Liquid composition, liquid discharge device, and liquid discharge method

Abstract

To provide a liquid composition that can prevent mist, splashing, and scattering due to torn-off liquid, in forming an image by using an image forming apparatus.SOLUTION: A liquid composition includes an active material and a dispersion medium. When the viscosity at a shear rate of 10-1 s-1 is defined as ηA, and the viscosity at a rate of sheer of 105 s-1 as ηB, ηA is 1000 mPa s or more, and ηB is 100 mPa s or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid composition, a liquid ejection device, and a liquid ejection method. [Background technology]

[0002] In recent years, the range of applications of electrochemical elements such as lithium ion secondary batteries, electric double layer capacitors, lithium ion capacitors, and redox capacitors has rapidly expanded from small consumer devices such as wearable devices and smartphones to large devices such as electric vehicles and stationary storage batteries.

[0003] The electrode includes an active material layer and an electrode mixture layer, which is a layer that contributes to battery characteristics such as capacity and electromotive force. The liquid composition for forming this electrode mixture layer generally contains an active material and a dispersion medium. Conventionally, it is a component of electrodes that constitute lithium-ion secondary batteries. Known methods for manufacturing such electrodes include contact manufacturing methods, such as die coating, gravure coating, dip coating, and screen printing, or non-contact manufacturing methods, such as jet dispenser, inkjet, and spray coating, to apply the liquid composition for the electrode mixture layer to an electrode substrate to form an electrode mixture layer. In recent years, non-contact manufacturing methods, particularly inkjet methods, that can apply a material to a substrate in any shape are gaining attention in order to reduce material waste.

[0004] Many physical properties of liquid compositions suitable for the various production methods described above have been disclosed. For example, Patent Document 1 discloses that a slurry composition containing carbon black with a crystallization rate of 60% or more as a conductive material has excellent viscosity characteristics and coatability. Patent Document 2 discloses that by using a composition in which the viscosity ratio at high shear rate and low shear rate falls within a specific range, a battery separator coating liquid can be obtained that has excellent coatability and is capable of forming a coating film with excellent surface smoothness. Patent Document 3 discloses that a battery electrode paste in which first to third shear viscosity values ​​at first to third shear rates fall within specific ranges respectively has excellent coatability. Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 lists the doctor blade method, roll coater method, and die coater method as methods for applying the liquid composition, but does not disclose any examples of application in an image-forming apparatus (also known as a liquid ejection apparatus). The same is true for Patent Documents 2 and 3. According to the authors' investigations, when an image is formed using an image-forming apparatus using the liquid compositions disclosed in Patent Documents 1 to 3, unintended splashing of the liquid composition around the image is observed. When an electrode is manufactured by applying a liquid composition for forming an electrode mixture layer onto a substrate, this splashing can cause a short circuit in the battery. For these reasons, there is room for further development in the properties of liquid compositions.

[0006] An object of the present invention is to provide a liquid composition that can suppress mist, splashing, and scattering due to liquid tearing when ejected from a liquid ejection device. [Means for solving the problem]

[0007] The liquid composition of the present invention as a means for solving the problems is a liquid composition containing an active material and a dispersion medium, -1 s -1 The viscosity at η A, shear rate 10 5 s -1 The viscosity at η B When this is the case, η A is 1000 mPa·s or more and η B is 100 mPa·s or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a liquid composition that can suppress mist, splashing, and scattering due to liquid breaking when ejected from a liquid ejection device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing unintended scattering of a liquid composition that may occur when the liquid composition is discharged onto a substrate using a liquid discharge device. [Figure 2] FIG. 2 is a schematic diagram showing the continuous application of a liquid composition onto a substrate using a liquid ejection device. [Figure 3] FIG. 3 is a schematic diagram showing how a liquid composition is applied discontinuously onto a substrate using a liquid ejection device. [Figure 4] FIG. 4 is a schematic diagram showing an example of a liquid ejection device according to an embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram showing another example of a liquid ejection device according to an embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram showing another example of a liquid ejection device according to an embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing an example of an electrode manufacturing apparatus using a liquid ejection apparatus according to one embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram showing another example of an electrode manufacturing apparatus using a liquid ejection apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a schematic diagram illustrating unintended scattering of a liquid composition that can occur when a liquid composition is ejected onto a substrate using a liquid ejection device. When a liquid composition 37 is ejected from a liquid ejection device 300 for the purpose of forming an image, as shown in FIG. 1A, a phenomenon known as "mist" occurs in which the liquid composition 37 is scattered in an unintended direction. This phenomenon is observed primarily immediately after ejection. As shown in FIG. 1B, the intermittently or continuously ejected liquid composition 37 may separate during its flight before landing on the substrate 34, resulting in a phenomenon known as "liquid tearing," in which the liquid composition 37 is scattered in an unintended direction. As shown in FIG. 1C, the impact of the liquid composition 37 landing on the substrate 34 may cause the liquid composition 37 to splash in an unintended direction, known as "rebound." In this specification, "mist," "rebound," and "rebound" are collectively referred to as "scattering." If scattering occurs, not only will the appearance of the image formed on the substrate 34 using the liquid composition 37 be impaired, but the surrounding area will also be contaminated, which may cause fatal safety problems such as short circuits during subsequent processing and lamination steps.

[0011] The present invention is based on the inventors' extensive research and discovery that by setting the shear viscosity characteristics of a liquid composition within an appropriate numerical range, it is possible to suppress the "spattering" that occurs when the liquid composition is ejected from a liquid ejection device.

[0012] The liquid composition, liquid ejection device, and liquid ejection method of the present invention will be described in detail below.

[0013] (liquid composition) The liquid composition of the present invention contains an active material and a dispersion medium, and may further contain other components as necessary.

[0014] <Active material> The active material is not particularly limited as long as the effects of the present invention can be obtained, and for example, a positive electrode active material or a negative electrode active material can be used. Note that the positive electrode active material or the negative electrode active material may be used alone or in combination of two or more types.

[0015] <<Cathode active material>> The positive electrode active material is not particularly limited as long as it is a material that can reversibly store and release alkali metal ions, and alkali metal-containing transition metal compounds can be used.

[0016] Examples of alkali metal-containing transition metal compounds include lithium-containing transition metal compounds such as composite oxides containing lithium and one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium.

[0017] Examples of lithium-containing transition metal compounds include lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide.

[0018] As the alkali metal-containing transition metal compound, a polyanion compound having an XO4 tetrahedron (X=P, S, As, Mo, W, Si, etc.) in the crystal structure can be used. Among these, lithium-containing transition metal phosphate compounds such as lithium iron phosphate and lithium vanadium phosphate are preferred from the viewpoint of cycle characteristics, and lithium vanadium phosphate is preferred from the viewpoint of lithium diffusion coefficient and output characteristics.

[0019] When a polyanion compound is used, it is preferable that the surface of the polyanion compound is coated with a conductive aid such as a carbon material to form a composite, in terms of electron conductivity.

[0020] The alkali metal-containing transition metal compound preferably has at least a portion of its surface coated with an ion-conductive oxide, preferably a lithium ion-conductive oxide.

[0021] The lithium ion conductive oxide is not particularly limited and can be appropriately selected depending on the purpose. For example, x AO y(A is B, C, Al, Si, P, S, Ti, Zr, Nb, Mo, Ta, Sc, V, Y, Ca, Sr, Ba, Hf, Ta, Cr, or W, and x and y are positive numbers.)

[0022] Specific examples of lithium ion conductive oxides include Li3BO3, LiBO2, Li2CO3, LiAlO2, Li4SiO4, Li2SiO3, Li3PO4, Li2SO4, Li2TiO3, and Li4Ti5O. 12 , Li2Ti2O5, Li2ZrO3, LiNbO3, LiTaO3, Li2MoO4, and Li2WO4. Among these, Li4Ti5O 12 , Li2ZrO3, or LiNbO3 are preferred.

[0023] The lithium ion conductive oxide may be a composite oxide, which may be any combination of lithium ion conductive oxides, such as Li4SiO4-Li3BO3 and Li4SiO4-Li3PO4.

[0024] <<Negative electrode active material>> The negative electrode active material is not particularly limited as long as it is a material that can reversibly absorb and 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.

[0025] Examples of carbon materials include natural graphite, spherical or fibrous artificial graphite, non-graphitizable carbon (hard carbon), and easily graphitizable carbon (soft carbon).

[0026] Examples of materials other than carbon materials include lithium titanate and titanium oxide.

[0027] From the viewpoint of increasing the energy density of a lithium ion battery, high-capacity materials such as silicon, silicon alloys, silicon oxide, and silicon nitride can also be suitably used as the negative electrode active material.

[0028] The median diameter of the active material (hereinafter sometimes referred to as D50) is preferably 0.5 μm or more and 20 μm or less, more preferably 3 μm or more and 10 μm or less. When the median diameter of the active material is 0.5 μm or more and 20 μm or less, the weight concentration of the active material in the liquid composition can be increased, and an electrode mixture layer with a homogeneous composition can be obtained in a subsequent appropriate drying process. Furthermore, when the median diameter of the active material is 3 μm or more and 10 μm or less, an electrode with better electrical properties can be obtained. The diameter at the maximum value of the distribution in the measured particle size distribution of the active material in the liquid composition for forming an electrode mixture layer was calculated as the median diameter.

[0029] The method for measuring the median diameter of the active material is not particularly limited and can be appropriately selected depending on the purpose, and can be measured, for example, in accordance with ISO 13320: 2009. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a laser diffraction particle size distribution analyzer (Mastersizer 3000, manufactured by Malvern Instruments).

[0030] The maximum particle size Dmax of the active material is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. When the maximum particle size Dmax of the active material is 40 μm or less, turbulence in the droplets or liquid column of the liquid composition ejected by the liquid ejection device is suppressed, and mist is less likely to occur even if the liquid composition travels a long distance from being ejected to reaching the substrate.

[0031] The method for measuring the maximum particle diameter Dmax of the active material is not particularly limited and can be appropriately selected depending on the purpose, and can be measured, for example, in accordance with ISO 13320: 2009. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a laser diffraction particle size distribution analyzer (Mastersizer 3000, manufactured by Malvern Instruments).

[0032] <Dispersion medium> The dispersion medium in the present invention is a liquid component that disperses the active material in the liquid composition. The dispersion medium has a boiling point lower than the decomposition temperature under normal pressure conditions and volatilizes during a suitable drying process. The dispersion medium may be used alone or in combination of two or more.

[0033] Examples of dispersion media include aqueous dispersion media such as water, ethylene glycol, and propylene glycol, lactam dispersion media such as N-methyl-2-pyrrolidone and 2-pyrrolidone, amide dispersion media such as N-dimethylacetamide, ketone dispersion media such as cyclohexanone, ester dispersion media such as ethyl acetate, butyl acetate, methyl butyrate, ethyl butyrate, butyl butyrate, methyl valerate, ethyl valerate, methyl hexanoate, ethyl hexanoate, methyl heptanoate, ethyl heptanoate, methyl octanoate, ethyl octanoate, ethyl decanoate, ethyl isovalerate, ethyl isobutyrate, butyl isobutyrate, and isobutyl isobutyrate, and aromatic dispersion media such as anisole, mesitylene, and p-cymene. When a positive electrode active material is contained as the active material, lactam dispersion media and amide dispersion media are preferred, and ester dispersion media are more preferred, because their excellent dispersibility increases the solids concentration, thereby preventing uneven drying during the appropriate drying process.

[0034] The boiling point of the dispersion medium is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100°C or higher from the viewpoint of storage stability, more preferably 120°C or higher from the viewpoint of preventing drying after ejection until landing on the substrate, and even more preferably 150°C or higher from the viewpoint of preventing drying of the ejection portion of the liquid composition of the liquid ejection device. Also, from the viewpoint of quick drying in the appropriate drying step, it is preferably 300°C or lower, from the viewpoint of thickness uniformity of the coating film obtained in the drying step, more preferably 250°C or lower, and even more preferably 200°C or lower from the viewpoint of composition uniformity of the coating film obtained in the drying step.

[0035] <Other ingredients> The other components are not particularly limited and can be selected appropriately depending on the purpose. Examples include conductive aids, solid electrolytes, dispersants, surfactants, pH adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, antireducing agents, evaporation promoters, chelating agents, thickeners, etc.

[0036] <<Binder>> The binder is not particularly limited as long as it can bind non-volatile components such as active materials together, and can be appropriately selected depending on the purpose.

[0037] As the binder, a polymer compound can be used. Examples of the polymer compound include thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylic resin, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate, polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, and polyethylene. Examples of such polymers include polyethylene glycol (PEO), polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA), polybutyl methacrylate (PBMA), polyethylene vinyl acetate (PEVA), poly2-(dimethylamino)ethyl methacrylate, poly2-(diethylamino)ethyl methacrylate, poly(2-(dimethylamino)ethyl methacrylate-polybutyl methacrylate) copolymer, poly(2-(diethylamino)ethyl methacrylate-polybutyl methacrylate) copolymer, and carboxymethyl cellulose.

[0038] The binder content relative to the active material is not particularly limited and can be set appropriately depending on the purpose, but is preferably 0.5% by mass or more from the viewpoint of improving the binding strength of the electrode mixture layer obtained in the appropriate drying step of the liquid composition, more preferably 1% by mass or more from the viewpoint of preventing damage during transportation, and even more preferably 1.5% by mass or more from the viewpoint of preventing damage during processing. Furthermore, the binder content is preferably 15% by mass or less from the viewpoint of preventing inhibition of ionic conduction, more preferably 10% by mass or less from the viewpoint of preventing inhibition of electronic conduction in the electrode mixture layer, and even more preferably 5% by mass or less from the viewpoint of improving energy density.

[0039] <<Conductive additives>> The conductive additive is not particularly limited and can be appropriately selected depending on the purpose. For example, carbon black produced by a furnace method, an acetylene method, a gasification method, or the like, or carbon materials such as carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used.

[0040] Examples of the conductive additive other than the carbon material include metal particles such as aluminum, metal fibers, etc. The conductive additive may be previously compounded with the active material.

[0041] The content of the conductive additive relative to the active material is not particularly limited and can be set appropriately depending on the purpose, but is preferably 0.01% by mass or more from the viewpoint of improving electronic conductivity in the electrode mixture layer, and is preferably 10% by mass or less from the viewpoint of preventing inhibition of ionic conduction in the electrode mixture layer, more preferably 5% by mass or less from the viewpoint of preventing damage during transportation and processing, and even more preferably 3% by mass or less from the viewpoint of improving energy density.

[0042] <<Solid electrolyte>> The solid electrolyte is not particularly limited and can be appropriately selected depending on the purpose as long as it has electronic insulation properties, exhibits ionic conductivity, and does not react with the organic dispersion medium. Examples of the solid electrolyte include oxide-based solid electrolytes and sulfide-based solid electrolytes.

[0043] Among these, sulfide solid electrolytes are preferred because they have high plasticity, allowing good interfaces to be formed between solid electrolyte particles or between the solid electrolyte and the active material. Crystalline argyrodite-type sulfide solid electrolytes are more preferred because they are particularly compatible with the dispersibility of the present invention and can provide an excellent dispersion effect similar to that of the active material.

[0044] Examples of oxide-based solid electrolytes include compounds that contain oxygen atoms (O), have the ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and have electronic insulation properties.

[0045] Here, "having electronic insulation" means that a short circuit does not occur when a positive electrode and a negative electrode are placed opposite each other with a solid electrolyte layer interposed therebetween, and "exhibiting ion conductivity" means that only ions move when a potential difference is applied when a positive electrode and a negative electrode are placed opposite each other with a solid electrolyte layer interposed therebetween.

[0046] Specific examples of oxide-based solid electrolyte compounds include Li xa La ya TiO3 [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 selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, and xb satisfies 5≦xb≦10, yb satisfies 1≦yb≦4, zb satisfies 1≦zb≦4, mb satisfies 0≦mb≦2, and nb satisfies 5≦nb≦20.), Li xc B yc Mcc zc O nc (Mcc is at least one element selected from C, S, Al, Si, Ga, Ge, In, and Sn, and xc satisfies 0≦xc≦5, yc satisfies 0≦yc≦1, zc satisfies 0≦zc≦1, and nc satisfies 0≦nc≦6.) Li xd (Al,Ga) yd (Ti,Ge) zd Si ad P mdO nd (where 1≦xd≦3, 0≦yd≦1, 0≦zd≦2, 0≦ad≦1, 1≦md≦7, 3≦nd≦13), Li(3-2xe)Mee xe DeeO (xe represents a number of 0 or more and 0.1 or less, Mee represents a divalent metal atom, and 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)、Li3BO3-Li2SO4、Li2O-B2O3-P2O5、Li2O-SiO2、Li6BaLa2Ta2O 12 , LiPO (4-3 / 2w) N w (w<1), Li with LISICON (Lithium super ionic conductor) type crystal structure 3.5 Zn 0.25 GeO4, La with perovskite crystal structure 0.55 Li 0.35 TiO3, LiTi2P3O with NASICON (sodium super ionic conductor) type crystal structure 12 , Li 1+xh+yh (Al,Ga) xh (Ti,Ge) 2-xh Si yh P 3-yh O 12 (where 0≦xh≦1, 0≦yh≦1), Li7La3Zr2O with a garnet-type crystal structure 12 (LLZ) and others.

[0047] Also desirable are phosphorus compounds containing Li, P, and O. Examples include lithium phosphate (Li3PO4), LiPON in which some of the oxygen in lithium phosphate has been substituted with nitrogen, and LiPOD1 (D1 is at least one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, Au, etc.).

[0048] Also, LiA 1 ON(A 1 is at least one selected from Si, B, Ge, Al, C, Ga, etc.) can also be preferably used.

[0049] Sulfide solid electrolytes can be broadly divided into, for example, crystalline sulfide solid electrolytes and glass-based solid electrolytes.

[0050] Examples of crystalline sulfide solid electrolytes include Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 , Li 9.6 P3S 12 , Li9P3S9O3, Li 9.81 Sn 0.81 P 2.19 S 12 , Li 9.42 Si 1.02 P 2.1 S 9.96 O 2.04 , Li 10 Ge(P 1-x Sb x )2S 12 (0≦x≦0.15), Li 10 SnP2S 12 , Li 10.35 [M1 1-x M2 x ] 1.35 P 1.65 S 12 (M1, M2 = Si, Ge, Sn, As, Sb, 0≦x≦0.15), Li 11 Si2PS 12 , Li 11 AlP2S 12 , Li 3.45 Si 0.45 P 0.55 S4, Li6PS5X(X=Cl,Br,I), Li5PS4X2(X=Cl,Br,I), Li 5.5 PS 4.5 Cl 1.5 , Li 5.35 Ca 0.1 PS 4.5 Cl 1.55 , Li 6+x M x Sb1-x S5I(M=Si,Ge,Sn,0≦x≦1), Li7P2S8I, γ-Li3PS4, Li4MS4(M=Ge,Sn,As), Li 4-x Sn 1-x SbxS4(0≦x≦0.15), Li 4-x Ge 1-x PxS4(0≦x≦0.15), Li 3+5x P 1-x Examples include S4 (0≦x≦0.3).

[0051] Examples of glass-based sulfide solid electrolytes include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-P2O5, Li2S-P2S5-LiCl, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-SiS2-Al2S3, and Li2S-SiS2-Li x MO y (M=Si, P, Ge), etc. Also, Li7P3S, which is a partially crystallized glass-based sulfide solid electrolyte, 11 Glass ceramics can also be used. Here, the mixing ratio of the raw materials of the glass-based sulfide solid electrolyte is not important.

[0052] The content of the conductive additive relative to the active material is not particularly limited and can be set appropriately depending on the purpose, but is preferably 10% by mass or more from the viewpoint of improving ionic conductivity in the electrode mixture layer, and more preferably 15% by mass or more from the viewpoint of improving processability. Also, from the viewpoint of preventing inhibition of electronic conduction in the electrode mixture layer, it is preferably 40% by mass or less, and from the viewpoint of improving processability, it is more preferably 30% by mass or less.

[0053] <<Dispersant>> The dispersant is not particularly limited as long as it is capable of improving the dispersibility of the active material in the liquid composition. The dispersant is not particularly limited, and conventionally known or commercially available dispersants can be used as appropriate. Examples of the dispersant include polymer dispersants such as carboxymethyl cellulose, polyethylene, polyethylene oxide, polypropylene oxide, polycarboxylic acid, naphthalene sulfonic acid formalin condensation, polyethylene glycol, polycarboxylic acid partial alkyl ester, polyether, and polyalkylene polyamine; low molecular weight dispersants such as alkyl sulfonic acid, quaternary ammonium, higher alcohol alkylene oxide, polyhydric alcohol ester, and alkyl polyamine; and inorganic dispersants such as polyphosphate dispersants.

[0054] <Shear viscosity of liquid composition> The liquid composition of the present invention is -1 s -1 The viscosity at low shear is defined as η A , shear rate 10 5 s -1 The viscosity at high shear is defined as η B When this is the case, η A is 1000 mPa·s or more and η B is 100 mPa·s or less.

[0055] Above η A and η B A liquid composition that exhibits the viscosity relationship is generally called a thixotropic fluid. When a liquid composition is ejected from a liquid ejection device, the liquid composition is pushed out of the liquid ejection device by an external force as described below, and at that time, a shear rate is applied to the liquid composition. B When the viscosity is 100 mPa·s or less, the liquid composition is ejected immediately after the application of an external force, thereby preventing the generation of mist. Furthermore, during the flight period from when the liquid composition is ejected from the liquid ejection device to when it lands on the substrate, the shear rate attenuates, causing the thixotropic liquid composition of the present invention to thicken. AWhen η is 1000 mPa·s or more, it is possible to prevent the liquid composition from separating during flight due to air resistance to the gas present between the substrate and the liquid discharge device. A When the viscosity is 1000 mPa·s or more, the liquid composition has a sufficiently high viscosity, that is, a viscous resistance, against the impact energy when it lands on a substrate, and therefore rebound can be suppressed.

[0056] In addition to the fact that the occurrence of tailing of the liquid composition during ejection, which is one of the causes of liquid tearing, is suppressed, the effect of airflow between the substrate and the liquid ejection device is small. A It is preferable that η is 5000 mPa·s or more. In addition, η is preferably 5000 mPa·s or more in order to improve the uniformity of the film thickness after landing on the substrate. A The viscosity is preferably 20,000 mPa·s or less, and particularly preferably 13,000 mPa·s or less.

[0057] η in order to prevent uneven drying due to heat convection during the drying process B is preferably 20 mPa·s or more.

[0058] The method for measuring the shear viscosity of a liquid composition is not particularly limited and can be selected appropriately depending on the purpose, and can be measured, for example, in accordance with JIS Z 8803. The device used for measurement is not particularly limited and can be selected appropriately depending on the purpose, and can be measured, for example, using a rheometer MCR302e or MCR702e space (manufactured by Anton Paar).

[0059] In addition, the η of the liquid composition of the present invention A , η B is measured in the following steps because it provides good reproducibility: First, at a shear rate of 0.1 s -1 The viscosity was measured for 1 minute at 100°C, and then the shear rate was reduced to 0.1 s -1 ~100000s -1 This is repeated twice in succession, and the viscosity is measured at 0.1 s for the second time. -1 The viscosity at η A , 10000s -1The viscosity at η B Due to limitations of the measuring device, the shear rate is limited to 0.1 to 10,000 s -1 If it is not possible to measure the viscosity continuously at this temperature, the shear rate range should overlap by at least one order of magnitude in each measurement. For example, when using an MCR302e (manufactured by Anton Paar), a cone plate (CP-50, manufactured by Anton Paar) should be used to measure the viscosity at a shear rate range of 0.1 to 1000 s. -1 The viscosity was measured at 100 to 100,000 s using a parallel plate (PP-50, manufactured by Anton Paar). -1 The viscosity is measured at 1000 kJ / min.

[0060] <Dynamic viscoelasticity of liquid composition> The loss tangent tanδ, defined as the ratio of the loss modulus to the storage modulus, is commonly used as an index of dynamic viscoelasticity. From the perspective of further reducing the risk of mist generation, it is preferable for the liquid composition to become predominantly viscous when strain is applied to the liquid composition due to the application of external force from the liquid ejection device for ejection. In this regard, it is preferable for tanδ1 at a strain rate of 100% when a shear force of 2 Hz frequency is applied to the liquid composition to be 1 or greater, and it is even more preferable for tanδ2 at a strain rate of 10% to be 1 or greater. Furthermore, from the perspective of further reducing the risk of "rebound" upon impact, it is preferable for the liquid composition to be predominantly elastic upon impact, and it is therefore preferable for tanδ3 at a strain rate of 1% to be 1 or less.

[0061] The method for measuring the shear viscosity of a liquid composition is not particularly limited and can be appropriately selected depending on the purpose. The device used for the measurement is not particularly limited and can be appropriately selected depending on the purpose, and for example, the measurement can be performed using a rheometer MCR302e or MCR702e space (manufactured by Anton Paar).

[0062] The tan δ1, tan δ2, and tan δ3 of the liquid composition of the present invention are measured in the following steps, because they provide good reproducibility. First, the dynamic viscoelasticity is measured for 1 minute at a frequency of 2 Hz and a strain rate of 0.1%, and then the dynamic viscoelasticity is measured while changing the strain rate from 0.01% to 1000%. This process is repeated twice consecutively, and the loss tangent at 100% strain in the second measurement is designated as tan δ1, the loss tangent at 10% strain, and the loss tangent at 1% strain are designated as tan δ2, tan δ3, and tan δ4, respectively. For example, when using an MCR302e (manufactured by Anton Paar), the dynamic viscoelasticity is measured at a frequency of 2 Hz and a strain rate of 0.1 to 1000% using a cone plate (CP-50, manufactured by Anton Paar). If it is not possible to continuously measure the dynamic viscoelasticity at a strain rate of 0.01 to 1000% due to limitations in the measuring device, measurements should be made so that the strain rate overlaps by at least one order of magnitude between each measurement.

[0063] The shear viscosity and dynamic viscoelasticity of the liquid composition can be easily adjusted by the solid concentration, type of dispersion medium, and blending ratio of other components, such as the conductive additive, dispersant, and binder, contained in the liquid composition.

[0064] <Solid content concentration> The "solid content concentration" of a liquid composition refers to the mass percentage of solid content relative to the total mass of the liquid composition. The solid content refers to the active material and other components that are not removed by the appropriate drying process, such as conductive additives, binders, solid electrolytes, and dispersants. The solid content concentration of the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. A solid content of 40% by mass or more is preferred in terms of suppressing film thickness unevenness due to thermal convection during drying and prolonged drying time. Furthermore, a solid content of 60% by mass or more is even more preferred in terms of suppressing composition unevenness in the film thickness direction due to thermal convection during drying. The upper limit of the solid content concentration is also not particularly limited and can be appropriately selected depending on the purpose, but 80% by mass or less is preferred in terms of suppressing drying of the liquid composition in the discharge section of the image forming apparatus.

[0065] The method for measuring the solids concentration of a liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, when the composition of the liquid composition is known, the solids concentration can be determined using the following formula; when the composition of the liquid composition is unknown, the solids concentration can be measured in accordance with JIS K5601-1-2. (Formula) Solids concentration = {total solids (parts by mass) / (total solids (parts by mass) + dispersion medium (parts by mass))}×100(%) The device used to measure the solid content concentration is not particularly limited and can be appropriately selected depending on the purpose. For example, a heat-drying solid content meter (MX-50, manufactured by A&D Co., Ltd.) can be used.

[0066] <Method of producing liquid composition> The liquid composition can be produced by dissolving or dispersing the active material and, if necessary, other components in a dispersion medium. Specifically, the liquid composition can be prepared by mixing the active material and other components with a dispersion medium using a mixer such as a ball mill, a sand mill, a bead mill, a planetary mixer, a film mixer, or an ultrasonic disperser.

[0067] <Electrode> The liquid composition of the present invention is suitable as a material for an electrode. The electrode is obtained by discharging the liquid composition of the present invention onto a substrate, followed by a drying step as necessary, and includes a substrate and an electrode mixture layer, and may also include other components as necessary.

[0068] <<Electrode composite layer>> The electrode mixture layer in the present invention refers to a coating film containing an active material, which is obtained by discharging the liquid composition of the present invention and, if necessary, other components onto a substrate, and then, if necessary, subjecting the substrate to a drying step.

[0069] <<Base>> The substrate for the electrode is not particularly limited as long as it has electronic conductivity and is stable to the applied potential, and can be appropriately selected depending on the purpose. Examples include aluminum foil, copper foil, stainless steel foil, titanium foil, etched foil obtained by etching these foils to form fine holes, carbon-coated foil whose surface is coated with a carbon-containing resin layer, foil coated with a PTC (Phase-Transfer Catalyst) layer, and perforated substrates used in lithium ion capacitors.

[0070] (Liquid discharge device) The liquid ejection device of the present invention has a storage container that stores the liquid composition of the present invention, and an ejection section that ejects the liquid composition stored in the storage container, and may further have other sections as necessary.

[0071] The liquid ejection device of the present invention is a device that forms an image by ejecting a liquid composition from an ejection portion using an external force as described below. The liquid ejection device is not particularly limited as long as the effects of the present invention can be obtained, and examples include an inkjet method, a spray coating method, and a jet dispenser method. In that the liquid composition is ejected from the liquid ejection device, the liquid ejection device of the present invention is clearly distinguished from contact coating methods such as comma coaters and gravure coaters, and methods that apply an extruded liquid composition by rubbing it against a substrate, such as those typified by die coaters.

[0072] The external force for ejecting the liquid composition from the liquid ejection device is not particularly limited and can be appropriately selected depending on the purpose. Examples include a piezoelectric method in which the liquid composition is ejected by changing the volume of a piezoelectric element (piezo element), a thermal method in which the liquid composition is ejected by generating bubbles in the liquid composition using heat from a heater, and a pressure method in which the liquid composition is ejected by applying pressure to the liquid composition. Specific examples of the pressure method include a method in which ejection is controlled by electronically controlling the applied pressure, as typified by a jet dispenser, and a method in which ejection is controlled by electronically controlling the opening and closing of a lid of an ejection part while applying pressure to the liquid composition, as typified by a valve-type nozzle disclosed in Patent Document 7271956.

[0073] <Containment Container> The storage container in the liquid ejection device of the present invention is not particularly limited as long as it can store the liquid composition of the present invention, and may be configured as an integral part of the liquid ejection device or may be configured as a removable container from the liquid ejection device. Furthermore, it may be a container used for adding to a storage container integrated with the liquid ejection device or a storage container removable from the liquid ejection device.

[0074] <Discharge part> The ejection section in the liquid ejection device of the present invention ejects the liquid composition contained in the storage container. The ejection section has an ejection port, which is a hole through which the liquid composition is ejected. The shape of the ejection port is not particularly limited as long as the effects of the present invention can be obtained, and a single ejection port or multiple ejection ports may be provided.

[0075]

[0033] Because the liquid composition of the present invention has thixotropy, after landing on a substrate, the viscosity increases over time, resulting in a loss of leveling ability. Therefore, in the step of ejecting the liquid composition onto a substrate from the ejection openings of a liquid ejection device by external force, from the viewpoint of film uniformity, a liquid ejection device having multiple ejection units is preferred in order to shorten the difference in landing time within the image plane to be drawn, and generally, an inkjet device with dense ejection units is particularly preferred.

[0076] In general, ejection patterns for ejecting a liquid composition can be roughly divided into a pattern in which a liquid column is ejected by continuously applying an external force as shown in Fig. 2, and a pattern in which a droplet is ejected by applying a discrete or amplitude-wise external force as shown in Fig. 3. In the present invention, from the viewpoint of film uniformity, it is preferable that the difference in landing time within an image is short, and it is preferable that liquid composition 37 is ejected onto a substrate while a liquid column is formed between liquid ejection head 306 and substrate 34, as shown in Fig. 2.

[0077] In the liquid ejection device of the present invention, the distance between the ejection unit and the substrate is not particularly limited as long as the effects of the present invention can be obtained, but it is preferably 4 mm or less, more preferably 3 mm or less, from the viewpoint of reducing the risk of the liquid being torn off due to air currents, etc. Furthermore, it is preferably 1 mm or more, since the risk of rebound can be reduced by ensuring that the liquid composition has time to thicken during flight before landing.

[0078] <Configuration example of liquid ejection device> Hereinafter, a configuration example of the liquid ejection device of the present invention will be described in detail with reference to FIGS.

[0079] 4 is a schematic diagram showing an example of a liquid ejection device according to an embodiment of the present invention. A liquid ejection device 300' has a tank 307 and an external tank 313 as storage containers, and a liquid ejection head 306 as an ejection unit.

[0080] Liquid ejection device 300 can circulate the liquid composition through liquid ejection head 306, tank 307, and tube 308 by controlling pump 310, valve 311, and valve 312. Liquid ejection device 300′ is also provided with external tank 313, and when the liquid composition in tank 307 decreases, it is also possible to supply the liquid composition from external tank 313 to tank 307 by controlling pump 310, valve 311, valve 312, and valve 314.

[0081] FIG. 5 is a schematic diagram showing another example of a liquid ejection device according to an embodiment of the present invention. 5, liquid ejection device 300A' and liquid ejection device 300B' may be used in combination. That is, the liquid composition may be supplied from external tanks 313A and 313B connected to tanks 307A and 307B, and the liquid ejection head may have multiple heads 306A and 306B. Accordingly, tubes 308A and 308B, valves 311A, 311B, 312A, 312B, valves 314A and 314B, and pumps 310A and 310B may be provided.

[0082] FIG. 6 is a schematic diagram showing another example of a liquid ejection device according to an embodiment of the present invention. 6, the liquid composition in tank 307A is pressurized via regulator 315 by pressurized gas generated from pressurized gas generator 316, and the liquid composition is supplied to liquid ejection head 306 due to the pressure difference with tank 307B. Liquid composition not ejected from liquid ejection head 306 is sent to tank 307B and circulated to tank 307A via pump 310.

[0083] <Electrode manufacturing equipment> A liquid ejection device according to one embodiment of the present invention can be suitably used as an electrode mixture layer forming unit in an electrode manufacturing apparatus. In the present invention, the electrode manufacturing apparatus has an electrode mixture layer forming unit that forms an electrode mixture layer, and further has a heating unit that heats the electrode mixture layer as needed. An electrode manufacturing apparatus using a liquid ejection device according to one embodiment of the present invention will be described in detail below with reference to Figures 7 and 8.

[0084] FIG. 7 is a schematic diagram showing an example of an electrode manufacturing apparatus using a liquid ejection apparatus according to one embodiment of the present invention. The electrode manufacturing apparatus 500 is an apparatus for forming an electrode mixture layer on a substrate using the liquid composition of the present invention. The electrode manufacturing apparatus 500 includes an electrode mixture layer forming section 100 that applies the liquid composition to a substrate 34 to form an electrode mixture layer, and, if necessary, a heating section 200. The electrode manufacturing apparatus 500 also includes a conveying section 35 that conveys the substrate 34, and the conveying section 35 conveys the substrate 34 at a preset speed from the electrode mixture layer forming section 100 to the heating section 200, if necessary.

[0085] The electrode composite layer forming section 100 includes a liquid ejection device 31a, which is an example of an ejection section that ejects a liquid composition 37 for forming an electrode composite layer on a substrate 34, a storage container 31b that stores the liquid composition 37, and a supply tube 31c that supplies the liquid composition 37 stored in the storage container 31b to the printing device 31a.

[0086] The storage container 31b stores a liquid composition 37, and the electrode mixture layer forming section 100 discharges the liquid composition 37 from the liquid discharge device 31a to form an electrode mixture layer on the substrate .

[0087] The storage container 31b and the supply tube 31c can be arbitrarily selected as long as they can stably store and supply the electrode mixture layer forming liquid composition 37.

[0088] The heating section 200 has a heating device 33a, and performs a drying step of drying the remaining liquid by heating the electrode mixture layer formed by the electrode mixture layer forming section 100 with the heating device 33a. The heating section 200 may remove the liquid under reduced pressure.

[0089] The heating device 33a is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include an IR heater and a hot air heater.

[0090] 8 is a schematic diagram showing another example of an electrode manufacturing apparatus using a liquid ejection apparatus according to one embodiment of the present invention. A method for manufacturing an electrode using the electrode manufacturing apparatus shown in FIG. 8 will be described below.

[0091] The electrode manufacturing apparatus shown in FIG. 8 has a liquid ejection device (electrode mixture layer forming unit) made up of a liquid ejection head 306, a tank 307, and a supply tube 308, and a heating unit 309.

[0092] First, an elongated substrate 211 is prepared. Then, the substrate 211 is wound around a cylindrical core and set on a feed roller 304 and a take-up roller 305 so that the side on which the electrode mixture layer is to be formed faces upward in FIG. 8. Here, the feed roller 304 and the take-up roller 305 rotate counterclockwise in FIG. 8, and the substrate 211 is transported from right to left in FIG. 8. Then, droplets of the liquid composition 12A are ejected onto the substrates 211 that are being transported sequentially from a liquid ejection head 306 installed above the substrate 211 between the feed roller 304 and the take-up roller 305, in the same manner as in FIG. 7.

[0093] A plurality of liquid ejection heads 306 may be installed in a direction substantially parallel to or substantially perpendicular to the transport direction of substrate 211. Next, substrate 211 onto which droplets of liquid composition 12A have been ejected is transported to heating section 309 by delivery roller 304 and take-up roller 305, where the remaining liquid is removed by heating and drying. Through the above steps, electrode 210 is obtained in which electrode mixture layer 212 is provided on substrate 211. [Example]

[0094] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0095] (Production Example 1) -Preparation of Liquid Composition 1- Liquid compositions were prepared using the materials and compositions listed in Table 1. Specifically, 100 parts by mass of NCM1 (nickel-based positive electrode active material, D50 particle size: 4 μm, manufactured by Toshima Manufacturing Co., Ltd.) as the active material, 1.5 parts by mass of polydiethylaminoethyl methacrylate-butyl methacrylate copolymer (hereinafter sometimes referred to as "P(DEAmEMA-BMA)") as the binder, 1 part by mass of multi-walled carbon nanotubes (hereinafter sometimes referred to as "MWCNT", manufactured by Nanosil Co., Ltd.) as the conductive additive, 2 parts by mass of acetylene black (hereinafter sometimes referred to as "AB", manufactured by Denka Co., Ltd.), 0.60 parts by mass of modified styrene-maleic acid copolymer (manufactured by BYK-Chemie AG) as the dispersant, and NMP (manufactured by Tokyo Chemical Industry Co., Ltd.) with a solids concentration of 66.0% by mass as the dispersion medium were mixed and dispersed using an ultrasonic homogenizer (manufactured by Nippon Seiki Co., Ltd.) to prepare Liquid Composition 1. In the dispersion treatment, NMP was added in several batches to adjust the solid content concentration of Liquid Composition 1 to 66.0% by mass.

[0096] -Measurement of solids concentration in liquid compositions- 10 g of the liquid composition was added to a heat-drying solid content analyzer (MX-50, manufactured by A&D Co., Ltd.), heated to 170°C, and dried to measure the solid content concentration.

[0097] -shear viscosity η of the liquid composition A , η B Measurement of - A cone plate (CP-50) was attached to a rheometer MCR302e (manufactured by Anton Paar), 0.8 mL of the liquid composition was dropped, and shear viscosity was measured at a gap of 0.098 mm and 25°C. Specifically, the shear viscosity was measured at a shear rate of 0.1 s -1 The viscosity was measured for 1 minute at 100°C, and then the shear rate was reduced to 0.1 s -1 ~1000S -1 This was repeated twice in succession, and the viscosity was measured at 0.1 s for the second time. -1 The viscosity at η A was adopted as. In addition, a parallel plate (PP-50) was attached, 0.2 mL of the liquid composition was dropped, and shear viscosity measurements were performed at a gap of 0.02 mm and 25°C. Specifically, the shear viscosity was measured at a shear rate of 100 s -1 The viscosity was measured for 1 minute at 100 s. -1 ~100,000S -1 This was repeated twice in succession, and the viscosity was measured at 0.1 s for the second time. -1 The viscosity at η B was adopted as.

[0098] -Measurement of loss tangent tanδ of liquid composition- A cone plate (CP-50) was attached to a rheometer MCR302e (manufactured by Anton Paar), 0.8 mL of the liquid composition was dropped, and dynamic viscoelasticity measurements were performed with a gap of 0.098 mm and at 25°C. Specifically, dynamic viscoelasticity measurements were performed for 1 minute at a frequency of 2 Hz and a strain rate of 0.1%, and then dynamic viscoelasticity measurements were performed at the same frequency while changing the strain rate from 0.01% to 1000%. This was repeated twice consecutively, and the loss tangent at the second strain rate of 100% was used as tanδ1, the loss tangent at the strain rate of 10% as tanδ2, and the loss tangent at the strain rate of 1% as tanδ3.

[0099] (Examples 2 to 55) Liquid compositions 2 to 55 were prepared in the same manner as in Production Example 1, except that the formulations of the liquid compositions were changed to those shown in Tables 1 to 3. Details of the materials shown in Tables 1 to 3 are as follows.

[0100] <Active material> <<Cathode active material>> NCM1: Nickel cobalt manganese oxide lithium (D50=4μm, manufactured by Toshima Manufacturing Co., Ltd.) NCM2: Nickel cobalt manganese oxide lithium (D50=4μm, manufactured by Toshima Manufacturing Co., Ltd.) LNO / NCM1: Lithium niobate coated nickel cobalt manganese oxide The lithium niobate layer was formed on the surface of NCM powder particles by hydrolysis of an alkoxide solution containing lithium and niobium, following the published literature (J. Mater. Chem. A. 2021, 9, 4117-4125). First, metallic lithium (Honjo Metals Co., Ltd.) was dissolved in absolute ethanol (Kanto Chemical Co., Ltd.) to prepare an ethanol solution of lithium ethoxide. Niobium pentaethoxide (Nb(OC2H5)5) (Kojundo Chemical Laboratory Co., Ltd.) was then added to this solution to form an alkoxide solution containing lithium and niobium. NCM1 powder was fluidized in a tumbling fluidizer (MP-01, Powrex Corporation) and the alkoxide solution was sprayed onto the fluidized bed to obtain a precursor powder with the alkoxide coating on the NCM1 powder particle surface. This powder was then heated at 350 °C in a dry air atmosphere to produce LNO / NCM1, which had a lithium niobate layer formed on the NCM surface.

[0101] <<Negative electrode active material>> Gr: Artificial graphite (Sigma-Aldrich, D50 = 5 μm) SiO: silicon oxide (Sigma-Aldrich, D50 = 8 μm)

[0102] <Dispersion medium> NMP: N-methyl-2-pyrrolidone (Tokyo Chemical Industry Co., Ltd.) Butyl butyrate: manufactured by Tokyo Chemical Industry Co., Ltd.

[0103] <Other ingredients> <<Binder>> P(DEAmEMA-BMA): Poly(diethylaminoethyl methacrylate-butyl methacrylate) copolymer PBMA: Polybutyl methacrylate (Sigma-Aldrich) SBR: Styrene-butadiene rubber (Sigma-Aldrich) P(DEAmEMA-BMA) was synthesized by the method described in Japanese Patent Application Laid-Open No. 2024-125167. The copolymerization ratio of diethylaminoethyl methacrylate (DEAmEMABMA) and butyl methacrylate (BMA) was 20 mol %:80 mol %.

[0104] <<Conductive additives>> AB: Acetylene black (Denka Black, manufactured by Denka Co., Ltd.) MWCNT: Multi-walled carbon nanotubes (manufactured by Nanosil) SWCNT: Single-walled carbon nanotubes (manufactured by Oxial)

[0105] <<Dispersant>> Modified styrene-maleic acid copolymer (manufactured by BYK) (manufactured by BYK) CMC: Sodium carboxymethylcellulose (Sigma-Aldrich) SC0708A: Marialim (registered trademark) SC-0708A (manufactured by NOF Corporation) S13940: Solsperse™ 13940 (manufactured by Lubrizol Industrial Co., Ltd.)

[0106] <<Solid electrolyte>> LPSC: Argyrodite-type sulfide solid electrolyte Li6PS5Cl The argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) was synthesized according to the known literature 1 "J. Power Sources. 2018, 396, 33-40." Specifically, the synthesis is as follows. A sulfide solid electrolyte was obtained by grinding 0.5 g of LiS (99.9%, Mitsuwa Chemical Co., Ltd.), 0.5 g of P2S5 (99%, Sigma-Aldrich), and 0.5 g of LiCl (99%, Sigma-Aldrich) for 40 hours using a planetary ball mill (PULVERISETTE, Fritsch, Germany). The grinding was carried out in a 45 mL zirconia pot using 15 zirconia balls (diameter: 10 mm) at 600 RPM.

[0107] [Table 1]

[0108] [Table 2]

[0109] [Table 3]

[0110] Tables 4 to 6 show the physical properties (viscosity η A , η B , loss tangent tanδ1, tanδ2, tanδ3).

[0111] [Table 4]

[0112] [Table 5]

[0113] [Table 6]

[0114] (Examples 1 to 56, Comparative Examples 1 to 4) Liquid compositions 1 to 55 were used under the conditions shown in Tables 7 to 9 to carry out coating of the liquid compositions, and evaluation of scattering and film thickness uniformity was carried out.

[0115] - Application of liquid composition - To obtain the device configuration shown in FIG. 6B, a valve-type nozzle disclosed in a patent document (Patent No. 7271956) was attached to an inkjet image forming device (EV2500, manufactured by Ricoh Co., Ltd.), and the liquid composition was filled. The liquid composition was applied to a stage carrying an aluminum foil (hereinafter referred to as AL foil) substrate for the positive electrode active material, or a copper foil (hereinafter referred to as Cu foil) substrate for the negative electrode active material, while the stage was conveyed at a speed of 60 MPM, and then dried on a hot plate to obtain an electrode. For the positive electrode, the discharge conditions were set to give a film thickness of 100 μm after drying, and the drying temperature was set to 120°C. For the negative electrode, the discharge conditions were set to give a film thickness of 100 μm after drying, and the drying temperature was set to 80°C. During coating, a square image measuring 20 mm in the conveying direction and 20 mm in the perpendicular direction was formed. The printing resolution in the direction perpendicular to the conveying direction was 20 dpi (i.e., 1.25 mm intervals). If the coatable width calculated from ([printing resolution] x [number of nozzles in the direction perpendicular to the conveying direction]) was less than 20 mm, coating was performed by sliding the nozzle in the direction perpendicular to the conveying direction each time. For example, if the nozzle has eight nozzles, the coatable width is calculated as 1.25 mm x 8 = 10 mm. Therefore, to coat a 20 mm width, coating must be performed in two steps in the width direction (20 / 10 = 2). Similarly, if there is one nozzle, the coatable width is calculated as 1.25 x 1 = 1.25 mm, and the 20 mm width was coated in 16 steps (20 / 1.25 = 16). The coatable width is listed in the table. The distance between the substrate and the discharge part is as shown in the table. The liquid composition was discharged in the following three ways.

[0116] [Discharge method: VJ-continuous] During the period of coating for 20 mm in the conveying direction, the valve of the valve-type nozzle was kept open at all times to continuously discharge the liquid composition.

[0117] [Discharge method: VJ-non-continuous] During the application period of 20 mm in the conveying direction, the valve of the valve-type nozzle was opened and closed at 1 kHz to eject the liquid composition discontinuously.

[0118] [Discharge method: JD-continuous] The liquid composition was ejected under the same conditions as in "ejection method: VJ-continuous" except that a jet dispenser (manufactured by Musashi Engineering Co., Ltd.) was used as the image forming apparatus.

[0119] - Evaluation of scattering - The electrodes obtained by applying the liquid composition were inspected for the presence or absence of spatter on the substrate within a 10 mm radius around a 20 mm square electrode composite layer using a laser microscope VK-X3000 (manufactured by Keyence Corporation) equipped with a white light interferometer. If spatter was observed, the thickness of the spattered film was measured using the same instrument, and the spatter was evaluated according to the following criteria: ◎ to △△ are acceptable, and × is unacceptable. The pass criteria were set based on the experience that if spatter corresponding to × was observed, short circuits frequently occurred when a battery was fabricated using the electrode. [Evaluation criteria] ◎: No scattering observed ○: Scattering was observed and the maximum film thickness was less than 1 μm △: Scattering was observed, and the maximum film thickness was 1 μm or more and less than 5 μm. △△: Scattering was observed, and the maximum film thickness was 5 μm or more and less than 10 μm. ×: Scattering was observed and the maximum film thickness was 10 μm or more

[0120] -Evaluation of film thickness uniformity- For the electrodes obtained by applying the liquid composition, the film thickness of a 20 mm square electrode mixture layer was measured using a laser microscope VK-X3000 (manufactured by Keyence Corporation) equipped with a white light interferometer. The surface roughness within a 17 mm square surface, excluding the inner 3 mm from the edge of the electrode mixture layer, was calculated, and the film thickness uniformity was evaluated according to the following criteria: ⊚ to △ are acceptable, and × is unacceptable. Note that film thickness uniformity was not evaluated for examples other than 16 to 31, and therefore is indicated as "-" in the table. [Evaluation criteria] ◎: Surface roughness is less than 2 μm ○: Surface roughness is 2 μm or more and less than 5 μm △: Surface roughness is 5 μm or more and less than 7 μm △△: Surface roughness is 7 μm or more and less than 10 μm ×: Surface roughness is 10 μm or more

[0121] [Table 7]

[0122] [Table 8]

[0123] [Table 9]

[0124] From the results of Examples 1 to 56, η A is 1000 mPa·s or more and η B By using a liquid composition having a viscosity of 100 mPa·s or less, an electrode with reduced scattering was obtained. A When a liquid composition having a viscosity of less than 1000 mPa·s was used, scattering that did not meet the acceptance criteria was observed. B Even when using liquid compositions with a viscosity greater than 100 mPa·s, splashing that did not meet the acceptance criteria was observed.

[0125] Thus, aspects of embodiments of the present invention are, for example, as follows. <1> A liquid composition comprising an active material and a dispersion medium, Shear rate 10 -1 s -1 The viscosity at η A , shear rate 10 5 s -1 The viscosity at η B When η A is 1000 mPa·s or more and η B The liquid composition is characterized in that the viscosity is 100 mPa·s or less. <2> When the tangent loss at a strain rate of 100% is tanδ1, the tanδ1 is 1.0 or more. <1> The liquid composition according to claim 1. <3> The η A is 20,000 mPa·s or less <1> from <2> The liquid composition according to any one of the preceding claims. <4> The η B is 10 mPa·s or more <1> from <3> The liquid composition according to any one of the preceding claims. <5> When the tangent loss at a strain rate of 10% is tanδ2, it is characterized by having tanδ2 of 1.0 or more. <1> from <4> The liquid composition according to any one of the preceding claims. <6> When the tangent loss at a strain rate of 1% is tanδ3, it is characterized by tanδ3 being smaller than 1.0. <1> from <5> The liquid composition according to any one of the preceding claims. <7> <1> from <6> a container containing the liquid composition according to any one of the preceding claims; a discharge unit that discharges the liquid composition from a liquid discharge head onto a substrate; The liquid ejection device is characterized by having the above. <8> The liquid composition is ejected onto the substrate while forming a liquid column between the liquid ejection head and the substrate. <7> 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus. <9> <1> from <6> A liquid ejection method for ejecting the liquid composition according to any one of the above items, The liquid ejection method comprises ejecting the liquid composition onto a substrate while forming a liquid column between a liquid ejection head and the substrate. [Explanation of symbols]

[0126] 12A Liquid composition 31a Liquid dispensing device 31b Containment vessel 34 Base 37 Liquid composition 211 Base 300' liquid dispensing device 306 Liquid ejection head (ejection part) 307 Tank (container) 313 External Tank (Containment Vessel) [Prior art documents] [Patent documents]

[0127] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-182962 [Patent Document 2] International Publication No. 2022 / 080280 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-113838

Claims

1. A liquid composition comprising an active material and a dispersion medium, Shear rate 10 －１ s －１ The viscosity at η Ａ , shear rate 10 ５ s －１ The viscosity at η Ｂ , and then, η Ａ is 1000 mPa·s or more and η Ｂ A liquid composition characterized in that the viscosity is 100 mPa·s or less.

2. 2. The liquid composition according to claim 1, wherein tan δ1 is 1.0 or more, where tan δ1 is the loss tangent at a strain rate of 100%.

3. The η Ａ 2. The liquid composition according to claim 1, wherein the viscosity is 20,000 mPa·s or less.

4. The η Ｂ 2. The liquid composition according to claim 1, wherein the viscosity is 10 mPa·s or more.

5. 2. The liquid composition according to claim 1, wherein tan δ2, the loss tangent at a strain rate of 10%, is 1.0 or more.

6. 2. The liquid composition according to claim 1, wherein tan δ3 is smaller than 1.0, where tan δ3 is the loss tangent at a strain rate of 1%.

7. A container containing the liquid composition according to any one of claims 1 to 6; a discharge unit that discharges the liquid composition from a liquid discharge head onto a substrate; A liquid ejection device comprising:

8. 8. The liquid ejection apparatus according to claim 7, wherein the liquid composition is ejected onto the substrate while forming a liquid column between the liquid ejection head and the substrate.

9. A liquid ejection method for ejecting the liquid composition according to any one of claims 1 to 6, comprising: A liquid ejection method comprising ejecting the liquid composition onto a substrate while forming a liquid column between a liquid ejection head and the substrate.

Images