JP2023135606A - Liquid composition, ink-jet discharge liquid composition, storage container, manufacturing device for member of electrochemical element, manufacturing device for electrochemical element, method for manufacturing member of electrochemical element, method for manufacturing electrochemical element, and electrochemical element - Google Patents

Abstract

To provide a liquid composition used for forming a member of an electrochemical element in which solid content concentration can be increased while viscosity is low enough to enable inkjet printing, and an obtained ion conductive material-containing layer has excellent peeling strength.SOLUTION: A liquid composition used for forming a member of an electrochemical element includes an ion conductive material, a dispersant, a polymer, and a solvent. The polymer is a (meth)acrylate-based polymer that contains a (meth)alkyl acrylate ester monomer and whose glass-transition temperature is 80°C or lower. The polymer is a liquid composition in which a mixed liquid obtained by being mixed with the solvent at a concentration of 10 wt.% has a viscosity of 50 mPa s or lower at 25°C.SELECTED DRAWING: None

Description

The present invention relates to a liquid composition, a liquid composition for inkjet ejection, a storage container, an apparatus for manufacturing an electrochemical element member, an apparatus for manufacturing an electrochemical element, a method for manufacturing an electrochemical element member, a method for manufacturing an electrochemical element, and related to electrochemical elements.

2. Description of the Related Art Electrochemical elements, such as secondary batteries such as lithium ion secondary batteries, are installed in portable devices, hybrid vehicles, electric vehicles, etc., and demand is increasing. Additionally, there is a growing need for thin batteries to be installed in various wearable devices and medical patches, and requirements for secondary batteries are diversifying.

A liquid composition for an electrode composite layer generally includes an active material, a dispersion medium, and a binder for improving the binding properties of the resulting electrode composite layer. Generally, in addition to using a polymer as a binder, the liquid composition for the electrode composite layer has a viscosity of 10 ³ to 10 ⁴ mPa. s, which is extremely high, and is slurry-like. Therefore, conventional methods for manufacturing electrodes constituting lithium ion secondary batteries have been to apply a liquid composition for an electrode composite layer onto an electrode base using a die coater, comma coater, reverse roll coater, etc. A method of forming an electrode composite material layer is known.

On the other hand, in recent years, from the viewpoint of reducing material costs and environmental impact, a manufacturing method in which a liquid composition for an electrode composite layer is applied using inkjet printing, which facilitates intermittent coating, has been attracting attention. However, inkjet printing is generally a manufacturing method that targets the application of low-viscosity liquid compositions, and even if it is a high-viscosity type, the upper limit of the viscosity of the liquid composition is 200 mPa・s, which is different from conventional printing. A viscosity level that is 1/10 to 1/100 times lower than that of the liquid composition for the slurry electrode composite layer is required.

As for a liquid composition for an electrode composite layer having a low viscosity, for example, in the example of Patent Document 1, the content of a binder whose viscosity in a 1% by weight aqueous solution is 1 to 20 mPa·s is 0.01 to 0.2 mPa·s. 5% by weight and a viscosity of 3.1 to 5.8 mPa·s for an electrode composite layer for inkjet printing is described.

Further, as a liquid composition for an electrode composite material layer having a high solid content concentration, for example, Patent Document 2 describes a binder composition for a non-aqueous secondary battery electrode containing a binder and an organic solvent, which The material contains a polymer A, the polymer A contains ethylenically unsaturated acid monomer units in a proportion of 1.00% by mass or more and 10.00% by mass or less, and the polymer A has a concentration of Use a binder composition for non-aqueous secondary battery electrodes that has a viscosity of 10,000 mPa s or less at a shear rate of 0.1 s ^-1 when mixed with the organic solvent at 8% by mass to obtain a mixed solution. It is described that by doing so, it is possible to provide a slurry composition for an electrode composite material layer having a high solid content concentration of 75% by weight or more.

The present invention has a low viscosity that allows inkjet printing, yet can have a high solid content concentration, and the resulting ion-conductive material-containing layer has excellent peel strength, and can be used to form a member of an electrochemical device. The purpose is to provide a liquid composition.

The liquid composition of the present invention as a means for solving the above problems is a liquid composition used for forming a member of an electrochemical element, and comprises an ion conductive material, a dispersant, a polymer, and a solvent. The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80° C. or lower, and the polymer is mixed with the solvent at a concentration of 10% by mass. The viscosity of the mixed liquid at 25° C. when mixed is 50 mPa·s or less.

According to the present invention, the solid content concentration can be increased while the viscosity is low enough for inkjet printing, and the resulting ion-conductive material-containing layer has excellent peel strength and can be used to form members of electrochemical devices. A liquid composition can be provided.

FIG. 1 is a schematic diagram showing an example of a method for manufacturing a member of an electrochemical device according to this embodiment. FIG. 2 is a schematic diagram showing an example of an apparatus for manufacturing members of an electrochemical device according to the present embodiment. FIG. 3 is a schematic diagram showing another example of the manufacturing apparatus for the member of the electrochemical element of this embodiment. FIG. 4 is a schematic diagram showing an example of the method for manufacturing the electrode of this embodiment. FIG. 5 is a schematic diagram showing an example of a modification of the liquid ejection device. FIG. 6 is a schematic diagram showing an example of the method for manufacturing the electrode of this embodiment. FIG. 7 is a schematic diagram showing an example of a modification of the liquid ejection device. FIG. 8 is a cross-sectional view showing an example of the negative electrode of this embodiment. FIG. 9 is a cross-sectional view showing an example of the positive electrode of this embodiment. FIG. 10 is a cross-sectional view showing an example of an electrode element used in the electrochemical device of this embodiment. FIG. 11 is a cross-sectional view showing an example of the electrochemical element of this embodiment. FIG. 12 is a schematic diagram showing an example of a mobile body equipped with an all-solid-state battery that is an example of the electrochemical element of this embodiment.

(liquid composition)
The liquid composition of the present invention is a liquid composition used for forming a member of an electrochemical device, and includes at least an ion-conductive material, a dispersant, a polymer, and a solvent, and further includes other components as necessary. Contains the following ingredients.

Conventional Patent Document 1 describes a composition for an electrode mixture layer for inkjet printing, but the solid content concentration of a general slurry-like liquid composition for an electrode mixture layer is 60% by mass to 70% by mass. In contrast, the solid content concentration of the composition for an electrode composite layer for inkjet printing in Patent Document 1 is only about 20% by mass to 40% by mass, and there is room for improvement in terms of productivity.
In addition, in order to obtain a slurry composition for an electrode mixture layer using the binder composition of Patent Document 2 in a viscosity range that can be used in inkjet printing, it is necessary to It was necessary to dilute to a solid content concentration lower than the solid content concentration.

Furthermore, if the amount of polymer added is simply lowered in order to lower the viscosity, it may not be possible to provide a sufficiently high binding capacity to the resulting ion conductive material-containing layer such as the electrode composite layer or solid electrolyte layer. The peel strength of the ion-conductive material-containing layer was insufficient.
Therefore, in order to achieve both a high solid content concentration comparable to that of conventional slurry liquid compositions for secondary batteries, a low viscosity that enables inkjet printing, and sufficient peel strength of the resulting ion-conductive material-containing layer, There was room for further improvement.

The liquid composition of the present invention is a liquid composition used for forming members of electrochemical devices, and can be used, for example, for forming electrodes of secondary batteries, solid electrolyte layers of secondary batteries, and the like. Further, the liquid composition for forming an electrode of a secondary battery can be used, for example, when forming an electrode of a non-aqueous secondary battery such as a lithium ion secondary battery. Further, the liquid composition for forming a solid electrolyte layer of a secondary battery can be used, for example, when forming a solid electrolyte layer of a non-aqueous secondary battery such as a lithium ion secondary battery.

<Polymer>
The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80° C. or lower. Further, when the polymer is mixed with the solvent at a concentration of 10% by mass, the viscosity of the mixture at 25° C. is 50 mPa·s or less.

The polymer is preferably blended within a mass concentration range that dissolves in the solvent.
The mass concentration range in which the polymer dissolves in the solvent refers to a range in which the polymer is compatible with the solvent. More specifically, the (meth)acrylate polymer is introduced into the solvent at a temperature of 25° C., and after being dissolved and left to stand for 10 minutes, the mass concentration is such that no precipitate or supernatant is visually confirmed. is within the range of The conditions for dissolving the polymer are not particularly limited as long as the polymer is dissolved.

The polymer is a component that does not excessively increase the viscosity of the liquid composition. In addition, in an electrode manufactured by forming an electrode mixture layer on a current collector using the liquid composition, the polymer can remove components contained in the electrode mixture layer from the electrode mixture layer. It is a component that holds the material in place (that is, functions as a binding material). Further, in a laminate produced by forming a solid electrolyte layer on an electrode using the liquid composition, the polymer retains components contained in the solid electrolyte layer so that they do not separate from the laminate. It is an ingredient.

[(meth)acrylic acid alkyl ester monomer]
The polymer contains a (meth)acrylic acid alkyl ester monomer that exhibits weaker adsorption energy for ion-conducting materials than the dispersant for ion-conducting materials described below, so it has good ion-conductivity. Hard to inhibit adsorption of dispersant for ion conductive materials onto materials. Therefore, the liquid composition of the present invention has an extremely low viscosity even though it has a high solid content concentration because the ion conductive material is unlikely to aggregate in an organic solvent.
In the present invention, the "presence or absence of (meth)acrylic acid alkyl ester monomer" can be measured using a nuclear magnetic resonance (NMR) method such as ¹ H-NMR.

Examples of the (meth)acrylic acid alkyl ester monomer include those having a linear alkyl group and those having a branched alkyl group. For example, (meth)acrylic acid ester monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, Acrylic acid alkyl esters such as 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, stearyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t- Examples include methacrylic acid alkyl esters such as butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, and stearyl methacrylate. Among these, those in which the alkyl has 2 to 4 carbon atoms are preferred, from the viewpoint of having a low glass transition temperature when made into a homopolymer, being highly flexible, and having low solubility in an electrolytic solution. More preferred are meth)acrylate and butyl(meth)acrylate.

[Glass-transition temperature]
The glass transition temperature of the polymer is not particularly limited as long as it is 80°C or lower and can be appropriately selected depending on the purpose, but it is preferably 40°C or lower, more preferably 15°C or lower. preferable. If the glass transition temperature of the polymer is below the above upper limit, the resulting electrode composite material layer or solid electrolyte layer will be highly flexible and the peel strength can be further improved.

The glass transition temperature of the polymer can be determined, for example, by changing the type and/or amount of the (meth)acrylic acid alkyl ester in the monomer composition used for preparing the polymer, or by changing the amount of other monomers. can be controlled by changing the type or ratio of Note that the glass transition temperature of the polymer can be measured according to JIS K7121.

[viscosity]
When the polymer is mixed with the solvent at a concentration of 10% by mass, the viscosity of the mixed liquid at 25° C. and a rotational speed of 100 rpm is 50 mPa·s or less. The solvent is a solvent contained together with the polymer in the liquid composition. Such solvents will be described later.
If the viscosity of the liquid mixture is 50 mPa·s or less, the solid content concentration of the liquid composition can be sufficiently increased when the liquid composition is prepared. The viscosity can be controlled, for example, by adjusting the number average molecular weight of the polymer, or by adjusting the amount of crosslinkable monomer in the monomer composition used for preparing the polymer. can.

In addition, in this specification, the "solid content concentration" of a liquid composition is the mass percentage of the mass of the contained components excluding a solvent with respect to the total mass of a liquid composition. The components other than the solvent refer to components that do not cause weight loss at 120° C. under vacuum, and include viscoelastic bodies such as dispersants in addition to the ion-conductive materials described below.

Further, in this specification, viscosity refers to viscosity at 25°C.

The method for measuring the viscosity of the liquid mixture and the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be measured according to JIS Z 8803. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, such as a TV25 viscometer (cone plate viscometer, manufactured by Toki Sangyo Co., Ltd.).

[Content]
The polymer is preferably blended in the liquid composition within a mass concentration range that dissolves in the solvent. If the content of the polymer in the liquid composition is within the mass concentration range that dissolves in the solvent, it is relatively easy to reduce the viscosity, and the insoluble portion of the polymer particles in the liquid composition is an ion-conductive material. It has excellent storage stability and redispersibility because it does not bind to pigments such as.

The upper limit of the content of the polymer in the liquid composition is preferably 10% by mass or less, more preferably 5% by mass or less, and 3% by mass or less, based on the ion conductive material. More preferably, the lower limit is 1% by mass or more. When the content of the polymer is within the preferable range, it is possible to obtain a liquid composition in which the solid content concentration is sufficiently high and the resulting electrode mixture layer or solid electrolyte layer has sufficiently high peel strength. can.

<Ion conductive material>
The ion conductive material in the present invention is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, a positive electrode active material, a negative electrode active material, a solid electrolyte, and the like. These may be used alone or in combination of two or more.

[Cathode active material]
The positive electrode active material is not particularly limited as long as it can insert or release alkali metal ions, and can be appropriately selected depending on the purpose. For example, an alkali metal-containing transition metal compound can be used. .

The alkali metal-containing transition metal compound is not particularly limited and can be appropriately selected depending on the purpose, for example, one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium. Examples include lithium-containing transition metal compounds such as composite oxides containing lithium and lithium.

The lithium-containing transition metal compound is not particularly limited and can be appropriately selected depending on the purpose, such as lithium-containing cobalt oxide (LiCoO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium-containing nickel oxide, etc. (LiNiO ₂ ), Co-Ni-Mn lithium-containing composite oxide (Li(CoMnNi)O ₂ ), Ni-Mn-Al lithium-containing composite oxide, Ni-Co-Al lithium-containing composite oxide material, olivine-type lithium iron phosphate (LiFePO ₄ ), olivine-type lithium manganese phosphate (LiMnPO ₄ ), Li ₂ MnO ₃ -LiNiO ₂ solid solution, Li _1+x Mn _2-x O ₄ (0<X<2) Examples include positive electrode active materials such as the lithium-excess spinel compound represented by Li[Ni _0.17 Li _0.2 Co _0.07 Mn _0.56 ]O ₂ and LiNi _0.5 Mn _1.5 O ₄ .

[Negative electrode active material]
The negative electrode active material is not particularly limited as long as it can insert or release alkali metal ions, and can be appropriately selected depending on the purpose. For example, a carbon material containing graphite having a graphite-type crystal structure can be used.

Examples of carbon materials include natural graphite, artificial graphite, non-graphitizable carbon (hard carbon), and easily graphitizable carbon (soft carbon).

Examples of negative electrode active materials other than carbon materials include lithium titanate and titanium oxide.

In addition, when using an electrochemical device using a nonaqueous electrolyte, from the viewpoint of energy density, high-capacity materials such as silicon, tin, silicon alloy, tin alloy, silicon oxide, silicon nitride, and tin oxide are used as the negative electrode active material. It is preferable to use

[Maximum particle diameter of active material]
The maximum particle diameter of the active material in the present invention is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose, but it is preferably smaller than the nozzle diameter of the inkjet head. It is preferable that the diameter is sufficiently smaller than the nozzle diameter of the inkjet head, since the inkjet ejection performance can be further improved. Specifically, the ratio between the maximum particle diameter of the active material contained in the liquid composition and the nozzle diameter of the inkjet head (maximum particle diameter of the active material contained in the liquid composition/nozzle diameter of the inkjet head) is 0. It is preferably at most .8, more preferably at most 0.6, even more preferably at most 0.5. When the maximum particle diameter of the active material is within these ranges, the ejection stability of the liquid composition is improved. For example, in the case of a droplet observation device (EV1000 (manufactured by Ricoh Co., Ltd.)), the nozzle diameter is 40 μm, and at this time, the maximum particle size of the active material contained in the liquid composition is preferably 32 μm or less, and 24 μm or less. It is more preferable that it is, and it is still more preferable that it is 20 μm or less. Note that the maximum particle size is the diameter that is the maximum value of the measured particle size distribution of the active material in the liquid composition.
The method for measuring the maximum particle size of the active material is not particularly limited, and can be appropriately selected depending on the purpose. For example, it can be measured according to ISO 13320:2009. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, a laser diffraction particle size distribution measuring device Mastersizer 3000 (manufactured by Malvern).

[Mode diameter of active material]
The mode diameter of the active material in the present invention is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose, but is preferably 0.5 μm or more and 10 μm or less, and 3 μm or more and 10 μm or less. is more preferable. When the mode diameter of the active material is 0.5 μm or more and 10 μm or less, ejection failure is less likely to occur when the liquid composition is ejected by a liquid ejection method. Further, when the mode diameter of the active material is 3 μm or more and 10 μm or less, an electrode composite material layer with better electrical properties can be obtained. Note that the mode diameter is a diameter that is the maximum value of the measured particle size distribution of the active material in the liquid composition.
The method for measuring the mode diameter of the active material is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be measured according to ISO 13320:2009. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, a laser diffraction particle size distribution measuring device Mastersizer 3000 (manufactured by Malvern).

[Solid electrolyte]
The solid electrolyte is not particularly limited as long as it has electronic insulating properties and ionic conductivity, but from the viewpoint of ionic conductivity, sulfide solid electrolytes containing sulfur in the composition formula or oxygen as an anion are recommended. An oxide solid electrolyte containing only ion-conducting materials is preferable, and a sulfide solid electrolyte is more preferable because it can form a good interface between ion-conducting materials.

The sulfide-based inorganic solid electrolyte is preferably a compound that contains a sulfur atom (S), has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and has electronic insulating properties. . The sulfide-based inorganic solid electrolyte preferably contains at least Li, S, and P as elements and has lithium ion conductivity, but depending on the purpose or case, other materials other than Li, S, and P may be used. May contain elements.

For example, a lithium ion conductive inorganic solid electrolyte that satisfies the composition represented by the following formula (1) can be mentioned.
L _a1 M _b1 P _c1 S _d1 A _e1 ... Formula (1)
In formula (1), L represents an element selected from Li, Na, K, and Ca, with Li being preferred. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, Ge, and Y. A represents an element selected from I, Br, Cl, and F. a1 to e1 indicate the composition ratio of each element, and a1:b1:c1:d1:e1 satisfies 1 to 12:0 to 5:1:2 to 12:0 to 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.

The composition ratio of each element can be controlled by adjusting the blending ratio of raw material compounds when producing the sulfide-based inorganic solid electrolyte, as described below. The sulfide-based inorganic solid electrolyte may be amorphous (glass) or crystallized (glass-ceramic), or only partially crystallized. For example, Li-P-S glass containing Li, P, and S, or Li-P-S glass ceramic containing Li, P, and S can be used. Sulfide-based inorganic solid electrolytes include, for example, lithium sulfide (Li ₂ S), phosphorus sulfide (e.g. diphosphorus pentasulfide (P ₂ S ₅ )), elemental phosphorus, elemental sulfur, sodium sulfide, hydrogen sulfide, lithium halide (e.g. LiI, LiBr, LiCl) and sulfides of the elements represented by M (for example, SiS ₂ , SnS, GeS ₂ ) can be produced by reacting at least two raw materials.

The ratio of Li ₂ S to P ₂ S ₅ in Li-P-S glass and Li-P-S glass ceramics is a molar ratio of Li ₂ S:P ₂ S ₅ , preferably 60:40 to 60:40. The ratio is 90:10, more preferably 68:32 to 78:22. By setting the ratio of Li ₂ S to P ₂ S ₅ within this range, lithium ion conductivity can be made high. Specifically, the lithium ion conductivity can be preferably set to 1×10 ⁻⁴ S/cm or higher, more preferably 1×10 ⁻³ S/cm or higher. Although there is no particular upper limit, it is practical to set it to 5×10 ⁻¹ S/cm or less.

Examples of combinations of raw materials are shown below as specific examples of sulfide-based inorganic solid electrolytes. For example, Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiCl, Li ₂ SP ₂ S ₅ -H ₂ S, Li ₂ SP ₂ S ₅ -H ₂ S-LiCl, Li ₂ S-LiI-P ₂ S ₅ , Li ₂ S-LiI-Li ₂ OP ₂ S ₅ , Li ₂ S-LiBr-P ₂ S ₅ , Li ₂ S-Li ₂ OP ₂ S ₅ , Li ₂ S-Li ₃ PO ₄ -P ₂ S ₅ , Li ₂ S-P ₂ S ₅ -P ₂ O ₅ , Li ₂ SP ₂ S ₅ -SiS ₂ , Li ₂ S-P ₂ S ₅ -SiS ₂ - LiCl, Li ₂ S-P ₂ S ₅ -SnS, Li ₂ S-P ₂ S ₅ -Al ₂ S ₃ , Li ₂ S-GeS ₂ , Li ₂ S-GeS ₂ -ZnS, Li ₂ S-Ga ₂ S ₃ , _Li2S - _{GeS2 - Ga2S3 , Li2S - GeS2} - _P2S5 , _Li2S - _GeS2 - _Sb2S5 , _Li2S - _GeS2 - _{Al2S3 ,} Li ₂ S-SiS ₂ , Li ₂ S-Al ₂ S ₃ , Li ₂ S-SiS ₂ -Al ₂ S ₃ , Li ₂ SSiS ₂ -P ₂ S ₅ , Li ₂ S-SiS ₂ -P ₂ S ₅ - Examples include LiI, Li ₂ S-SiS ₂ -LiI, Li ₂ S-SiS ₂ -Li ₄ SiO ₄ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ and Li ₁₀ GeP ₂ S ₁₂ . However, the mixing ratio of each raw material does not matter. An example of a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition is an amorphization method. Examples of the amorphization method include a mechanical milling method, a solution method, and a melt quenching method. This is because processing at room temperature becomes possible and the manufacturing process can be simplified.

The oxide-based inorganic solid electrolyte is preferably a compound that contains an oxygen atom (O), has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and has electronic insulating properties. .
Specific examples of compounds include, for example, Li _xa La _ya TiO ₃ [xa=0.3-0.7, ya=0.3-0.7] (LLT), Li _xb La _yb Zr _zb Mbb _mb O _nb (Mbb is at least one element of Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, xb satisfies 5≦xb≦10, and yb satisfies 1≦yb≦4 , zb satisfies 1≦zb≦4, mb satisfies 0≦mb≦2, and nb satisfies 5≦nb≦20.), Li _{xc Byc} Mcc _zc O _nc (Mcc is C, S, At least one element of Al, Si, Ga, Ge, In, and Sn, xc satisfies 0≦xc≦5, yc satisfies 0≦yc≦1, zc satisfies 0≦zc≦1, nc satisfies 0≦nc≦6), Li _xd (Al, Ga) _yd (Ti, Ge) _zd Si _ad P _md O _nd (However, 1≦xd≦3, 0≦yd≦1, 0≦zd ≦2, 0≦ad≦1, 1≦md≦7, 3≦nd≦13), Li _(3-2xe) Mee _x DeeO (xe represents a number from 0 to 0.1, Mee represents a divalent Represents a metal atom. Dee represents a halogen atom or a combination of two or more halogen atoms), Li _xf Si _yf O _zf (1≦xf≦5, 0<yf≦3, 1≦zf≦10), Li _xg S _yg O _zg (1≦xg≦3, 0<yg≦2, 1≦zg≦10), Li ₃ BO ₃ -Li ₂ SO ₄ , Li ₂ O-B ₂ O ₃ -P ₂ O ₅ , Li ₂ O-SiO ₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _(4-3/2w) N _w (w<1), Li having a LISICON (Lithium super ionic conductor) type crystal structure _{3. 5} Zn _0.25 GeO ₄ , La _0.55 Li _0.35 TiO ₃ with perovskite crystal structure, LiTi ₂ P ₃ O ₁₂ with NASICON (Natrium super ionic conductor) crystal structure, Li _1+xh+yh (Al, Ga ) _xh (Ti,Ge) _2-xh Si _yh P _3-yh O ₁₂ (0≦xh≦1, 0≦yh≦1), Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ) having a garnet-type crystal structure ) etc. Also desirable are phosphorus compounds containing Li, P and O. For example, lithium phosphate (Li ₃ PO ₄ ), LiPON in which part of the oxygen in lithium phosphate is replaced with nitrogen, LiPOD1 (D1 is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb , Mo, Ru, Ag, Ta, W, Pt, Au, etc.). Furthermore, LiA1ON (A1 is at least one selected from Si, B, Ge, Al, C, Ga, etc.) can also be preferably used.

The maximum particle diameter of the solid electrolyte in the present invention is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose. It is preferably smaller than the nozzle diameter of the inkjet head, and is preferably sufficiently smaller than the nozzle diameter of the inkjet head, since the inkjet ejection performance can be further improved. Specifically, the ratio between the maximum particle diameter of the solid electrolyte contained in the liquid composition and the nozzle diameter of the inkjet head (maximum particle diameter of the solid electrolyte contained in the liquid composition/nozzle diameter of the inkjet head) is 0. It is preferably at most .8, more preferably at most 0.6, even more preferably at most 0.5. When the maximum particle size of the solid electrolyte is within these ranges, the discharge stability of the liquid composition will be improved. For example, in the case of a droplet observation device (EV1000 (manufactured by Ricoh Co., Ltd.)), the nozzle diameter is 40 μm, and at this time, the maximum particle size of the active material contained in the liquid composition is preferably 32 μm or less, and 24 μm or less. It is more preferable that it is, and it is still more preferable that it is 20 μm or less. Note that the maximum particle size is the diameter that is the maximum value of the measured particle size distribution of the solid electrolyte in the liquid composition.
The method for measuring the maximum particle size of the solid electrolyte is not particularly limited and can be appropriately selected depending on the purpose. Examples include the same method as the method for measuring the maximum particle size of the active material described above.

The mode diameter of the solid electrolyte in the present invention is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected depending on the purpose, but is preferably 0.1 μm or more and 10 μm or less, and 0.5 μm or more. More preferably, the thickness is 3 μm or less. When the mode diameter of the solid electrolyte is 0.1 μm or more and 10 μm or less, ejection failure is less likely to occur when the liquid composition is ejected by a liquid ejection method. Note that the mode diameter is a diameter that is the maximum value of the measured particle size distribution of the solid electrolyte in the liquid composition.
The method for measuring the mode diameter of the solid electrolyte is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include the same method as the method for measuring the mode diameter of the active material described above.

<Dispersant>
The dispersant is used to disperse the ion conductive material and/or the conductive aid.
Some of the dispersants function as a dispersant for both the ion conductive material and the conductive additive. Such a dispersant corresponds to both a dispersant for ion conductive materials and a dispersant for conductive aids.

<<Dispersant for ion conductive materials>>
The dispersant for ion conductive materials in the present invention is not particularly limited as long as it does not react with the ion conductive materials and can be dispersed, but from the viewpoint of dispersibility, dispersants with ionic adsorption groups are preferred. preferable. As the dispersant for the ion conductive material, conventionally known ones or commercially available ones can be used as appropriate. For example, polymer dispersants such as polyethylene, polyethylene oxide, polypropylene oxide, polycarboxylic acid, naphthalene sulfonic acid formalin condensation, polyethylene glycol, polycarboxylic acid partial alkyl ester, polyether, polyalkylene polyamine, etc. , low-molecular dispersants such as alkyl sulfonic acid type, quaternary ammonium type, higher alcohol alkylene oxide type, polyhydric alcohol ester type, alkyl polyamine type, and inorganic dispersants such as polyphosphate dispersants. These may be used alone or in combination of two or more.

The upper limit of the content of the dispersant for ion conductive materials in the liquid composition is preferably 5% by mass or less, more preferably 3% by mass or less, based on the ion conductive material. , more preferably 1% by mass or less, and the lower limit is preferably 0.1% by mass or more. When the content of the dispersant for ion conductive materials is within the preferable range, the dispersion stability of the ion conductive material can be ensured without impairing the surface function of the ion conductive material.

<<Dispersant for conductive aid>>
The dispersant for the conductive aid is not particularly limited as long as it does not react with the conductive aid and can be dispersed, and conventionally known or commercially available dispersants can be used as appropriate. For example, the same dispersants as the above-mentioned dispersants for ion conductive materials can be mentioned.

The upper limit of the content of the dispersant for the conductive aid in the liquid composition is preferably 100% by mass or less, more preferably 50% by mass or less, and 30% by mass or less, based on the conductive aid. It is more preferably at most 15% by mass, and the lower limit is preferably at least 15% by mass. When the content of the dispersant for the conductive aid is within the preferable range, the dispersion stability of the conductive aid can be ensured without impairing the surface function of the conductive aid. In particular, when the dispersant for the conductive aid has adsorption ability to the ion conductive material, free components can be prevented from adsorbing to the ion conductive material and impairing the surface function of the ion conductive material. .

<Solvent>
The solvent (sometimes referred to as "solvent") used in the present invention is not particularly limited as long as it dissolves the polymer, and can be appropriately selected depending on the purpose, such as acetone, methyl ethyl ketone, etc. , ketones such as cyclohexanone, ethyl acetate, butyl acetate, methyl butyrate, ethyl butyrate, butyl butyrate, methyl hexanoate, ethyl hexanoate, methyl heptanoate, ethyl heptanoate, ethyl isobutyrate, isobutyl isobutyrate, isoamyl isobutyrate, Esters such as ethyl isovalerate and isobutyl isovalerate; ethers such as diethyl ether, dioxane, and tetrahydrofuran; amide polar organic solvents such as N,N-dimethylformamide and N-methyl-2-pyrrolidone (NMP); Examples include aromatic hydrocarbons such as toluene, xylene, and anisole, γ-butyrolactone, and dimethyl sulfoxide. These may be used alone or in combination of two or more. Among these, esters, ethers, and aromatic hydrocarbons are preferred as aprotic organic solvents that do not react with the ion conductive material.
In addition, methyl butyrate, ethyl butyrate, butyl butyrate, methyl hexanoate, ethyl hexanoate, methyl heptanoate, ethyl heptanoate, ethyl isobutyrate can lower the viscosity of the liquid composition and have better dispersibility. , water-insoluble solvents such as isobutyl isobutyrate, isoamyl isobutyrate, ethyl isovalerate, and isobutyl isovalerate, N-methyl-2-pyrrolidone, γ-butyrolactone, dimethyl sulfoxide, and N,N-dimethylformamide. Water-soluble solvents are preferred.
In addition, methyl butyrate, methyl valerate, methyl hexanoate, methyl heptanoate, methyl decanoate, ethyl butyrate, Carboxylic acid esters such as ethyl grassate, ethyl hexanoate, ethyl heptanoate, ethyl decanoate, butyl butyrate, ethyl isobutyrate, isobutyl isobutyrate, isoamyl isobutyrate, ethyl isovalerate, isobutyl isovalerate, and isoamyl isovalerate. is preferred.

<Other ingredients>
Other components are not particularly limited as long as they do not impair the effects of the present invention, and can be appropriately selected depending on the purpose, such as conductive aids.

[Conductivity aid]
As the conductive aid, for example, carbon black manufactured by a furnace method, an acetylene method, a gasification method, etc., and carbon materials such as carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used. As the conductive aid other than the carbon material, for example, metal particles such as aluminum or metal fibers can be used. Note that the conductive aid may be composited with the active material in advance.

The upper limit of the mass ratio of the conductive aid to the active material is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and the lower limit is preferably 1% by mass or more. . When the mass ratio of the conductive aid to the active material is equal to or higher than the above lower limit, the conductivity of the resulting electrode mixture layer is further improved. When the mass ratio of the conductive aid to the active material is below the above upper limit, the conductivity of the resulting electrode mixture layer is not impaired, and the energy density can be further improved.

<Viscosity and solid content concentration of liquid composition>
The viscosity of the liquid composition is preferably such that it can be ejected from a liquid ejection head, and the upper limit is preferably 200 mPa·s or less, more preferably 100 mPa·s or less, and 50 mPa·s or less.・S or less is more preferable. Moreover, as a lower limit, it is preferable that it is 10 mPa*s or more, and it is more preferable in it being 30 mPa*s or more. By setting the viscosity to the above lower limit value or more, flow is suppressed in the step of drying the applied liquid composition, and unevenness in film thickness and composition due to drying is suppressed.

The solid content concentration of the liquid composition is preferably 20% by mass or more, more preferably 60% by mass or more, and even more preferably 65% by mass or more. By setting the solid content concentration to the above lower limit value or more, thixotropy is easily expressed, flow is suppressed in the step of drying the applied liquid composition, and unevenness in film thickness and composition due to drying is suppressed.

Further, when the liquid composition contains an active material as an ion-conductive material, the viscosity of the liquid composition is preferably more than 20 mPa·s and less than 200 mPa·s. When the liquid composition contains an active material as an ion conductive material, the solid content concentration in the liquid composition is preferably 60% by mass or more.

Further, when the liquid composition includes a solid electrolyte as an ion-conductive material, the viscosity of the liquid composition is preferably 20 mPa·s or less. When the liquid composition includes a solid electrolyte as an ion-conductive material, the solid content concentration in the liquid composition is preferably 20% by mass or more, and more preferably 30% by mass or more.

<Method for producing liquid composition>
The liquid composition can be manufactured by dissolving or dispersing each of the above components in the above solvent.
Specifically, each of the above components and the above solvent are mixed using a mixer such as a ball mill, sand mill, bead mill, pigment dispersion machine, crusher, ultrasonic dispersion machine, homogenizer, planetary mixer, film mix, etc. A liquid composition can be prepared by:

The use of the liquid composition is not particularly limited and can be appropriately selected depending on the purpose, for example, forming an ion conductive material-containing layer such as an electrode composite layer or a solid electrolyte layer in an electrochemical device. It can be suitably used as a material.
For example, a liquid composition containing at least the above-mentioned positive electrode active material or negative electrode active material as an ion-conductive material can be used as a liquid composition for forming an electrode for a secondary battery. The product can be suitably used as a liquid composition for forming a solid electrolyte layer of a secondary battery.

(Liquid composition for inkjet discharge)
The liquid composition of this embodiment can be suitably used as a liquid composition for inkjet discharge.

(electrode)
The electrode according to this embodiment (sometimes referred to as an electrode for a secondary battery) includes an electrode base and an electrode mixture layer formed on the electrode base. The electrode mixture layer is formed using the liquid composition of this embodiment. That is, the electrode mixture layer contains at least the ion conductive material, the ion conductive material dispersant, and the polymer. In addition, each component contained in the electrode composite material layer was contained in the above-mentioned liquid composition, and the preferable abundance ratio of each component is determined by the preferable abundance ratio of each component in the liquid composition. It is the same as the abundance ratio.
Since the electrode of this embodiment uses the liquid composition of this embodiment, an electrode mixture layer with high peel strength can be satisfactorily formed on the current collector.

<Electrode base (current collector)>
As the material constituting the electrode base, a material that is electrically conductive and electrochemically durable is used. Specifically, as the electrode base, for example, an electrode base made of iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, platinum, etc. can be used. Note that the above-mentioned materials may be used alone or in combination of two or more in any ratio.

<Electrode manufacturing method>
The method for manufacturing an electrode of this embodiment includes a step of applying the liquid composition of this embodiment onto an electrode base, and further includes other steps as necessary.

There are no particular restrictions on the method for applying the liquid composition, and examples include liquid ejection methods such as inkjet method, spray coating method, and dispenser method, spin coating method, casting method, microgravure coating method, gravure coating method, and bar coating method. method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method, etc. . Among these, the inkjet method is particularly preferred. Using the inkjet method, electrodes can be manufactured without contact and in any shape. As a result, there are effects such as less loss of active material due to die cutting during the production process of the electrode. At this time, the liquid composition may be applied to only one side of the current collector, or may be applied to both sides. The thickness of the liquid composition on the current collector after coating and before drying can be appropriately set depending on the thickness of the electrode composite material layer obtained by drying.

The method for drying the liquid composition on the current collector is not particularly limited, and any known method can be used. For example, drying methods using hot air, hot air, low humidity air, vacuum drying methods, infrared rays, electron beams, etc. An example is a drying method using irradiation. By drying the liquid composition on the current collector in this manner, an electrode mixture layer can be formed on the current collector, and an electrode including the current collector and the electrode mixture layer can be obtained.

(Laminated body of solid electrolyte layer and electrode)
A laminate of a solid electrolyte layer and an electrode according to this embodiment includes an electrode and a solid electrolyte layer formed on the electrode. The solid electrolyte layer is formed using the liquid composition of this embodiment. That is, the solid electrolyte layer contains at least the ion conductive material, the ion conductive material dispersant, and the polymer. The components contained in the solid electrolyte layer are those contained in the above liquid composition, and the preferred abundance ratio of each component is determined by the preferred abundance ratio of each component in the liquid composition. Same as ratio.
Since the laminate of this embodiment uses the liquid composition of this embodiment, a solid electrolyte layer with high peel strength can be satisfactorily formed on the electrode.
Note that the solid electrolyte layer can be formed in the same manner as the electrode manufacturing method described above, except that it is formed on the electrode.

(Storage container)
The storage container of the present invention is a storage container in which the above-described liquid composition of the present invention or the liquid composition for inkjet discharge is stored.
The shape, structure, and size of the storage container are not particularly limited and can be appropriately selected depending on the purpose.

In the following, a method for manufacturing members of an electrochemical device using an inkjet method will be explained in particular.

(Manufacturing device for electrochemical device components, method for manufacturing electrochemical device components)
The apparatus for manufacturing a member for an electrochemical element of the present invention uses the above-described storage container of the present invention and an inkjet head (sometimes referred to as a "liquid ejection head") to produce a liquid composition contained in the storage container. and a discharge means for discharging, and further includes other configurations as necessary.
The method for producing a member for an electrochemical element of the present invention includes a discharge step of discharging the liquid composition of the present invention or the liquid composition for inkjet discharge using an inkjet head, and further includes other steps as necessary. including.
The members of the electrochemical element can be various members depending on the type of ion conductive material used, and examples thereof include an electrode composite layer, a solid electrolyte layer, and the like.

<Discharge means, discharge process>
The ejecting means is a means for ejecting the liquid composition or the liquid composition for inkjet ejection contained in the storage container using an inkjet head.
The ejection step is a step of ejecting the liquid composition or the liquid composition for inkjet ejection using an inkjet head.
By the ejection, the liquid composition or the liquid composition for inkjet ejection can be applied onto the object to form a liquid composition layer.
The target object (hereinafter sometimes referred to as "discharge target object") is not particularly limited as long as it forms an ion-conductive material-containing layer, and can be selected as appropriate depending on the purpose. Examples include an electrode substrate (sometimes referred to as a "current collector"), an active material layer, and the like.

<Other configurations, other processes>
Other configurations in the electrochemical device member manufacturing apparatus are not particularly limited as long as they do not impair the effects of the present invention, and can be appropriately selected depending on the purpose, such as heating means.
Other steps in the method for manufacturing the electrochemical element member are not particularly limited as long as they do not impair the effects of the present invention, and can be appropriately selected depending on the purpose, such as a heating step.

-Heating means, heating process-
The heating means is a means for heating the liquid composition or the liquid composition for inkjet discharge discharged by the discharge means.
The heating step is a step of heating the liquid composition or inkjet ejection liquid composition ejected in the ejection step.
The heating can dry the liquid composition layer.

[Embodiment in which a member of an electrochemical device is formed by directly applying a liquid composition to a base material] FIG. 1 is a schematic diagram showing an example of a method for manufacturing a member of an electrochemical device according to this embodiment. be.
The liquid composition 12A is stored in a tank 307 of the liquid ejection device 300, and is supplied from the tank 307 to the liquid ejection head 306 via a tube 308. Note that the number of liquid ejecting devices is not limited to one, and may be two or more.
When manufacturing an electrode, the electrode base 11 is placed on the stage 310, and then droplets of the liquid composition 12A are discharged onto the electrode base 11 from the liquid discharge head 306. At this time, the stage 310 may move, and the liquid ejection head 306 may move. The discharged liquid composition 12A becomes the electrode composite material layer 12.
Further, the liquid ejection device 300 may be provided with a mechanism for capping the nozzle to prevent the liquid composition 12A from drying out when the liquid composition 12A is not ejected from the liquid ejection head 306.

FIG. 2 is a schematic diagram showing an example of an apparatus for manufacturing an electrochemical element member for realizing the method for manufacturing an electrochemical element member according to the present embodiment.

The apparatus for manufacturing members of an electrochemical element shown in FIG. 2 is an apparatus for manufacturing a solid electrolyte layer or an electrode mixture layer using the above-described liquid composition. The apparatus for manufacturing a member of an electrochemical element includes a discharge process section 10 that includes a step of applying a liquid composition to form a liquid composition layer on a printing substrate 4 having a discharge target object, and a discharge process section 10 that includes a step of applying a liquid composition to form a liquid composition layer. A heating process section 30 including a heating process of heating to obtain an ion conductive material-containing layer is provided. The apparatus for manufacturing members for electrochemical elements includes a conveying section 5 that conveys a printing substrate 4, and the conveying section 5 conveys the printing substrate 4 in the order of a discharge process section 10 and a heating process section 30 at a preset speed. transport.
There is no particular restriction on the method for producing the printing base 4 having the objects to be discharged, such as the electrode base or the active material layer, and any known method can be selected as appropriate.

The discharge process unit 10 includes an arbitrary printing device 1a according to an inkjet printing method, which is a applying means for realizing the applying process of applying the liquid composition onto the printing substrate 4, and a storage container 1b that stores the liquid composition. , a supply tube 1c is provided for supplying the liquid composition stored in the storage container 1b to the printing device 1a.

The storage container 1b stores the liquid composition 7, and the discharge process unit 10 discharges the liquid composition 7 from the printing device 1a and applies the liquid composition 7 onto the printing substrate 4 to form a liquid composition layer. Form into a thin film. Note that the storage container 1b may have a structure that is integrated with the apparatus for manufacturing electrochemical element members, or may have a structure that is removable from the apparatus for manufacturing electrochemical element members. Alternatively, it may be a container that is integrated with an apparatus for manufacturing electrochemical element members or a container used for adding to a container that is removable from the apparatus for manufacturing electrochemical element members.

The storage container 1b and the supply tube 1c can be arbitrarily selected as long as they can store and supply the liquid composition 7 stably.

As shown in FIG. 2, the heating step section 30 includes a heating device 3a, and includes a solvent removal step in which the solvent remaining in the liquid composition layer is heated and dried by the heating device 3a to be removed. This makes it possible to form an ion-conductive material-containing layer. The heating process section 30 may perform the solvent removal process under reduced pressure.

The heating device 3a is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a substrate heating, an IR heater, a hot air heater, etc., and a combination of these may be used.

Further, the heating temperature and time can be appropriately selected depending on the boiling point of the solvent contained in the liquid composition 7 and the thickness of the formed film.

FIG. 3 is a schematic diagram showing another example of an electrochemical element member manufacturing apparatus (liquid ejection apparatus) for realizing the method of manufacturing an electrochemical element member of the present embodiment.

The liquid ejection device 300' can circulate the liquid composition through the liquid ejection head 306, the tank 307, and the tube 308 by controlling the pump 3101 and the valves 311 and 312.

In addition, the liquid discharging device 300' is provided with an external tank 313, and when the liquid composition in the tank 307 decreases, the external tank 313 is It is also possible to supply the liquid composition to tank 307 from.

When the electrochemical element member manufacturing apparatus described above is used, the liquid composition can be ejected to a targeted location on the object to be ejected.

The solid electrolyte layer and electrode composite layer, which are examples of the ion-conductive material-containing layer, can be suitably used, for example, as part of the structure of an electrochemical device. The components of the electrochemical device other than the solid electrolyte layer or the electrode mixture layer are not particularly limited and can be appropriately selected from known components, such as a positive electrode, a negative electrode, a separator, and the like.

FIG. 4 shows an example of the method for manufacturing the electrode of this embodiment.
The method for manufacturing the electrode 100 includes the steps of sequentially discharging the liquid composition 12A onto the electrode base 11 using the liquid discharging device 300'.

First, an elongated electrode base 11 is prepared. Then, the electrode base 11 is wound around a cylindrical core and set on the feed roller 304 and the take-up roller 305 so that the side on which the electrode composite material layer 12 will be formed is on the upper side in the figure. Here, the feed roller 304 and the take-up roller 305 rotate counterclockwise, and the electrode base 11 is conveyed from right to left in the figure. Then, in the same manner as in FIG. 1, droplets of the liquid composition 12A are sequentially delivered to the electrode from the liquid ejection head 306 installed above the electrode base 11 between the delivery roller 304 and the take-up roller 305. Discharge onto the base 11.

Note that a plurality of liquid ejection heads 306 may be installed in a direction substantially parallel or substantially perpendicular to the transport direction of the electrode base 11. Next, the electrode substrate 11 onto which the droplets of the liquid composition 12A have been ejected is conveyed to the heating mechanism 309 by the delivery roller 304 and the take-up roller 305. As a result, the electrode mixture layer 12 is formed and the electrode 100 is obtained. Thereafter, the electrode 100 is cut into a desired size by punching or the like.

The heating mechanism 309 may be installed either above or below the electrode base 11, or a plurality of heating mechanisms 309 may be installed.

The heating mechanism 309 is not particularly limited as long as it does not come into direct contact with the liquid composition 12A, and examples thereof include a resistance heater, an infrared heater, a fan heater, and the like. Note that a plurality of heating mechanisms 309 may be installed. Further, a curing device using ultraviolet rays for polymerization may be installed.

Further, the liquid composition 12A discharged onto the electrode base 11 is preferably heated, and when heated, it may be heated by a stage or by a heating mechanism other than the stage. The heating mechanism may be installed either above or below the electrode base 11, or a plurality of heating mechanisms may be installed.

The heating temperature is not particularly limited. The liquid composition 12A is dried by heating to form an electrode composite material layer.

Further, as shown in FIG. 5, the tank 307 may be supplied with ink from tanks 313A and 313B connected to the tanks 307A and 307B, and the liquid ejection head 306 may have a plurality of heads 306A and 306B. good.

[Embodiment in which a member of an electrochemical element is formed by indirectly applying a liquid composition to a base material]
6 to 7 are configuration diagrams showing an example of a printing section that employs an inkjet method and a transfer method as application means, as an apparatus for manufacturing members of an electrochemical element according to the present embodiment, and FIG. 6 shows a drum-shaped printing section. FIG. 7 is a configuration diagram showing a printing section using an endless belt-shaped intermediate transfer body.
The printing unit 400' shown in FIG. 6 forms an ion-conductive material-containing layer on the base material by transferring the liquid composition layer or the ion-conductive material-containing layer to the base material via the intermediate transfer body 4001. , an inkjet printer.

The printing section 400' includes an inkjet section 420, a transfer drum 4000, a preprocessing unit 4002, an absorption unit 4003, a heating unit 4004, and a cleaning unit 4005.
The inkjet section 420 includes a head module 422 holding a plurality of heads 401. The head 401 discharges a liquid composition onto an intermediate transfer member 4001 supported by a transfer drum 4000 to form a liquid composition layer on the intermediate transfer member 4001 . Each head 401 is a line head, and has nozzles arranged in a range that covers the width of the recording area of the largest usable base material. The head 401 has a nozzle surface formed with nozzles on its lower surface, and the nozzle surface faces the surface of the intermediate transfer body 4001 with a small gap interposed therebetween. In this embodiment, since the intermediate transfer body 4001 is configured to circulate and move on a circular orbit, the plurality of heads 401 are arranged radially.

Transfer drum 4000 faces impression cylinder 621 and forms a transfer nip. The pretreatment unit 4002 applies, for example, a reaction liquid to increase the viscosity of the liquid composition onto the intermediate transfer member 4001 before the head 401 discharges the liquid composition. Absorption unit 4003 absorbs a liquid component from the liquid composition layer on intermediate transfer body 4001 before transfer. A heating unit 4004 heats the ink layer on the intermediate transfer body 4001 before transfer. The liquid composition layer is dried by heating to form an ion-conductive material-containing layer. In addition, the organic solvent is removed and the transferability to the substrate is improved. A cleaning unit 4005 cleans the intermediate transfer body 4001 after the transfer, and removes foreign matter such as ink and dust remaining on the intermediate transfer body 4001.
The outer peripheral surface of the impression cylinder 621 is in pressure contact with the intermediate transfer body 4001, and when the base material passes through the transfer nip between the impression cylinder 621 and the intermediate transfer body 4001, the liquid composition layer on the intermediate transfer body 4001 is The ionically conductive material-containing layer is transferred to the substrate. Note that the impression cylinder 621 may be configured to include at least one grip mechanism on its outer circumferential surface for holding the tip of the base material.

The printing unit 400'' shown in FIG. 7 forms an ion-conductive material-containing layer on the base material by transferring the liquid composition layer or the ion-conductive material-containing layer to the base material via an intermediate transfer belt 4006. It is an inkjet printer.
The printing section 400'' discharges droplets of the liquid composition from a plurality of heads 401 provided in the inkjet section 420 to form a liquid composition layer on the outer peripheral surface of the intermediate transfer belt 4006. The liquid composition layer formed on the intermediate transfer belt 4006 is heated by a heating unit 4007 and dried to form an ion conductive material-containing layer, which is formed into a film on the intermediate transfer belt 4006.

At the transfer nip portion where the intermediate transfer belt 4006 faces the transfer roller 622, the ion conductive material-containing layer formed into a film on the intermediate transfer belt 4006 is transferred to the base material. After the transfer, the surface of the intermediate transfer belt 4006 is cleaned by a cleaning roller 4008.
The intermediate transfer belt 4006 spans a driving roller 4009a, a facing roller 4009b, a plurality (four in this example) of shape maintaining rollers 4009c, 4009d, 4009e, 4009f, and a plurality (four in this example) of support rollers 4009g. and move in the direction of the arrow in the figure. A support roller 4009g provided opposite to the head 401 maintains the tension state of the intermediate transfer belt 4006 when ink droplets are ejected from the head 401.

<Negative electrode>
FIG. 8 shows an example of the negative electrode of this embodiment.
In the negative electrode 101, a negative electrode composite layer 121 is formed on one side of a negative electrode base 111. The shape of the negative electrode 100 is not particularly limited, and examples include a flat plate shape. Examples of the material constituting the negative electrode substrate 111 include stainless steel, nickel, aluminum, copper, and the like.
Note that the negative electrode composite material layer 121 may be formed on both sides of the negative electrode substrate 111.
The negative electrode can be manufactured using the above-mentioned manufacturing apparatus for electrochemical element members.

<Positive electrode>
FIG. 9 shows an example of the positive electrode of this embodiment.
In the positive electrode 20, a positive electrode composite layer 22 is formed on one side of a positive electrode base 21. The shape of the positive electrode 20 is not particularly limited, and examples thereof include a flat plate shape. Examples of the material constituting the positive electrode substrate 21 include stainless steel, aluminum, titanium, tantalum, and the like.
Note that the positive electrode composite material layer 22 may be formed on both sides of the positive electrode substrate 21.
The positive electrode can be manufactured using the above-mentioned manufacturing apparatus for electrochemical element members.

(electrochemical device)
The electrochemical device of the present invention has a layer containing at least an ion conductive material, a dispersant for the ion conductive material, and a polymer on a current collector, and further has other configurations as necessary. . The layer containing at least the ion conductive material, the dispersant for the ion conductive material, and the polymer may be disposed directly on the current collector, or may be disposed through another layer. good.

The electrochemical element can include a separator and an exterior in addition to a positive electrode, a negative electrode, a solid electrolyte layer or an electrolytic solution. The electrochemical device uses the liquid composition of the present invention as at least one of a positive electrode, a negative electrode, and a solid electrolyte layer.
Note that when using a solid electrolyte or a gel electrolyte, a separator is not necessary.

The current collector is the same as the above-described current collector (electrode base).

The ion conductive material, the dispersant for the ion conductive material, and the polymer are the same as the ion conductive material, the dispersant for the ion conductive material, and the polymer in the liquid composition described above.

Note that the electrochemical device of the present invention preferably uses the electrode of this embodiment as a positive electrode. Further, although a lithium ion secondary battery will be described below as an example of the electrochemical element, the present invention is not limited to the following example.

<Electrode>
Electrodes other than the electrodes of this embodiment described above that can be used in the secondary battery are not particularly limited, and known electrodes used in the manufacture of secondary batteries can be used. Specifically, an electrode formed by forming an electrode mixture layer on a current collector using a known manufacturing method can be used.

<Electrolyte>
Electrolytes other than the solid electrolyte layer of this embodiment described above that can be used in the secondary battery are not particularly limited, and known solid electrolytes or electrolytes used in the manufacture of secondary batteries can be used. be able to.

[Electrolyte]
As the electrolytic solution, an organic electrolytic solution in which a supporting electrolyte is dissolved in an organic solvent is usually used. For example, a lithium salt is used as a supporting electrolyte for a lithium ion secondary battery. Examples of lithium salts include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) ₂ NLi. , (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) NLi, and the like. Among these, LiPF ₆ , LiClO ₄ and CF ₃ SO ₃ Li are preferred, and LiPF ₆ is more preferred since they are easily soluble in solvents and exhibit a high degree of dissociation. Note that one type of electrolyte may be used alone, or two or more types may be used in combination in any ratio. Usually, the lithium ion conductivity tends to increase as a supporting electrolyte with a higher degree of dissociation is used, so the lithium ion conductivity can be adjusted depending on the type of supporting electrolyte.

The organic solvent used in the electrolyte is not particularly limited as long as it can dissolve the supporting electrolyte, but examples include dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), Carbonates such as butylene carbonate (BC) and ethylmethyl carbonate (EMC); Esters such as γ-butyrolactone and methyl formate; Ethers such as 1,2-dimethoxyethane and tetrahydrofuran; Sulfur-containing compounds such as sulfolane and dimethyl sulfoxide etc. are preferably used. Alternatively, a mixture of these solvents may be used. Among these, it is preferable to use carbonates because they have a high dielectric constant and a wide stable potential range, and it is more preferable to use a mixture of ethylene carbonate and diethyl carbonate.
Note that the concentration of the electrolyte in the electrolytic solution can be adjusted as appropriate. Additionally, known additives such as vinylene carbonate can be added to the electrolyte.

<Separator>
The separator is not particularly limited, and includes, for example, paper such as kraft paper, vinylon mixed paper, synthetic pulp mixed paper, cellophane, polyethylene graft membrane, polyolefin nonwoven fabric such as polypropylene melt-blown nonwoven fabric, polyamide nonwoven fabric, glass fiber nonwoven fabric, micro Examples include pore membranes.

<Exterior>
The exterior is not particularly limited as long as it can seal the electrode, electrolyte, separator, solid electrolyte, or gel electrolyte.

(Electrochemical device manufacturing device, electrochemical device manufacturing method)
The electrochemical device manufacturing apparatus of the present invention includes an electrochemical device component manufacturing section that manufactures electrochemical device components by the above-described electrochemical device component manufacturing device of the present invention, and further includes other parts as necessary. Contains the configuration of
The method for manufacturing an electrochemical device of the present invention includes a step of manufacturing an electrochemical device member by the above-described method for manufacturing an electrochemical device member of the present invention, and further includes other configurations as necessary.

The electrochemical device manufacturing apparatus and the electrochemical device manufacturing method of this embodiment are the same as those of the known method, except that the electrochemical device component manufacturing section and the step of manufacturing the electrochemical device components described above are those of the present invention. Means and methods can be selected as appropriate.

In the electrochemical device of this embodiment, for example, a positive electrode and a negative electrode are stacked on top of each other with a separator interposed therebetween, and this is rolled or folded according to the shape of the battery as necessary, and then placed in a battery container. It can be manufactured by injecting an electrolyte and sealing.

FIG. 10 shows an example of an electrode element used in the electrochemical device according to this embodiment.
In the electrode element 40, a negative electrode 15 and a positive electrode 25 are laminated with a separator 30 in between. Here, the positive electrode 25 is laminated on both sides of the negative electrode 15. Further, a lead wire 41 is connected to the negative electrode base 11 , and a lead wire 42 is connected to the positive electrode base 21 .
In the case of a solid electrochemical device, the separator 30 may be replaced with a solid electrolyte or a gel electrolyte.

In the negative electrode 15, negative electrode composite material layers 12 are formed on both sides of the negative electrode base 11.
In the positive electrode 25, positive electrode composite layers 22 are formed on both sides of a positive electrode base 21.
Note that the number of stacked layers of the negative electrode 15 and the positive electrode 25 of the electrode element 40 is not particularly limited. Further, the number of negative electrodes 15 and the number of positive electrodes 25 of the electrode element 40 may be the same or different.

<Electrochemical element>
FIG. 11 shows an example of an electrochemical element according to this embodiment.
When the electrochemical element 1 is a liquid-based electrochemical element, an electrolyte layer 51 is formed by injecting an electrolyte aqueous solution or a non-aqueous electrolyte into the electrode element 40, and is sealed with an exterior 52. . In the electrochemical device 1, the lead wires 41 and 42 are drawn out to the outside of the sheath 52.
Further, when the electrochemical device 1 is a solid electrochemical device, the separator 30B may be replaced with a solid electrolyte or a gel electrolyte.

The shape of the electrochemical element 1 is not particularly limited, and examples include a laminate type, a cylinder type with a sheet electrode and a separator in a spiral shape, a cylinder type with an inside-out structure in which a pellet electrode and a separator are combined, a pellet electrode and a separator. Examples include a stacked coin type.

<Applications of electrochemical devices>
There are no particular restrictions on the uses of electrochemical elements; for example, mobile objects such as vehicles; smartphones, notebook computers, pen input computers, mobile computers, e-book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, and headphones. Stereos, video movies, LCD TVs, handy cleaners, portable CDs, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, lighting equipment, toys, game equipment, clocks, strobes, Examples include electrical equipment such as cameras. Among these, vehicles and electrical equipment are particularly preferred.
Examples of the moving object include a regular car, a large special car, a small special car, a truck, a large motorcycle, and a regular motorcycle.

[Mobile object]
FIG. 12 shows an example of a mobile body equipped with an all-solid-state battery, which is an example of the electrochemical element of this embodiment. Mobile object 550 is, for example, an electric vehicle. The moving body 550 includes a motor 551, an electrochemical element 552, and wheels 553 as an example of moving means. The electrochemical element 552 is the electrochemical element of this embodiment described above. The electrochemical element 552 drives the motor 551 by supplying power to the motor 551. The driven motor 551 can drive the wheels 553, and as a result, the moving body 550 can move.
According to the above configuration, the movable body can be moved safely because it is driven by electric power from the electrochemical element that has excellent peel strength.
The moving body 550 is not limited to an electric vehicle, but may be a PHEV, a HEV, or a locomotive or motorcycle that can run using a diesel engine and an electrochemical element. Further, the moving object may be a transport robot used in a factory or the like, which can move using only an electrochemical element or a combination of an engine and an electrochemical element. In addition, a moving object is one in which the whole object does not move, but only a part of it moves, such as an arm that uses only an electrochemical element or a combination of an engine and an electrochemical element, which is placed on a factory production line. It may also be an assembly robot that can operate.

Examples of the present invention will be described below, but the present invention is not limited to these Examples in any way.

In the following Examples and Comparative Examples, the viscosity of a liquid mixture prepared by mixing a polymer concentration of 10% by mass with a solvent and the viscosity of a liquid composition were measured as follows. The thixotropic index of the liquid composition was evaluated as follows. The solid content concentration of the liquid composition was calculated as follows. The film thickness variations and peel strength of the electrode mixture layer or solid electrolyte layer obtained using the liquid composition were measured and evaluated as follows.

[Viscosity of mixed liquid mixed with solvent at polymer concentration of 10% by mass and viscosity of liquid composition]
The viscosity of the obtained liquid mixture or liquid composition at 100 rpm was measured at room temperature (25° C.) using a TV25 type viscometer (cone plate viscometer, manufactured by Toki Sangyo Co., Ltd.).
Note that the solvent in the liquid mixture refers to the solvent in the liquid composition.

[Thixotropic index of liquid composition]
The viscosity of the obtained liquid composition at 100 rpm and 10 rpm was measured at room temperature (25° C.) using a TV25 type viscometer (cone plate viscometer, manufactured by Toki Sangyo Co., Ltd.). In addition, the thixotropy index (TI) was calculated from the ratio using the following formula, and evaluated based on the following criteria.
<Formula>
TI=(viscosity at 10 rpm)/(viscosity at 100 rpm)
<Standards>
A: TI value is 2.0 or more B: TI value is 1.5 or more and less than 2.0 C: TI value is less than 1.5

[Solid content concentration of liquid composition]
The solid content concentration of the liquid composition was calculated using the following formula. Note that the total solid content refers to components that do not cause weight loss under vacuum at 120°C.
<Formula>
Solid concentration = {total solids (parts by mass) / (total solids (parts by mass) + solvent (parts by mass))} x 100 (%)

[Variations in film thickness of electrode mixture layer or solid electrolyte layer]
The positive electrode for a secondary battery or the solid electrolyte layer/positive electrode laminate for a secondary battery produced in Examples and Comparative Examples was cut into a rectangle with a length of 50 mm and a width of 30 mm to prepare a test piece. The film thickness of this test piece was measured at six points in total at intervals of 15 mm in width in the short axis direction and long axis direction. The value obtained by subtracting the base material thickness from the measured value is the positive electrode composite layer or solid electrolyte layer thickness. In addition, in the case of the positive electrode for secondary batteries, the base material is aluminum foil, and in the case of the solid electrolyte/positive electrode laminate for secondary batteries, the base material is the positive electrode for secondary batteries. The average value and standard deviation of the thickness of the positive electrode mixture layer or solid electrolyte layer at six locations were determined and evaluated based on the following criteria. The smaller the ratio of the standard deviation to the average thickness, the more uniform the coating.
<Standards>
A: The ratio of standard deviation to the average value of thickness is less than 1%. B: The ratio of standard deviation to the average value of thickness is 1% or more, but less than 3%. C: The ratio of standard deviation to the average value of thickness is 3% or more. Less than 5% D: The ratio of standard deviation to the average thickness is 5% or more

[Peel strength of electrode mixture layer or solid electrolyte layer]
The positive electrode for a secondary battery or the solid electrolyte layer/positive electrode laminate for a secondary battery produced in Examples and Comparative Examples was cut into a rectangle with a length of 50 mm and a width of 30 mm to prepare a test piece. Cellophane tape (compliant with JIS Z1522) was attached to this test piece with the side with the positive electrode composite layer or solid electrolyte layer facing up, and one end of the current collector was pulled vertically at a pulling speed of 30 mm/min. The stress when peeled off was measured. This stress was defined as peel strength, and evaluation was made based on the following criteria. A to C in the following evaluations are considered acceptable, and the larger the peel strength value, the better the adhesion.
A: Peel strength is 100 N/m or more B: Peel strength is 80 N/m or more and less than 100 N/m C: Peel strength is 60 N/m or more and less than 80 N/m D: Peel strength is less than 60 N/m

(Example 1)
<Preparation of a mixed solution containing a polymer at a concentration of 10% by mass and a solvent>
A mixture of 10% by mass of polybutyl methacrylate (hereinafter sometimes referred to as "PBMA", manufactured by Sigma-Aldrich) as a polymer was dissolved in anisole as a solvent, and mixed with a solvent at a polymer concentration of 10% by mass. Obtained. The viscosity of the liquid mixture was measured by the method described above. The evaluation results are shown in Table 1.

<Preparation of liquid composition>
Nickel-based positive electrode active material (hereinafter sometimes referred to as "NCM") (manufactured by Toshima Seisakusho) and a dispersant for ion conductive materials at a mass ratio such that the solid content concentration according to the preparation calculation is 55% by mass. An acidic dispersant (manufactured by NOF Corporation, SC-0708A, 1% by mass based on the active material), PBMA (3% by mass based on the active material), and anisole as a solvent were mixed to obtain a liquid composition. Ta. The viscosity of the liquid composition was measured by the method described above. The evaluation results are shown in Table 1.

<Manufacture of positive electrode for secondary batteries>
The liquid composition obtained as described above was applied using an applicator onto a 20 μm thick aluminum foil serving as a current collector so that the average film thickness of the positive electrode composite layer was 80 μm. Furthermore, the liquid composition on the aluminum foil was dried in an oven at a temperature of 120° C. to obtain a positive electrode for a secondary battery in which a positive electrode composite layer was formed on the current collector. The film thickness variation and peel strength of the positive electrode for secondary batteries were evaluated by the method described above. The evaluation results are shown in Table 1.

(Example 2)
Example 1 was carried out in the same manner as in Example 1, except that poly(butyl methacrylate-methyl methacrylate) copolymer (hereinafter sometimes referred to as "P(BMA-MMA)", manufactured by Sigma-Aldrich) was used as the polymer. Various operations, measurements, and evaluations were performed. The results are shown in Table 1.

(Example 3)
Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that polyethyl methacrylate (hereinafter sometimes referred to as "PEMA", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 1.

(Comparative example 1)
Example 1 was carried out in the same manner as in Example 1, except that poly(methyl methacrylate-methacrylic acid) copolymer (hereinafter sometimes referred to as "P(MMA-MA)", manufactured by Sigma-Aldrich) was used as the polymer. , various operations, measurements, and evaluations were performed. The results are shown in Table 2.

(Comparative example 2)
Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that polymethyl methacrylate (hereinafter sometimes referred to as "PMMA", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 2.

(Comparative example 3)
Various operations, measurements, and evaluations were performed in the same manner as in Comparative Example 2, except that the amount of the polymer was 10% by mass based on the active material. The results are shown in Table 2.

(Example 4)
Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that the solid content concentration of the liquid composition was 58% by mass. The results are shown in Table 3.

(Example 5)
Various operations, measurements, and evaluations were performed in the same manner as in Example 4, except that a basic dispersant (S13940, manufactured by Lubrizol) was used as a dispersant for ion-conductive materials. The results are shown in Table 3.

(Examples 6 to 21)
Various operations, measurements, and evaluations were performed in the same manner as in Example 4, except that the solvents listed in Tables 3 to 7 were used as the solvents. The results are shown in Tables 3-7.

(Example 22)
Other additive components include acetylene black (hereinafter sometimes referred to as "AB"; 1% by mass based on the active material) (manufactured by Denka) as a conductive aid, and a basic dispersant as a dispersant for the conductive aid. Various operations, measurements, and evaluations were performed in the same manner as in Example 5, except that (20% by mass based on the conductive aid) (S13940, manufactured by Lubrizol) was added. The results are shown in Table 8.

(Example 23)
In the same manner as in Example 22, except that the amount of the conductive additive was 3% by mass relative to the active material, and the amount of the dispersant for the conductive agent was 0.6% by mass relative to the active material, Various operations, measurements, and evaluations were performed. The results are shown in Table 8.

(Example 24)
In the same manner as in Example 22, except that the amount of the conductive additive was 5% by mass relative to the active material, and the amount of the dispersant for the conductive agent was 1.0% by mass relative to the active material, Various operations, measurements, and evaluations were performed. The results are shown in Table 8.

(Example 25)
Various operations, measurements, and evaluations were performed in the same manner as in Example 24, except that the solid content concentration of the liquid composition was 70% by mass. The results are shown in Table 9.

(Examples 26-42)
Various operations, measurements, and evaluations were performed in the same manner as in Example 25, except that the solvents listed in Tables 9 to 13 were used as the solvents. The results are shown in Tables 9-13.

(Example 43)
A solid electrolyte was added so that the composition ratio was as shown in Table 13, and in order to disperse the solid electrolyte, the amount of dispersant for ion conductive materials was changed to 2.7% by mass, and methyl hexanoate was used as a solvent. Various operations, measurements, and evaluations were performed in the same manner as in Example 25, except that . The results are shown in Table 13.

(Example 44)
Various operations, measurements, and evaluations were performed in the same manner as in Example 43, except that the solvent was replaced with methyl heptanoate. The results are shown in Table 13.

(Example 45)
<Preparation of a mixed solution containing a polymer at a concentration of 10% by mass and a solvent>
A mixture of 10% by mass of polybutyl methacrylate (hereinafter sometimes referred to as "PBMA", manufactured by Sigma-Aldrich) as a polymer was dissolved in anisole as a solvent, and mixed with a solvent at a polymer concentration of 10% by mass. Obtained. The viscosity of the liquid mixture was measured by the method described above. The evaluation results are shown in Table 14.

<Preparation of liquid composition>
A solid electrolyte (argyrodite-type sulfide solid electrolyte Li ₆ PS ₅ Cl (LPSC)) and an acidic dispersant (as a dispersant for ion conductive materials) were added at a mass ratio such that the solid content concentration in the preparation calculation was 20% by mass. S13940, manufactured by Lubrizol, 5% by mass based on the solid electrolyte), PBMA (3% by mass based on the solid electrolyte), and anisole as a solvent were mixed to obtain a liquid composition. The viscosity of the liquid composition was measured by the method described above. The evaluation results are shown in Table 14.
Note that the solid electrolyte layer/positive electrode laminate for a secondary battery was manufactured as follows.

<Manufacture of solid electrolyte layer/positive electrode laminate for secondary batteries>
The liquid composition obtained as described above was applied with an applicator onto the 100 μm thick secondary battery positive electrode prepared in Example 24 (positive electrode composite layer 80 μm, aluminum foil 20 μm) so that the average film thickness of the solid electrolyte layer was It was coated to a thickness of 10 μm. Furthermore, the liquid composition on the positive electrode for a secondary battery was dried in an oven at a temperature of 120°C to obtain a solid electrolyte layer/positive electrode laminate for a secondary battery in which a solid electrolyte layer was formed on the positive electrode for a secondary battery. . The film thickness variation and peel strength of the solid electrolyte layer for secondary batteries were evaluated by the method described above. The evaluation results are shown in Table 14.

(Example 46)
Example 45 was carried out in the same manner as in Example 45, except that poly(butyl methacrylate-methyl methacrylate) copolymer (hereinafter sometimes referred to as "P(BMA-MMA)", manufactured by Sigma-Aldrich) was used as the polymer. Various operations, measurements, and evaluations were performed. The results are shown in Table 14.

(Example 47)
Various operations, measurements, and evaluations were performed in the same manner as in Example 45, except that polyethyl methacrylate (hereinafter sometimes referred to as "PEMA", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 14.

(Comparative example 4)
Example 45 was carried out in the same manner as in Example 45, except that poly(methyl methacrylate-methacrylic acid) copolymer (hereinafter sometimes referred to as "P(MMA-MA)", manufactured by Sigma-Aldrich) was used as the polymer. , various operations, measurements, and evaluations were performed. The results are shown in Table 15.

(Comparative example 5)
Various operations, measurements, and evaluations were performed in the same manner as in Example 45, except that polymethyl methacrylate (hereinafter sometimes referred to as "PMMA", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 15.

(Example 48)
Various operations, measurements, and evaluations were performed in the same manner as in Example 47, except that the solid content concentration of the liquid composition was 15% by mass. The results are shown in Table 16.

(Example 49)
Various operations, measurements, and evaluations were performed in the same manner as in Example 47, except that the solid content concentration of the liquid composition was 30% by mass. The results are shown in Table 16.

(Example 50)
Various operations, measurements, and evaluations were performed in the same manner as in Example 47, except that the solvent was replaced with xylene. The results are shown in Table 16.

(Comparative example 6)
Various operations, measurements, and evaluations were performed in the same manner as in Example 23, except that polyvinylidene fluoride (hereinafter sometimes referred to as "PVdF", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 17.

(Comparative Example 7)
Various operations, measurements, and evaluations were performed in the same manner as in Example 23, except that polyfluorinated vinylidene styrene butadiene rubber (hereinafter sometimes referred to as "SBR", manufactured by Sigma-Aldrich) was used as the polymer. . The results are shown in Table 17.

(Comparative example 8)
Various operations, measurements, and evaluations were performed in the same manner as in Example 23, except that acrylonitrile butadiene rubber (hereinafter sometimes referred to as "NBR", manufactured by Sigma-Aldrich) was used as the polymer. The results are shown in Table 17.

(Comparative example 9)
With reference to Example 1 of Patent Document 2, an n-butyl acrylate (BA)-methyl methacrylate (MMA)-methacrylic acid (MA)-allyl methacrylate (AMA) copolymer was synthesized. Various operations, measurements, and evaluations were performed in the same manner as in Example 7, except that the above polymer was used as the polymer and N-methyl-2-pyrrolidone (NMP) was used as the organic solvent. The evaluation results are shown in Table 17.

Abbreviations in Tables 1 to 17 indicate the following.
・BMA: Butyl methacrylate ・EMA: Ethyl methacrylate ・MMA: Methyl methacrylate ・MA: Methacrylic acid ・PVdF: Polyvinylidene fluoride ・SBR: Styrene butadiene rubber ・NBR: Acrylonitrile butadiene rubber ・BA: n-butadiene rubber Thyl acrylate/AMA : Allyl methacrylate ・NCM: Nickel-based positive electrode active material ・SE: Argyrodite-type sulfide solid electrolyte ・AB: Acetylene black ・NMP: N-methyl-2-pyrrolidone ・GBL: γ-butyrolactone ・DMSO: Dimethyl sulfoxide ・DMF: N ,N-dimethylformamide

From Tables 1 to 17, the glass transition temperature of the polymer includes an ion conductive material, a dispersant for the ion conductive material, a polymer, and a solvent, and the polymer includes an alkyl (meth)acrylate monomer. The liquid composition is a (meth)acrylate polymer having a temperature of 80° C. or less, and the polymer has a viscosity of 50 mPa·s or less at 25° C. when the polymer is mixed with the solvent at a concentration of 10% by mass. It can be seen that in Examples 1 to 3, the solid content concentration in the liquid composition was sufficiently increased, and electrode mixture layers were obtained that exhibited extremely low viscosity and had high peel strength.
Comparative Examples 1 and 2 using (meth)acrylate polymers containing a (meth)acrylic acid alkyl ester monomer but having a glass transition temperature higher than 80°C showed good peel strength as in Examples 1 and 3. was not obtained. Even in Comparative Example 3, which contained a large amount of a (meth)acrylate polymer with a glass transition temperature higher than 80°C, only an increase in viscosity occurred, and good peel strength as in Examples 1 to 3 was not obtained. .
It can be seen that in Example 4, in which the solid content concentration was adjusted so that the viscosity of the liquid composition was greater than 20 mPa·s, flow during drying of the coating film was suppressed and film thickness variation was improved.
It can be seen that in Example 5, in which a basic dispersant was used as the dispersant for ion conductive materials, the same effects as in Example 4 were obtained.
It can be seen that the same effects as in Example 4 were obtained in Examples 6 to 21 in which various solvents were used as solvents.
In Examples 22 to 25, which contained a conductive aid and a dispersant for the conductive aid as other additive components, thixotropy was developed when the solid content concentration was 60% by mass or more, and as a result, film thickness variations were significant. I can see that it has improved. In particular, it can be seen that in Examples 26 to 42, in which various carboxylic acid esters were used as solvents, not only the same effect as Example 25 was obtained, but also lower viscosity and higher solid content concentration were achieved. . Furthermore, it can be seen that the same effects as in Example 25 were obtained in Examples 43 to 44 containing two or more types of ion conductive materials.
Examples 45 to 47 using liquid compositions prepared using a sulfide solid electrolyte as the ion conductive material are different from those using the liquid compositions for secondary battery electrodes shown in Examples 1 to 24. Similarly, it can be seen that a solid electrolyte layer was obtained in which the solid content concentration of the liquid composition was sufficiently increased, extremely low viscosity was achieved, and the solid electrolyte layer had high peel strength. Also, compared to Example 48, which was prepared so that the solid content concentration was less than 20% by mass, Example 47 and Example 49, which were prepared so that the solid content concentration was 20% by mass or more, had a film thickness It can be seen that the variation has been significantly improved.
It can be seen that the same effect as in Example 47 was obtained in Example 50 using xylene as the solvent.
In Comparative Examples 4 and 5, a solid electrolyte was used as the ion conductive material and a (meth)acrylate polymer containing an alkyl (meth)acrylate monomer but having a glass transition temperature higher than 80°C was used. Good peel strength as in Examples 45 to 47 was not obtained.
It can be seen that in Comparative Examples 6 to 8, which used a crystalline binder or a latex binder, which are commonly used as polymers, it was not possible to achieve both high solid content concentration, low viscosity, and excellent peel strength. .
Although the polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80°C or less, when mixed with the solvent at a concentration of 10% by mass, the mixed liquid Using the n-butyl acrylate (BA)-methyl methacrylate (MMA)-methacrylic acid (MA)-allyl methacrylate (AMA) copolymer published in Patent Document 2, which has a viscosity at 25 ° C. of greater than 50 mPa s. It can be seen that in Comparative Example 9, the viscosity was outside the range suitable for inkjet printing.

Aspects according to this embodiment are, for example, as follows.
<1> A liquid composition used for forming members of an electrochemical device, comprising:
Including an ion conductive material, a dispersant, a polymer, and a solvent,
The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80°C or lower,
The polymer is a liquid composition characterized in that when mixed with the solvent at a concentration of 10% by mass, the viscosity of the mixture at 25° C. is 50 mPa·s or less.
<2> The ion conductive material is an active material,
The liquid composition according to <1> above, wherein the liquid composition has a viscosity at 25° C. of more than 20 mPa·s and less than 200 mPa·s.
<3> The liquid composition according to <2> above, wherein the solid content concentration is 60% by mass or more.
<4> The ion conductive material is a solid electrolyte,
The liquid composition according to <1> above, wherein the liquid composition has a viscosity of 20 mPa·s or less at 25°C.
<5> The liquid composition according to <4> above, wherein the solid content concentration is 20% by mass or more.
<6> The liquid composition according to any one of <1> to <5>, wherein the alkyl in the (meth)acrylic acid alkyl ester monomer has 2 to 4 carbon atoms.
<7> The liquid composition according to any one of <1> to <6>, wherein the polymer has a glass transition temperature of 40° C. or lower.
<8> A liquid composition for inkjet discharge comprising the liquid composition according to any one of <1> to <7>.
<9> A container containing the liquid composition according to any one of <1> to <7> or the liquid composition for inkjet ejection according to <8>.
<10> The storage container according to <9>above;
a discharge means for discharging the liquid composition contained in the storage container using an inkjet head;
1 is a manufacturing apparatus for a member of an electrochemical element, characterized by having the following.
<11> An electrochemical device manufacturing device characterized by having an electrochemical device component manufacturing section that manufactures electrochemical device components using the electrochemical device component manufacturing device described in <10> above.
<12> The method includes a discharging step of discharging the liquid composition according to any one of <1> to <7> or the liquid composition for inkjet discharge according to <8> using an inkjet head. This is a method of manufacturing a member of an electrochemical device.
<13> A method for manufacturing an electrochemical device, comprising a step of manufacturing a member for an electrochemical device by the method for manufacturing a member for an electrochemical device according to <12> above.
<14> An electrochemical element having a layer containing at least an ion conductive material, a dispersant, and a polymer on a current collector,
The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80°C or lower,
The electrochemical device is characterized in that the polymer has a viscosity of 50 mPa·s or less at 25° C. when mixed with a solvent at a concentration of 10% by mass.
<15> The electrochemical device according to <14>, wherein the electrochemical device is a secondary battery.

The liquid composition according to any one of <1> to <7>, the liquid composition for inkjet ejection according to <8>, the container according to <9>, and the electricity according to <10>. An apparatus for manufacturing a member of a chemical element, an apparatus for manufacturing an electrochemical element according to <11> above, a method for manufacturing a member for an electrochemical element according to <12> above, and a manufacturing apparatus for an electrochemical element according to <13> above. According to the method or the electrochemical device described in any one of <14> to <15> above, various conventional problems can be solved and the object of the present invention can be achieved.

1 Electrochemical element 1a Printing device 1b Storage container 1c Supply tube 3a Heating device 4 Printing base material 5 Transport section 7 Liquid composition 10 Discharge process section 11 Electrode substrate 11B Negative electrode substrate 12 Electrode composite material layer 12A Liquid composition 12B Negative electrode composite material Layer 15 Negative electrode 20 Positive electrode 21 Positive electrode substrate 22 Positive electrode composite layer 25 Positive electrode 30 Heating process section 30B Separator 40 Electrode element 41 Lead line 42 Lead line 51 Electrolyte layer 52 Exterior 100 Electrode 101 Negative electrode 111 Negative electrode base 121 Negative electrode composite layer 300 Liquid discharge Out Device 300' Liquid discharge device 304 Sending roller 305 Take-up roller 306 Liquid discharge head 307 Tank 308 Tube 309 Heating mechanism 310 Stage 311 Valve 312 Valve 313 External tank 314 Valve 400' Printing section 400'' Printing section 401 Head 420 Inkjet section 422 Head module 550 Moving body 551 Motor 552 Electrochemical element 553 Wheel 621 Impression cylinder 622 Transfer roller 3101 Pump 4000 Transfer drum 4001 Intermediate transfer body 4002 Pre-processing unit 4003 Absorption unit 4004 Heating unit 4005 Cleaning unit 4006 Intermediate transfer belt 4007 Heating unit 40 08 Cleaning Roller 4009a Drive roller 4009b Opposing roller 4009c Shape maintenance roller 4009d Shape maintenance roller 4009e Shape maintenance roller 4009f Shape maintenance roller 4009g Support roller

Japanese Patent Application Publication No. 2009-152180 International Publication No. 2019/044452

Claims (15)

A liquid composition used for forming members of an electrochemical device, comprising:
Including an ion conductive material, a dispersant, a polymer, and a solvent,
The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80°C or lower,
A liquid composition, wherein the polymer has a viscosity of 50 mPa·s or less at 25° C. when mixed with the solvent at a concentration of 10% by mass. the ion conductive material is an active material,
The liquid composition according to claim 1, wherein the liquid composition has a viscosity at 25°C of more than 20 mPa·s and less than 200 mPa·s. The liquid composition according to claim 2, having a solid content concentration of 60% by mass or more. the ion conductive material is a solid electrolyte,
The liquid composition according to claim 1, wherein the liquid composition has a viscosity at 25°C of 20 mPa·s or less. The liquid composition according to claim 4, having a solid content concentration of 20% by mass or more. The liquid composition according to any one of claims 1 to 5, wherein the alkyl in the (meth)acrylic acid alkyl ester monomer has 2 to 4 carbon atoms. The liquid composition according to any one of claims 1 to 5, wherein the polymer has a glass transition temperature of 40°C or less. A liquid composition for inkjet discharge comprising the liquid composition according to any one of claims 1 to 5. A container containing the liquid composition according to any one of claims 1 to 5. A storage container according to claim 9;
a discharge means for discharging the liquid composition contained in the storage container using an inkjet head;
An apparatus for manufacturing a member of an electrochemical element, comprising: An electrochemical device manufacturing apparatus comprising an electrochemical device component manufacturing section that manufactures electrochemical device components using the electrochemical device component manufacturing device according to claim 10. A method for manufacturing a member for an electrochemical device, comprising a discharging step of discharging the liquid composition according to any one of claims 1 to 5 using an inkjet head. A method for manufacturing an electrochemical device, comprising the step of manufacturing a member for an electrochemical device by the method for manufacturing a member for an electrochemical device according to claim 12. An electrochemical element having a layer containing at least an ion conductive material, a dispersant, and a polymer on a current collector,
The polymer is a (meth)acrylate polymer containing a (meth)acrylic acid alkyl ester monomer and having a glass transition temperature of 80°C or lower,
An electrochemical device characterized in that the polymer has a viscosity of 50 mPa·s or less at 25° C. when mixed with a solvent at a concentration of 10% by mass. The electrochemical device according to claim 14, wherein the electrochemical device is a secondary battery.