of the total amount, stirring was carried out for about 2 hours to polymerize an aromatic polyamide (polymer p-4). The obtained polymerization solution was neutralized with lithium carbonate (manufactured by Honjo Chemical Co., Ltd.) at 97 mol% and diethanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.) at 6 mol% based on the total amount of acid chloride to obtain a polymer solution. The inherent viscosity ηinh of the obtained polymer was 2.6 dl / g. Next, this polymer solution was poured into purified water at a mass ratio of 10 times or more, and the solvent and neutralization salts were extracted into water. After separating only the precipitated polymer, it was vacuum dried at 100°C for 10 hours to obtain a polymer powder. Thereafter, the ratio of the polymer powder to lithium salt LiTFSI (lithium bis(trifluoromethanesulfonyl)imide) was set to 70:30 by mass ratio, and it was redissolved in dehydrated NMP (manufactured by Mitsubishi Chemical Corporation) so that the polymer concentration became 9 mass% to obtain a polymer solution P7.

[0103] (Example 7) Ion-conductive polymer film F1 Polymer solution P1 was cast on a PET film as a support and dried at a hot air temperature of 120°C until the polymer film had self-supporting properties. After removing the polymer film from the PET, vacuum drying was performed at a temperature of 120°C, 200 Pa, for 1 hour to obtain a polymer film.

[0104] (Example 8) Ion-conductive polymer film F2 Polymer solution P2 was cast on glass as a support and dried by vacuum drying at a temperature of 90°C, 200 Pa, for 20 minutes until it had self-supporting properties. Next, vacuum drying was performed at a temperature of 90°C, 200 Pa, for 5 hours to obtain a polymer film.

[0105] (Example 9) Ion-conductive polymer film F3 A polymer film was obtained in the same manner as in Example 8, except that P3 was used instead of the polymer solution P2.

[0106] (Example 10) Ion-conductive polymer film F4 The polymer solution P4 was cast on glass as a support and dried by vacuum drying at a temperature of 90 °C and 200 Pa until it became self-supporting. Next, after removing the polymer film from the glass, it was subjected to vacuum drying at a temperature of 90 °C, 200 Pa, for 5 hours to obtain a polymer film.

[0107] (Example 11) Ion-conductive polymer film F5 A polymer film was obtained in the same manner as in Example 10, except that P5 was used instead of the polymer solution P4.

[0108] (Example 12) Ion-conductive polymer film F6 A polymer film was obtained in the same manner as in Example 10, except that P6 was used instead of the polymer solution P4.

[0109] (Comparative Example 2) Ion-conductive polymer film F7 The polymer solution P6 was cast on PET as a support and dried by drying at a temperature of 130 °C and normal pressure until it became self-supporting. Next, after removing the polymer film from the glass, it was subjected to vacuum drying at a temperature of 130 °C, 200 Pa, for 1 hour to obtain a polymer film.

[0110] (Comparative Example 3) Ion-conductive polymer film F8 A polyethylene porous membrane (manufactured by Toray Industries, Inc., thickness 5 μm, air permeability 110 seconds / 100 cc) was used.

[0111] (Examples 13, 14, Comparative Example 4) Using an HS cell (manufactured by Takizawa Co., Ltd.), metallic Li, the ion-conductive polymer film described in Table 3, and metallic Li were laminated in an argon atmosphere (oxygen concentration of 0.1 ppm or less, dew point of -75 °C or less), and 300 μL of 1 M LiTFSI EC / DEC = 1 / 1 (volume ratio) was injected and sealed. For the fabricated cell, after performing a preliminary operation test with a current density of 0.1 mA / cm 2 for 1 hour each for charge and discharge and 3 cycles, a cycle test was performed at each current density and charge / discharge time described in Table 3, and the number of cycles at the point when the applied voltage became 250 mV or more and 20 mV or less was recorded. The weight ratio of the electrolyte to the film was calculated by measuring the weight of the ion-conductive polymer film and the amount of the electrolyte during cell fabrication.

[0112] (Examples 15, 16, Comparative Example 5) Using an HS cell (manufactured by Takizawa Co., Ltd.), metallic Li, a polyethylene porous membrane (manufactured by Toray Industries, Inc., thickness 5 μm, air permeability 160 seconds / 100 cc) previously immersed in 1 M LiTFSI EC / DEC = 1 / 1 (volume ratio) for 24 hours, the ion-conductive polymer film described in Table 3, a polyethylene porous membrane (manufactured by Toray Industries, Inc., thickness 5 μm, air permeability 110 seconds / 100 cc) previously immersed in 1 M LiTFSI EC / DEC = 1 / 1 (volume ratio) for 24 hours, and metallic Li were laminated and sealed. For the fabricated cell, after performing a preliminary operation test with a current density of 0.1 mA / cm 2 for 1 hour each for charge and discharge and 3 cycles, a cycle test was performed at a current density of 0.5 mA / cm 2 for 1 hour each for charge and discharge. The number of cycles at the point when the applied voltage became 250 mV or more and 20 mV or less was recorded. The weight ratio of the electrolyte to the film was calculated by measuring the weight of the ion-conductive polymer film and the amount of the electrolyte during cell fabrication. The weight of the electrolyte at this time is the weight difference of the polyethylene porous membrane before and after electrolyte immersion.

[0113] (Example 17) The polymer solution P4 was cast onto glass as a support and dried by vacuum drying at a temperature of 90 °C, 200 Pa for 20 minutes until it became self-supporting. Next, metallic Li was placed on the polymer film under an Ar atmosphere, and after removing it from the glass, it was subjected to vacuum drying at a temperature of 90 °C, 200 Pa for 5 hours to obtain an electrode composite.

[0114] Using an HS cell (manufactured by Takizawa Co., Ltd.), an electrode composite, a polyethylene porous membrane (manufactured by Toray Industries, Inc., thickness 5 μm, air permeability 110 seconds / 100 cc), and the electrode composite were laminated in an argon atmosphere (oxygen concentration 0.1 ppm or less, dew point -75 °C or less), and 300 μL of 1 M LiTFSI EC / DEC = 1 / 1 (volume ratio) was injected and sealed. At that time, the ion-conductive polymer film of the electrode composite was laminated so as to be in contact with the polyethylene porous membrane. For the fabricated cell, after performing a preliminary operation test with a current density of 0.1 mA / cm 2 , charge and discharge for 1 hour each, and 3 cycles, a cycle test was performed at each current density and charge-discharge time described in Table 3, and the number of cycles when the applied voltage became 250 mV or more and 20 mV or less was recorded.

[0115] Compared with the comparative examples, the ion-conductive polymer film of the example is excellent in ion conductivity or liquid separation property. For the microporous membranes widely used in conventional lithium-ion batteries, the cation transference rate and liquid separation property are extremely high. These ion-conductive polymer films of the examples are effective for batteries that require ion conductivity and liquid separation property, particularly lithium-air batteries. Compared with Comparative Example 4, Example 13 has a high number of cycles, and Example 14 has a high current density, so it can be seen that they are excellent in battery life and capacity, respectively.

[0116]

Table 1

[0117]

Table 2

[0118]

Table 3

[0119]

Table 4

Claims

1. In the NanoESI (Nano Electrospray Ionization)-MS (Mass spectrometry) analysis, ClO ４ An ion-conductive polymer film comprising a polymer having a unit having an association strength ratio to ionic strength of 0.6 or more.

2. The ion-conducting polymer film according to claim 1, comprising a polymer having a unit having an irradiation energy of more than 0 eV and less than 2.0 eV at which the Li-associated peak intensity ratio measured by NanoESI-MS / MS analysis is 0.

5.

3. An ion-conducting polymer film comprising a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group.

4. 4. The ion-conducting polymer film of claim 1, which has a non-porous region.

5. 4. The ion-conductive polymer film according to claim 1, wherein the polymer has an aromatic structure in the main chain.

6. 4. The ion-conductive polymer film according to claim 1, wherein the glass transition temperature of the polymer is 51° C. or higher and 400° C. or lower.

7. 4. The ion-conductive polymer film according to claim 1, wherein the cation concentration is from 1 μmol / g to 50,000 μmol / g.

8. 4. The ion-conducting polymer film according to claim 1, wherein the lithium ion concentration is from 1 μmol / g to 50,000 μmol / g.

9. Ion conductivity is 1.0 x 10 －７ 4. The ion-conductive polymer film according to claim 1, wherein the electrochemical conductivity is from 1.0×10 S / cm to 1.0×10 S / cm.

10. 4. The ion-conductive polymer film according to claim 1, wherein the cationic transport number is from 0.5 to 1.

0.

11. 4. The ion-conductive polymer film according to claim 1, wherein the haze is from 0% to 30%.

12. The film contains bis(trifluorosulfonamide) ions, bis(fluorosulfonamide) ions, trifluorosulfonic acid ions, PF ６ ion, ClO ４ Ion, BF ４ 4. The ion-conducting polymer film according to claim 1 or 3, comprising at least one of the following ions:

13. 4. The ion-conductive polymer film according to claim 1, wherein the weight concentration of the lithium salt is from 0% by weight to 80% by mass.

14. The association constant with the polymer is 1.0 M －１ Above 1.0 x 10 １０ M －１ 4. The ion-conducting polymer film of claim 1 or 3, comprising an anion that is:

15. 4. An electrode composite comprising the ion-conductive polymer film according to claim 1 or 3 and an electrode disposed adjacent to each other.

16. A battery comprising the ion-conducting polymer film according to claim 1 or 3.

17. 17. The battery in accordance with claim 16, wherein the weight ratio of the electrolyte to the film (weight of the electrolyte / weight of the film) is 0 or more and 5 or less.

18. 20. A vehicle, unmanned vehicle, electronic device, unmanned air vehicle, or stationary power source comprising the battery of claim 16.

19. In the NanoESI (Nano Electrospray Ionization)-MS (Mass spectrometry) analysis, ClO ４ A solution containing a polymer having a unit having an association strength ratio to ionic strength of 0.6 or more.

20. The solution according to claim 19, comprising a polymer having a unit having an irradiation energy of more than 0 eV and less than 2.0 eV at which the Li-associated peak intensity ratio measured by NanoESI-MS / MS analysis is 0.

5.

21. A solution containing a polymer containing at least one of a thiocarbonyl group, a thiourea group, a thioamide group, and a thiourethane group.

Images