CN113614960A - Solid electrolyte composition, sheet for all-solid-state secondary battery, sheet for all-solid-state secondary battery, and method for producing all-solid-state secondary battery - Google Patents

Solid electrolyte composition, sheet for all-solid-state secondary battery, sheet for all-solid-state secondary battery, and method for producing all-solid-state secondary battery Download PDF

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CN113614960A
CN113614960A CN202080023128.3A CN202080023128A CN113614960A CN 113614960 A CN113614960 A CN 113614960A CN 202080023128 A CN202080023128 A CN 202080023128A CN 113614960 A CN113614960 A CN 113614960A
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安田浩司
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Abstract

The present invention provides a solid electrolyte composition, an all-solid-state secondary battery sheet and an all-solid-state secondary battery using the solid electrolyte composition, and a method for manufacturing the all-solid-state secondary battery sheet and the all-solid-state secondary battery, the solid electrolyte composition of the present invention contains an inorganic solid electrolyte, a polymer and a dispersion medium, wherein the polymer has a polymer segment in a main chain, and the main chain includes a specific bond, and the polymer segment has: a constituent component derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more; and a constituent derived from a cyclic ester compound or a carboxylic acid compound.

Description

Solid electrolyte composition, sheet for all-solid-state secondary battery, sheet for all-solid-state secondary battery, and method for producing all-solid-state secondary battery
Technical Field
The present invention relates to a solid electrolyte composition, a sheet for an all-solid secondary battery, a sheet for an all-solid secondary battery, and a method for manufacturing an all-solid secondary battery.
Background
In all-solid-state secondary batteries, all of the negative electrode, electrolyte, and positive electrode are made of solid, and safety and reliability, which are problems of batteries using an organic electrolyte solution, can be greatly improved. And can also extend life. In addition, the all-solid-state secondary battery can have a structure in which electrodes and an electrolyte are directly arranged and arranged in series. Therefore, the energy density can be increased as compared with a secondary battery using an organic electrolytic solution, and application to electric vehicles, large-sized storage batteries, and the like is expected.
In such an all-solid-state secondary battery, any one of layers (an inorganic solid electrolyte layer, a negative electrode active material layer, a positive electrode active material layer, and the like) formed of a material containing an inorganic solid electrolyte or an active material and binder particles (a binder) composed of a specific polymer has been proposed. For example, patent document 1 describes a solid electrolyte composition containing (a) an inorganic solid electrolyte, (B) a polymer having a hydrocarbon polymer segment in the main chain, the main chain including at least 1 specific bond, and (C) a dispersion medium.
Prior art documents
Patent document
Patent document 1: international publication No. 2018/020827
Disclosure of Invention
Technical problem to be solved by the invention
When the constituent layers of the all-solid secondary battery are formed from solid particles (inorganic solid electrolyte, solid particles, conductive assistant, etc.), the material forming the constituent layers preferably exhibits excellent dispersibility by dispersing the solid particles in a dispersion medium or the like. However, even when a material having good dispersibility is used, in general, in a constituent layer formed of solid particles, the interfacial contact state between the solid particles is insufficient and the interfacial resistance tends to be increased. In addition, if the adhesiveness between the solid particles by the binder is weak, a contact failure between the solid particles is caused. Further, the active material expands and contracts due to charge and discharge, and thus, contact failure between the active material layer and the solid electrolyte layer occurs. In addition, if the adhesion between the solid particles and the current collector is weak, contact failure between the active material layer and the current collector may also occur. When such contact failure occurs, the resistance of the all-solid secondary battery increases (battery performance decreases).
The inorganic solid electrolyte composition described in patent document 1 can impart excellent cycle characteristics to an all-solid-state secondary battery by improving the adhesion between solid particles and the adhesion between a current collector and the solid particles (also referred to as the adhesion of the solid particles).
However, in recent years, research and development for improving the performance of electric vehicles and for practical use has been rapidly advanced, and battery performance required for all-solid-state secondary batteries has been increasing. Therefore, it is required to develop an all-solid-state secondary battery that exhibits more excellent battery performance by further improving the adhesiveness of solid particles and the like.
The present invention addresses the problem of providing a solid electrolyte composition that exhibits excellent dispersibility and that, when used as a material for forming layers of an all-solid secondary battery, can improve the adhesion of solid particles to impart excellent battery performance to the all-solid secondary battery. Further, an object of the present invention is to provide a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery using the solid electrolyte composition, and a method for producing a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery.
Means for solving the technical problem
The present inventors have conducted various studies and as a result, have found that a solid electrolyte composition which is highly dispersed in a dispersion medium and exhibits excellent dispersibility can be produced by using a polymer obtained by introducing a specific bond into a main chain in combination with an inorganic solid electrolyte and a dispersion medium, the polymer having a polymer segment derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and a polymer segment derived from a cyclic compound having an ester bond or a compound having at least 2 carboxyl groups. Further, it was found that the solid electrolyte composition can form a constituent layer in which other solid particles including an inorganic solid electrolyte are firmly bonded to each other and further the solid particles and a current collector are firmly bonded when an active material layer is formed on the surface of the current collector. Further, it was found that excellent battery performance can be imparted to an all-solid secondary battery by using the solid electrolyte composition as a constituent material of a sheet for an all-solid secondary battery and a constituent layer of an all-solid secondary battery. The present inventors have further conducted repeated studies based on these findings, and have completed the present invention.
That is, the above problems are solved by the following means.
<1> a solid electrolyte composition comprising an inorganic solid electrolyte having ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, a polymer and a dispersion medium, wherein,
the polymer has a polymer segment having an oxygen or nitrogen atom as a bonding portion in a main chain, and includes at least one bond selected from the following bond group (I) in the main chain, the polymer segment having: a constituent component derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more; and a constituent derived from a cyclic compound having an ester bond or a compound having at least 2 carboxyl groups.
< Key group (I) >
Ester bonds, amide bonds, urethane bonds, urea bonds, imide bonds, ether bonds, and carbonate bonds.
<2> the solid electrolyte composition according to <1>, wherein,
the polymer segment includes at least one of a polymer segment represented by formula (1) and a polymer segment represented by formula (2).
[ chemical formula 1]
Figure BDA0003272287090000031
In the formula, RaRepresents a hydrocarbon polymer chain in the above-mentioned hydrocarbon polymer.
XaRepresents an oxygen atom or-NH-.
R1Represents an aliphatic hydrocarbon group having 3 to 15 carbon atoms.
R2Represents an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aliphatic hydrocarbon group having 1 to 20 carbon atoms.
n1 is 1 to 100, and n2 is 1 to 10.
<3> the solid electrolyte composition according to <1> or <2>, wherein,
the cyclic compound having an ester bond or the compound having at least 2 carboxyl groups includes a lactone compound.
<4> the solid electrolyte composition according to any one of claims 1 to 3, wherein,
the polymer is a particulate polymer having an average particle diameter of 10 to 1000 nm.
<5> the solid electrolyte composition according to any one of <1> to <4>, wherein,
the content of the polymer segment in the polymer is 5 to 80 mass%.
<6> the solid electrolyte composition according to any one of <1> to <5>, wherein,
the polymer includes at least one of a polymer represented by the following formula (3) and a polymer represented by the following formula (4).
[ chemical formula 2]
Figure BDA0003272287090000041
In the formula, RaRepresents a hydrocarbon polymer chain in the above-mentioned hydrocarbon polymer.
XaRepresents an oxygen atom or-NH-.
R1Represents an aliphatic hydrocarbon group having 3 to 15 carbon atoms.
R2Represents an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aliphatic hydrocarbon group having 1 to 20 carbon atoms.
nl is 1 to 100, and n2 is 1 to 10.
Rb1Represents an aromatic hydrocarbon group having 6 to 22 carbon atoms, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a combination of 2 or more of these groups.
Rb2Represents an alkylene group having 2 to 12 carbon atoms.
Rb3Represents an alkylene group having at least 1 functional group selected from the following functional group (II).
Rb4Represents an alkylene group having at least 1 functional group selected from the following functional group (III).
Rb5The term "2-valent chain" as used herein means a polyalkylene oxide chain, a polycarbonate chain, a polyester chain or a silicone chain, or a combination of 2 or more of these chains, having a number average molecular weight of 100 or more.
Xb2、Xb3、Xb4And Xb5Represents an oxygen atom or-NH-.
a. b, c, d, e and f are the molar ratio of each constituent, a is 0.1 to 30 mol%, b is 40 to 60 mol%, c and e are 0 to 30 mol%, d and f are 0 to 49 mol%, a + b + c + d + e + f is 100 mol%,
< functional group (II) >
Carboxyl group, sulfonic group, phosphoric group, amino group, hydroxyl group, sulfanyl group, isocyanato group, alkoxysilyl group, and group obtained by fusing 3 or more rings
< functional group (III) >
Group having carbon-carbon unsaturated bond, epoxy group and oxetanyl group
<7> the solid electrolyte composition according to any one of <1> to <6>, wherein,
the content of the polymer is 0.001-10 mass% in the solid component of the solid electrolyte composition.
<8> the solid electrolyte composition according to any one of <1> to <7>, wherein,
the inorganic solid electrolyte is represented by the following formula (S1).
La1Mb1Pc1Sd1Ae1 (S1)
Wherein L represents an element selected from Li, Na and K, M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, A1 and Ge, A represents an element selected from I, Br, Cl and F, a 1-e 1 represents the composition ratio of the elements, and a1: B1: c1: d1: e1 satisfies 1-12: 0-5: 1: 2-12: 0-10.
<9> the solid electrolyte composition according to any one of <1> to <8>, wherein,
the dispersion medium is selected from a ketone compound, an aliphatic compound or an ester compound.
<10> the solid electrolyte composition according to any one of <1> to <9>, which contains an active material.
<11> an all-solid-state secondary battery sheet having a layer composed of the solid electrolyte composition <1> to <10> described above.
<12> an all-solid-state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer and a negative electrode active material layer in this order,
at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer composed of the solid electrolyte composition described in any one of the above <1> to <10 >.
<13> a method for producing an all-solid-state secondary battery sheet, which comprises forming a film from the solid electrolyte composition according to any one of <1> to <10 >.
<14> a method for manufacturing an all-solid-state secondary battery, which comprises manufacturing the all-solid-state secondary battery by the method <13> above.
Effects of the invention
The solid electrolyte composition of the present invention has excellent dispersibility, and can form a sheet or a constituent layer having strong adhesion of solid particles. The sheet for an all-solid secondary battery of the present invention exhibits strong adhesion of solid particles, and the all-solid secondary battery of the present invention exhibits excellent battery performance. The sheet for an all-solid-state secondary battery and the method for manufacturing an all-solid-state secondary battery of the present invention can manufacture the sheet for an all-solid-state secondary battery and the all-solid-state secondary battery of the present invention that exhibit the above-described excellent characteristics.
The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.
Drawings
Fig. 1 is a schematic longitudinal sectional view of an all-solid secondary battery according to a preferred embodiment of the present invention.
Fig. 2 is a longitudinal sectional view schematically showing an all-solid secondary battery (button cell) produced in example.
Detailed Description
In the present specification, the numerical range represented by "to" means a range in which the numerical values before and after "to" are included as the lower limit value and the upper limit value.
In the present specification, the expression "compound" (for example, when the compound is referred to as being attached to the end of the specification) means that the compound itself contains a salt thereof or an ion thereof. Further, the term "derivative" includes derivatives in which a part such as a substituent is introduced by modification within a range not to impair the effects of the present invention.
In the present specification, the term "substituted or unsubstituted substituent, linking group or the like (hereinafter referred to as" substituent or the like ") is not specifically described, and means that the group may have an appropriate substituent. Therefore, in the present specification, even when a YYY group is simply referred to, the YYY group includes an unsubstituted form and a substituted form. This also applies to compounds which are not explicitly described as substituted or unsubstituted. Examples of preferable substituents include a substituent T described below.
In the present specification, the presence of a plurality of substituents or the like represented by specific symbols or the presence of a plurality of substituents or the like defined simultaneously or selectively means that the substituents or the like may be the same or different from each other. Further, unless otherwise specified, when a plurality of substituents and the like are adjacent to each other, these may be connected to each other or fused to form a ring.
[ solid electrolyte composition ]
The solid electrolyte composition (also referred to as an inorganic solid electrolyte-containing composition) of the present invention contains an inorganic solid electrolyte having conductivity of an ion of a metal belonging to group 1 or group 2 of the periodic table, a polymer, and a dispersion medium. The solid electrolyte composition of the present invention is preferably a slurry in which an inorganic solid electrolyte and a polymer are dispersed in a dispersion medium. The polymer contained in the solid electrolyte layer (hereinafter, sometimes referred to as a specific polymer) contains a specific polymer segment described later in the main chain and has a specific bond. The polymer is excellent in dispersibility in a solid electrolyte composition (dispersion medium) and functions as a dispersant for dispersing solid particles with high dispersibility. The polymer also functions as a binder (binder) for binding solid particles (for example, inorganic solid electrolytes, active materials, and active materials) to each other, and further binding a current collector and the solid particles in a sheet or a constituent layer formed of the solid electrolyte composition.
The solid electrolyte composition of the present invention is capable of highly dispersing solid particles and exhibits excellent dispersibility. The specific polymer contained in the solid electrolyte composition exhibits high dispersibility to the dispersion medium. In particular, when the dispersion medium is a hydrophobic dispersion medium described later, the specific polymer is aggregated into particles by a plurality of molecules. At this time, it is considered that the polymer segments incorporated into the main chain of each polymer are located outside the particles and sterically repel each other, so that the dispersion stability of the particles is improved. In particular, as described later, the polymer segment is a segment having a high molecular weight and containing a specific hydrocarbon polymer, a cyclic compound, or the like as a constituent, and the steric repulsion effect in the dispersion medium is considered to be further improved. Therefore, solid particles capable of adsorbing a specific polymer on the surface are highly and stably dispersed in a dispersion medium, and the solid electrolyte composition of the present invention exhibits excellent dispersibility.
In addition, the solid electrolyte composition of the present invention can firmly bind solid particles when formed into a sheet or a constituent layer. When the active material layer is formed on the surface of the current collector using the solid electrolyte composition, the solid particles and the current collector can be firmly bonded together in addition to the bonding of the solid particles to each other. As a result, the all-solid-state secondary battery provided with the sheet or the constituent layer formed using the solid electrolyte composition of the present invention exhibits excellent battery performance. The detailed reason is not clear, but is considered as follows. That is, the solid electrolyte composition of the present invention can bind solid particles while suppressing formation of aggregates of a specific polymer which has high dispersibility of the specific polymer and can become a resistance component. Further, since the specific polymer exhibits high dispersibility, it is possible to maintain high dispersibility even in the case of forming a sheet or a constituent layer with respect to solid particles or the like in a dispersion medium (the solid electrolyte composition is excellent in dispersion stability). Therefore, it is considered that the sheet or the constituent layers are excellent in the adhesiveness of the solid particles and contribute to high battery performance.
The solid electrolyte composition of the present invention can be preferably used as a sheet for an all-solid secondary battery or a molding material for a solid electrolyte layer or an active material layer of an all-solid secondary battery.
The solid electrolyte composition of the present invention is not particularly limited, and the water content (also referred to as moisture content) is preferably 500ppm or less, more preferably 200ppm or less, further preferably 100ppm or less, and particularly preferably 50ppm or less. If the water content of the solid electrolyte composition is small, deterioration of the inorganic solid electrolyte can be suppressed. The water content represents the amount of water contained in the solid electrolyte composition (mass ratio to the solid electrolyte composition), and specifically is a value obtained by filtration through a 0.02 μm membrane filter and measurement by karl fischer titration.
The components contained in the solid electrolyte composition of the present invention and components that can be contained therein will be described below.
< inorganic solid electrolyte >
The solid electrolyte composition of the present invention contains an inorganic solid electrolyte.
In the present invention, the inorganic solid electrolyte refers to an inorganic solid electrolyte, and the solid electrolyte refers to a solid electrolyte capable of moving ions inside thereof. From the viewpoint of not containing organic substances as main ion conductive materials, they are clearly distinguished from organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO) and the like, organic electrolyte salts typified by lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) and the like). Further, since the inorganic solid electrolyte is a solid in a stable state, it is not usually dissociated or dissociated into cations and anions. At this point, the ionic liquid is dissociated or dissociated with an inorganic electrolyte salt (LiPF) in the electrolyte or the polymer to form a cation and an anion6、LiBF4Lithium bis (fluorosulfonyl) imide (LiFSI), LiCl, etc.) are clearly distinguished. The inorganic solid electrolyte is not particularly limited as long as it has ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, and usually does not have electron conductivity. When the all-solid-state secondary battery of the present invention is a lithium ion battery, the inorganic solid electrolyte preferably has ion conductivity of lithium ions.
The inorganic solid electrolyte material can be used by appropriately selecting a solid electrolyte material generally used for all-solid secondary batteries. The inorganic solid electrolyte includes (i) a sulfide-based inorganic solid electrolyte, (ii) an oxide-based inorganic solid electrolyte, (iii) a halide-based inorganic solid electrolyte, and (iv) a hydride-based solid electrolyte, and is preferably a sulfide-based inorganic solid electrolyte from the viewpoint that a more favorable interface can be formed between the active material and the inorganic solid electrolyte.
(i) Sulfide-based inorganic solid electrolyte
The sulfide-based inorganic solid electrolyte preferably contains a sulfur atom, has ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, and has electronic insulation properties. The sulfide-based inorganic solid electrolyte preferably contains at least Li, S, and P as elements and has lithium ion conductivity, but may contain other elements than Li, S, and P according to the purpose or circumstances.
As the sulfide-based inorganic solid electrolyte, for example, a lithium ion conductive inorganic solid electrolyte satisfying a composition represented by the following formula (S1) can be cited.
La1Mb1Pc1Sd1Ae1 (S1)
In the formula, L represents an element selected from Li, Na and K, and Li is preferable. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al and Ge, A represents an element selected from I, Br, Cl and F, a 1-e 1 represents the composition ratio of the elements, and a1: B1: c1: d1: e1 satisfies 1-12: 0-5: 1: 2-12: 0-10. a1 is preferably 1 to 9, more preferably 1.5 to 7.5. b1 is preferably 0 to 3, more preferably 0 to 1. d1 is preferably 2.5 to 10, more preferably 3.0 to 8.5. e1 is preferably 0 to 5, more preferably 0 to 3.
As described below, the composition ratio of each element can be controlled by adjusting the amount of the raw material compound to be mixed in the production of the sulfide-based inorganic solid electrolyte.
The sulfide-based inorganic solid electrolyte may be amorphous (glass), may be crystallized (glass-ceramic), or may be partially crystallized. For example, a Li-P-S glass containing Li, P, and S or a Li-P-S glass ceramic containing Li, P, and S can be used.
The sulfide-based inorganic solid electrolyte can be prepared by reacting lithium sulfide (Li)2S), phosphorus sulfides (e.g., phosphorus pentasulfide (P)2S5) Phosphorus monomer, sulfur monomer, sodium sulfide, hydrogen sulfide, halogenLithium (for example, LiI, LiBr, LiCl) and sulfide (for example, SiS) of the element represented by M2、SnS、GeS2) At least 2 or more raw materials.
Li-P-S glass and Li-P-S glass ceramic2S and P2S5In the ratio of Li2S:P2S5The molar ratio of (a) to (b) is preferably 60:40 to 90:10, and more preferably 68:32 to 78: 22. By mixing Li2S and P2S5When the ratio (b) is in this range, the lithium ion conductivity can be improved. Specifically, the lithium ion conductivity can be preferably set to 1 × 10-4S/cm or more, more preferably 1X 10-3And more than S/cm. Although the upper limit is not particularly set, it is actually 1X 10-1S/cm or less.
Specific examples of the sulfide-based inorganic solid electrolyte include the following combinations of raw materials. For example, Li is cited2S-P2S5、Li2S-P2S5-LiCl、Li2S-P2S5-H2S、Li2S-P2S5-H2S-LiCl、Li2S-LiI-P2S5、Li2S-LiI-Li2O-P2S5、Li2S-LiBr-P2S5、Li2S-Li2O-P2S5、Li2S-Li3PO4-P2S5、Li2S-P2S5-P2O5、Li2S-P2S5-SiS2、Li2S-P2S5-SiS2-LiCl、Li2S-P2S5-SnS、Li2S-P2S5-Al2S3、Li2S-GeS2、Li2S-GeS2-ZnS、Li2S-Ga2S3、Li2S-GeS2-Ga2S3、Li2S-GeS2-P2S5、Li2S-GeS2-Sb2S5、Li2S-GeS2-Al2S3、Li2S-SiS2、Li2S-Al2S3、Li2S-SiS2-Al2S3、Li2S-SiS2-P2S5、Li2S-SiS2-P2S5-LiI、Li2S-SiS2-LiI、Li2S-SiS2-Li4SiO4、Li2S-SiS2-Li3PO4、Li10GeP2S12And the like. The mixing ratio of the raw materials is not limited. As a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition, for example, an amorphization method can be cited. Examples of the amorphization method include a mechanical polishing method, a solution method, and a melt quenching method. The treatment at normal temperature can be performed, and the manufacturing process can be simplified.
(ii) Oxide-based inorganic solid electrolyte
The oxide-based inorganic solid electrolyte is preferably a compound containing an oxygen atom, having ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, and having electronic insulation properties.
As for the oxide-based inorganic solid electrolyte, 1 × 10 is preferable as the ion conductivity-6S/cm or more, more preferably 5X 10-6S/cm or more, particularly preferably 1X 10-5And more than S/cm. Although the upper limit is not particularly set, it is actually 1X 10-1S/cm or less.
Specific examples of the compound include LixaLayaTiO3[ xa satisfies 0.3. ltoreq. xa. ltoreq.0.7, and ya satisfies 0.3. ltoreq. ya. ltoreq.0.7. (LLT); lixbLaybZrzbMbb mbOnb(MbbIs at least 1 element selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In and Sn. xb is more than or equal to 5 and less than or equal to 10, yb is more than or equal to 1 and less than or equal to 4, zb is more than or equal to 1 and less than or equal to 4, mb is more than or equal to 0 and less than or equal to 2, nb is more than or equal to 5 and less than or equal to 20. ) (ii) a LixcBycMcc zcOnc(MccIs at least 1 element selected from C, S, Al, Si, Ga, Ge, In and Sn. xc is more than 0 and less than or equal to 5, yc is more than 0 and less than or equal to 1, zc is more than 0 and less than or equal to 1, and nc is more than 0 and less than or equal to 6. ) (ii) a Lixd(Al,Ga)yd(Ti,Ge)zdSiadPmdOnd(xd satisfies 1 ≤ xd ≤ 3, yd satisfies 0 ≤ yd ≤ 1, zd satisfies 0 ≤ zd ≤ 2, ad satisfies 0 ≤ ad ≤ 1, md satisfies 1 ≤ md ≤ 7, and nd satisfies 3 ≤ nd ≤ 13.); li(3-2xe)Mee xeDeeO (xe represents a number of 0 to 0.1, M)eeRepresents a 2-valent metal atom. DeeRepresents a halogen atom or a combination of 2 or more halogen atoms. ) (ii) a LixfSiyfOzf(xf satisfies 1. ltoreq. xf.ltoreq.5, yf satisfies 0. ltoreq. yf.ltoreq.3, zf satisfies 1. ltoreq. zf.ltoreq.10); lixgSygOzg(xg satisfies 1. ltoreq. xg. ltoreq.3, yg satisfies 0. ltoreq. yg. ltoreq.2, zg satisfies 1. ltoreq. zg. ltoreq.10); li3BO3;Li3BO3-Li2SO4;Li2O-B2O3-P2O5;Li2O-SiO2;Li6BaLa2Ta2O12;Li3PO(4-3/2w)Nw(w satisfies w < 1); li having a lisicon (lithium super ionic conductor) type crystal structure3.5Zn0.25GeO4(ii) a La having perovskite-type crystal structure0.55Li0.35TiO3(ii) a LiTi having NASICON (Natrium super ionic conductor) type crystal structure2P3O12;Li1+xh+yh(Al,Ga)xh(Ti,Ge)2-xhSiyhP3-yhO12(xh satisfies 0. ltoreq. xh. ltoreq.1, yh satisfies 0. ltoreq. yh. ltoreq.1); li having garnet-type crystal structure7La3Zr2O12(LLZ) and the like.
Also, a phosphorus compound containing Li, P, and O is preferable. For example, lithium phosphate (Li) is cited3PO4) (ii) a LiPON in which a part of oxygen in lithium phosphate is substituted with nitrogen; LiPOD1(D1Preferably selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt andmore than 1 element in Au. ) And the like.
In addition, LiA can also be preferably used1ON(A1Is at least 1 element selected from the group consisting of Si, B, Ge, Al, C and Ga. ) And the like.
(iii) Halide-based inorganic solid electrolyte
The halide-based inorganic solid electrolyte is preferably a compound containing a halogen atom, having ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, and having electronic insulating properties.
The halide-based inorganic solid electrolyte is not particularly limited, and examples thereof include Li described in LiCl, LiBr, LiI, ADVANCED MATERIALS, 2018,30,18030753YBr6、Li3YCl6And (c) a compound such as a quaternary ammonium compound. Among them, Li is preferable3YBr6、Li3YCl6
(iv) Hydride inorganic solid electrolyte
The hydride-based inorganic solid electrolyte is preferably a compound containing a hydrogen atom, having ion conductivity of a metal belonging to group 1 or group 2 of the periodic table, and having electronic insulation properties.
The hydride-based inorganic solid electrolyte is not particularly limited, and examples thereof include LiBH4、Li4(BH4)3I、3LiBH4-LiCl, etc.
The inorganic solid electrolyte is preferably a particle. In this case, the particle diameter (volume average particle diameter) of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. The upper limit is preferably 100 μm or less, and more preferably 50 μm or less.
The particle size of the inorganic solid electrolyte was measured by the following procedure. In a 20mL sample bottle, the inorganic solid electrolyte particles were diluted with water (heptane in the case of a water-unstable substance) to prepare a1 mass% dispersion. The diluted dispersion sample was irradiated with ultrasonic waves at 1kHz for 10 minutes and then immediately used in the test. Using this dispersion sample, data acquisition was performed 50 times using a laser diffraction/scattering particle size distribution measuring apparatus LA-920 (trade name, HORIBA, ltd.) at a temperature of 25 ℃ using a quartz cell for measurement, thereby obtaining a volume average particle diameter. Other detailed conditions and the like are as required in reference to JIS Z8828: 2013 "particle size analysis-dynamic light scattering method". 5 samples were prepared for each grade and the average was used.
The inorganic solid electrolyte may contain 1 species or 2 or more species.
In the case of forming the solid electrolyte layer, the solid electrolyte layer has a unit area (cm)2) The mass (mg) (weight per unit area) of the inorganic solid electrolyte of (2) is not particularly limited. Can be determined appropriately according to the designed battery capacity, and can be set to 1 to 100mg/cm, for example2
When the solid electrolyte composition contains an active material described later, the total amount of the active material and the inorganic solid electrolyte is preferably within the above range with respect to the weight per unit area of the inorganic solid electrolyte.
From the viewpoint of dispersibility, reduction in interface resistance, and adhesion, the content of the inorganic solid electrolyte in the solid electrolyte composition is preferably 50 mass% or more, more preferably 70 mass% or more, and particularly preferably 90 mass% or more, of 100 mass% of the solid content. From the same viewpoint, the upper limit is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and particularly preferably 99% by mass or less.
However, when the solid electrolyte composition contains an active material described later, the total content of the active material and the inorganic solid electrolyte is preferably in the above range with respect to the content of the inorganic solid electrolyte in the solid electrolyte composition.
In the present specification, the solid component refers to a component that volatilizes or evaporates without disappearing when the solid electrolyte composition is subjected to a drying treatment at 170 ℃ for 6 hours under a pressure of 1mmHg and under a nitrogen atmosphere. Typically, the components are components other than the dispersion medium described later.
< Polymer >
The specific polymer contained in the solid electrolyte composition of the present invention is a polymer having a polymer segment described later as a constituent in the main chain and having at least 1 bond selected from the following bond group (I). As described above, the specific polymer functions as a binder (adhesive), and more preferably functions as a dispersant.
In the solid electrolyte composition of the present invention, the specific polymer may be contained in a form of being dissolved in a dispersion medium, but is preferably contained as particles.
< key group (I) >
Ester bonds, amide bonds, urethane bonds, urea bonds, imide bonds, ether bonds, and carbonate bonds.
In the present invention, the main chain of the polymer means all molecular chains other than that constituting the polymer, which may be regarded as linear molecular chains of branched or comb-type chains with respect to the main chain. Although it depends on the mass average molecular weight of the molecular chain regarded as a branched or comb-type chain, typically, the longest chain among the molecular chains constituting the polymer becomes the main chain. However, the functional group at the end of the polymer is not included in the main chain.
The position of introduction of the bond selected from the above-mentioned bond group (I) is not particularly limited as long as it is contained in the main chain of the polymer, and it may be either a form contained as a bond linking different constituent units constituting the polymer or a form contained in the constituent units, and is preferably a form contained as a bond linking different constituent units. In this preferred embodiment, the ester bond in the above-mentioned group (I) means a bond different from the ester bond present in the polymer segment.
The bond selected from the above bond group (I) of the specific polymer is preferably an ester bond, an amide bond, a urethane bond, or a urea bond, and more preferably a urethane bond.
Also, the imide bond, ether bond and carbonate bond are preferably incorporated into the main chain in combination with at least 1 of the ester bond, amide bond, urethane bond and urea bond.
The number of the above-mentioned bonds in the main chain is not particularly limited, but is preferably 1 to 6, more preferably 1 to 4. The number of the above-mentioned bonds in the main chain varies depending on the mass average molecular weight, the characteristics and the like of the polymer, and is not exclusive and can be determined appropriately.
Specific polymers having a bond selected from the above-mentioned bond group (I) in the main chain include polymers of polyester, polyamide, polyurethane, polyurea, polyimide, polyether and polycarbonate, and copolymers thereof. The copolymer may be a block copolymer having the above-mentioned respective polymers as segments, or a random copolymer in which respective constituent components constituting 2 or more of the above-mentioned respective polymers are randomly bonded.
Among them, the specific polymer is preferably polyurethane, polyester, polyamide, polyether, or polyurea or a copolymer (polymer polymerized in sequence) of 2 or more thereof, and more preferably polyurethane, polyester, polyamide, or polyurea or a copolymer of 2 or more thereof having an ester bond, an imide bond, an ether bond, and a carbonate bond in the main chain.
The specific polymer has at least one polymer segment as a constituent in the main chain. The details of the polymer segment will be described later. The number of types of polymer segments in the main chain is not particularly limited, but is preferably 1 to 3, and more preferably 1.
The content of the polymer segment in the specific polymer is not particularly limited, and may be appropriately set in consideration of dispersibility and the like. For example, the content (mass%) of the polymer segment is preferably 5 to 80 mass%, more preferably 8 to 60 mass%, even more preferably 10 to 40 mass%, and particularly preferably 10 to 30 mass%, from the viewpoints of dispersibility and adhesiveness of solid particles and battery performance of a solid secondary battery. When the content of the polymer segment is defined by mol%, the value of "a (molar ratio)" in the following formulae (3) and (4) can be applied regardless of the content (mass%).
The specific polymer preferably has a functional group for improving wettability or adsorptivity to the surface of the solid particle. The functional group includes a functional group that exhibits an interaction such as a hydrogen bond on the surface of the solid particle and a functional group that can form a chemical bond with a group present on the surface of the solid particle, and more specifically, a functional group having at least one kind selected from the following functional group (II) is more preferable. Among them, from the viewpoint of more effectively exhibiting wettability and adsorbability to the surface of the solid particles, it is preferable that 2 or more functional groups capable of forming a bond between the functional groups are not present.
< group of functional groups (II) >)
Carboxyl group and sulfonic group (-SO)3H) Phosphate group (-PO)4H2) Amino (-NH-)2) A hydroxyl group, a sulfanyl group, an isocyanate group, an alkoxysilyl group, and a group having a fused ring structure of 3 or more rings
The sulfonic acid group and the phosphoric acid group may be salts thereof, and examples thereof include sodium salts and calcium salts.
The alkoxysilyl group may be a silyl group in which the Si atom is substituted with at least one alkoxy group (preferably, 1 to 12 carbon atoms), and examples of the other substituent on the Si atom include an alkyl group and an aryl group. As the alkoxysilyl group, for example, the following description of the alkoxysilyl group in the substituent T can be preferably applied.
The group having a fused ring structure of 3 or more rings is preferably a group having a cholesterol ring structure or a group having a structure in which aromatic rings of 3 or more rings are fused, and more preferably a cholesterol residue or a pyrenyl group.
The specific polymer preferably has a functional group selected from the above functional group (II) in the constituent other than the polymer segment.
The content of the functional group selected from the functional group (II) in the specific polymer is not particularly limited, and the proportion of the constituent having the functional group selected from the functional group (II) among all the constituents constituting the specific polymer is preferably 0 to 50 mol%, preferably 0 to 49 mol%, more preferably 0.1 to 40 mol%, further preferably 1 to 30 mol%, and particularly preferably 3 to 25 mol%. The content of the compound (A) may be, for example, the content based on mass, the content of the compound (A) and the content of the compound (B) having an alkylene group (R) described laterb3The content of the constituent components (c) is in the same range.
< crosslinkable functional group >
The specific polymer is also selected to have a functional group capable of forming a crosslinked structure by radical polymerization, cationic polymerization, or anionic polymerization (hereinafter, also referred to as a crosslinkable functional group). By forming a bond by reacting the crosslinkable functional groups with each other, the specific polymer can form a crosslinked structure in or between polymer particles, and the strength can be improved.
The crosslinkable functional group is preferably a group having a carbon-carbon unsaturated bond and/or a cyclic ether group. The group having a carbon-carbon unsaturated bond is a group capable of forming a crosslinked structure by radical polymerization (i.e., a group having a polymerizable carbon-carbon unsaturated bond), and specifically, an alkenyl group (preferably 2 to 12, more preferably 2 to 8 carbon atoms), an alkynyl group (preferably 2 to 12, more preferably 2 to 8 carbon atoms), an acryloyl group and a methacryloyl group are preferably mentioned, and a vinyl group, an ethynyl group, an acryloyl group, a methacryloyl group and a 2-trifluoromethylacryloyl group are more preferably mentioned. The cyclic ether group is a group capable of forming a crosslinked structure by cationic polymerization, and specifically, an epoxy group and an oxetanyl group are preferable.
That is, the specific polymer preferably has at least one functional group selected from the following functional group (III).
< functional group (III) >
Group having carbon-carbon unsaturated bond, epoxy group and oxetanyl group
The group having a carbon-carbon unsaturated bond is as described above.
The specific polymer preferably has the crosslinkable functional group in the constituent other than the polymer segment. In the case where the hydrocarbon polymer has a carbon-carbon unsaturated bond (for example, a polybutadiene constituent and a polyisoprene constituent), a crosslinkable functional group (for example, a vinyl group and a propenyl group) composed of a carbon atom and a hydrogen atom may be present in the hydrocarbon polymer segment.
The content of the crosslinkable functional group in the specific polymer is not particularly limited, but the proportion of the crosslinkable functional group-containing component in all the components constituting the specific polymer is preferably 0 to 30 mol%, more preferably 0 to 25 mol%, further preferably 0 to 20 mol%, particularly preferably 0 to 20 mol%It is preferably 0 to 10 mol%. The content of the compound (A) may be, for example, the content based on mass, the content of the compound (A) and the content of the compound (B) having an alkylene group (R) described laterb4The content of the constituent components (c) is in the same range.
The specific polymer having the crosslinkable functional group includes both a form in which the crosslinkable functional group is an uncrosslinked polymer and a form in which the functional group is a crosslinked polymer.
The reaction of the crosslinkable functional groups with each other may be carried out by including a polymerization initiator (radical, cationic or anionic polymerization initiator) corresponding to each crosslinkable functional group in the solid electrolyte composition of the present invention in advance, and carrying out the reaction by the polymerization initiator, or by a redox reaction at the time of driving the battery. In addition, the radical polymerization initiator may be any one of the following: a thermal radical polymerization initiator that is cleaved by heat to generate an initiating radical; and a photo radical polymerization initiator which generates an initiating radical by light, electron beam or radiation.
As the polymerization initiator that may be contained in the solid electrolyte composition of the present invention, a commonly used polymerization initiator can be used without particular limitation.
(Polymer segment)
The polymer segment is a segment (constituent component) derived from a polymer obtained by a condensation reaction (polycondensation reaction) of a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and a number average molecular weight of 500 or more, which will be described later, with a cyclic compound having an ester bond or a compound having at least 2 carboxyl groups, which will be described later.
The polymer has a hydroxyl group or an amino group at both ends of a segment by a combination of a group of a hydrocarbon polymer and a cyclic compound having an ester bond (referred to as a cyclic ester compound) or a compound having at least 2 carboxyl groups (a carboxylic acid compound). For example, polyester polyols, polyester polyamines, polyamide polyols and polyamide polyamines are included, with polyester polyols being preferred.
The polyester polyol has at least 2 or more ester bonds and 2 or more hydroxyl groups in its molecule, and preferably has hydroxyl groups at both ends of the main chain. The polyester polyamine has at least 2 or more ester bonds and 2 or more amino groups in its molecule, and preferably has amino groups at both ends of the main chain. The polyamide polyol has at least 2 amide bonds and 2 or more hydroxyl groups in its molecule, and preferably has hydroxyl groups at both ends of the main chain. The polyamide polyamine has at least 2 amide bonds and 2 or more amino groups in its molecule, and preferably has amino groups at both ends of the main chain.
The polymer segment has the above-described structure (structure in which an oxygen or nitrogen atom is bonded to the main chain) excluding hydrogen atoms of hydroxyl groups or amino groups at both ends of the polymer chain, and preferably includes at least one of a polymer segment represented by formula (1) and a polymer segment represented by formula (2) described later, and more preferably includes at least one segment represented by formula (1) described later.
A polymer segment composed of a hydrocarbon polymer and a cyclic ester compound
Examples of the polymer constituting the polymer segment composed of the hydrocarbon polymer and the cyclic ester compound include polyester polyol and polyamide polyol, and the number of ester bonds, amide bonds, hydroxyl groups, and the like in the polymer is not particularly limited, but is preferably 2 or more. Among them, polyester diols are preferable. The bonding mode of the hydrocarbon polymer and the cyclic ester compound is not particularly limited, and when the hydrocarbon polymer and the cyclic ester compound are 2-functional, a BAB type is preferable. Here, a is a constituent derived from a hydrocarbon polymer, and B is a constituent derived from a cyclic ester compound. More preferably, the ring-opened product of the cyclic ester compound is bonded to 2 hydroxyl groups or amino groups of the hydrocarbon polymer having 2 hydroxyl groups or amino groups, respectively, via ester groups. The ring-opened product of the cyclic ester compound bonded to the hydroxyl group or the amino group of the hydrocarbon polymer may be a 1-molecule ring-opened product, and is usually a ring-opened polymer of the cyclic compound. The average polymerization degree of the ring-opened polymer is not particularly limited, and is appropriately determined depending on the molecular weight and the like, and is, for example, as defined in n1 of the following formula (1).
The polymer segment composed of the hydrocarbon polymer and the cyclic ester compound is preferably a segment represented by the following formula (1).
[ chemical formula 3]
Figure BDA0003272287090000161
In the formula (1), RaRepresents a hydrocarbon polymer chain in a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more. The hydrocarbon polymer chain is the same as the hydrocarbon polymer chain constituting the hydrocarbon polymer described later.
XaEach atom derived from a hydroxyl group or an amino group of the hydrocarbon polymer represents an oxygen atom or-NH-. Wherein, 2XaThe same is true. XaPreferably, all are oxygen atoms (the segment represented by formula (1) is a polyester polyol segment).
R1Each represents an aliphatic hydrocarbon group having 3 to 15 carbon atoms, preferably an aliphatic hydrocarbon group having 4 to 10 carbon atoms. The aliphatic hydrocarbon group may be an unsaturated aliphatic hydrocarbon group, preferably a saturated aliphatic hydrocarbon group (alkylene group). 2 of R in the formula1May be the same or different, preferably the same. R1The number of carbon atoms in (B) means that R is bonded1The smallest number of carbon atoms of the bonded oxygen atom and carbonyl carbon atoms.
RaAnd R1Each of the substituents may be, for example, a substituent T described later. As R1Preferred substituents to be contained herein include alkyl groups.
n1 represents a number average polymerization degree, and is 1 to 100, preferably 1 to 50, and more preferably 1 to 25, from the viewpoint of improving dispersibility, adhesiveness, and battery performance in a well-balanced manner. In formula (1), 2 n1 may be the same or different.
A polymer segment composed of a hydrocarbon polymer and a carboxylic acid compound
The polymer constituting the polymer segment composed of the hydrocarbon polymer and the carboxylic acid compound is a polyester polyol and a polyamide polyamine, and the number of ester bonds, amide bonds, hydroxyl groups, and amino groups in the polymer is not particularly limited, and is preferably 2 or more. Among them, polyester diols and polyamide diamines are preferable, and diester diols and diamide diamines are preferable. The bonding mode between the hydrocarbon polymer and the carboxylic acid compound is not particularly limited, and when the hydrocarbon polymer and the carboxylic acid compound are 2-functional, the structure is usually (AB) xA type. Here, a is a constituent derived from a hydrocarbon polymer, and B is a constituent derived from a carboxylic acid compound. x is an integer of 1 or more, and the upper limit is appropriately set depending on the molecular weight and the like. When x is 1, it is an ABA-type diester diol or polyamide diamine in which 1 hydrocarbon polymer is bonded to 2 carboxyl groups of a carboxylic acid compound.
The polymer segment composed of the hydrocarbon polymer and the carboxylic acid compound is preferably a segment represented by the following formula (2).
[ chemical formula 4]
Figure BDA0003272287090000171
In the formula (2), RaRepresents a hydrocarbon polymer chain in a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more, and is bonded to R in the formula (1)aThe meaning is the same.
XaEach atom derived from a hydroxyl group or an amino group of the hydrocarbon polymer represents an oxygen atom or-NH-. Wherein, with 1RaBonded 2XaAre the same. XaPreferably, all are oxygen atoms (the segment represented by formula (2) is a polyester polyol segment) or-NH- (the segment represented by formula (2) is a polyamide polyamine segment), and more preferably all are oxygen atoms.
R2Represents an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms. The aromatic hydrocarbon group having 6 to 20 carbon atoms is not particularly limited, and the number of carbon atoms is as described in the following aromatic dicarboxylic acid compound. The aromatic hydrocarbon group includes an aromatic residue obtained by removing each hydroxyl group of 2 carboxyl groups from an aromatic dicarboxylic acid compound described below. The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be an unsaturated aliphatic hydrocarbon group, and is preferably a saturated aliphatic hydrocarbon group (alkylene group). The number of carbon atoms of which is as described in the following carboxylic acid compound. Examples of the aliphatic hydrocarbon group include aliphatic groups obtained by removing each hydroxyl group of 2 carboxyl groups from an aliphatic dicarboxylic acid compound described below as a carboxylic acid compound. R2The number of carbon atoms in (B) means that R is bonded2The smallest number of carbon atoms of the 2 carbonyl carbon atoms bonded.
RaAnd R2Each of the substituents may be, for example, a substituent T described later. As R2Preferable substituents include carbonyl groups, sulfonic acid groups, phosphoric acid groups, ether groups (alkoxy groups, aryloxy groups, and heterocyclic oxy groups), and halogen atoms.
n2 represents a number average polymerization degree of 1 to 10, preferably 1 to 5, and more preferably 1 to 3.
The polymer segment may have a constituent derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and a constituent derived from a cyclic ester compound or a carboxylic acid compound, and the two constituents may be 1 type or 2 or more types, respectively.
In the present invention, the polymer segment may have a constituent other than the two constituents, and is preferably a segment composed of the two constituents.
In the above polymer segment, R is appropriately selectedaAnd R1Or R2The chemical structure of (b), the number of carbon atoms, and the like, and the affinity to a dispersion medium described later, particularly a hydrophobic dispersion medium, can be adjusted (improved). If the affinity for the dispersion medium is further improved, the dispersibility of the specific polymer in the solid electrolyte composition can be expected to be further improved, and the adhesion of the solid particles and the battery performance of the all-solid secondary battery can be realized at a higher level.
The number average molecular weight of the polymer segment is not particularly limited, but is preferably more than 500, more preferably 1500 or more, and further preferably 3000 or more. The upper limit is not particularly limited, and is, for example, preferably 100,000 or less, more preferably 30,000 or less, and still more preferably 10,000 or less. The number average molecular weight can be determined as a number average molecular weight in terms of standard polystyrene in the same manner as the mass average molecular weight of the specific polymer.
(constituent component derived from hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more)
The constituent derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and a number average molecular weight of 500 or more (also referred to as a hydrocarbon polymer constituent) is a constituent constituting the polymer segment, and is a constituent formed by a condensation reaction of a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and a number average molecular weight of 500 or more with a cyclic ester compound or a carboxylic acid compound described later. The constituent component is a residue obtained by removing a hydrogen atom from a hydroxyl group or an amino group of the hydrocarbon polymer, and corresponds to "-X" in the formulae (1) and (2)a-Ra-Xa-”(XaAnd RaAs described above. ).
The hydrocarbon polymer forming the constituent has at least 2 hydroxyl groups or at least 2 amino groups, preferably at least 2 hydroxyl groups. The number of hydroxyl groups or amino groups in the hydrocarbon polymer is not particularly limited, but is preferably 2 to 6, and more preferably 2. The hydrocarbon polymer may have a hydroxyl group or an amino group at any position of the main chain, and preferably has a hydroxyl group or an amino group at both ends.
Hydrocarbon polymers having at least 2 hydroxyl or amino groups and a number average molecular weight of 500 or more
The hydrocarbon polymer is a polymer having at least 2 hydroxyl groups or amino groups in the polymer chain of a hydrocarbon polymer obtained by polymerizing a polymerizable hydrocarbon (at least 2 hydrocarbons).
The hydrocarbon polymer is an oligomer or polymer composed of carbon atoms and hydrogen atoms, and the number of carbon atoms constituting the hydrocarbon polymer is preferably 30 or more, and more preferably 50 or more. The upper limit of the number of carbon atoms constituting the hydrocarbon polymer is not particularly limited, and may be, for example, 3000. The hydrocarbon polymer is preferably a chain (hydrocarbon polymer chain) having a main chain satisfying the above carbon number and containing a hydrocarbon polymer composed of an aliphatic hydrocarbon, and more preferably a chain containing a polymer (preferably an elastomer) composed of an aliphatic saturated hydrocarbon or an aliphatic unsaturated hydrocarbon. Specific examples of the hydrocarbon polymer include diene polymers having a double bond in the main chain and non-diene polymers having no double bond in the main chain. Examples of the diene-based polymer include a styrene-butadiene copolymer, a styrene-vinyl-butadiene copolymer, a copolymer of isobutylene and isoprene (preferably, butyl rubber (IIR)), a butadiene polymer, an isoprene polymer, and a vinyl-propenyl-diene copolymer. Examples of the non-diene polymer include olefin polymers such as ethylene-propylene-based copolymers and styrene-ethylene-propylene-based copolymers, and hydrogen-reduced products of the diene polymers.
The number average molecular weight of the hydrocarbon polymer having at least 2 hydroxyl groups or amino groups is 500 or more. When the number average molecular weight of the polymer is 500 or more, the dispersibility itself is excellent, and an effect of functioning as a dispersant for dispersing solid particles with high dispersibility can be obtained. From the viewpoint of further improving the effect, the number average molecular weight is preferably 1000 or more, and more preferably 1500 or more. The upper limit is not particularly limited, and is, for example, preferably less than 100,000, more preferably less than 30,000, and further preferably less than 10,000. The number average molecular weight can be determined as a number average molecular weight in terms of standard polystyrene in the same manner as the mass average molecular weight of the specific polymer.
As the hydrocarbon polymer having a hydroxyl group or an amino group, for example, NISSO-PB series (NIPPON SODA CO., manufactured by LTD.), Claysol series (TOMOE Engineering Co., manufactured by Ltd.), polyVEST-HT series (EVONIK CO., manufactured by LTD.), poly-bd series (Idemitsu Kosan Co., manufactured by Ltd.), poly-ip series (Idemitsu Kosan Co., manufactured by Ltd.), Idemitsu L (Idemitsu Kosan Co., manufactured by Ltd.), POLYTAIL series (Mitsubishi Chemical Corporation), etc., which are all trade names, can be preferably used.
(constituent derived from a cyclic ester compound or a carboxylic acid compound)
The constituent (also referred to as an acid constituent) is a constituent constituting the polymer segment, and is a constituent formed by a condensation reaction of a cyclic ester compound or a carboxylic acid compound with the hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more. The acid component is a residue obtained by removing a hydroxyl group from a ring opening body of a cyclic ester compound or a carboxyl group of a carboxylic acid compound, and corresponds to-CO-R in the above formula (1)1-O-”(R1As described above. ) Or "-CO-R in the above formula (2)2-CO-”(R2As described above. ).
The cyclic ester compound and the carboxylic acid compound which form the acid component are preferably cyclic ester compounds, and more preferably lactone compounds described below.
Cyclic ester compounds
The cyclic ester compound may be a compound having a cyclic structure including at least one ester bond, and in general, a compound having a cyclic structure including 1 ester bond (lactone compound) is preferable.
The lactone compound is not particularly limited, and an aliphatic lactone compound and an aromatic lactone compound are exemplified, and an aliphatic lactone compound is preferable. The aliphatic lactone compound includes an aliphatic group having an ester bond and 3 to 15 carbon atoms (preferably R in the formula (1))1) The compound having a cyclic structure. Specific examples thereof include epsilon-caprolactone, 4-methylhexanolactone, 3,5, 5-trimethylcaprolactone, 3, 5-trimethylcaprolactone, beta-propiolactone, gamma-butyrolactone, delta-valerolactone, gamma-valerolactone and heptalactone. Among these, from the viewpoint of easy availability and high reactivity, epsilon-caprolactone, delta-valerolactone and gamma-valerolactone are preferable, and epsilon-caprolactone is more preferable.
The lactone compound may have a substituent such as γ -valerolactone, and examples thereof include a substituent T described later, and preferably an alkyl group.
The lactone compounds may be used alone or in combination of two or more.
Carboxylic acid compounds
The carboxylic acid compound may be a compound having at least 1 carboxyl group in the molecule, and preferably a compound having at least 2 carboxyl groups. The number of carboxylic acids contained in the carboxylic acid compound is not particularly limited, but is preferably 2 to 6, and more preferably 2 (dicarboxylic acid compound). The carboxylic acid compound may have a hydroxyl group or an alkoxy group. In the present invention, the carboxylic acid compound is a compound capable of undergoing an esterification reaction with the above-mentioned hydrocarbon polymer, and includes a compound having an ester group (e.g., methoxycarbonyl group) having an alkyl group or an aryl group in place of a carboxyl group.
The carboxylic acid compound may be an aliphatic carboxylic acid compound or an aromatic carboxylic acid compound, and is preferably an aliphatic carboxylic acid compound.
The dicarboxylic acid compound is not particularly limited, and examples thereof include aliphatic dicarboxylic acid compounds and aromatic dicarboxylic acid compounds.
The number of carbon atoms (excluding carbon atoms forming a carbonyl group) of the aliphatic dicarboxylic acid compound is not particularly limited, and is 1 or more, preferably 2 or more, more preferably 3 or more, further preferably 4 or more, preferably 20 or less, more preferably 16 or less, further preferably 15 or less, and particularly preferably 14 or less. Specific examples thereof include malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1, 9-nonamethylenedicarboxylic acid, 1, 10-decamethylenedicarboxylic acid, 1, 11-undecamethylenedicarboxylic acid, and 1, 12-dodecamethylenedicarboxylic acid.
The number of carbon atoms of the aromatic dicarboxylic acid compound (excluding carbon atoms forming a carbonyl group) is not particularly limited, but is preferably 6 to 20, and the upper limit is more preferably 16 or less, and still more preferably 14 or less. Specific examples thereof include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, anthracenedicarboxylic acid and phenanthrenedicarboxylic acid.
Among them, from the viewpoint of easy availability and high thermal stability, an aliphatic dicarboxylic acid compound is preferable, malonic acid, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid are more preferable, and succinic acid and adipic acid are still more preferable.
The dicarboxylic acid compound can also be used as an acid anhydride, an ester body of an alkyl group or an aryl group, a halogen substituent of an unsaturated bond, or the like, but is not included as an imide body.
The carboxylic acid compound may have a substituent, and examples thereof include a substituent T described later.
One kind of the carboxylic acid compound may be used alone, or two or more kinds may be used.
Synthesis of the Polymer segment
The method for synthesizing the polymer into which the polymer segment is introduced is not particularly limited, and examples thereof include a method in which the above-mentioned hydrocarbon polymer having at least 2 hydroxyl groups or amino groups is subjected to a condensation (polycondensation) reaction with a cyclic ester compound or a carboxylic acid compound. As the condensation reaction, a known synthesis method (esterification method or amide method) can be applied without particular limitation. For example, a polyester polyol comprising the above-mentioned hydrocarbon polymer and cyclic ester compound can be synthesized by a method of reacting the hydrocarbon polymer and cyclic ester compound in the absence of a solvent and in the presence of a catalyst such as tetraisopropyl titanate or tetrabutyl titanate. Specific examples of the synthesis method include the synthesis methods described in examples.
Specific examples of the polymer segment include, for example, the individual segments shown in the specific examples of the polymer described below, but the present invention is not limited to these.
The polymer segment (each constituent and the raw material compound) may have a substituent. The substituent is not particularly limited, and preferably a group selected from the following substituents T is exemplified.
The substituent T-
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms such as methyl, ethyl, isopropyl, tert-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl group, etc.), an alkenyl group (preferably an alkenyl group having 2 to 20 carbon atoms such as vinyl, allyl, oleyl, etc.), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms such as ethynyl, butadiynyl, phenylethynyl, etc.), a cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc., and when an alkyl group is used in the present specification, the alkyl group usually represents an alkyl group including a cycloalkyl group, but is described separately herein), an aryl group (preferably an aryl group having 6 to 26 carbon atoms such as phenyl, 1-naphthyl, 4-methoxyphenyl, etc.), 2-chlorophenyl group, 3-methylphenyl group, etc.), an aralkyl group (preferably an aralkyl group having 7 to 23 carbon atoms, for example, benzyl group, phenethyl group, etc.), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, preferably a heterocyclic group having 5 or 6-membered ring having at least one oxygen atom, sulfur atom, nitrogen atom. The heterocyclic group includes aromatic heterocyclic groups and aliphatic heterocyclic groupsA heterocyclic group. Examples thereof include tetrahydropyranyl group, tetrahydrofuranyl group, 2-pyridyl group, 4-pyridyl group, 2-imidazolyl group, 2-benzimidazolyl group, 2-thiazolyl group, 2-oxazolyl group, and pyrrolidinonyl group, alkoxy group (preferably, alkoxy group having 1 to 20 carbon atoms, for example, methoxy group, ethoxy group, isopropoxy group, and benzyloxy group), aryloxy group (preferably, aryloxy group having 6 to 26 carbon atoms, for example, phenoxy group, 1-naphthyloxy group, 3-methylphenoxy group, and 4-methoxyphenoxy group), and when referred to as aryloxy group in the present specification, it means that an aroyloxy group is included. ) A heterocyclic oxy group (a group in which an-O-group is bonded to the heterocyclic group), an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, for example, an ethoxycarbonyl group, a 2-ethylhexyloxycarbonyl group, etc.), an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 6 to 26 carbon atoms, for example, a phenoxycarbonyl group, a 1-naphthyloxycarbonyl group, a 3-methylphenoxycarbonyl group, a 4-methoxyphenoxycarbonyl group, etc.), an amino group (preferably an amino group, an alkylamino group, an arylamino group, for example, an amino group (-NH-) having 0 to 20 carbon atoms2) N, N-dimethylamino group, N, N-diethylamino group, N-ethylamino group, anilino group, etc.), a sulfamoyl group (preferably a sulfamoyl group having 0 to 20 carbon atoms, such as N, N-dimethylsulfamoyl group, N-phenylsulfamoyl group, etc.), an acyl group (including an alkylcarbonyl group, an alkenylcarbonyl group, an alkynylcarbonyl group, an arylcarbonyl group, a heterocyclic carbonyl group, preferably an acyl group having 1 to 20 carbon atoms, such as an acetyl group, a propionyl group, a butyryl group, an octanoyl group, a hexadecanoyl group, an acryloyl group, a methacryloyl group, a crotonyl group, a benzoyl group, a naphthoyl group, a nicotinoyl group, etc.), an acyloxy group (including an alkylcarbonyloxy group, an alkenylcarbonyloxy group, an alkynylcarbonyloxy group, an arylcarbonyloxy group, a heterocyclic carbonyloxy group, preferably an acyloxy group having 1 to 20 carbon atoms, such as an acetoxy group, a propionyloxy group, a butyryloxy group, an anilino group, etc, Octanoyloxy group, hexadecanoyloxy group, acryloyloxy group, methacryloyloxy group, crotonyloxy group, benzoyloxy group, naphthoyloxy group, nicotinoyloxy group, etc.), aroyloxy group (preferably aroyloxy group having 7 to 23 carbon atoms, e.g., benzoyloxy group, etc.), carbamoyl group (preferably carbamoyl group having 1 to 20 carbon atoms, e.g., N, N-dimethylcarbamoyl group, N-phenylcarbamoyl group, etc.), acylamino group (preferably carbamoyl group having 1 to 20 carbon atomsAcylamino group, e.g., acetylamino group, benzoylamino group, etc.), alkylsulfanyl group (preferably C1-20 alkylsulfanyl group, e.g., methylsulfanyl group, ethylsulfanyl group, isopropylsulfanyl group, benzylsulfanyl group, etc.), arylsulfanyl group (preferably C6-26 arylsulfanyl group, e.g., phenylsulfanyl group, 1-naphthylsulfanyl group, 3-tolylsulfanyl group, 4-methoxyphenylsulfanyl group, etc.), alkylthio group (preferably C1-20 alkylthio group, e.g., methylthio group, ethylthio group, isopropylthio group, benzylthio group, etc.), arylthio group (preferably C6-26 arylthio group, e.g., phenylthio group, 1-naphthylthio group, 3-methylphenylthio group, 4-methoxyphenylthio group, etc.), heterocyclylthio group (-S-group) to which the above-mentioned heterocyclic group is bonded, Alkylsulfonyl (preferably alkylsulfonyl having 1 to 20 carbon atoms, e.g., methylsulfonyl, ethylsulfonyl, etc.), arylsulfonyl (preferably arylsulfonyl having 6 to 22 carbon atoms, e.g., phenylsulfonyl, etc.), alkylsilyl (preferably alkylsilyl having 1 to 20 carbon atoms, e.g., monomethylsilyl, dimethylsilyl, trimethylsilyl, triethylsilyl, etc.), arylsilyl (preferably arylsilyl having 6 to 42 carbon atoms, e.g., triphenylsilyl, etc.), alkoxysilyl (preferably alkoxysilyl having 1 to 20 carbon atoms, e.g., monomethoxysilyl, dimethoxysilyl, trimethoxysilyl, triethoxysilyl, etc.), aryloxysilyl (preferably aryloxysilyl having 6 to 42 carbon atoms, for example, triphenoxysilyl group, etc.), a phosphoryl group (preferably, a phosphoric acid group having 0 to 20 carbon atoms, for example, -OP (═ O) (R)P)2) A phosphono group (preferably a phosphono group having 0 to 20 carbon atoms, for example, -P (═ O) (R)P)2) A phosphinyl group (preferably a phosphinyl group having 0 to 20 carbon atoms, e.g., -P (R)P)2) A sulfo group (sulfonic acid group), a carboxyl group, a hydroxyl group, a sulfanyl group, a cyano group, and a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.). RPIs a hydrogen atom or a substituent (preferably a group selected from the substituent T).
And, each group listed in these substituents T may be further substituted with the above-mentioned substituents T.
The alkyl group, alkylene group, alkenyl group, alkenylene group, alkynyl group, and/or alkynylene group may be cyclic or linear, and may be linear or branched.
(other constituent components)
The specific polymer may have, in addition to the above-mentioned constituent components and polymer segments, constituent components that can be contained in the above-mentioned various polymers having a bond selected from the above-mentioned bond group (I). For example, a low-molecular component derived from a polyol compound or a polyamine compound, or a high-molecular component (for example, a component derived from a later-described Rb5A predetermined polymer chain as a molecular chain), a constituent component derived from a polyol compound or a polyamine compound.
The specific polymer preferably contains at least one of a polymer represented by the following formula (3) and a polymer represented by the following formula (4), and more preferably contains at least one polymer represented by the following formula (3). Each constituent component of the polymer represented by each formula below may be 1 kind, or 2 or more kinds.
The bonding mode of the constituent components of the polymer represented by the following formulae is not particularly limited, and examples thereof include random bonding, block bonding, graft bonding, and the like.
[ chemical formula 5]
Figure BDA0003272287090000241
In the formula, Ra、Xa、R1、R2N1 and n2 are respectively related to R in the above formulas (1) and (2)a、Xa、R1、R2N1 and n2 have the same meanings, and the preferred embodiments are also the same.
Rb1Represents an aromatic hydrocarbon group having 6 to 22 carbon atoms, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a combination of 2 or more of these groups.
Can be used as Rb1The number of carbon atoms of the aliphatic hydrocarbon group (2) is the smallest number of carbon atoms connecting 2 nitrogen atoms and can be used as Rb1The number of carbon atoms of the aromatic hydrocarbon group (2) means the number of carbon atoms when unsubstituted.
The aliphatic hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 13 carbon atoms) may be saturated or unsaturated, may be linear or cyclic, and may have a branched chain, for example, an alkylene group having the above carbon atoms, a hydrogenolytic agent of an aromatic hydrocarbon group represented by the following formula (M2), a partial structure (for example, a group composed of isophorone) of a known aliphatic diisocyanate compound, 1, 3-trimethylcyclohexanediyl, or methylenebis (cyclohexylene).
Examples of the aromatic hydrocarbon group having 6 to 22 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms) include a phenylene group and a naphthalenediyl group.
The aromatic hydrocarbon group and the aliphatic hydrocarbon group are combined with at least 2 groups, more preferably phenylene group and the aliphatic hydrocarbon group are combined with at least 2 groups, and the total number of carbon atoms is preferably 7 to 15, more preferably 8 to 15. The combined group may include a group containing an oxygen atom, a sulfur atom, or a nitrogen atom in the molecular chain. Examples thereof include biphenylene groups and aromatic hydrocarbon groups represented by the following formula (M2), and more specifically, methylene bis (phenylene), phenylene dimethylene groups and the like.
[ chemical formula 6]
Figure BDA0003272287090000251
In the formula (M2), X represents a single bond, -CH2-、-C(CH3)2-、-SO2-, -S-, -CO-or-O-, preferably-CH from the viewpoint of adhesiveness2-or-O-, more preferably-CH2-. The alkyl group and the alkylene group exemplified herein may be substituted with a substituent T, preferably a halogen atom (more preferably a fluorine atom).
RM2~RM5Each represents a hydrogen atom or a substituent, preferably a hydrogen atom. As RM2~RM5The substituent that can be used is not particularly limited, and examples thereof include an alkyl group having 1 to 20 carbon atoms, and a carbon atomAn alkenyl group having 1 to 20 atoms, -ORM6、―N(RM6)2、-SRM6(RM6The substituent preferably represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 10 carbon atoms. ) A halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom). as-N (R)M6)2Examples thereof include alkylamino groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 6 carbon atoms) and arylamino groups (preferably having 6 to 40 carbon atoms, more preferably 6 to 20 carbon atoms).
Rb1Examples of the substituent which may be contained include a substituent T described later.
Rb2The resin composition is characterized by representing alkylene with 2-12 carbon atoms and further comprising a group formed by combining more than 2 alkylene.
As useful as Rb2The alkylene group (b) may be a chain or a ring, may have a branch, and has 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms. Can be used as Rb2~Rb4The number of carbon atoms of each alkylene group in (a) means that 2X's are bondedbThe smallest number of carbon atoms.
Examples of the alkylene group include an ethylene group, a1, 2-propylene group, a1, 3-butylene group, a1, 4-butylene group, a hexylene group, an octylene group, and a cyclohexylene group.
Wherein, can be used as Rb2The alkylene group (b) does not have a functional group selected from the functional group (II) described later and a functional group selected from the functional group (III) described later.
Rb3Represents an alkylene group having at least 1 functional group selected from the following functional group (II).
As useful as Rb3The alkylene group (b) may be a chain or a ring, may have a branched chain, and has preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. For example, 2-ethylpropenyl is exemplified.
The functional group selected from the following functional group (II) may be bonded to any carbon atom in the alkylene group, but is preferably bonded to 2Xb3The carbon atoms of the shortest carbon chain to which they are bonded. The number of functional groups of the alkylene group is not particularly limited, and is preferably1 to 5, more preferably 1 or 2.
As Rb3The functional group (II) in (4) above can be preferably used as the functional group (II) above which the specific polymer has.
As Rb3Examples thereof include 2-ethyl-2-carboxypropenyl.
< group of functional groups (II) >)
Carboxyl group, sulfonic group, phosphoric group, amino group, hydroxyl group, sulfanyl group, isocyanato group, alkoxysilyl group, and group obtained by fusing 3 or more rings
Rb4Represents an alkylene group having at least 1 functional group selected from the following functional group (III).
As useful as Rb4The alkylene group (b) may be a chain or a ring, may have a branched chain, and has preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. For example, an acryl group is exemplified.
The functional group selected from the following functional group (III) may be bonded to any carbon atom of the alkylene group. The number of functional groups of the alkylene group is not particularly limited, but is preferably 1 to 5, and more preferably 1 or 2.
As Rb4The functional group (III) in (4) can be preferably used, and the functional group (III) contained in the specific polymer can be preferably used.
< functional group (III) >
Group having carbon-carbon unsaturated bond, epoxy group and oxetanyl group
In addition, as described above, the functional group selected from the above group includes a crosslinked form.
Rb5The term "2-valent chain" as used herein means a polyalkylene oxide chain, a polycarbonate chain, a polyester chain or a silicone chain, or a combination of 2 or more of these chains, having a number average molecular weight of 100 or more.
Can be used as Rb5The number average molecular weight of each chain of (2) is preferably 100 to 100000, more preferably 100 to 10000, and further preferably 150 to 5000. The number average molecular weight can be determined as a standard in the same manner as the mass average molecular weight of a specific polymerNumber average molecular weight in terms of polystyrene.
Can be used as Rb5The polyalkylene oxide chain of (a) is not particularly limited. The alkylene group constituting the alkylene oxide chain preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 2 or 3 carbon atoms. The total number of alkyleneoxy groups constituting the alkylene oxide chain is preferably 1 to 100, more preferably 3 to 100, and still more preferably 4 to 50. As Rb5The number of the constituent components having a polyalkylene oxide chain may be 1, but is preferably 2 or more, and more preferably 2, from the viewpoint of battery performance. In this case, the combination of the polyalkylene oxide chain is not particularly limited, and for example, it preferably contains an ethylene oxide chain, and examples thereof include a combination of an ethylene oxide chain or a propylene oxide chain and an alkylene oxide chain having 4 or more carbon atoms.
Can be used as Rb5The polycarbonate chain(s) is not particularly limited. The number of carbon atoms of the repeating unit constituting the carbonate chain is preferably 1 to 15, more preferably 1 to 10. The number of repeating units constituting the carbonate chain is preferably 4 to 40, more preferably 4 to 20.
Can be used as Rb5By polyester chain is meant a poly (alkylene-ester) chain or a poly (arylene-ester) chain, not comprising the polymer segments described above. The number of carbon atoms of the alkylene group constituting the polyester chain is preferably 1 to 10, more preferably 1 to 8, and the number of carbon atoms of the arylene group constituting the polyester chain is preferably 6 to 14, more preferably 6 to 10. The number of repeating units constituting the polyester chain is preferably 2 to 40, more preferably 2 to 20.
Can be used as Rb5The silicone chain of (2) is a chain having a siloxane bond (-Si-O-, Si atom having 2 organic groups such as alkyl group and aryl group), and the number of repetition of the siloxane bond is preferably 1 to 200, more preferably 1 to 100.
For the purpose of facilitating the synthesis of a polymer depending on the structure of a commercially available product to be used, it can be used as Rb5Each chain of (2) may have a group such as an alkylene group at its terminal.
In the process of using as Rb5In the case of a chain having a different structure (e.g., a polyethylene oxide chain and a polypropylene oxide chain), the total number of repetitions of the repeating units constituting the chain isRefers to the sum of the number of repeats of the repeating units constituting each chain.
And, as a combination, can be used as Rb5Examples of the chain of the above-mentioned chain include a chain in which a polyalkylene oxide chain and a polycarbonate chain or a polyester chain are combined, and a chain having a polycarbonate chain or a polyester chain in a polyalkylene oxide chain is preferable.
Xb2、Xb3、Xb4And Xb5Each represents an oxygen atom or-NH-.
In each constituent component, there are 2X' sb2、Xb3、Xb4And Xb5The same or different, but preferably the same.
a. b, c, d, e and f represent the molar ratios of the respective constituent components, and a + b + c + d + e + f is 100 mol%. The total of c + d + e + f may be 0 mol%, preferably not 0 mol%, and more preferably 40 mol% or more.
The amount of a is not particularly limited, but is preferably 0.1 to 30 mol%, more preferably 0.3 to 20 mol%, even more preferably 0.5 to 15 mol%, and particularly preferably 1 to 10 mol%, from the viewpoints of dispersibility and adhesiveness of solid particles and battery performance of a solid secondary battery.
b is preferably 40 to 60 mol%, more preferably 43 to 58 mol%, and further preferably 45 to 55 mol%.
c is preferably 0 to 30 mol%, more preferably 0 to 25 mol%, further preferably 0 to 20 mol%, and particularly preferably 0 to 15 mol%.
d is preferably 0 to 49 mol%, more preferably 0.1 to 40 mol%, still more preferably 1 to 30 mol%, and particularly preferably 3 to 25 mol%.
e is preferably 0 to 30 mol%, more preferably 0 to 25 mol%, further preferably 0 to 20 mol%, and particularly preferably 0 to 10 mol%.
f is preferably 0 to 49 mol%, more preferably 5 to 49 mol%, further preferably 10 to 47 mol%, and particularly preferably 20 to 45 mol%.
When the molar ratios a to f are defined as contents (% by mass), the following ranges are preferred, and the total is 100% by mass.
The content (mass%) of a is as described above.
The content (mass%) of b is not particularly limited, but is preferably 20 to 60 mass%, more preferably 25 to 55 mass%, and still more preferably 30 to 50 mass%.
The content (% by mass) of c is not particularly limited, but is preferably 0 to 25% by mass, more preferably 0 to 15% by mass, and still more preferably 0 to 10% by mass.
The content (mass%) of d is not particularly limited, but is preferably 0 to 40 mass%, more preferably 1 to 25 mass%, and still more preferably 1 to 15 mass%.
The content (mass%) of e is not particularly limited, but is preferably 0 to 20 mass%, more preferably 0 to 15 mass%, and still more preferably 0 to 10 mass%.
The content (mass%) of f is not particularly limited, but is preferably 0 to 55 mass%, more preferably 10 to 50 mass%, and still more preferably 20 to 40 mass%.
The specific polymer is preferably amorphous. In the present invention, the polymer being "amorphous" typically means that no endothermic peak due to crystal melting is observed when measured at the glass transition temperature.
The mass average molecular weight of the specific polymer is not particularly limited. For example, it is preferably 5000 or more, more preferably 10,000 or more, and further preferably 20,000 or more. The upper limit is preferably 5,000,000 or less, more preferably 500,000 or less, and still more preferably 200,000 or less.
Determination of the molecular weight
In the present invention, the mass average molecular weight is a mass average molecular weight in terms of standard polystyrene measured by Gel Permeation Chromatography (GPC). The measurement method is basically a value measured by the method of the following condition 1 or condition 2 (priority). Among these, an appropriate eluent can be appropriately selected and used according to the type of a polymer (specific polymer, etc.) to be measured.
(Condition 1)
Pipe column: 2 TOSOH TSKgel Super AWM-H are connected
Carrier: 10 mMLiBr/N-methylpyrrolidone
Measuring the temperature: 40 deg.C
Carrier flow rate: 1.0ml/min
Sample concentration: 0.1% by mass
A detector: RI (refractive index) detector
(Condition 2)
Pipe column: using a column to which TOSOH TSKgel Super HZM-H, TOSOH TSKgel Super HZ4000 and TOSOH TSKgel Super HZ2000 were attached
Carrier: tetrahydrofuran (THF)
Measuring the temperature: 40 deg.C
Carrier flow rate: 1.0ml/min
Sample concentration: 0.1% by mass
A detector: RI (refractive index) detector
The specific polymer may be a non-crosslinked polymer or a crosslinked polymer. When the specific polymer is crosslinked by heating or applying a voltage, the molecular weight may be higher than the above molecular weight. Preferably, the mass average molecular weight of the specific polymer at the time of starting to use the all-solid secondary battery is in the above range.
The shape of the specific polymer is not particularly limited, and is preferably particulate. The particles may be flat, amorphous, etc., but are preferably spherical or granular. The particle size of the particulate polymer is not particularly limited, but is preferably 10 to 1000 nm. This improves the dispersibility of the solid electrolyte composition and the adhesion between solid particles. From the viewpoint of further improving dispersibility and adhesiveness, the particle diameter is preferably 20 to 500nm, more preferably 30 to 300nm, and still more preferably 50 to 200 nm. The particle diameter of the particulate polymer can be measured in the same manner as the inorganic solid electrolyte by appropriately changing the diluting solvent (for example, the same solvent as the polymer dispersion, more specifically, a hydrophobic solvent such as heptane, diisobutyl ketone, butyl butyrate, or the like).
The particle diameter of the particulate polymer in the constituent layers of the all-solid secondary battery can be measured, for example, as follows: after the battery was decomposed and the constituent layer containing the particulate polymer was peeled off, the constituent layer was measured, and the measured value of the particle diameter of the particles other than the particulate polymer, which had been measured in advance, was removed.
The particle size of the particulate polymer can be adjusted by, for example, the type of the dispersion medium, the content and the content of the constituent components in the polymer, and the like.
The water content of the specific polymer is preferably 100ppm (by mass) or less. The specific polymer may be crystallized and dried, or a polymer dispersion may be used as it is.
Method for the synthesis of specific polymers
The method for synthesizing the specific polymer can be a known polymerization method without particular limitation. For example, the polymerization methods described in examples can be cited.
Examples of the compound used for the synthesis include the compounds described in patent document 1.
Specific examples of the specific polymer are shown below, but the present invention is not limited to these.
In each specific example, the components constituting the specific polymer are shown, and the molar ratio thereof is appropriately set.
[ chemical formula 7]
Figure BDA0003272287090000311
[ chemical formula 8]
Figure BDA0003272287090000321
[ chemical formula 9]
Figure BDA0003272287090000331
The solid electrolyte composition of the present invention may contain 1 specific polymer alone, or may contain 2 or more specific polymers.
The content of the specific polymer in the solid electrolyte composition is preferably 0.001 mass% or more, more preferably 0.01 mass% or more, further preferably 0.1 mass% or more, and particularly preferably 0.3 mass% or more in the solid content thereof. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less. By using the specific polymer within the above range, the adhesiveness of the solid particles can be more effectively improved, and the battery performance can be further improved.
In the present invention, the mass ratio of the total mass (total amount) of the inorganic solid electrolyte and the active material to the mass of the specific polymer [ (mass of the inorganic solid electrolyte + mass of the active material)/mass of the specific polymer ] is preferably in the range of 1,000 to 1. The ratio is more preferably 500 to 2, and still more preferably 100 to 10.
< dispersing Medium >
The dispersion medium (dispersion medium) contained in the solid electrolyte composition of the present invention may be a dispersion medium in which the above components are dispersed or dissolved, and is preferably a dispersion medium in which particles of a polymer and solid particles are dispersed. Examples of the dispersion medium include various organic solvents. Examples of the organic solvent include alcohol compounds, ether compounds, amide compounds, amine compounds, ketone compounds, aromatic compounds, aliphatic compounds, nitrile compounds, ester compounds, and the like.
The dispersion medium may be either a hydrophobic dispersion medium or a hydrophilic dispersion medium, but is preferably a hydrophobic dispersion medium from the viewpoint of being able to exhibit excellent dispersibility of the polymer. In the present invention, hydrophobicity generally means a property of having a low affinity for water, but in the present invention, hydrophobicity also means a property of having a high affinity for a polymer segment, particularly a hydrocarbon polymer, which the specific polymer has. Specifically, the dispersion medium may be an aromatic compound, an aliphatic compound, a ketone compound or an ester compound.
Specific examples of the solvents are shown below.
Examples of the alcohol compound include methanol, ethanol, 1-propanol, 2-butanol, ethylene glycol, propylene glycol, glycerol, 1, 6-hexanediol, cyclohexanediol, sorbitol, xylitol, 2-methyl-2, 4-pentanediol, 1, 3-butanediol, and 1, 4-butanediol.
Examples of the ether compound include alkylene glycols (diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, etc.), alkylene glycol monoalkyl ethers (ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, etc.), dialkyl ethers (dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, etc.), cyclic ethers (tetrahydrofuran, dioxane (including 1,2-, 1,3-, and 1, 4-isomers), etc.).
Examples of the amide compound include N, N-dimethylformamide, N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, epsilon-caprolactam, formamide, N-methylformamide, acetamide, N-methylacetamide, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide, and the like.
Examples of the amine compound include triethylamine, diisopropylethylamine, and tri-n-butylamine.
Examples of the ketone compound include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and diisobutyl ketone.
Examples of the aromatic compound include aromatic hydrocarbon compounds such as benzene, toluene, and xylene.
Examples of the aliphatic compound include aliphatic hydrocarbon compounds such as hexane, heptane, octane, and decane.
Examples of the nitrile compound include acetonitrile, propionitrile, and isobutyronitrile.
Examples of the ester compound include carboxylic acid ester compounds such as ethyl acetate, butyl acetate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, butyl valerate, ethyl isobutyrate, propyl isobutyrate, isopropyl isobutyrate, isobutyl isobutyrate, propyl pivalate, isopropyl pivalate, butyl pivalate, and isobutyl pivalate.
Examples of the nonaqueous dispersion medium include the above aromatic compound and aliphatic compound.
In the present invention, among them, an ether compound, a ketone compound, an aromatic compound, an aliphatic compound, or an ester compound is preferable, and a ketone compound, an aliphatic compound, or an ester compound is more preferable. In the present invention, the specific organic solvent is preferably further selected using a sulfide-based inorganic solid electrolyte. By selecting such a combination, the sulfide-based inorganic solid electrolyte can be stably handled because the sulfide-based inorganic solid electrolyte does not contain a functional group that is active for the sulfide-based inorganic solid electrolyte. In particular, a combination of a sulfide-based inorganic solid electrolyte and an aliphatic compound is preferable.
The boiling point of the dispersion medium at normal pressure (1 atm) is preferably 50 ℃ or higher, more preferably 70 ℃ or higher. The upper limit is preferably 250 ℃ or lower, and more preferably 220 ℃ or lower.
The dispersion medium may contain 1 kind alone or 2 or more kinds.
In the present invention, the content of the dispersion medium in the solid electrolyte composition is not particularly limited and can be appropriately set. For example, the solid electrolyte composition is preferably 20 to 99% by mass, more preferably 25 to 70% by mass, and particularly preferably 30 to 60% by mass.
< active substance >
The solid electrolyte composition of the present invention can further contain an active material capable of intercalating and deintercalating ions of metals belonging to the first group or the second group of the periodic table. As the active material, a positive electrode active material and a negative electrode active material are exemplified below.
In the present invention, a solid electrolyte composition containing an active material (a positive electrode active material or a negative electrode active material) is sometimes referred to as a composition for an electrode layer (a composition for a positive electrode layer or a composition for a negative electrode layer).
(Positive electrode active Material)
The positive electrode active material is an active material capable of inserting and extracting ions of a metal belonging to group 1 or group 2 of the periodic table, and preferably an active material capable of reversibly inserting and extracting lithium ions. The material is not particularly limited as long as it has the above-mentioned properties, and may be a transition metal oxide, an organic substance, an element capable of forming a complex with Li such as sulfur, a complex of sulfur and a metal, or the like.
Among these, as the positive electrode active material, a transition metal oxide is preferably used, and a transition metal element M is more preferably containeda(1 or more elements selected from Co, Ni, Fe, Mn, Cu and V). Further, the transition metal oxide may be mixed with the element Mb(elements of group 1(Ia), elements of group 2(IIa), Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, B and the like of the periodic Table of metals other than lithium). The amount to be mixed is preferably in relation to the transition metal element MaThe amount (100 mol%) of the (C) component is 0 to 30 mol%. More preferably as Li/MaIs mixed so that the molar ratio of (A) to (B) is 0.3 to 2.2.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock-salt structure, (MB) a transition metal oxide having a spinel structure, (MC) a lithium-containing transition metal phosphate compound, (MD) a lithium-containing transition metal halophosphoric acid compound, and (ME) a lithium-containing transition metal silicate compound.
Specific examples of (MA) transition metal oxides having a layered rock-salt structure include LiCoO2(lithium cobaltate [ LCO ]])、LiNi2O2(lithium nickelate) and LiNi0.85Co0.10Al0.05O2(Nickel cobalt lithium aluminate [ NCA)])、LiNi1/3Co1/3Mn1/3O2(lithium nickel manganese cobaltate [ NMC ]]) And LiNi0.5Mn0.5O2(lithium manganese nickelate).
Specific examples of (MB) transition metal oxides having a spinel structure include LiMn2O4(LMO)、LiCoMnO4、Li2FeMn3O8、Li2CuMn3O8、Li2CrMn3O8And Li2NiMn3O8
As (MC) lithium-containing compoundsTransition metal phosphate compounds, for example, LiFePO can be cited4And Li3Fe2(PO4)3Isoolivine-type iron phosphate salt, LiFeP2O7Iso-pyrophosphoric acid iron species, LiCoPO4Isophosphoric acid cobalt compounds and Li3V2(PO4)3Monoclinic NASICON-type vanadium phosphate salts such as (lithium vanadium phosphate).
Examples of the (MD) lithium-containing transition metal halophosphor compound include Li2FePO4F, etc. iron fluorophosphate, Li2MnPO4F, etc. manganese fluorophosphate and Li2CoPO4And cobalt fluorophosphates such as F.
As the (ME) lithium-containing transition metal silicate compound, for example, Li is cited2FeSiO4、Li2MnSiO4、Li2CoSiO4And the like.
In the present invention, (MA) a transition metal oxide having a layered rock-salt type structure is preferable, and LCO or NMC is more preferable.
The shape of the positive electrode active material is not particularly limited, and is preferably a particle shape. The particle diameter (volume average particle diameter) of the positive electrode active material is not particularly limited. For example, the thickness can be set to 0.1 to 50 μm. The particle diameter of the positive electrode active material particles can be measured in the same manner as the particle diameter of the inorganic solid electrolyte. In order to make the positive electrode active material have a predetermined particle size, a general pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibration ball mill, a satellite ball mill, a planetary ball mill, a rotary air-flow type jet mill, a sieve, or the like can be suitably used. In the pulverization, it is also possible to appropriately perform wet pulverization in the coexistence of an organic solvent such as water or methanol. In order to obtain a desired particle diameter, classification is preferably performed. The classification is not particularly limited, and can be performed using a screen, an air classifier, or the like. Both dry and wet classification can be used.
The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, and an organic solvent.
The positive electrode active material may be used alone in 1 kind, or may be used in combination in 2 or more kinds.
In the case of forming the positive electrode active material layer, the positive electrode active material layer has a unit area (cm)2) The mass (mg) (weight per unit area) of the positive electrode active material (b) is not particularly limited. Can be determined appropriately according to the designed battery capacity, and can be set to 1 to 100mg/cm, for example2
The content of the positive electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 97 mass%, more preferably 30 to 95 mass%, further preferably 40 to 93 mass%, and particularly preferably 50 to 90 mass% in 100 mass% of the solid content.
(negative electrode active Material)
The negative electrode active material is an active material capable of inserting and extracting ions of a metal belonging to group 1 or group 2 of the periodic table, and preferably an active material capable of reversibly inserting and extracting lithium ions. The material is not particularly limited as long as it is a material having the above-described characteristics, and examples thereof include a carbonaceous material, a metal oxide, a metal composite oxide, a lithium monomer, a lithium alloy, and a negative electrode active material capable of forming an alloy (capable of being alloyed) with lithium. Among them, carbonaceous materials, metal composite oxides, and lithium monomers are preferably used from the viewpoint of reliability. From the viewpoint of enabling the all-solid-state secondary battery to have a large capacity, an active material that can be alloyed with lithium is preferable. The solid particles in the constituent layer formed of the solid electrolyte composition of the present invention are strongly bonded to each other, and therefore, a negative electrode active material capable of forming an alloy with lithium can be used as the negative electrode active material. Thereby, the capacity of the all-solid-state secondary battery can be increased and the life of the battery can be extended.
The carbonaceous material used as the negative electrode active material means a material substantially composed of carbon. Examples of the carbonaceous material include carbon materials obtained by firing various synthetic resins such as petroleum pitch, carbon black such as Acetylene Black (AB), graphite (e.g., artificial graphite such as natural graphite and vapor-phase-grown graphite), PAN (polyacrylonitrile) resin, and furfuryl alcohol resin. Further, various carbon fibers such as PAN-based carbon fibers, cellulose-based carbon fibers, pitch-based carbon fibers, vapor grown carbon fibers, dehydrated PVA (polyvinyl alcohol) -based carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers, mesophase microspheres, graphite whiskers, and tabular graphite can be cited.
These carbonaceous materials are classified into non-graphitizable carbonaceous materials (also referred to as hard carbon) and graphite-based carbonaceous materials by the degree of graphitization. The carbonaceous material preferably has the surface spacing, density, and crystallite size described in Japanese patent application laid-open Nos. 62-22066, 2-6856, and 3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in Japanese patent application laid-open No. 5-90844, graphite having a coating layer described in Japanese patent application laid-open No. 6-4516, and the like can be used.
As the carbonaceous material, hard carbon or graphite is preferably used, and graphite is more preferably used.
The oxide of a metal or semimetal element suitable as the negative electrode active material is not particularly limited as long as it is an oxide capable of absorbing and releasing lithium, and an oxide of a metal element (metal oxide), a composite oxide of a metal element or a composite oxide of a metal element and a semimetal element (collectively referred to as a metal composite oxide), and an oxide of a semimetal element (semimetal oxide) may be mentioned. The oxide is preferably an amorphous oxide, and further preferably a chalcogenide compound which is a reaction product of a metal element and an element of group 16 of the periodic table. In the present invention, a semimetal element refers to an element showing properties intermediate of metal elements and non-semimetal elements, and typically includes 6 elements of boron, silicon, germanium, arsenic, antimony, and tellurium, and further includes 3 elements of selenium, polonium, and astatine. The amorphous substance refers to a material having a broad scattering band having an apex in a region having a 2 θ value of 20 ° to 40 ° by X-ray diffraction using CuK α rays, and may have a crystal diffraction line. Among the crystalline diffraction lines appearing in the region having a 2 θ value of 40 ° to 70 °, the strongest intensity is preferably 100 times or less, more preferably 5 times or less, and particularly preferably a diffraction line having no crystallinity, as the intensity of a diffraction line at the top of a wide scattering band appearing in the region having a 2 θ value of 20 ° to 40 °.
Among the group of compounds containing the above amorphous oxide and chalcogenide, the amorphous oxide or chalcogenide of a semimetal element is more preferable, and the (composite) oxide or chalcogenide containing 1 kind of element selected from elements of groups 13(IIIB) to 15(VB) of the periodic table (for example, Al, Ga, Si, Sn, Ge, Pb, Sb, and Bi) alone or a combination of 2 or more kinds thereof is particularly preferable. Specific examples of preferred amorphous oxides and chalcogenides include, for example, Ga2O3、GeO、PbO、PbO2、Pb2O3、Pb2O4、Pb3O4、Sb2O3、Sb2O4、Sb2O8Bi2O3、Sb2O8Si2O3、Sb2O5、Bi2O3、Bi2O4、GeS、PbS、PbS2、Sb2S3Or Sb2S5
Examples of the negative electrode active material that can be used together with an amorphous oxide mainly containing Sn, Si, and Ge include carbonaceous materials, lithium monomers, lithium alloys, and negative electrode active materials that can be alloyed with lithium, which can absorb and/or release lithium ions or lithium metal.
From the viewpoint of high current density charge/discharge characteristics, the oxide of a metal or semimetal element, particularly the metal (composite) oxide and the chalcogenide compound preferably contain at least one of titanium and lithium as a constituent component. Examples of the lithium-containing metal composite oxide (lithium composite metal oxide) include a composite oxide of lithium oxide and the above-mentioned metal (composite) oxide or the above-mentioned chalcogenide, and more specifically, Li2SnO2
The negative electrode active material, for example, a metal oxide preferably contains titanium (titanium oxide). In particular, due to Li4Ti5O12(lithium titanate [ LTO ]]) Since the volume change is small when lithium ions are occluded and released, the lithium ion battery has excellent rapid charge and discharge characteristics, suppresses deterioration of an electrode, and can improve lithium ionThe secondary battery is preferable in terms of the life thereof.
The lithium alloy as the negative electrode active material is not particularly limited as long as it is an alloy generally used as a negative electrode active material of a secondary battery, and examples thereof include a lithium aluminum alloy.
The negative electrode active material capable of forming an alloy with lithium is not particularly limited as long as it is a negative electrode active material generally used as a secondary battery. Such an active material undergoes large expansion and contraction due to charge and discharge, and as described above, the adhesiveness of the solid particles is lowered, but in the present invention, high adhesiveness can be achieved by the specific polymer. Examples of such an active material include a negative electrode active material (alloy) containing silicon or tin, and metals such as Al and In, preferably a negative electrode active material (silicon-containing active material) containing silicon capable of achieving a higher battery capacity, and more preferably a silicon-containing active material containing silicon In an amount of 50 mol% or more of all the constituent elements.
In general, negative electrodes containing these negative electrode active materials (for example, Si negative electrodes containing active materials containing silicon elements, Sn negative electrodes containing active materials containing tin elements) can absorb Li ions more than carbon negative electrodes (graphite, acetylene black, and the like). That is, the amount of Li ions absorbed per unit mass increases. Therefore, the battery capacity (energy density) can be increased. As a result, the battery driving time can be prolonged.
Examples of the active material containing a silicon element include silicon materials such as Si and SiOx (0 < x.ltoreq.1), and silicon-containing alloys containing titanium, vanadium, chromium, manganese, nickel, copper, lanthanum and the like (for example, LaSi2、VSi2La-Si, Gd-Si, Ni-Si) or organized active substances (e.g. LaSi2/Si) and additionally SnSiO3、SnSiS3And active materials of silicon element and tin element. SiOx itself can be used as a negative electrode active material (semimetal oxide) and Si is generated by the operation of an all-solid-state secondary battery, and thus can be used as a negative electrode active material (precursor material thereof) that can be alloyed with lithium.
As the negative electrode active material having the tin element,examples thereof include Sn, SnO and SnO2、SnS、SnS2And active materials of the silicon element and the tin element. Further, a composite oxide with lithium oxide, for example, Li, can also be cited2SnO2
In the present invention, the negative electrode active material can be used without particular limitation, but from the viewpoint of battery capacity, an embodiment in which a negative electrode active material capable of alloying with lithium is preferable as the negative electrode active material is preferable, and among these, the silicon material or the silicon-containing alloy (alloy containing a silicon element) is more preferable, and silicon (Si) or the silicon-containing alloy is further preferable.
The chemical formula of the compound obtained by the above firing method can be calculated from the mass difference of the powder before and after firing by Inductively Coupled Plasma (ICP) emission spectroscopy as a measurement method and as a simple method.
The shape of the negative electrode active material is not particularly limited, and is preferably a particle shape. The volume average particle diameter of the negative electrode active material is not particularly limited, but is preferably 0.1 to 60 μm. The volume average particle diameter of the negative electrode active material particles can be measured in the same manner as the particle diameter of the inorganic solid electrolyte. In order to obtain a predetermined particle size, a general pulverizer or classifier is used as in the case of the positive electrode active material.
The negative electrode active material may be used alone in 1 kind, or may be used in combination in 2 or more kinds.
In the case of forming the anode active material layer, the anode active material layer has a unit area (cm)2) The mass (mg) (weight per unit area) of the negative electrode active material (b) is not particularly limited. Can be determined appropriately according to the designed battery capacity, and can be set to 1 to 100mg/cm, for example2
The content of the negative electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 90 mass%, more preferably 20 to 85 mass%, even more preferably 30 to 80 mass%, and even more preferably 40 to 75 mass% of the solid content of 100 mass%.
In the present invention, when the anode active material layer is formed by charging of the secondary battery, an ion belonging to a metal of the first group or the second group of the periodic table generated in the all-solid secondary battery can be used instead of the above-described anode active material. The negative electrode active material layer can be formed by bonding the ions to electrons to precipitate as a metal.
(coating of active Material)
The surfaces of the positive electrode active material and the negative electrode active material may be coated with different metal oxides. Examples of the surface coating agent include metal oxides containing Ti, Nb, Ta, W, Zr, Al, Si, or Li. Specific examples thereof include titanic acid spinel, tantalum oxide, niobium oxide, and lithium niobate compound, and specific examples thereof include Li4Ti5O12、Li2Ti2O5、LiTaO3、LiNbO3、LiAlO2、Li2ZrO3、Li2WO4、Li2TiO3、Li2B4O7、Li3PO4、Li2MoO4、Li3BO3、LiBO2、Li2CO3、Li2SiO3、SiO2、TiO2、ZrO2、Al2O3、B2O3And the like.
Also, the surface of the electrode containing the positive electrode active material or the negative electrode active material may be surface-treated with sulfur or phosphorus.
The particle surface of the positive electrode active material or the negative electrode active material may be subjected to surface treatment with actinic rays or an active gas (plasma or the like) before and after the surface coating.
< conductive assistant >
The solid electrolyte composition of the present invention may suitably contain a conduction aid, and particularly, a silicon atom-containing active material as a negative electrode active material is preferably used together with the conduction aid.
The conductive aid is not particularly limited, and a conductive aid generally known as a conductive aid can be used. For example, as the electron conductive material, graphite such as natural graphite and artificial graphite, acetylene black, carbon black such as Ketjen black (Ketjen black) and furnace black, amorphous carbon such as needle coke, carbon fiber such as vapor-grown carbon fiber and carbon nanotube, and carbonaceous material such as graphene and fullerene may be used, metal powder or metal fiber such as copper and nickel may be used, and conductive polymer such as polyaniline, polypyrrole, polythiophene, polyacetylene and polyphenylene derivative may be used.
In the present invention, when the active material and the conductive assistant are used in combination, the conductive assistant does not cause intercalation and deintercalation of ions (preferably Li ions) of metals belonging to the first group or the second group of the periodic table at the time of charging and discharging the battery, and does not function as the active material. Therefore, among the conductive aids, those capable of exerting the function of the active material in the active material layer at the time of charging and discharging the battery are classified as active materials rather than conductive aids. Whether or not to function as an active material when charging and discharging a battery is determined by combination with the active material, rather than globally.
The conductive additive may contain 1 species or 2 or more species.
The shape of the conductive aid is not particularly limited, and is preferably a particle shape.
When the solid electrolyte composition of the present invention contains a conductive additive, the content of the conductive additive in the solid electrolyte composition is preferably 0 to 10% by mass in the solid component.
< lithium salt >
The solid electrolyte composition of the present invention also preferably contains a lithium salt (supporting electrolyte).
The lithium salt is preferably a lithium salt generally used in such products, and is not particularly limited, and is preferably a lithium salt described in paragraphs 0082 to 0085 of Japanese patent laid-open publication No. 2015-088486, for example.
When the solid electrolyte composition of the present invention contains a lithium salt, the content of the lithium salt is preferably 0.1 parts by mass or more, and more preferably 5 parts by mass or more, with respect to 100 parts by mass of the solid electrolyte. The upper limit is preferably 50 parts by mass or less, and more preferably 20 parts by mass or less.
< dispersant >
In the solid electrolyte composition of the present invention, the specific polymer functions as a dispersant, and therefore, a dispersant other than the specific polymer may not be included, and a dispersant may be included. As the dispersant, a dispersant generally used for all-solid secondary batteries can be appropriately selected and used. In general, the desired compounds in particle adsorption, steric repulsion, and/or electrostatic repulsion are suitably used.
< other additives >
The solid electrolyte composition of the present invention may suitably contain, as other components than the above-described components, an ionic liquid, a thickener, a crosslinking agent (a substance which undergoes a crosslinking reaction by radical polymerization, polycondensation, or ring-opening polymerization, or the like), a polymerization initiator (a substance which generates an acid or a radical by heat or light, or the like), a defoaming agent, a leveling agent, a dehydrating agent, an antioxidant, or the like. The ionic liquid is a liquid contained to further improve the ionic conductivity, and a known liquid can be used without particular limitation. Further, a polymer other than the above-mentioned polymers, a binder generally used, and the like may be contained.
(preparation of solid electrolyte composition)
The solid electrolyte composition of the present invention can be prepared by, for example, mixing the inorganic solid electrolyte, the above-mentioned specific polymer, the dispersion medium, and an appropriate lithium salt, and optionally other components in various generally used mixers, as a mixture, preferably as a slurry.
The mixing method is not particularly limited, and the mixing may be performed at once or sequentially. The mixing environment is not particularly limited, and examples thereof include a dry air atmosphere and an inert gas atmosphere.
The composition for forming an active material layer (composition for an electrode layer) of the present invention can be a dispersion liquid containing highly dispersed solid particles by suppressing reagglomeration of the solid particles.
[ sheet for all-solid-state secondary battery ]
The sheet for an all-solid secondary battery of the present invention is a sheet-like molded body capable of forming a constituent layer of an all-solid secondary battery, and includes various embodiments depending on the use thereof. For example, a sheet preferably used for the solid electrolyte layer (also referred to as a solid electrolyte sheet for all-solid secondary battery), a sheet preferably used for an electrode or a laminate of an electrode and a solid electrolyte layer (an electrode sheet for all-solid secondary battery), and the like can be cited. In the present invention, these various sheets are sometimes collectively referred to as an all-solid-state secondary battery sheet.
The solid electrolyte sheet for all-solid secondary batteries of the present invention may be a sheet having a solid electrolyte layer, and may be a sheet having a solid electrolyte layer formed on a substrate or a sheet having no substrate and formed of a solid electrolyte layer. The solid electrolyte sheet for an all-solid secondary battery may have other layers in addition to the solid electrolyte layer. Examples of the other layer include a protective layer (release sheet), a current collector, and a coating layer.
The solid electrolyte sheet for all-solid-state secondary batteries of the present invention includes, for example, a sheet having a layer composed of the solid electrolyte composition of the present invention, a normal solid electrolyte layer, and a protective layer in this order on a substrate.
The substrate is not particularly limited as long as it can support the solid electrolyte layer, and examples thereof include materials described below for the current collector, and sheet bodies (plate-like bodies) such as organic materials and inorganic materials. Examples of the organic material include various polymers, and specific examples thereof include polyethylene terephthalate, polypropylene, polyethylene, and cellulose. Examples of the inorganic material include glass and ceramic.
The configuration and layer thickness of the solid electrolyte layer of the sheet for an all-solid secondary battery are the same as those of the solid electrolyte layer described in the all-solid secondary battery of the present invention.
The electrode sheet for all-solid-state secondary batteries (also simply referred to as "electrode sheet") of the present invention may be a sheet in which an active material layer is formed on a substrate (current collector), or may be a sheet in which an active material layer is formed without a substrate. The electrode sheet is generally a sheet having a current collector and an active material layer, but may be a sheet having a current collector, an active material layer, and a solid electrolyte layer in this order, or a sheet having a current collector, an active material layer, a solid electrolyte layer, and an active material layer in this order. The electrode sheet of the present invention may have the other layers described above. The active material layer is preferably formed of the solid electrolyte composition (composition for an electrode layer) of the present invention. The constitution and layer thickness of each layer constituting the electrode sheet of the present invention are the same as those of each layer described in the all-solid-state secondary battery described later.
In the sheet for an all-solid-state secondary battery of the present invention, at least 1 layer of the solid electrolyte layer and the active material layer is formed of the solid electrolyte composition of the present invention, and solid particles in the layer are firmly bonded to each other. In addition, the active material layer formed from the solid electrolyte composition of the present invention in the electrode sheet for all-solid-state secondary batteries is also strongly bonded to the current collector. In the present invention, an increase in the interface resistance between solid particles can be effectively suppressed. Therefore, the sheet for an all-solid secondary battery of the present invention is suitable as a sheet capable of forming constituent layers of an all-solid secondary battery.
When an all-solid secondary battery is produced using the sheet for an all-solid secondary battery of the present invention, excellent battery performance is exhibited.
[ method for producing sheet for all-solid-State Secondary Battery ]
The method for producing the sheet for an all-solid-state secondary battery of the present invention is not particularly limited, and the sheet can be produced by forming each layer using the solid electrolyte composition of the present invention. For example, a method of forming a layer (coating and drying layer) composed of a solid electrolyte composition on a substrate or a current collector (optionally through another layer) by film formation (coating and drying) is preferably used. This makes it possible to produce an all-solid-state secondary battery sheet having a substrate or a current collector and a coating dry layer. Here, the application drying layer refers to a layer formed by applying the solid electrolyte composition of the present invention and drying the dispersion medium (that is, a layer formed using the solid electrolyte composition of the present invention and having a composition in which the dispersion medium is removed from the solid electrolyte composition of the present invention). The active material layer and the coating dry layer may be left in the dispersion medium as long as the effects of the present invention are not impaired, and the residual amount may be 3 mass% or less in each layer, for example.
In the method for producing a sheet for an all-solid secondary battery of the present invention, the steps of coating, drying, and the like will be described in the following method for producing an all-solid secondary battery.
In the method for producing a sheet for an all-solid secondary battery of the present invention, the coating dry layer obtained in the above-described manner can also be pressurized. The pressurizing conditions and the like will be described in a method for manufacturing an all-solid-state secondary battery described later.
In the method for producing an all-solid-state secondary battery sheet of the present invention, the substrate, the protective layer (particularly, the release sheet), and the like can be released.
[ all-solid-state secondary battery ]
The all-solid-state secondary battery of the present invention has a positive electrode active material layer, a negative electrode active material layer facing the positive electrode active material layer, and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer. The positive electrode active material layer is preferably formed on a positive electrode current collector and constitutes a positive electrode. The anode active material layer is preferably formed on an anode current collector and constitutes an anode.
At least 1 layer of the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer is preferably formed of the solid electrolyte composition of the present invention, and among them, it is more preferable that all the layers are formed of the solid electrolyte composition of the present invention. The active material layer or solid electrolyte layer formed from the solid electrolyte composition of the present invention is preferably the same as in the solid components of the solid electrolyte composition of the present invention with respect to the types of components contained and the content ratio thereof. When the active material layer or the solid electrolyte layer is not formed from the solid electrolyte composition of the present invention, a known material can be used.
The respective thicknesses of the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer are not particularly limited. In view of the size of a general all-solid secondary battery, the thickness of each layer is preferably 10 to 1,000 μm, and more preferably 20 μm or more and less than 500 μm. In the all-solid-state secondary battery of the present invention, the thickness of at least one of the positive electrode active material layer and the negative electrode active material layer is more preferably 50 μm or more and less than 500 μm.
The positive electrode active material layer and the negative electrode active material layer may each include a current collector on the opposite side of the solid electrolyte layer.
[ casing ]
The all-solid-state secondary battery of the present invention can be used as an all-solid-state secondary battery in the state of the above-described structure according to the application, but is preferably used by being further enclosed in an appropriate case in order to be a form of a dry battery. The case may be a metallic case or a resin (plastic) case. When a metallic case is used, for example, a case made of aluminum alloy or stainless steel can be used. Preferably, the metallic case is divided into a positive-electrode-side case and a negative-electrode-side case, and is electrically connected to the positive-electrode current collector and the negative-electrode current collector, respectively. Preferably, the case on the positive electrode side and the case on the negative electrode side are joined and integrated via a short-circuit prevention gasket.
Hereinafter, an all-solid secondary battery according to a preferred embodiment of the present invention will be described with reference to fig. 1, but the present invention is not limited thereto.
Fig. 1 is a cross-sectional view schematically showing an all-solid secondary battery (lithium-ion secondary battery) according to a preferred embodiment of the present invention. The all-solid-state secondary battery 10 of the present embodiment includes, in order from the negative electrode side, a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5. The layers are in contact with each other respectively and are in an adjacent structure. With such a configuration, electrons (e) are supplied to the negative electrode side during charging-) And accumulating lithium ions (Li) therein+). On the other hand, lithium ions (Li) accumulated in the negative electrode during discharge+) Returning to the positive electrode side, electrons are supplied to the working site 6. In the illustrated example, a bulb is used as a model at the work site 6, and the bulb is turned on by discharge.
When the all-solid-state secondary battery having the layer structure shown in fig. 1 is placed in a 2032-type coin cell case, the all-solid-state secondary battery is also referred to as a laminate for all-solid-state secondary batteries, and a battery produced by placing the laminate for all-solid-state secondary battery in a 2032-type coin cell case is sometimes referred to as an all-solid-state secondary battery.
(Positive electrode active material layer, solid electrolyte layer, negative electrode active material layer)
In the all-solid-state secondary battery 10, the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer are each formed of the solid electrolyte composition of the present invention. The all-solid secondary battery 10 exhibits excellent battery performance. The inorganic solid electrolyte and the specific polymer contained in the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 may be the same type or different types, respectively.
In the present invention, either one or both of the positive electrode active material layer and the negative electrode active material layer are simply referred to as an active material layer or an electrode active material layer. Either or both of the positive electrode active material and the negative electrode active material are simply referred to as an active material or an electrode active material.
In the present invention, when the specific polymer is used in combination with solid particles such as an inorganic solid electrolyte or an active material, as described above, the adhesion of the solid particles can be improved, and the separation of the solid particles from the current collector can be suppressed while suppressing the contact failure between the solid particles. Further, an increase in the interface resistance between the solid particles and the current collector can be suppressed. Therefore, the all-solid secondary battery of the present invention exhibits excellent battery performance.
In the all-solid-state secondary battery 10, the negative electrode active material layer can be a lithium metal layer. Examples of the lithium metal layer include a layer formed by stacking or molding lithium metal powder, a lithium foil, and a lithium vapor deposited film. The thickness of the lithium metal layer is not limited to the thickness of the negative electrode active material layer, and may be, for example, 1 to 500 μm.
The positive electrode current collector 5 and the negative electrode current collector 1 are preferably electron conductors.
In the present invention, either one or both of the positive electrode current collector and the negative electrode current collector may be simply referred to as a current collector.
As a material for forming the positive electrode current collector, in addition to aluminum, an aluminum alloy, stainless steel, nickel, titanium, and the like, a material (a material forming a thin film) in which carbon, nickel, titanium, or silver is treated on the surface of aluminum or stainless steel is preferable, and among them, aluminum and an aluminum alloy are more preferable.
As a material forming the negative electrode current collector, in addition to aluminum, copper, a copper alloy, stainless steel, nickel, titanium, and the like, a material obtained by treating the surface of aluminum, copper, a copper alloy, or stainless steel with carbon, nickel, titanium, or silver is preferable, and aluminum, copper, a copper alloy, and stainless steel are more preferable.
The shape of the current collector is generally a diaphragm shape, but a mesh, a perforated body, a lath body, a porous body, a foam, a molded body of a fiber group, or the like can also be used.
The thickness of the current collector is not particularly limited, but is preferably 1 to 500 μm. Further, it is also preferable to provide irregularities on the surface of the current collector by surface treatment.
In the present invention, functional layers, members, and the like may be appropriately inserted or disposed between or outside each of the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector. Each layer may be a single layer or a plurality of layers.
[ production of all-solid-State Secondary Battery ]
The all-solid secondary battery can be manufactured by a conventional method. Specifically, an all-solid-state secondary battery can be manufactured by forming the above-described layers using the solid electrolyte composition of the present invention or the like. Thereby, an all-solid-state secondary battery exhibiting excellent battery performance and exhibiting a smaller resistance can be manufactured. The following is a detailed description.
The all-solid-state secondary battery of the present invention can be produced by performing a method (a method for producing a sheet for an all-solid-state secondary battery of the present invention) including a step of forming a coating film (film formation) by appropriately applying the solid electrolyte composition of the present invention to a substrate (for example, a metal foil serving as a current collector).
For example, a positive electrode sheet for an all-solid-state secondary battery is produced by coating a metal foil as a positive electrode current collector with a solid electrolyte composition containing a positive electrode active material as a positive electrode material (positive electrode layer composition) to form a positive electrode active material layer. Next, a solid electrolyte layer is formed by coating a solid electrolyte composition for forming a solid electrolyte layer on the positive electrode active material layer. Further, the negative electrode active material layer is formed by applying a solid electrolyte composition containing a negative electrode active material as a material for a negative electrode (a composition for a negative electrode layer) on the solid electrolyte layer. By stacking an anode current collector (metal foil) on the anode active material layer, an all-solid-state secondary battery having a structure in which a solid electrolyte layer is sandwiched between a cathode active material layer and an anode active material layer can be obtained. It can be sealed in a case to obtain a desired all-solid-state secondary battery.
In addition, contrary to the method of forming each layer, an all-solid-state secondary battery can also be manufactured by forming a negative electrode active material layer, a solid electrolyte layer, and a positive electrode active material layer on a negative electrode current collector and stacking the positive electrode current collector thereon.
As another method, the following method can be mentioned. That is, the positive electrode sheet for all-solid-state secondary battery was produced as described above. Then, a solid electrolyte composition containing a negative electrode active material as a negative electrode material (negative electrode layer composition) was applied onto a metal foil as a negative electrode current collector to form a negative electrode active material layer, thereby producing a negative electrode sheet for an all-solid secondary battery. Next, a solid electrolyte layer was formed on the active material layer of any of these sheets as described above. The other of the positive electrode sheet for an all-solid secondary battery and the negative electrode sheet for an all-solid secondary battery is laminated on the solid electrolyte layer so that the solid electrolyte layer is in contact with the active material layer. In this manner, an all-solid-state secondary battery can be manufactured.
As another method, the following method can be mentioned. That is, the positive electrode sheet for the all-solid-state secondary battery and the negative electrode sheet for the all-solid-state secondary battery were produced as described above. In addition, a solid electrolyte composition is applied to a substrate to produce a solid electrolyte sheet for an all-solid-state secondary battery, which is composed of a solid electrolyte layer. The positive electrode sheet for all-solid-state secondary batteries and the negative electrode sheet for all-solid-state secondary batteries are stacked so as to sandwich the solid electrolyte layer peeled from the base material. In this manner, an all-solid-state secondary battery can be manufactured.
In addition, as described above, the positive electrode sheet for the all-solid secondary battery, the negative electrode sheet for the all-solid secondary battery, and the solid electrolyte sheet for the all-solid secondary battery were produced. Next, the positive electrode sheet for all-solid-state secondary battery or the negative electrode sheet for all-solid-state secondary battery and the solid electrolyte sheet for all-solid-state secondary battery are stacked and pressed in a state where the positive electrode active material layer or the negative electrode active material layer is in contact with the solid electrolyte layer. In this way, the solid electrolyte layer is transferred to the positive electrode sheet for an all-solid secondary battery or the negative electrode sheet for an all-solid secondary battery. Then, the solid electrolyte layer obtained by peeling off the base material of the solid electrolyte sheet for all-solid secondary battery and the negative electrode sheet for all-solid secondary battery or the positive electrode sheet for all-solid secondary battery (in a state where the negative electrode active material layer or the positive electrode active material layer is in contact with the solid electrolyte layer) are stacked and pressurized. In this manner, an all-solid-state secondary battery can be manufactured. The method of applying pressure and the conditions of applying pressure in this method are not particularly limited, and the method and the conditions of applying pressure described in the description of applying pressure to the composition to be applied can be applied.
In the above-described manufacturing method, the solid electrolyte composition of the present invention may be used in any one of the composition for a positive electrode layer, the solid electrolyte composition and the composition for a negative electrode layer, and is preferably used in all of them.
When the solid electrolyte layer or the active material layer is formed from a composition other than the solid electrolyte composition of the present invention, examples of the material include a composition generally used. In addition, the negative electrode active material layer can also be formed by bonding ions of a metal belonging to the first group or the second group of the periodic table, which is accumulated in the negative electrode current collector by the later-described initialization or charging at the time of use, with electrons, and depositing the metal as a metal on the negative electrode current collector or the like, without forming the negative electrode active material layer at the time of manufacturing the all-solid secondary battery.
The solid electrolyte layer and the like may be formed by, for example, pressure molding under a pressure condition described later on a substrate or an active material layer to form a solid electrolyte composition and the like, or may be formed as a sheet molded body of a solid electrolyte or an active material.
< formation of layers (film formation) >
The method of applying the solid electrolyte composition is not particularly limited, and can be appropriately selected. Examples thereof include coating (preferably wet coating), spray coating, spin coating, dip coating, slot coating, stripe coating, and bar coating.
In this case, the solid electrolyte composition may be separately coated and then dried, or may be dried after being coated in multiple layers. The drying temperature is not particularly limited. The lower limit is preferably 30 ℃ or higher, more preferably 60 ℃ or higher, and still more preferably 80 ℃ or higher. The upper limit is preferably 300 ℃ or lower, more preferably 250 ℃ or lower, and still more preferably 200 ℃ or lower. By heating in such a temperature range, the dispersion medium can be removed to obtain a solid state (coating dry layer). Further, it is preferable that the temperature is not excessively high, and the components of the all-solid-state secondary battery are not damaged. Thus, in the all-solid-state secondary battery, excellent overall performance is exhibited and good adhesion and good ionic conductivity without pressurization can be obtained.
As described above, when the solid electrolyte composition of the present invention is applied and dried, the solid particles are firmly bonded, and a dried-applied layer having a small interfacial resistance between the solid particles can be formed.
After the solid electrolyte composition is applied, the constituent layers are preferably stacked or the all-solid secondary battery is preferably manufactured, and then the layers or the all-solid secondary battery is pressurized. Further, it is also preferable to apply pressure in a state where the layers are laminated. Examples of the pressurizing method include a hydraulic cylinder press. The pressurizing force is not particularly limited, but is preferably in the range of 5 to 1500 MPa.
Also, the coated solid electrolyte composition may be heated while being pressurized. The heating temperature is not particularly limited, but is generally in the range of 30 to 300 ℃. It is also possible to perform pressing at a temperature higher than the glass transition temperature of the inorganic solid electrolyte. On the other hand, when the inorganic solid electrolyte and the specific polymer coexist, pressing can also be performed at a temperature higher than the glass transition temperature of the specific polymer. However, it is generally a temperature not exceeding the melting point of the above-mentioned specific polymer.
The pressurization may be performed in a state where the solvent or the dispersion medium is applied in advance in a dry state, or may be performed in a state where the solvent or the dispersion medium remains.
The respective compositions may be applied simultaneously, or may be applied, dried, and pressed simultaneously and/or stepwise. The lamination may be performed by transfer after coating to the respective substrates.
The atmosphere during coating or pressurization is not particularly limited, and any atmosphere may be used, such as atmospheric pressure, dry air (dew point-20 ℃ or lower), inert gas (e.g., argon, helium, nitrogen), and the like.
The pressing time may be a short time (for example, within several hours) to apply a high pressure, or may be a long time (for example, 1 day or more) to apply an intermediate pressure. In addition to the sheet for the all-solid secondary battery, for example, in the case of the all-solid secondary battery, it is possible to use a restraining tool (screw fastening pressure or the like) of the all-solid secondary battery to continuously apply moderate pressure.
The pressing pressure may be uniform or different with respect to the pressed portion such as the sheet surface.
The pressing pressure can be changed according to the area or the film thickness of the pressure receiving portion. Further, the same portion can be changed in stages with different pressures.
The stamping surface may be smooth or rough.
< initialization >
The all-solid secondary battery manufactured as described above is preferably initialized after manufacture or before use. The initialization is not particularly limited, and for example, it can be performed by performing initial charge and discharge in a state where the pressing pressure is increased, and thereafter releasing the pressure until reaching the general use pressure of the all-solid secondary battery.
[ uses of all-solid-state Secondary batteries ]
The all-solid-state secondary battery of the present invention can be applied to various uses. The application method is not particularly limited, and examples of the electronic device include a notebook computer, a pen-input computer, a mobile computer, an electronic book reader, a mobile phone, a wireless telephone handset, a pager, a handheld terminal, a portable facsimile machine, a portable copier, a portable printer, a stereo headphone, a camcorder, a liquid crystal television, a portable vacuum cleaner, a portable CD, a compact disc, an electric shaver, a transceiver, an electronic organizer, a calculator, a portable recorder, a radio, a backup power source, and a memory card. Other consumer goods include automobiles (e.g., electric cars), electric cars, motors, lighting fixtures, toys, game machines, load regulators, clocks, flashlights, cameras, and medical devices (e.g., cardiac pacemakers, hearing aids, and shoulder massagers). Moreover, it can be used as various military supplies and aviation supplies. And, it can also be combined with a solar cell.
The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto and is explained below. In the following examples, "parts" and "%" representing the composition are based on mass unless otherwise specified. In the present invention, "room temperature" means 25 ℃.
1. Synthesis of polymers used in examples and comparative examples
The polymers D-01 to D-12 are as described above. The polymers cD-01 and cD-02 used in the comparative examples are shown below.
[ chemical formula 10]
Figure BDA0003272287090000501
Synthetic example 1: synthesis of Polymer PS1 (for polymers D-01, D-06, D-07 and D-08) having Polymer segment introduced thereinto
To a 200 ml three-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube were added hydrogenated polybutadiene polyol NISSO-PB GI-1000 (trade name, number average molecular weight 1500, manufactured by Nippon Soda Co., Ltd.) (30.0g), epsilon-caprolactone (50.2g) and tetrabutyl orthotitanate (10mg), and the mixture was stirred for 7 hours while the temperature was raised to 190 ℃ under a nitrogen stream. Then, the reaction solution was cooled to synthesize PS1 into which the segment represented by formula (1) was introduced.
Synthesis examples 2 and 3: synthesis of polymers PS2 and PS3 (for polymers D-02 and D-03) ]
Polymers PS2 and PS3, into which a segment represented by formula (1) was introduced, were synthesized in the same manner as in synthesis example 1, except that in the synthesis of synthesis example 1, epsilon-caprolactone was changed to a cyclic lactone compound corresponding to each of polymers D-02 and D-03 shown in the above chemical formulae, and the amounts of these compounds and the amount of the catalyst used were changed as appropriate.
[ Synthesis example 4: synthesis of Polymer PS4 (for Polymer D-04) having Polymer segment introduced thereinto ]
To a 200 ml three-necked flask equipped with a stirrer, a thermometer, a reflux condenser of a dean and Stark apparatus, and a nitrogen inlet tube were added hydrogenated polybutadiene polyol NISSO-PB GI-1000 (trade name) (30.0g), dimethyl adipate (1.7g), and tetrabutyl orthotitanate (10mg), and the mixture was heated to 190 ℃ under a nitrogen stream and stirred for 7 hours. Then, the reaction solution was cooled to synthesize PS4 into which the segment represented by formula (2) was introduced.
[ Synthesis example 5: synthesis of Polymer PS5 (for Polymer D-05) into which Polymer segment was introduced
In the synthesis of synthesis example 4, a polymer PS5 into which a segment represented by formula (2) was introduced was synthesized in the same manner as in synthesis example 4, except that dimethyl adipate was changed to a dicarboxylic acid diester compound corresponding to each polymer D-05 represented by the above chemical formula, and the amount of the compound used and the amount of the catalyst used were changed as appropriate.
[ Synthesis example 6: synthesis of Polymer PS6 (for Polymer D-09) ]
PS6, a polymer having a segment represented by the formula (1) introduced thereinto, was synthesized in the same manner as in Synthesis example 1, except that the hydrogenated polybutadiene polyol was changed to hydrogenated polybutadiene diamine corresponding to each polymer D-09 represented by the above chemical formula, and the amount used of the catalyst were changed as appropriate in the synthesis of Synthesis example 1. In addition, hydrogenated polybutadiene diamine was synthesized by reacting acrylonitrile by adding a catalytic amount of potassium tert-butoxide to hydrogenated polybutadiene polyol NISSO-PB GI-1000, and subjecting the resulting mixture to hydrogen reduction with Raney nickel.
Synthetic examples 7, 8 and 9: synthesis of polymers PS7, PS8 and PS9 (for polymers D-10, D-11 and D-12) into which Polymer segment was introduced
Polymers PS7, PS8, and PS9, into which a segment represented by formula (1) was introduced, were synthesized in the same manner as in synthesis example 1, except that the amount of epsilon-caprolactone used in the synthesis of synthesis example 1 was changed to an amount corresponding to each polymer represented by the above chemical formula and the amount of catalyst used was changed as appropriate.
[ Synthesis example 10: synthesis of Polymer D-01
Polymer D-01 was synthesized as follows.
To a 500 ml three-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube were added diphenylmethane diisocyanate (17.5g), polyethylene glycol 200 (number average molecular weight 200, 13.2g), polymer PS1(7.7g) synthesized in synthetic example 1 and tetrahydrofuran (dehydrated product, 149.5g), and the temperature was raised to 60 ℃ under a nitrogen stream. Next, NEOSTANN U-600(NITTOH CHEMICAL Co., Ltd., 0.08mg) and tetrahydrofuran (dehydrated product, 4.0g) were added as a bismuth-based catalyst, and the mixture was stirred at 60 ℃ for 5 hours. Then, methanol (1.2g) was added thereto, and after stirring at 60 ℃ for 30 minutes, the reaction solution was cooled to obtain a polymer D-01 solution.
Next, a dispersion of polymer D-01 was prepared as follows.
A300-mL three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet was charged with a polymer D-01 solution (15.0g) and tetrahydrofuran (dehydrated product, 15.0g), and the mixture was stirred at room temperature under a nitrogen flow. Butyl butyrate (90g) was gradually added thereto, the obtained mixed solution was distilled off under reduced pressure, and butyl butyrate was added so that the solid content concentration became 5%, thereby preparing a dispersion of polymer D-01.
[ Synthesis examples 11 to 21: synthesis of polymers D-02 to D-12 and preparation of Dispersion
Polymers D-02 to D-12 were synthesized in the same manner as in synthesis example 1, except that the compounds introduced into the respective components shown in table 1 were used in amounts such that the contents shown in table 1 were used in synthesis example 1.
Comparative synthesis example 1: synthesis of Polymer cD-01 and preparation of Dispersion
Polymer cD-01 was synthesized in the same manner as in synthesis example 1, except that the compound having each of the components shown in table 1 was used in an amount to be used in the content shown in table 1 in synthesis example 1.
Comparative synthesis example 2: synthesis of Polymer cD-02 and preparation of Dispersion
Polymer cD-02 was synthesized in the same manner as in synthesis example 1, except that the compound having each of the components shown in table 1 was used in an amount to be the content shown in table 1 in synthesis example 1.
Polymer cD-02 coagulated and precipitated in butyl butyrate, and a dispersion of polymer cD-02 could not be prepared.
The mass average molecular weight of each polymer synthesized and the number average molecular weight of the polymer segment (constituent component a) were measured by the above-described method (condition 2). The particle size of each polymer was measured by the above-described method. The results are shown in Table 1.
The bonds selected from the group (I) of bonds possessed by each polymer (excluding the polymer segment) are shown in table 1.
In table 1, the components a to f correspond to the respective components expressed by the molar ratios a to f in the above formula (3) or formula (4). Since the polymers D-01 to D-12 do not have the constituent component c and the constituent component e, the description in Table 1 is omitted. Incidentally, GI-1000 of the polymer cD-01 does not correspond to the constituent component f, but for convenience is described in the column of the constituent component f. The 1, 10-decanediol (DDO) of the polymer cD-02 corresponds to the constituent c, but is described in the column of the constituent d for convenience.
Figure BDA0003272287090000531
Abbreviation of < TABLE >
In the table, "-" in the column of the constituent component and the crosslinking agent means that no corresponding constituent component is present.
In the columns of the components a to f in the table, the following abbreviations represent names of the compounds introduced into the respective structural units.
Constituent component a-
PS 1-PS 9: the polymers PS 1-PS 9 synthesized in synthetic examples 1-9
Constituent component b-
MDI: diphenylmethane diisocyanate (manufactured by FUJIFILM Wako Pure Chemical Corporation)
Constituent component c-
DDO: 1, 10-decanediol (Tokyo Chemical Industry Co., Ltd.)
Constituent component d-
DMBA: 2, 2-bis (hydroxymethyl) butanoic acid (Tokyo Chemical Industry Co., Ltd., manufactured by Ltd.)
Constituent component f-
PEG 200: polyethylene glycol 200 (number average molecular weight 200, manufactured by FUJIFILM Wako Pure Chemical Corporation)
PTMG 250: polytetramethylene glycol (number average molecular weight 250, Aldrich, manufactured by CO. LTD.)
G3450J: polycarbonate diol G3450J (trade name, number average molecular weight 800, ASAHI KASEI CORPORATION)
Other constituent components
GI-1000: hydrogenated polybutadiene polyol NISSO-PB GI-1000 (trade name, number average molecular weight 1500, Nippon Soda Co., Ltd., manufactured by Ltd.)
In the column of "linkage group (I)", U represents a urethane bond, E represents an ether bond, and C represents a carbonate bond. When the polymer has a plurality of bonds, "/" is also used for description. That is, U/E represents that the polymer has a urethane bond and an ether bond.
In the column of "component f", when 2 or more components are contained, abbreviations and contents of the components are described by "/".
2. Synthesis of sulfide inorganic solid electrolyte
Sulfide-based inorganic solid electrolytes were synthesized with reference to non-patent documents of t.ohtomo, a.hayashi, m.tatsumisago, y.tsuchida, s.hama, k.kawamoto, Journal of Power Sources, 233, (2013), pp231-235, and a.hayashi, s.hama, h.morimoto, m.tatsumisago, t.minai, chem.lett, (2001), pp 872-873.
Specifically, 2.42g of lithium sulfide (Li) was weighed in a glove box under an argon atmosphere (dew point-70 ℃ C.)2Manufactured by Aldrich. Inc, purity > 99.98%) and 3.90g of phosphorus pentasulfide (P)2S5Inc., aldrich. having a purity of > 99%), and put into a mortar made of agate and mixed for 5 minutes using a pestle made of agate. Li2S and P2S5Is given as Li in terms of molar ratio2S:P2S5=75:25。
A45 mL vessel (Fritsch Co., Ltd.) made of zirconia was charged with 66g of zirconia beads having a diameter of 5mm, and the total amount of the mixture of lithium sulfide and phosphorus pentasulfide was charged, and the vessel was completely sealed under an argon atmosphere. 6.20g of a sulfide-based inorganic solid electrolyte (Li/P/S glass, hereinafter sometimes referred to as LPS.) was obtained by mechanically grinding a mixture of 6.20g of yellow powder at a rotation speed of 510rpm at a temperature of 25 ℃ for 20 hours in a planetary ball mill P-7 (trade name, Fritsch co., Ltd).
[ example 1]
In example 1, a sheet for an all-solid secondary battery and an all-solid secondary battery having a layer structure shown in fig. 1 were produced using a solid electrolyte composition prepared using a dispersion of polymer D-01, and the performance thereof was evaluated. The results are shown in table 2.
< preparation of solid electrolyte composition D-01 >
Into a 45mL vessel (manufactured by Fritsch Co., Ltd.) made of zirconia, 180 beads of zirconia having a diameter of 5mm were put, and 9.5g of the LPS synthesized above and 2.5g of butyl butyrate as a dispersion medium were put. Then, 0.5g of the polymer D-01 dispersion was charged in terms of solid content and placed in a planetary ball mill P-7 (trade name, Fritsch Co., Ltd.). The mixing was continued at a temperature of 25 ℃ and a rotation speed of 300rpm for 3 hours to prepare a solid electrolyte composition D-01.
< production of Positive electrode sheet D-01 for all-solid-State Secondary Battery
To a 45mL vessel (manufactured by Fritsch Co., Ltd.) made of zirconia, 180 zirconia beads having a diameter of 5mm were put, 1.9g of the solid electrolyte composition D-01 prepared above was put in terms of solid content, and 12.3g of butyl butyrate was put as the total amount of the dispersion medium. Further, NCA (LiNi) as a positive electrode active material was added thereto0.85Co0.10Al0.05O2)8.0g of acetylene black and 0.1g of acetylene black were placed in a planetary ball mill P-7 and mixed continuously at a temperature of 25 ℃ and a rotation speed of 200rpm for 20 minutes. Thus, a composition (slurry) D-01 for a positive electrode layer was prepared.
The composition D-01 for a positive electrode layer prepared as described above was applied to an aluminum foil having a thickness of 20 μm as a current collector by means of a baking applicator (trade name: SA-201, STER SANGYO CO, manufactured by LTD.), heated at 80 ℃ for 1 hour, and further heated at 110 ℃ for 1 hour, thereby drying the composition D-01 for a positive electrode layer. Then, the dried composition D-01 for a positive electrode layer was heated (120 ℃ C.) and pressed (20MPa, 1 minute) using a hot press to prepare a positive electrode sheet D-01 for an all-solid-state secondary battery having a laminated structure of a positive electrode active material layer/aluminum foil with a layer thickness of 60 μm.
< production of negative electrode sheet D-01 for all-solid-state secondary battery >
Subsequently, 180 zirconia beads having a diameter of 5mm were put into a 45mL vessel made of zirconia (manufactured by Fritsch Co., Ltd.), 5.0g of the solid electrolyte composition D-01 prepared above was put into the vessel, and 12.3g of butyl butyrate was put into the vessel as a dispersion medium. Then, the vessel was placed in a planetary ball mill P-7 (trade name, manufactured by Fritsch Co., Ltd.) and stirred at a temperature of 25 ℃ and a rotation speed of 300rpm for 3 hours. Thereafter, 5.0g of graphite as a negative electrode active material was charged, and the container was again set in a planetary ball mill P-7, and mixing was continued at a temperature of 25 ℃ and a rotation speed of 100rpm for 15 minutes. Thus, negative electrode layer composition (slurry) D-01 was obtained.
The composition D-01 for a negative electrode layer obtained above was applied to a stainless steel foil 10 μm thick by the above baking applicator, and heated at 80 ℃ for 2 hours, thereby drying the composition D-01 for a negative electrode layer. Then, the dried composition D-01 for the negative electrode layer was heated (120 ℃ C.) and pressed (600MPa, 1 minute) using a hot press to prepare a negative electrode sheet D-01 for an all-solid-state secondary battery having a laminated structure of a negative electrode active material layer/stainless steel foil with a layer thickness of 120 μm.
< production of all-solid-state Secondary Battery D-01 >
The prepared solid electrolyte composition D-01 was applied to the negative electrode active material layer of the fabricated negative electrode sheet D-01 for an all-solid secondary battery by the above-mentioned baking applicator, and after heating at 80 ℃ for 1 hour, further heating at 110 ℃ for 6 hours was carried out to dry the solid electrolyte composition D-01. Negative electrode sheet D-01 having a laminated structure of solid electrolyte layer/negative electrode active material layer/stainless steel foil with a layer thickness of 60 μm was produced by heating (120 ℃) and pressing (30MPa, 1 minute) negative electrode sheet D-01 having the solid electrolyte layer (coating and drying layer) formed on the negative electrode active material layer using a hot press.
The negative electrode sheet was cut into a disk shape having a diameter of 15 mm. On the other hand, the positive electrode sheet D-01 for all-solid-state secondary battery thus produced was cut into a disk shape having a diameter of 13 mm. After the positive electrode active material layer of the positive electrode sheet D-01 for the all-solid-state secondary battery and the solid electrolyte layer formed on the negative electrode sheet D-01 were arranged (laminated) to face each other, the laminate for the all-solid-state secondary battery having a laminated structure of aluminum foil/positive electrode active material layer/solid electrolyte layer/negative electrode active material layer/stainless steel foil was produced by heating (120 ℃) and pressing (40MPa, 1 minute) using a hot press.
Next, the stacked body 12 for an all-solid-state secondary battery thus produced was put into a 2032-type button case 11 made of stainless steel and equipped with a spacer and a gasket (not shown in fig. 2), and the 2032-type button case 11 was crimped, thereby producing an all-solid-state secondary battery D-01 indicated by reference numeral 13 in fig. 2.
Examples 2 to 12 (Nos. D-02 to D-12), comparative example 1(No. cD-01) and comparative example 2
Positive electrode sheets for all-solid secondary batteries and negative electrode sheets for all-solid secondary batteries were produced in the same manner as in example 1 except that each composition prepared using the polymer dispersion shown in table 2 in place of the polymer D-01 dispersion was used in the preparation of the solid electrolyte composition D-01, the production of the positive electrode sheet D-01 for all-solid secondary batteries, the production of the negative electrode sheet D-01 for all-solid secondary batteries, and the production of the all-solid secondary batteries D-01, and the all-solid secondary batteries nos. D-02 to D-12 and cD-01 were produced, respectively.
Since the polymer dispersion cD-02 could not be prepared, the production and evaluation of a sheet for an all-solid secondary battery and an all-solid secondary battery using the polymer cD-02 were not carried out.
< dispersibility test of solid electrolyte composition >
Each solid electrolyte composition prepared as described above was separated from the planetary ball mill P-7 and filled to a height of 3cm in a transparent glass tube having a diameter of 10 mm. The mixture was allowed to stand at 25 ℃ for 48 hours. Then, the phase separation state and the degree of phase separation (dispersion stability) of the composition were determined by the following evaluation criteria. In this test, the evaluation criterion "C" or more is a pass level.
Evaluation criteria-
A: the part (interface with the supernatant layer) where the delamination (phase separation) occurs is less than 2mm from the liquid surface
B: the part with delamination is more than 2mm and less than 4mm from the liquid surface
C: the part with delamination is 4mm or more and less than 7mm from the liquid surface
D: the part with delamination is 7mm or more and less than 10mm from the liquid surface
< adhesion test of electrode sheet for all-solid-state secondary battery >
As the adhesion test of the positive electrode sheet for all-solid-state secondary batteries, the evaluation was made by a bending resistance test (based on JIS K5600-5-1) using a mandrel tester. Specifically, a long test piece having a width of 50mm and a length of 100mm was cut out from each sheet. After the active material layer surface of the test piece was provided on the opposite side of the mandrel (the current collector was on the mandrel side) and the width direction of the test piece was set parallel to the axis of the mandrel, and the test piece was bent 180 degrees (1 time) along the outer peripheral surface of the mandrel, it was observed whether cracks and fractures occurred in the active material layer. In the bending test, first, when the mandrel having a diameter of 32mm was used and neither cracking nor cracking occurred, the diameter (unit mm) of the mandrel was gradually reduced to 25, 20, 16, 12, 10, 8, 6, 5, 3, and 2, and the diameter of the mandrel at which cracking and/or cracking occurred first was recorded. The adhesiveness was evaluated by which of the following evaluation criteria the diameter at which the crack and fracture first occurred (defect occurrence diameter) was included. In the present invention, the smaller the defect occurrence diameter, the stronger the adhesiveness of the solid particles, and the standard of evaluation "B" or more is a pass level.
Evaluation criteria-
AA:2mm
A:3mm
B: 5mm or 6mm
C: over 8mm
(measurement of Battery Performance (discharge Capacity))
Except for using the positive electrode sheet produced as follows, the discharge capacity was measured as the battery performance using the all-solid-state secondary battery produced in the same manner as the above-described production > of the all-solid-state secondary battery D-01.
That is, 180 zirconia beads having a diameter of 5mm were put into a 45mL vessel made of zirconia (manufactured by Fritsch co., Ltd), 1.9g of the solid electrolyte composition shown in table 2 was put into the vessel, and 12.3g of butyl butyrate was put into the vessel as the total amount of the dispersion medium. Further, NCA (LiNi) as a positive electrode active material was added thereto0.85Co0.10Al0.05O2)8.0g of acetylene black, 0.1g ofMixing was continued in a planetary ball mill P-7 at 25 ℃ and 200rpm for 20 minutes. In this way, compositions (slurries) for positive electrode layers for capacity measurement were prepared, respectively.
Subsequently, the composition for a positive electrode layer prepared as described above was allowed to stand at 25 ℃ for 2 hours, and then applied as a current collector to an aluminum foil having a thickness of 20 μm by a baking applicator (trade name: SA-201, Tester Sangyo CO, manufactured by LTD.), heated at 80 ℃ for 1 hour, and further heated at 110 ℃ for 1 hour, thereby drying the composition for a positive electrode layer. Then, the dried composition for a positive electrode layer was heated (120 ℃ C.) and pressurized (20MPa, 1 minute) using a hot press to prepare positive electrode sheets for an all-solid-state secondary battery for capacity measurement each having a laminated structure of a positive electrode active material layer/aluminum foil with a layer thickness of 60 μm.
The discharge capacity of each all-solid-state secondary battery manufactured using the positive electrode sheet for an all-solid-state secondary battery was measured by a charge/discharge evaluation device "TOSCAT-3000" (product name, TOYO SYSTEM co., LTD). The all-solid secondary battery was charged at a current value of 0.2mA until the battery voltage became 4.2V, and then discharged at a current value of 0.2mA until the battery voltage became 3.0V. The charge and discharge were repeated as 1 cycle. In this charge-discharge cycle, the discharge capacity in the 3 rd cycle was obtained. The discharge capacity was converted to 100cm per the positive electrode active material layer2The surface area of (a) and the discharge capacity of the all-solid-state secondary battery were determined by the following evaluation criteria. In this test, the evaluation criterion "B" or more is a pass level.
Evaluation criteria-
AA: the discharge capacity is more than 200mAh
A: the discharge capacity is more than 180mAh and less than 200mAh
B: the discharge capacity is more than 150mAh and less than 180mAh
C: the discharge capacity is more than 120mAh and less than 150mAh
[ Table 2]
Figure BDA0003272287090000591
The following is evident from the results shown in Table 2.
That is, in the solid electrolyte composition cD-01 in which the polymer cD-01 not containing the polymer segment defined in the present invention as a constituent component is used together with the inorganic solid electrolyte and the dispersion medium, the dispersibility of the solid electrolyte composition is insufficient. In addition, the adhesiveness of the positive electrode sheet cD-01 and the battery performance (discharge capacity) of the all-solid secondary battery cD-01 are also unsatisfactory.
The polymer cD-02 itself containing a constituent derived from an alkylene group having a molecular weight of less than 500 in place of the hydrocarbon polymer having a number average molecular weight of 500 or more is extremely poor in dispersibility. Therefore, it was found that even when the positive electrode sheet and the all-solid-state secondary battery were produced using the polymer cD-02, the adhesiveness of the positive electrode sheet cD-02 and the battery performance (discharge capacity) of the all-solid-state secondary battery cD-02 were not sufficient.
On the other hand, in the solid electrolyte compositions D-01 to D-12 in which the polymers D-01 to D-12 having the polymer segment defined in the present invention as a constituent are used together with the inorganic solid electrolyte and the dispersion medium, the solid particles are highly dispersed and excellent dispersibility (dispersion stability) is exhibited. Further, it was found that the positive electrode sheets D-01 to D-12 produced from these solid electrolyte compositions were all strongly bonded with solid particles (excellent in adhesion of solid particles), and all-solid secondary batteries D-01 to D-12 provided with these positive electrode sheets as constituent layers exhibited high battery performance (discharge capacity).
From the above results, it is understood that when the specific polymer contained in the solid electrolyte layer and the active material layer is different, the above effects are exhibited when the specific polymer is further contained in at least 1 layer of the solid electrolyte layer and the active material layer.
The present invention has been described in connection with the embodiments thereof, but unless otherwise specified, the invention is not limited to any of the details of the description, and should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.
This application claims priority based on japanese patent application 2019-.
Description of the symbols
1-negative electrode current collector, 2-negative electrode active material layer, 3-solid electrolyte layer, 4-positive electrode active material layer, 5-positive electrode current collector, 6-working site, 10-all-solid-state secondary battery, 11-button case, 12-laminate for all-solid-state secondary battery, 13-all-solid-state secondary battery (button battery).

Claims (14)

1. A solid electrolyte composition comprising: an inorganic solid electrolyte having conductivity of an ion of a metal belonging to group 1 or group 2 of the periodic table, a polymer and a dispersion medium, wherein,
the polymer has a polymer segment having an oxygen or nitrogen atom as a bonding portion in a main chain and contains at least one bond selected from the following bond group (I) in the main chain,
the polymer segment has the following constituent components: a constituent component derived from a hydrocarbon polymer having at least 2 hydroxyl groups or amino groups and having a number average molecular weight of 500 or more; and a constituent derived from a cyclic compound having an ester bond or a compound having at least 2 carboxyl groups,
< key group (I) >
Ester bonds, amide bonds, urethane bonds, urea bonds, imide bonds, ether bonds, and carbonate bonds.
2. The solid electrolyte composition of claim 1,
the polymer segment includes: at least one of a polymer segment represented by the following formula (1) and a polymer segment represented by the following formula (2),
[ chemical formula 1]
Figure FDA0003272287080000011
In the formula, RaIn the hydrocarbon polymerA chain of a hydrocarbon polymer, wherein the hydrocarbon polymer,
Xarepresents an oxygen atom or-NH-,
R1an aliphatic hydrocarbon group having 3 to 15 carbon atoms,
R2an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aliphatic hydrocarbon group having 1 to 20 carbon atoms,
n1 is 1 to 100, and n2 is 1 to 10.
3. The solid electrolyte composition according to claim 1 or 2,
the cyclic compound having the ester bond or the compound having at least 2 carboxyl groups includes a lactone compound.
4. The solid electrolyte composition according to any one of claims 1 to 3, wherein,
the polymer is a particulate polymer having an average particle diameter of 10 to 1000 nm.
5. The solid electrolyte composition of any one of claims 1 to 4,
the polymer has a polymer segment content of 5 to 80 mass%.
6. The solid electrolyte composition of any one of claims 1 to 5, wherein,
the polymer includes at least one of a polymer represented by the following formula (3) and a polymer represented by the following formula (4),
[ chemical formula 2]
Figure FDA0003272287080000021
In the formula, RaRepresents a hydrocarbon polymer chain in the hydrocarbon polymer,
Xarepresents an oxygen atom or-NH-,
R1an aliphatic hydrocarbon group having 3 to 15 carbon atoms,
R2an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aliphatic hydrocarbon group having 1 to 20 carbon atoms,
n1 is 1 to 100, n2 is 1 to 10,
Rb1an aromatic hydrocarbon group having 6 to 22 carbon atoms, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a combination of 2 or more of these groups,
Rb2an alkylene group having 2 to 12 carbon atoms,
Rb3represents an alkylene group having at least 1 functional group selected from the following functional group (II),
Rb4represents an alkylene group having at least 1 functional group selected from the following functional group (III),
Rb5is a 2-valent chain having a number average molecular weight of 100 or more, and represents a polyalkylene oxide chain, a polycarbonate chain, a polyester chain or a silicone chain, or represents a chain obtained by combining 2 or more of these chains,
Xb2、Xb3、Xb4and Xb5Represents an oxygen atom or-NH-,
a. b, c, d, e and f are the molar ratio of each constituent, a is 0.1 to 30 mol%, b is 40 to 60 mol%, c and e are 0 to 30 mol%, d and f are 0 to 49 mol%, a + b + c + d + e + f is 100 mol%,
< group of functional groups (II) >)
Carboxyl group, sulfonic group, phosphoric group, amino group, hydroxyl group, sulfanyl group, isocyanato group, alkoxysilyl group, and group obtained by fusing 3 or more rings
< functional group (III) >
A group having a carbon-carbon unsaturated bond, an epoxy group and an oxetanyl group.
7. The solid electrolyte composition of any one of claims 1 to 6, wherein,
the content of the polymer in the solid electrolyte composition is 0.001-10 mass%.
8. The solid electrolyte composition of any one of claims 1 to 7,
the inorganic solid electrolyte is represented by the following formula (S1),
La1Mb1Pc1Sd1Ae1(S1)
wherein L represents an element selected from Li, Na and K, M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al and Ge, A represents an element selected from I, Br, Cl and F, a 1-e 1 represents the composition ratio of the elements, and a1: B1: c1: d1: e1 satisfies 1-12: 0-5: 1: 2-12: 0-10.
9. The solid electrolyte composition of any one of claims 1 to 8,
the dispersion medium is selected from a ketone compound, an aliphatic compound or an ester compound.
10. The solid electrolyte composition according to any one of claims 1 to 9, which contains an active material.
11. A sheet for an all-solid secondary battery having a layer composed of the solid electrolyte composition described in any one of claims 1 to 10.
12. An all-solid-state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer and a negative electrode active material layer in this order,
at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer composed of the solid electrolyte composition according to any one of claims 1 to 10.
13. A method for manufacturing a sheet for an all-solid secondary battery, which comprises forming a film from the solid electrolyte composition described in any one of claims 1 to 10.
14. A method for manufacturing an all-solid-state secondary battery, by the manufacturing method according to claim 13.
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