Commonly combined organic constructs and methods of manufacturing them

Abstract

To provide a solid electrolyte that shows ionic conductivity, is excellent in thermostability, and has a wide potential window.SOLUTION: An covalent organic structure disclosed herein is an organic porous material comprising non-metal covalent bond, which is constituted by polymerization by imidazole ligation formed from the condensation of an amino group and an aldehyde group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a covalent organic framework and a method for producing the same. [Background technology]

[0002] The development of all-solid-state lithium-ion secondary batteries, which replace conventional (organic solvent-based) electrolytes with solid electrolytes (such as sulfide-based solid electrolytes), is expected to reduce the risk of leakage and to increase the energy density of the cell package unit, as the electrode layer and electrolyte layer can be stacked.

[0003] However, sulfide solid electrolytes react with water molecules in the atmosphere to generate hydrogen sulfide, raising manufacturing costs and safety concerns about cell configuration. Therefore, all-solid-state lithium-ion secondary batteries that combine high safety and high energy density have not yet been realized. Conventional polymer electrolytes consist of electrolyte salts dissolved in chain-like polymers, and their ionic conductivity depends on the segmental motion of the polymer, resulting in a low transport number. Therefore, there has been a demand for the development of polymer solid electrolytes that simultaneously satisfy the following requirements: high lithium-ion transport number and ionic conductivity, high chemical stability, and easy processing and molding.

[0004] As a solid electrolyte, for example, a porous lithium ion conductive polymer has been proposed which has a large number of pores, holds an organic electrolyte solution inside the pores, and ensures ion diffusion paths (see, for example, Patent Document 1).

[0005] Furthermore, a chain lithium ion conductive polymer has also been proposed that exhibits lithium ion conductivity at room temperature, has excellent thermal stability, and has an excellent lithium ion transport number when mixed with an ionic liquid (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-373705 [Patent Document 2] Japanese Patent Application Publication No. 2019-160566 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the potential window of the porous lithium ion conductive polymers and chain lithium ion conductive polymers reported so far is only about 0 to 4.5 V at most, which is not much different from that of an electrolyte solution. It is known that a wide potential window of a solid electrolyte leads to a high energy density.

[0008] The present invention has been made in view of the above-mentioned current state of the prior art, and has as its object to provide a solid electrolyte that exhibits ionic conductivity, excellent thermal stability, and a wide potential window. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to achieve the above-mentioned object. As a result, they have found that a covalent organic framework having a specific structure is a solid electrolyte that exhibits ionic conductivity, has excellent thermal stability, and has a wide potential window. Based on this finding, the present inventors have conducted further research and completed the present invention. That is, the present invention includes the following configurations.

[0010] Item 1. A covalent organic framework that is an organic porous material formed by non-metallic covalent bonds, General formula (1A) and / or (1B):

[0011] [ka]

[0012] [In the formula, R 1 , R 2 and R 3 are the same or different and represent an alkyl group or an aryl group. Ar 1, Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. M 1 , M 2 and M 3 are the same or different and represent alkali metals. A covalent organic framework is formed by covalently bonding repeating units represented by the formula:

[0013] Section 2. Said R 1 , R 2 and R 3 and are the same or different and are an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0014] Item 3. Said Ar 1 , Ar 2 and Ar 3 Item 3. The covalent organic structure according to Item 1 or 2, wherein

[0015] Section 4. Said M 1 , M 2 and M 3 are the same or different and are at least one selected from the group consisting of lithium, sodium, and potassium.

[0016] Item 5. A method for producing a covalent organic framework according to any one of items 1 to 4, (III) General formula (2A) and / or (2B):

[0017] [ka]

[0018] [In the formula, Ar 1 , Ar 2 , Ar 3 , M 1 , M 2 and M 3 is the same as above.] A step of reacting a covalently bonded organic framework constituted by covalently bonding repeating units represented by the formula: with a borane compound. A manufacturing method comprising:

[0019] Item 6. A covalent organic framework that is an organic porous material formed by non-metallic covalent bonds, General formula (2A) and / or (2B):

[0020] [ka]

[0021] [In the formula, Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. M 1 , M 2 and M 3 are the same or different and represent alkali metals. A covalent organic framework is formed by covalently bonding repeating units represented by the formula:

[0022] Item 7. Said Ar 1 , Ar 2 and Ar 3 Item 7. The covalent organic structure according to Item 6, wherein is a benzene ring.

[0023] Section 8. Said M 1 , M 2 and M 3 are the same or different and are at least one selected from the group consisting of lithium, sodium, and potassium.

[0024] Item 9. A method for producing a covalent organic framework according to any one of items 6 to 8, (II) General formula (3A) and / or (3B):

[0025] [ka]

[0026] [In the formula, Ar 1 , Ar 2 and Ar 3 is the same as above.] and reacting the covalently bonded organic framework constituted by covalently bonding repeating units represented by the formula: with an alkali metal hydride and / or an alkali metal hydroxide. A manufacturing method comprising:

[0027] Item 10. A covalent organic framework that is an organic porous material formed by non-metallic covalent bonds, General formula (3A) and / or (3B):

[0028] [ka]

[0029] [In the formula, Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. A covalent organic framework is formed by covalently bonding repeating units represented by the formula:

[0030] Item 11. Said Ar 1 , Ar 2 and Ar 3 Item 11. The covalent organic structure according to item 10, wherein is a benzene ring.

[0031] Item 12. A method for producing a covalent organic framework according to item 10 or 11, (I) Hexaaminobenzene or a salt thereof and a compound represented by the general formula (4A) and / or (4B):

[0032] [ka]

[0033] [In the formula, Ar 1 is the same as above. R 4 and R 5 are the same or different and represent a hydrogen atom or an alkyl group. with a compound represented by the formula A manufacturing method comprising:

[0034] Item 13. A solid electrolyte comprising the covalent organic framework according to any one of Items 1 to 4.

[0035] Item 14. The solid electrolyte according to Item 13, which is a solid electrolyte for a lithium ion secondary battery.

[0036] Item 15. An ion-conductive composition comprising the covalent organic framework according to any one of items 1 to 4 or the solid electrolyte according to item 13 or 14, and a solvent.

[0037] Item 16. A lithium ion secondary battery comprising the solid electrolyte according to item 13 or 14 or the ion-conductive composition according to item 15.

[0038] Item 17. A carbon dioxide adsorption material comprising the covalent organic framework according to any one of items 1 to 4, the solid electrolyte according to item 13 or 14, or the ion-conductive composition according to item 15. [Effects of the Invention]

[0039] According to the present invention, it is possible to provide a solid electrolyte that exhibits ionic conductivity, excellent thermal stability, and a wide potential window. [Brief explanation of the drawings]

[0040]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0041] In this specification, the term "containing" is a concept that encompasses all of "comprise," "consist essentially of," and "consist only of." Furthermore, in this specification, when a numerical range is expressed as "A to B," it means A or more and B or less.

[0042] 1. Covalently bonded organic structures (general formulas (1A) and (1B)) The covalent organic framework of the present invention is a covalent organic framework that is an organic porous material constituted by non-metallic covalent bonds, General formula (1A) and / or (1B):

[0043] [ka]

[0044] [In the formula, R 1 , R 2 and R 3 are the same or different and represent an alkyl group or an aryl group. Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. M 1 , M 2 and M 3 are the same or different and represent alkali metals. It is composed of repeating units represented by the following covalent bonds.

[0045] The covalent organic framework of the present invention has anionic moieties fixed in the skeleton, and therefore can form a regularly continuous potential field for ion migration, thereby improving the potential window.

[0046] Specifically, while the potential window of conventional organic solid electrolytes was at most 4.5 V, the covalent organic framework of the present invention has an extremely wide potential window of 5.0 V or more (preferably 6.0 V or more), making it possible to achieve a high energy density for lithium ion secondary batteries.

[0047] The covalent organic framework of the present invention is lightweight because it can be composed of light elements such as C, H, O, N, and B, and is expected to contribute to weight reduction of lithium ion secondary batteries.

[0048] In addition, the covalent organic framework of the present invention is 1 , Ar 2 and Ar 3 By combining these, the pore size of the covalent organic framework can be adjusted, and the ionic conductivity can also be adjusted appropriately depending on the required properties.

[0049] Furthermore, since the covalent organic framework of the present invention is an organic material, it is flexible and can be formed into a thin film.

[0050] Furthermore, the covalent organic framework of the present invention is composed of covalent bonds centered around a skeleton in which three imidazoles are condensed to a benzene ring, and therefore has excellent stabilities such as thermal stability and stability against lithium ions, and can be handled under atmospheric exposure conditions. + Since lithium deposition behavior is observed below, it is possible to improve the electrochemical stability.

[0051] In general formulas (1A) and (1B), R 1 , R2 and R 3 The alkyl group represented by the formula (I) is not particularly limited, and either a linear alkyl group or a branched alkyl group can be used, but a linear alkyl group is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. The number of carbon atoms in such an alkyl group is preferably 1 to 12, more preferably 1 to 10, still more preferably 1 to 6, and particularly preferably 1 to 2, from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. Specific examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0052] In general formulas (1A) and (1B), R 1 , R 2 and R 3 The aryl group represented by the formula (I) is not particularly limited, and either a monocyclic aryl group (phenyl group) or a polycyclic aryl group can be used, but a monocyclic aryl group (phenyl group) is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. The number of carbon atoms in such an aryl group is preferably 6 to 12, more preferably 6 to 11, and even more preferably 6 to 10, from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. Specific examples of such an aryl group include a phenyl group, a naphthyl group, and a biphenyl group.

[0053] In general formulas (1A) and (1B), R 1 , R 2 and R 3 As the organic group, an alkyl group is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc.

[0054] In the general formulas (1A) and (1B), Ar 1 , Ar 2 and Ar 3Although either an aromatic ring (aromatic hydrocarbon ring) or a heteroaromatic ring can be used as the (hetero)aromatic ring represented by the formula (I), an aromatic ring (aromatic hydrocarbon ring) is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. The number of carbon atoms in such a (hetero)aromatic ring is preferably 6 to 20, more preferably 6 to 18, and even more preferably 6 to 16, from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. Specific examples of such an aromatic ring include a benzene ring, a naphthalene ring, a pyrene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring. These aromatic rings (aromatic hydrocarbon rings) may have about 1 to 6 (particularly 1 to 3) substituents such as phenyl groups.

[0055] In the general formulas (1A) and (1B), M 1 , M 2 and M 3 Examples of the alkali metal represented by the formula (I) include lithium, sodium, potassium, etc. These alkali metals can be appropriately adjusted depending on the type of battery to be constructed, and for example, lithium can be used when constructing a lithium ion secondary battery.

[0056] Examples of repeating units represented by general formulas (1A) and (1B) that satisfy the above conditions include:

[0057] [ka]

[0058] etc.

[0059] The covalent organic framework of the present invention is one in which the repeating units described above are constituted by covalent bonds, but may be constituted only of the same repeating units or may be constituted of a plurality of types of repeating units. In particular, according to the production method described below, a covalent organic framework constituted only of the same repeating units is easily produced.

[0060] The covalent organic framework of the present invention having such conditions has a borane compound introduced into the central skeleton, and exhibits ionic conductivity due to the steric hindrance. Specifically, the ionic conductivity of the covalent organic framework of the present invention at room temperature (25°C) is 1.0 × 10 -7 S / cm or more is preferable, and 2.0×10 -7 S / cm or more is more preferable. By intentionally adding an organic electrolyte solution or the like to the covalent organic framework of the present invention, the ionic conductivity can be further improved. The higher the ionic conductivity of the covalent organic framework of the present invention, the better, and no upper limit is particularly set, but for example, 1.0 × 10 -1 S / cm or less.

[0061] The covalent organic framework of the present invention, which is constituted by covalently bonding repeating units represented by general formula (1A) and / or (1B) and satisfies the above-mentioned conditions, exhibits ionic conductivity, excellent thermal stability, and a wide potential window, and is therefore useful as a solid electrolyte constituting the electrolyte layer of a lithium ion secondary battery.

[0062] Furthermore, a covalent organic framework formed by covalently bonding repeating units represented by general formula (1A) and / or (1B) of the present invention and satisfying the above conditions has a significantly larger carbon dioxide adsorption specific surface area than its nitrogen adsorption specific surface area. In other words, a covalent organic framework formed by covalently bonding repeating units represented by general formula (1A) and / or (1B) of the present invention and satisfying the above conditions selectively adsorbs carbon dioxide gas compared to nitrogen gas. Therefore, a covalent organic framework formed by covalently bonding repeating units represented by general formula (1A) and / or (1B) of the present invention and satisfying the above conditions is useful as a carbon dioxide adsorption material.

[0063] 2. Covalently bonded organic structures (general formulas (2A) and (2B)) The covalent organic framework of the present invention is a covalent organic framework that is an organic porous material constituted by non-metallic covalent bonds, General formula (2A) and / or (2B):

[0064] [ka]

[0065] [In the formula, Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. M 1 , M 2 and M 3 are the same or different and represent alkali metals. It is composed of repeating units represented by the following covalent bonds.

[0066] In the general formulas (2A) and (2B), Ar 1 , Ar 2 and Ar 3 Although either an aromatic ring (aromatic hydrocarbon ring) or a heteroaromatic ring can be used as the (hetero)aromatic ring represented by the formula (I), an aromatic ring (aromatic hydrocarbon ring) is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. The number of carbon atoms in such a (hetero)aromatic ring is preferably 6 to 12, more preferably 6 to 11, and even more preferably 6 to 10, from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. Specific examples of such an aromatic ring include a benzene ring, a naphthalene ring, a pyrene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring. These aromatic rings (aromatic hydrocarbon rings) may have about 1 to 6 (particularly 1 to 3) substituents such as phenyl groups.

[0067] In the general formulas (2A) and (2B), M 1 , M 2 and M 3Examples of the alkali metal represented by the formula (I) include lithium, sodium, potassium, etc. These alkali metals can be appropriately adjusted depending on the type of battery to be constructed, and for example, lithium can be used when constructing a lithium ion secondary battery.

[0068] Examples of repeating units represented by general formulas (2A) and (2B) that satisfy the above conditions include:

[0069] [ka]

[0070] etc.

[0071] The covalent organic framework of the present invention is one in which the repeating units described above are constituted by covalent bonds, but may be constituted only of the same repeating units or may be constituted of a plurality of types of repeating units. In particular, according to the production method described below, a covalent organic framework constituted only of the same repeating units is easily produced.

[0072] 3. Covalently bonded organic structures (general formulas (3A) and (3B)) The covalent organic framework of the present invention is a covalent organic framework that is an organic porous material constituted by non-metallic covalent bonds, General formula (3A) and / or (3B):

[0073] [ka]

[0074] [In the formula, Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. It is composed of repeating units represented by the following covalent bonds.

[0075] In the general formulas (3A) and (3B), Ar1 , Ar 2 and Ar 3 Although either an aromatic ring (aromatic hydrocarbon ring) or a heteroaromatic ring can be used as the (hetero)aromatic ring represented by the formula (I), an aromatic ring (aromatic hydrocarbon ring) is preferred from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. The number of carbon atoms in such a (hetero)aromatic ring is preferably 6 to 12, more preferably 6 to 11, and even more preferably 6 to 10, from the viewpoints of potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. Specific examples of such an aromatic ring include a benzene ring, a naphthalene ring, a pyrene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and a pyridazine ring. These aromatic rings (aromatic hydrocarbon rings) may have about 1 to 6 (particularly 1 to 3) substituents such as phenyl groups.

[0076] Examples of repeating units represented by general formulas (3A) and (3B) that satisfy the above conditions include:

[0077] [ka]

[0078] etc.

[0079] The covalent organic framework of the present invention is one in which the repeating units described above are constituted by covalent bonds, but may be constituted only of the same repeating units or may be constituted of a plurality of types of repeating units. In particular, according to the production method described below, a covalent organic framework constituted only of the same repeating units is easily produced.

[0080] The covalent organic framework of the present invention may contain repeating units other than the repeating units described above. However, from the viewpoints of readily having suitable pores, readily having excellent flexibility, ease of synthesis and analysis, potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc., it is preferable that the covalent organic framework of the present invention is composed only of the repeating units described above.

[0081] The specific surface area of ​​the covalent organic framework of the present invention, measured by the BET method using argon gas as the adsorption gas, is not particularly limited, but is preferably 80 to 700 m from the viewpoints of the ease of synthesis and analysis, potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc., as well as the likelihood of having suitable pores and excellent flexibility. 3 / g is preferred, and 100 to 650m 3 / g is more preferred.

[0082] The pore volume of the covalent organic framework of the present invention, as measured by the BET method using argon gas as the adsorption gas, is not particularly limited, but is preferably 0.30 to 2.00 m from the viewpoints of the ease of having suitable pores, excellent flexibility, ease of synthesis and analysis, potential window, stability (thermal stability, electrochemical stability, etc.), ionic conductivity, etc. 3 / g is preferred, and 0.35 to 1.50 m 3 / g is more preferred.

[0083] 4. Method for producing covalently bonded organic structures (Step (I)) The method for producing the covalent organic framework (general formulas (3A) and (3B)) of the present invention is not particularly limited.

[0084] for example, (I) Hexaaminobenzene or a salt thereof and a compound represented by the general formula (4A) and / or (4B):

[0085] [ka]

[0086] [In the formula, Ar 1 is the same as above. R 4 and R 5 are the same or different and represent a hydrogen atom or an alkyl group. with a compound represented by the formula Thus, the general formula (3A) and / or (3B):

[0087] [ka]

[0088] [In the formula, Ar 1 , Ar 2 and Ar 3 are the same or different and represent a (hetero)aromatic ring. It is possible to produce a covalent organic framework constituted by covalently bonding repeating units represented by the following formula:

[0089] Hexaaminobenzene or a salt thereof can synthesize a covalent organic framework having a nucleosomal skeleton in which three imidazole rings are fused to a benzene ring by reacting the amino group bonded to the benzene ring with the aldehyde group in the compound represented by general formula (4A) and / or (4B).

[0090] The salt of hexaaminobenzene is not particularly limited as long as it can react with the aldehyde group in the compounds represented by general formulas (4A) and (4B). For example, organic acid salts such as acetates and formates; inorganic acid salts such as sulfates, nitrates, carbonates, hydrochlorides and hydrobromides; and the like can be used.

[0091] Hexaaminobenzene or a salt thereof can be used alone or in combination of two or more.

[0092] Next, in the general formulas (4A) and (4B), Ar 1 A (hetero)aromatic ring represented by R 4 and R 5 The alkyl group represented by the formula (I) can be the same as those described above. Preferred examples are also the same.

[0093] Specific examples of the compounds represented by general formulas (4A) and (4B) include:

[0094] [ka]

[0095] etc.

[0096] The amount of the compounds represented by general formulas (4A) and (4B) used is not particularly limited, but from the viewpoint of yield and the like, it is preferably 0.3 to 3.0 mol, more preferably 0.5 to 2.0 mol, per 1 mol of hexaaminobenzene or a salt thereof.

[0097] The reaction in step (I) can usually be carried out in the presence of a solvent. Usable solvents are not particularly limited, and amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone can be used. From the viewpoint of easily suppressing side reactions, these solvents are preferably dehydrated solvents from which water has been removed. These solvents can be used alone or in combination of two or more.

[0098] The reaction in step (I) is preferably carried out in an atmosphere from which moisture has been removed, particularly in an inert atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere, in order to easily suppress side reactions.

[0099] The reaction temperature in step (I) may be any temperature that allows the reaction to proceed sufficiently, and is, for example, preferably −100 to 200° C., more preferably −50 to 150° C. For example, the reaction can be carried out at −100 to 50° C. (particularly −50 to 0° C.), and then the reaction can be carried out at 50 to 200° C. (particularly 100 to 150° C.) after bubbling oxygen for dehydrocyclization.

[0100] The reaction time in step (I) may be adjusted appropriately as long as the reaction proceeds sufficiently.

[0101] After the reaction is completed, the reaction product may be precipitated in an alcohol solvent such as methanol, if necessary, and then dried and purified by a conventional method, if necessary.

[0102] 5. Method for producing covalently bonded organic structures (Step (II)) The method for producing the covalent organic framework (general formulas (2A) and (2B)) of the present invention is not particularly limited.

[0103] for example, (II) General formulas (3A) and (3B):

[0104] [ka]

[0105] [In the formula, Ar 1 , Ar 2 and Ar 3 is the same as above.] and reacting the covalently bonded organic framework constituted by covalently bonding repeating units represented by the formula: with an alkali metal hydride and / or an alkali metal hydroxide. Thus, general formula (2A) and / or (2B):

[0106] [ka]

[0107] [In the formula, Ar 1 , Ar 2 , Ar 3 , M 1 , M 2 and M 3 is the same as above.] It is possible to synthesize a covalent organic framework constituted by covalently bonding repeating units represented by the following formula:

[0108] The covalent organic framework constituted by the covalent bonding of the repeating units represented by general formulas (3A) and (3B) obtained in the above step (I) can be used.

[0109] Examples of alkali metals in the alkali metal hydrides and alkali metal hydroxides include lithium, sodium, potassium, etc. These alkali metals can be appropriately adjusted depending on the type of battery constituted by the covalent organic framework of the present invention, and for example, lithium can be used when a lithium ion secondary battery is constituted.

[0110] Specific examples of the alkali metal hydride and alkali metal hydroxide include lithium hydride, sodium hydride, potassium hydride, lithium hydroxide, sodium hydroxide, and potassium hydroxide.

[0111] The alkali metal hydrides and alkali metal hydroxides may be used alone or in combination of two or more.

[0112] The amount of the alkali metal hydride and / or alkali metal hydroxide used is not particularly limited, but from the viewpoint of yield and the like, it is preferably 1.0 to 10.0 mol, and more preferably 2.0 to 5.0 mol, per 1 mol of the covalent organic framework constituted by the covalent bonding of the repeating units represented by general formula (3A) and / or (3B).

[0113] The reaction in step (II) can usually be carried out in the presence of a solvent. Usable solvents are not particularly limited, and amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone can be used. From the viewpoint of easily suppressing side reactions, these solvents are preferably dehydrated solvents from which water has been removed. These solvents can be used alone or in combination of two or more.

[0114] The reaction in step (II) is preferably carried out in an atmosphere free of moisture, particularly in an inert atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere, from the viewpoint of easily suppressing side reactions.

[0115] The reaction temperature in step (II) may be any temperature that allows the reaction to proceed sufficiently, and is, for example, preferably −50 to 150° C., more preferably 0 to 100° C. For example, the reaction can be carried out at −50 to 100° C. (particularly 0 to 50° C.) and then at 0 to 150° C. (particularly 50 to 100° C.).

[0116] The reaction time in step (II) may be adjusted appropriately as long as the reaction proceeds sufficiently.

[0117] After the reaction is complete, the reaction product can be purified by a conventional method, if necessary.

[0118] 6. Method for producing covalently bonded organic structures (Step (III)) The method for producing the covalent organic framework (general formulas (1A) and (1B)) of the present invention is not particularly limited.

[0119] for example, (III) General formula (2A) and / or (2B):

[0120] [ka]

[0121] [In the formula, Ar 1 , Ar 2 , Ar 3 , M 1 , M 2 and M 3 is the same as above.] A step of reacting a covalently bonded organic framework constituted by covalently bonding repeating units represented by the formula: with a borane compound. Thus, the general formula (1A) and / or (1B):

[0122] [ka]

[0123] [In the formula, R 1 , R 2 , R 3 , Ar1 , Ar 2 , Ar 3 , M 1 , M 2 and M 3 is the same as above.] It is possible to synthesize a covalent organic framework constituted by covalently bonding repeating units represented by the following formula:

[0124] The covalent organic framework constituted by the covalent bonding of repeating units represented by general formula (2A) and / or (2B) can be that obtained in the above step (II).

[0125] The borane compound reacts with the nitrogen anion in the covalent organic framework constituted by the covalent bonding of the repeating units represented by general formula (2A) and / or (2B) to form -BR 1 3 - , -BR 2 3 - , -BR 3 3 - A compound capable of introducing the general formula (5): BR 1 3(5) [In the formula, R 1 is the same as above.] A compound represented by the following formula can be used.

[0126] In general formula (5), R 1 The same applies to the preferred specific examples.

[0127] Specific examples of such compounds represented by general formula (5) include trimethylborane, triethylborane, triphenylborane, etc. These borane compounds can be used alone or in combination of two or more.

[0128] The amount of the borane compound used is not particularly limited, but from the viewpoint of yield and the like, it is preferably 2.0 to 20.0 mol, and more preferably 4.0 to 10.0 mol, per 1 mol of the covalent organic framework constituted by the covalent bonding of the repeating units represented by general formula (2A) and / or (2B).

[0129] The reaction in step (III) can usually be carried out in the presence of a solvent. Usable solvents are not particularly limited, and amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone can be used. From the viewpoint of easily suppressing side reactions, these solvents are preferably dehydrated solvents from which water has been removed. These solvents can be used alone or in combination of two or more.

[0130] The reaction in step (III) is preferably carried out in an atmosphere free of moisture, particularly in an inert atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere, from the viewpoint of easily suppressing side reactions.

[0131] The reaction temperature in step (III) may be any temperature that allows the reaction to proceed sufficiently, and is, for example, preferably 0 to 150°C, more preferably 50 to 100°C.

[0132] The reaction time in step (III) may be adjusted appropriately as long as the reaction proceeds sufficiently.

[0133] After the reaction is complete, the reaction product can be purified by filtration and drying in a conventional manner, if necessary.

[0134] 7. Ion-conductive composition As described above, the covalent organic framework of the present invention, which is constituted by covalently bonding repeating units represented by general formula (1), is useful as a solid electrolyte.

[0135] When the covalent organic framework of the present invention constituted by covalently bonding repeating units represented by general formula (1) is used as a solid electrolyte, it can be used as is, or it can be mixed with a solvent, and the covalent organic framework of the present invention constituted by covalently bonding repeating units represented by general formula (1A) and / or (1B) can be used as an ion-conductive composition containing the solid electrolyte and the solvent.

[0136] The solvent that can be used is not particularly limited, and amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone can be used. From the viewpoint of easily suppressing side reactions, these solvents are preferably dehydrated solvents from which water has been removed. Furthermore, these solvents can be used alone or in combination of two or more.

[0137] 8. Lithium-ion secondary battery A lithium ion secondary battery (preferably an all-solid-state lithium ion secondary battery) using a covalently bonded organic framework constituted by covalently bonding repeating units represented by general formula (1) of the present invention can be produced by a known method.

[0138] For example, a covalent organic framework constituted by covalently bonding repeating units represented by general formula (1) of the present invention can be formed into a layer by a conventional method and used as an electrolyte layer.

[0139] Furthermore, a lithium ion secondary battery (all-solid-state lithium ion secondary battery) can be assembled using other known battery components according to a conventional method. In the present invention, the term "lithium ion secondary battery" is a concept that also encompasses "lithium secondary batteries" that use metallic lithium as the negative electrode material. [Example]

[0140] EXAMPLES Hereinafter, examples and comparative examples will be shown to further clarify the features of the present invention, but the present invention is not limited to the following examples.

[0141] [Example 1] 1,2,3,4,5,6-Benzenehexamine trihydrochloride (hexaaminobenzethionyl chloride; 64.9 mg, 1 equivalent) was placed in a flask, the atmosphere was purged with Ar gas, 50 mL of dehydrated dimethylformamide was added, and the flask was cooled to -30°C. A solution of 1,3,5-benzenetricarbaldehyde (113 mg, 1 equivalent) dissolved in 15 mL of dehydrated dimethylformamide was slowly added dropwise to the flask, and the mixture was stirred under Ar gas at -30°C for approximately 1 hour, followed by stirring at room temperature for 8 to 15 hours. Oxygen bubbling was then performed for approximately 20 minutes, the flask was sealed, and the mixture was placed in a thermostatic chamber at 130°C for 3 days. Soxhlet extraction with methanol was then performed for 24 hours to obtain the reaction mixture. The resulting mixture was purged with ethanol, then tert-butyl alcohol, freeze-dried, and vacuum-dried at room temperature to 100°C to obtain an orange-brown product of the following formula:

[0142] [ka]

[0143] A covalent organic framework was obtained, which is constituted by covalently bonding repeating units represented by the following formula: Imidazole-linked polymer: Element Anal. Cald for (C5H2N2·H2O) n : C, 55.56; H, 3.73; N, 25.91. Found: C, 53.61; H, 4.91; N, 16.03.

[0144] FIG. 1 shows the infrared absorption spectrum (IR spectrum) of the obtained covalent organic framework, and FIG. 2 shows the solid-state nuclear magnetic resonance spectrum (solid-state NMR spectrum).

[0145] [Example 2] The covalent organic framework (99.9 mg, 1 equivalent) obtained in Example 1 was placed in a flask, and the atmosphere was replaced with Ar gas. 4 mL of dehydrated dimethyl sulfoxide was added, and while stirring, a dispersion of LiH (78.5 mg, 3.2 equivalents) in dehydrated dimethyl sulfoxide was added, and the mixture was stirred at room temperature for 3 hours under an Ar gas atmosphere, and then at 80°C for 2 hours. As a result, the following formula:

[0146] [ka]

[0147] A covalent organic framework was obtained, which is constituted by covalently bonding repeating units represented by the following formula:

[0148] [Example 3] After Example 2, the mixture was allowed to cool to room temperature, then cooled to 0°C, and then 2.3 mL (6 equivalents) of triethylborane was added, followed by stirring at 80°C for 8 to 15 hours. The resulting reaction mixture was filtered with a mixed solvent of acetone and toluene (acetone:toluene (weight ratio) = 1:1), and the resulting polymer was dried under reduced pressure (100°C, 3 hours). This gave a polymer of the following formula:

[0149] [ka]

[0150] A covalent organic framework was obtained, which is constituted by covalently bonding repeating units represented by the following formula: Imidazole-linked polymer- Li salt: Element Anal. Cald for (C 11 H 16 BLiN2·2DMSO) n : C, 51.44; H, 8.06; N, 8.00. Found: C,42.47; H, 6.09; N, 8.18.

[0151] FIG. 3 shows the infrared absorption spectrum (IR spectrum) of the obtained covalent organic framework, and FIG. 4 shows the solid-state nuclear magnetic resonance spectrum (solid-state NMR spectrum).

[0152] [Example 4] 22.2 mg of the covalent organic framework obtained in Example 3 and 4 μL of dimethyl sulfoxide were mixed in an agate mortar to obtain a powdery lithium ion conductive composition A.

[0153] [Example 5] 4 μL of dimethyl sulfoxide was added to the lithium ion conductive composition A obtained in Example 4 to obtain a powdery lithium ion conductive composition B.

[0154] [Example 6] The lithium ion conductive composition B obtained in Example 5 was ground in an agate mortar, and 4 μL of dimethyl sulfoxide was added thereto, followed by mixing in the agate mortar to obtain a powdery lithium ion conductive composition C.

[0155] [Test Example 1: BET Measurement] In order to determine the specific surface area, total pore volume, and average pore diameter of the covalent organic framework obtained in Example 1, adsorption isotherms were measured using nitrogen gas (77 K), Ar gas (87 K), or carbon dioxide gas (273 K) as the adsorption gas. The results are shown in Table 1.

[0156] [Table 1]

[0157] As a result, it can be seen that carbon dioxide gas is more easily adsorbed than nitrogen gas or Ar gas, and therefore it can be seen that this is useful as a carbon dioxide adsorption material that selectively adsorbs carbon dioxide gas.

[0158] [Test Example 2: Ionic Conductivity] As a physical property of the covalent organic framework obtained in Example 3 and the lithium ion conductive compositions A to C obtained in Examples 4 to 6, ionic conductivity was measured.

[0159] Li-TBI-COF pellets were prepared by molding them into a thickness of 174 μm using a hydraulic press. Next, the Li-TBI-COF pellets were sandwiched between two stainless steel (SUS) electrodes to form an all-solid-state battery evaluation cell (manufactured by Hosen Co., Ltd.), and the ionic conductivity was measured at temperatures of 25 to 60°C.

[0160] The results are shown in Table 2.

[0161] [Table 2]

[0162] As a result, the compound (comparative example) described in J. Am. Chem. Soc. 2019, 141, 7518-7525:

[0163] [ka]

[0164] The ionic conductivity of -7 Compared to the ionic conductivity when no organic solvent was used, which was S / cm, an ionic conductivity that is one order of magnitude higher was achieved.

[0165] [Test Example 3: Dissolution and Deposition Behavior of Lithium and Potential Window] Li-TBI-COF pellets were produced by molding the covalent organic framework of Example 3 to a thickness of 100 to 200 μm using a hydraulic press. Next, an all-solid-state battery evaluation cell (manufactured by Hosen Co., Ltd.) was constructed using the Li-TBI-COF pellets as a working electrode made of stainless steel (SUS) and a lithium metal as a counter electrode, with an electrode area of ​​0.78 cm. 2The cyclic voltammogram (CV curve) was measured at room temperature (25°C) and 1 V / s. The results are shown in Figure 5 (top). As a result, a redox wave corresponding to the dissolution and deposition of lithium was observed, but at 0 V vs Li / Li + The lithium deposition behavior observed below suggests excellent electrochemical stability.

[0166] Next, to measure the potential window, a similarly constructed all-solid-state battery evaluation cell was used with an electrode area of ​​0.78 cm. 2 A linear sweep voltammogram (LSV curve) was measured at room temperature (25°C) and 50 mV / s. The results are shown in Figure 5 (bottom). As a result, no significant redox reaction peak was observed in the range of 0 to 7.0 V, and the potential window was at least 7.0 V or higher, suggesting that the material is electrochemically stable in this range. [Industrial Applicability]

[0167] The covalent organic framework of the present invention can be used, for example, as a solid electrolyte for various secondary batteries including lithium ion secondary batteries, a carbon dioxide adsorption material, etc.

Claims

1. A covalent organic framework is an organic porous material formed by non-metallic covalent bonds, General formula (1A) and / or (1B): 【Chemistry 1】 [In the formula, R １ , R ２ and R ３ are the same or different and represent an alkyl group or an aryl group. Ar １ , Ar ２ and Ar ３ are the same or different and represent a (hetero)aromatic ring. M １ , M ２ and M ３ are the same or different and represent alkali metals. A covalent organic framework is formed by covalently bonding repeating units represented by the formula:

2. The R １ , R ２ and R ３ are the same or different and are an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. The covalent organic framework according to claim 1.

3. The Ar １ , Ar ２ and Ar ３ The covalent organic framework according to claim 1 or 2, wherein is a benzene ring.

4. Said M １ , M ２ and M ３ are the same or different and are at least one selected from the group consisting of lithium, sodium, and potassium. The covalent organic framework according to any one of claims 1 to 3.

5. A method for producing a covalent organic framework according to any one of claims 1 to 4, (III) General formula (2A) and / or (2B): 【Chemistry 2】 [In the formula, Ar １ , Ar ２ , Ar ３ , M １ , M ２ and M ３ is the same as above.] A step of reacting a covalently bonded organic framework constituted by covalently bonding repeating units represented by the formula: with a borane compound. A manufacturing method comprising:

6. A solid electrolyte comprising the covalent organic framework according to any one of claims 1 to 4.

7. The solid electrolyte according to claim 6, which is a solid electrolyte for a lithium ion secondary battery.

8. An ion-conductive composition comprising the covalent organic framework according to any one of claims 1 to 4 or the solid electrolyte according to claim 6 or 7, and a solvent.

9. A lithium ion secondary battery comprising the solid electrolyte according to claim 6 or 7 or the ion-conductive composition according to claim 8.

10. A carbon dioxide adsorption material comprising the covalent organic framework according to any one of claims 1 to 4, the solid electrolyte according to claim 6 or 7, or the ion-conductive composition according to claim 8.

Images