JP2022134091A - Electrode manufacturing method and electrode manufacturing apparatus - Google Patents

Abstract

To provide an electrode manufacturing method that achieves both a high degree of design freedom, high quality, and high productivity.SOLUTION: An electrode manufacturing method includes a first step of applying an electrode liquid composition containing an electrode mixture to an arbitrary position on a substrate in an arbitrary shape, a second step of acquiring information indicating a position in which the electrode liquid composition containing the electrode mixture is applied, and a third step of cutting out only the substrate at an arbitrary position in a region excluding an electrode mixture region to which the electrode liquid composition containing the electrode mixture is applied, and cutting out the electrode in an arbitrary shape.SELECTED DRAWING: Figure 6

Description

The present invention relates to an electrode manufacturing method and an electrode manufacturing apparatus.

In recent years, secondary batteries that can be charged and discharged have rapidly expanded in usage scenes, from small consumer devices such as wearable devices and smartphones to large devices such as electric vehicles and stationary storage batteries. In response to these diversified needs, it is difficult for the conventional battery electrode manufacturing method to flexibly switch the manufacturing type, and a new manufacturing method is desired.

Conventionally, positive electrodes and negative electrodes for secondary batteries are made by mixing battery materials mainly containing ceramics and carbon with sub-members such as conductive aids and binders to form a coating liquid, and this coating liquid is continuously applied on a metal substrate. It is common to manufacture by coating each by an (analog-like) coating method. As the metal substrate, for example, aluminum foil or the like is used. As a continuous (analog) coating method, for example, die coating or gravure printing is used.

The positive electrode and the negative electrode coated with the positive electrode mixture layer and the negative electrode mixture layer are processed into a required size and shape, and combined with an insulating sheet made of a separator or a solid electrolyte to form the basic structure of the cell. For shape processing, a punching method using a punching die with a Thomson blade, etc. is mainly used, and when changing the battery shape, it is necessary to change the setup such as redesigning the punching die, stopping the production line, and replacing the punching die. . In addition, as the edge shape of the positive electrode and the negative electrode becomes more complicated, quality deterioration such as chipping of the electrode mixture layer at the time of punching becomes a problem.

On the other hand, in recent years, an electrode cutting technique using a laser has been proposed (see, for example, Patent Document 1). Laser cutting technology eliminates mold redesign and setup changes, and can reduce costs associated with product changeovers. In addition, laser cutting technology has a high degree of freedom in design, making it easy to manufacture batteries of any shape that matches the shape of the device. Therefore, a battery system with high energy density can be provided by effectively utilizing the limited space.

However, if an attempt is made to cut the electrode, including the region where the electrode mixture layer is applied, with a laser, the periphery of the cut electrode will be damaged due to the effects of heat, and there is a concern that the battery performance will deteriorate. In addition, in order to cut the electrode mixture layer at the same time as compared to cutting only the metal foil of about 5 μm to 20 μm used as the base material, it is necessary to reduce the laser scanning speed or increase the number of scanning times. Action is required. As a result, the processing time using the laser becomes long, which causes a decrease in productivity and an increase in cost. Thus, conventionally, there has not been established an electrode manufacturing method with a high degree of freedom in design, high quality, and high productivity.

The present invention has been made in view of the above, and an object of the present invention is to provide an electrode manufacturing method that achieves both a high degree of freedom in design, high quality, and high productivity.

This electrode manufacturing method includes a first step of applying an electrode liquid composition containing an electrode mixture to an arbitrary position on a substrate in an arbitrary shape, and applying the electrode liquid composition containing the electrode mixture. In a second step of obtaining positional information, only the base material is cut at an arbitrary position in the region excluding the electrode mixture region to which the electrode liquid composition containing the electrode mixture is applied, and the electrode is formed into an arbitrary shape. and a third step of clipping out the .

According to the disclosed technology, it is possible to provide an electrode manufacturing method that achieves both a high degree of freedom in design, high quality, and high productivity.

4 is a plan view illustrating electrodes according to the first embodiment; FIG. 3 is a cross-sectional view illustrating an electrode according to the first embodiment; FIG. FIG. 1 is a diagram (part 1) illustrating the electrode manufacturing method according to the first embodiment; FIG. 2 is a diagram (part 2) illustrating the electrode manufacturing method according to the first embodiment; FIG. 3 is a diagram (part 3) illustrating the electrode manufacturing method according to the first embodiment; FIG. 4 is a diagram (part 4) illustrating the electrode manufacturing method according to the first embodiment; FIG. 10 is a plan view illustrating electrodes according to a second embodiment; FIG. 5 is a cross-sectional view illustrating an electrode according to a second embodiment; FIG. 10 is a diagram (part 1) illustrating the electrode manufacturing method according to the second embodiment; It is a figure (2) which illustrates the electrode manufacturing method which concerns on 2nd Embodiment. FIG. 11 is a plan view illustrating electrodes according to a modification of the second embodiment; FIG. 10 is a cross-sectional view illustrating an electrode according to a modification of the second embodiment; FIG. 11 is a cross-sectional view illustrating an electrode according to a third embodiment; It is a figure which illustrates the electrode manufacturing method which concerns on 3rd Embodiment. FIG. 11 is a cross-sectional view illustrating an electrode according to a modification of the third embodiment; It is a figure which illustrates the electrode manufacturing method based on the modification of 3rd Embodiment. 1 is a schematic diagram (part 1) illustrating an electrode manufacturing apparatus; FIG. It is an example of the main hardware block diagrams of a control apparatus. It is an example of a main functional block diagram of a control device. FIG. 2 is a schematic diagram (part 2) illustrating an electrode manufacturing apparatus;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<First Embodiment>
[Electrode structure]
FIG. 1 is a plan view illustrating electrodes according to the first embodiment. FIG. FIG. 2 is a cross-sectional view illustrating the electrode according to the first embodiment, showing a cross section along line AA of FIG.

As shown in FIGS. 1 and 2, the electrode 10 has a substrate 11 and an electrode mixture layer 12 formed on one surface 11 a of the substrate 11 . The electrode 10 can be used, for example, in electrochemical devices such as primary batteries, secondary batteries, or capacitors, and is particularly suitable for lithium ion secondary batteries. In the electrode 10, the thickness of the base material 11 is, for example, about 5 μm to 20 μm, and the thickness of the electrode mixture layer 12 is, for example, about several tens of μm to 100 μm. The planar shape of the substrate 11 and the electrode mixture layer 12 (the shape viewed from the normal direction of one surface 11a of the substrate 11) is an example, and is not limited to the shape shown in FIG.

On one surface 11a of the base material 11, the uncoated portion 11m is annularly provided outside the outer peripheral portion 12p of the electrode mixture layer 12 in plan view. The uncoated portion 11m is a portion where one surface 11a of the substrate 11 is exposed without being covered with the electrode mixture layer 12 . The portion indicated by the low-density dot pattern in FIG. 1 is the uncoated portion 11m.

The uncoated portion is not necessarily arranged outside the outer peripheral portion 12 p of the electrode mixture layer 12 . For example, a through-hole may be formed through the base material 11 and the electrode mixture layer 12. In this case,
The uncoated portion is also formed annularly inside the inner peripheral portion of the electrode mixture layer 12 (that is, around the through-hole provided in the substrate 11) in plan view.

1 and 2, the X direction is the longitudinal direction of the electrodes 10. As shown in FIG. Also, the Y direction is the lateral direction of the electrodes 10 . Also, the Z direction is the thickness direction of the electrode 10 . The X direction, Y direction, and Z direction are orthogonal to each other.

[Method for manufacturing electrode]
Next, a method for manufacturing an electrode according to the first embodiment will be described. The electrode mixture layer 12 can be formed on the base material 11 by using an electrode liquid composition, which is a material for forming the electrode mixture layer 12, and applying a printing process. As the printing process, it is preferable to use a printing method that can apply the electrode liquid composition in any desired shape to any desired position according to digital data. Ink jet printing is particularly preferable because it enables direct printing of digital images. Here, the digital data refers to information relating to the number or amount, such as the application amount, application shape, or application position of the electrode liquid composition containing the electrode mixture, which is represented by a series of numerical values.

In the following, the electrode manufacturing method according to the first embodiment will be described with an example of using inkjet printing.

(Step of applying an electrode liquid composition containing an electrode mixture onto a substrate)
FIG. 3 is a diagram (part 1) illustrating the electrode manufacturing method according to the first embodiment, and schematically shows a step of applying an electrode liquid composition containing an electrode mixture onto a substrate.

In FIG. 3, the electrode manufacturing apparatus 100 has an inkjet head 101A, an image sensor 102A, and a conveyor belt 103. As shown in FIG. The electrode manufacturing apparatus 100 may have multiple inkjet heads and multiple image sensors.

The inkjet head 101A is a line head and ejects an electrode liquid composition such as ink containing the electrode mixture 12A onto the substrate 11 . The inkjet head 101A has a plurality of nozzles arranged in a direction perpendicular to the transport direction. The inkjet head 101A can apply the electrode liquid composition containing the electrode mixture 12A to any position on the substrate 11 in any shape.

The image sensor 102A acquires, for example, positional information to apply the electrode liquid composition containing the electrode mixture 12A. The image sensor 102A is, for example, a CCD (Charge Coupled Device), a CMD (Cold Metal Detector), or a CMOS (Complementary Metal Oxide Semiconductor) sensor. The image sensor 102A can be appropriately selected from among these according to the required reading accuracy and speed.

The conveyor belt 103 is, for example, an endless belt, and is looped around two rollers. Here, the conveying direction (sub-scanning direction) of the conveying belt 103 is defined as the Y direction, and the direction (main scanning direction) perpendicular to the conveying direction is defined as the X direction. These directions coincide with the X and Y directions in FIGS.

Before the electrode liquid composition containing the electrode mixture 12A is applied onto the substrate 11, the electrode manufacturing apparatus 100 detects a position where the electrode liquid composition containing the electrode mixture 12A on the substrate 11 is to be applied by using an image sensor. A decision is made based on the information obtained in 102A. For example, the image sensor 102A reads the distance from the end portion 11e of the base material 11 along the width direction (X direction) of the base material 11, and adjusts the speed of the base material 11 along the conveyance direction Y to convey the distance. to calculate the application interval of the electrode liquid composition containing the electrode mixture 12A.

As shown in FIG. 3 , for example, a long base material 11 is arranged on the conveying belt 103 . While the conveying belt 103 conveys the substrate 11 along the conveying direction Y, the inkjet head 101A ejects the electrode liquid composition containing the electrode mixture 12A from the nozzles. As a result, the electrode liquid composition containing the electrode mixture 12A having a predetermined shape is applied onto the substrate 11 . After being applied to the base material 11 , the electrode liquid composition containing the electrode mixture 12</b>A is dried in a drying process to form the electrode mixture layer 12 .

By using a method such as inkjet printing that can directly print a digital image, the electrode liquid composition containing the electrode mixture 12A can be printed on the substrate 11 in any position and in any shape based on the digital source. Can be applied. Digital data can be created by using commercially available drawing software such as Adobe Illustrator.

(Step of Acquiring Position Information Where Electrode Liquid Composition Containing Electrode Mixture is Applied)
4 and 5 are diagrams (part 2) and (part 3) illustrating the electrode manufacturing method according to the first embodiment. The process of acquiring the positional information of the electrode liquid composition containing ) is schematically shown.

The position information of the electrode mixture layer 12 can be acquired by image recognition, for example. Alternatively, the positional information of the electrode mixture layer 12 can be obtained by irradiating the base material 11 and the electrode mixture layer 12 with light and receiving the reflected light to detect a step between the base material 11 and the electrode mixture layer 12. It may be acquired by the method of The method using image recognition is preferable in that it is less susceptible to disturbances such as vibration of the conveyor belt 103 and can accurately acquire the positional information of the electrode mixture layer 12 . In the following, an example of acquiring the position information of the electrode mixture layer 12 by image recognition will be described.

As shown in FIG. 4, the position information of the electrode mixture layer 12 can be acquired using the image sensor 102B. Specifically, the image sensor 102B, for example, images the end shape 12e of the electrode mixture region (the region where the electrode mixture layer 12 is formed) coated with the electrode liquid composition containing the electrode mixture 12A. By recognizing it, the positional information of the electrode mixture layer 12 can be acquired.

Further, as shown in FIG. 5, the image sensor 102B is formed in a region excluding the electrode mixture region (the region where the electrode mixture layer 12 is formed) coated with the electrode liquid composition containing the electrode mixture 12A. The positional information of the electrode mixture layer 12 may be obtained by image recognition of the mark (alignment mark). Specifically, positional information of the electrode mixture layer 12 can be image-recognized using at least two alignment marks 300 provided in the vicinity of the electrode mixture layer 12 . Note that one image sensor may be arranged for each alignment mark.

Among these, the method of image recognition using the alignment mark 300 is preferable in that it does not require a change in image recognition algorithm depending on the shape of the electrode mixture layer 12 . Alignment marks 300 can be formed, for example, by inkjet printing or laser engraving.

When inkjet printing is used, the alignment mark 300 can be formed by printing a color material recognizable by the image sensor 102B on the base material 11 in, for example, a cross shape. The coloring material used for forming the alignment mark 300 may be the same material as the material used for forming the electrode mixture layer 12, or the material used for forming the electrode mixture layer 12 as long as it is a coloring material that can be ejected by inkjet. A different material may be used.

At this time, it is preferable to use the same material as the material used for forming the electrode mixture layer 12 as the coloring material for the alignment mark 300 . As a result, the inkjet head and ink for printing the material used for forming the alignment mark 300 can be shared with the inkjet head and ink for printing the material used for forming the electrode mixture layer 12, and the configuration of the printing system can be simplified. .

The alignment mark 300 may be formed using a laser other than the printing described above. For example, a laser may be used to form, for example, a cross-shaped through-hole in the substrate 11 , and this through-hole may be used as the alignment mark 300 .

(Step of cutting out electrodes)
FIG. 6 is a diagram (part 4) illustrating the electrode manufacturing method according to the first embodiment, and schematically shows a step of cutting out an electrode in an arbitrary shape.

After recognizing the positional information of the electrode mixture layer 12 (that is, the positional information of the electrode liquid composition containing the applied electrode mixture 12A) by image recognition, the electrode liquid composition containing the electrode mixture 12A was applied. Only the base material 11 is cut at an arbitrary position in the area excluding the electrode mixture area. For example, as shown in FIG. 6, at an arbitrary position 11c outside the electrode mixture layer 12 of the substrate 11 (i.e., a region not coated with the electrode liquid composition containing the electrode mixture 12A), 11 only. As a result, an electrode 10 (see FIGS. 1 and 2) having an arbitrary shape can be produced by cutting out the electrode liquid composition containing the electrode mixture 12A.

As a method for cutting only the base material 11, a method in which a processing position can be arbitrarily designated by digital data is preferable, and a laser beam 104L emitted from a laser head 104 is more preferable. An attenuator for laser power adjustment, a reflecting mirror, a beam expander for laser beam diameter adjustment, a galvanometer scanner for laser scanning, a condenser lens, etc. are required between the laser head 104 and the substrate 11. You may prepare accordingly. As the wavelength range of the laser light 104L, it is preferable to use a wavelength range from visible to ultraviolet from the viewpoint of processing accuracy, and the oscillation pulse width is preferably shorter than nanoseconds and several tens of picoseconds in consideration of the thermal influence of the base material 11. is more preferable.

(Effect of combining digital printing and digital processing technology)
As described above, by combining inkjet printing, which is a digital printing technology, and laser cutting technology, which is a digital processing technology, for example, by changing the digital data commonly available for each, the electrode mixture layer 12 of an arbitrary shape can be manufactured efficiently. In other words, the electrode manufacturing apparatus 100 stores, as digital data, an arbitrary position at which the electrode liquid composition containing the electrode mixture is applied, an arbitrary shape of the electrode liquid composition containing the electrode mixture, and an arbitrary position at which the substrate is cut. can be controlled by This makes it possible to realize an electrode manufacturing method with a high degree of freedom in design.

Regarding the cutting of electrodes by laser cutting, for example, Patent Document 1 (JP 2018-129222), Patent Document 2 (JP 6432990), Patent Document 3 (JP 2012-221912), and Patent Document 4 (Japanese Unexamined Patent Application Publication No. 2018-37143). However, all of these disclosed technologies are methods in which the electrode liquid composition containing the electrode mixture applied together with the base material is also cut by a laser for electrodes intermittently or continuously coated with a material forming the electrode. be.

In these methods, the laser cutting efficiency of the electrode liquid composition containing the base material and the electrode compound material differs greatly. Therefore, as disclosed in Patent Document 3, it is necessary to change the laser intensity according to changes in the cut site, and as disclosed in Patent Document 4, depending on the material of the electrode liquid composition containing the electrode mixture, the laser energy may not be absorbed. As a result, the process of manufacturing the electrode becomes complicated, such as the need for a process of printing the laser light absorbing member.

In addition, since the cutting speed of the electrode liquid composition containing the electrode mixture is much lower than the cutting speed of the base material, the production efficiency in the electrode cutting process is lowered. Further, Patent Document 1 (Japanese Patent Application Laid-Open No. 2018-129222) discloses that the thermal effect of laser cutting on an electrode liquid composition containing an electrode mixture cannot be ignored.

In the electrode manufacturing method according to the first embodiment, in order to solve such a problem, the electrode liquid composition containing the electrode mixture 12A is digitally printed in an arbitrary shape. Only the base material 11 can be laser-cut in such a way as to avoid the position where the is applied. By cutting only the base material 11 without cutting the electrode mixture layer 12 at all, it is possible to suppress the complexity of the process such as the detailed design of the laser intensity in the electrode cutting process and the decrease in productivity. It is possible to obtain an electrode of any shape with stable quality without the thermal influence of the electrode liquid composition containing the electrode mixture in the above. That is, in the electrode manufacturing method according to the first embodiment, it is possible to realize an electrode manufacturing method with high quality and high productivity.

In the electrode manufacturing method according to the first embodiment, only the base material 11 is cut by laser while avoiding the electrode mixture layer 12. Therefore, as shown in FIGS. 1 and 2, the electrode mixture layer 12 is not formed. An uncoated portion 11m is provided on one surface 11a of the substrate 11 located around the electrode mixture region. The length L (see FIG. 1) of the uncoated portion 11m can be appropriately adjusted according to the oscillation pulse width in laser cutting, but is preferably 10 μm or more and 500 μm or less. If the length L is less than 10 μm, the electrode liquid composition containing the electrode mixture forming the electrode mixture layer 12 is affected by heat and deteriorates. If the length L is more than 500 μm, the ratio of the area occupied by the electrode mixture layer 12 to the area of the base material 11 will decrease, resulting in a decrease in the energy density of the battery.

The electrode 10 will be described in detail below.

(Base material 11)
Various metal foils or insulating substrates can be used for the substrate 11 . The form of the base material 11 is not particularly limited, and may be, for example, a sheet or a long band. Metal foils include copper foil, aluminum foil, stainless steel foil, nickel foil, and the like. Examples of insulating substrates include glass, glass epoxy, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), cellulose paper, rubber, and the like.

(Electrode Liquid Composition Containing Electrode Mixture 12A))
The electrode liquid composition applied by inkjet printing contains at least one of a positive electrode active material and a negative electrode active material. The electrode liquid composition applied by inkjet printing further becomes a gel electrolyte through a dispersion medium, a dispersant, a conductive aid, a binder, a non-aqueous electrolyte, a solid electrolyte, a gel electrolyte, or a polymerization process, if necessary. It may contain one or more of the monomers.

(Positive electrode active material)
The positive electrode active material may be used alone, or two or more kinds may be mixed and used. The positive electrode active material is not particularly limited as long as it can reversibly occlude and release alkali metal ions, but an alkali metal-containing transition metal compound can be used.

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

Lithium-containing transition metal compounds include, for example, lithium-containing transition metal oxides such as lithium cobaltate, lithium nickelate, and lithium manganate.

As the alkali metal-containing transition metal compound, a polyanionic compound having an XO ₄ tetrahedron (X=P, S, As, Mo, W, Si, etc.) in the crystal structure can also be used. Among these, a lithium-containing transition metal phosphate compound such as lithium iron phosphate or lithium vanadium phosphate is preferable in terms of cycle characteristics. In particular, lithium vanadium phosphate has a high lithium diffusion coefficient and excellent output characteristics.

From the viewpoint of electron conductivity, it is preferable that the surface of the polyanionic compound is coated with a conductive agent such as a carbon material to form a composite.

Examples of sodium-containing transition metal compounds include NaMO ₂ type oxides, sodium chromite (NaCrO ₂ ), sodium ferrate (NaFeO ₂ ), sodium nickelate (NaNiO ₂ ), sodium cobaltate (NaCoO ₂ ), sodium manganate (NaMnO _{2 ), sodium vanadate (NaVO 2 )} , and the like. Part of M may be substituted with at least one selected from the group consisting of metal elements other than M and Na, such as Cr, Ni, Fe, Co, Mn, V, Ti, and Al. Also, _Na2FePO4F , _NaVPO4F , _NaCoPO4 , _NaNiPO4 , _NaMnPO4 , _{NaMn1.5Ni0.5O4} , or _{Na2V2 ( PO4} ) as _{sodium - containing} metal _oxides . ₃ or the like can also be used.

(Negative electrode active material)
As the negative electrode active material, a material capable of intercalating and deintercalating a metal alloyed with alkali metal ions such as Li ions or Na ions can be used. Examples of such materials include composite oxides of transition metals and Li, metal oxides, alloy materials, inorganic compounds such as transition metal sulfides, carbon materials, organic compounds, Li metal, and Na metal. be done.

The composite oxides include LiMnO ₂ , LiMn ₂ O ₄ , lithium titanate (Li ₄ Ti ₅ O ₁₂ , Li ₂ Ti ₃ O ₇ ), lithium manganese titanate (LiMg _1/2 Ti _3/2 O ₄ ), lithium cobalt titanate (LiCo _1/2 Ti _3/2 O ₄ ), lithium zinc titanate (LiZn _1/2 Ti _3/2 O ₄ ), lithium iron titanate (LiFeTiO ₄ ), lithium chromium titanate (LiCrTiO ₄ ), lithium strontium titanate (Li ₂ SrTi ₆ O ₁₄ ), or lithium barium titanate (Li ₂ BaTi ₆ O ₁₄ ).

Examples of sodium composite oxides include sodium titanate such as Na ₂ Ti ₃ O ₇ and Na ₄ Ti ₅ O ₁₂ . Part of Ti or Na in sodium titanate may be replaced with other elements. Such elements include, for example, at least one selected from the group consisting of Ni, Co, Mn, Fe, Al, and Cr.

Examples of metal oxides include TiO ₂ , Nb ₂ TiO ₇ , WO ₃ , MoO ₂ , MnO ₂ , V ₂ O ₅ , SiO ₂ , SiO, SnO ₂ and the like.

Examples of alloy materials include Al, Si, Sn, Ge, Pb, As, Sb, and the like. Examples of transition metal sulfides include FeS and TiS. Examples of carbon materials include graphite, non-graphitizable carbon, and graphitizable carbon. As the inorganic compound, a compound obtained by substituting a different element for the transition metal of the above composite oxide may be used.

These negative electrode active materials may be used singly or in combination of two or more.

(dispersion medium)
The dispersion medium is not particularly limited as long as it can disperse the active material, but water, an aqueous dispersion medium such as ethylene glycol or propylene glycol, N-methyl-2-pyrrolidone, 2-pyrrolidone, cyclohexanone, Ethyl lactate, butyl acetate, mesitylene, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether , dibutyl ether, diethyl ether, di-tert-butyl ether, 2-n-butoxymethanol, 2-dimethylethanol, N,N-dimethylacetamide, anisole, diethoxyethane, normal hexane, heptane, octane, nonane, decane, or Examples include organic dispersion media such as p-menthane. In addition, a dispersion medium may be used individually and may use 2 or more types together.

(Conductivity aid)
The conductive aid may be compounded with the active material in advance, or may be added when the dispersion is prepared.

As the conductive aid, for example, in addition to conductive carbon black formed by a furnace method, an acetylene method, a gasification method, or the like, carbon materials such as carbon nanofibers, carbon nanotubes, graphene, or graphite particles can be used. can.

As the conductive aid other than the carbon material, for example, metal particles such as aluminum, or metal fibers can be used.

The mass ratio of the conductive aid to the active material is preferably 10% or less, more preferably 8% or less. When the mass ratio of the conductive aid to the active material is 10% or less, the stability of the dispersion is improved.

(dispersant)
The dispersant is not particularly limited as long as it can improve the dispersibility of the active material, polymer particles, or conductive aid in the dispersion medium. Condensation type, polyethylene glycol, polycarboxylic acid partial alkyl ester type, polyether type, polymer type such as polyalkylene polyamine type, alkyl sulfonic acid type, quaternary ammonium type, higher alcohol alkylene oxide type, polyhydric alcohol ester type, Surfactant type such as alkyl polyamine type, inorganic type such as polyphosphate type, and the like can be mentioned.

(binder)
The binder is added when the binding between the positive electrode materials or between the negative electrode materials, or the binding between the positive electrode material or the negative electrode material and the electrically conductive layer is not sufficient with the dispersant or the electrolyte material, thereby ensuring the binding force. be able to. The binder is not particularly limited as long as it can impart a binding force, but from the viewpoint of inkjet ejection properties, a compound that does not increase viscosity is preferred. As for the binder, there is a method of polymerizing a monomer compound after inkjet printing, or using polymer particles. As a material that does not increase the viscosity of the liquid composition, a polymer compound that can be dispersed in a dispersion medium can be used. When using a polymer compound that can be dissolved in a dispersion medium, the liquid composition in which the polymer compound is dissolved in the dispersion medium may have a viscosity that allows it to be ejected from the liquid ejection head. .

Examples of using a monomer compound include a method of applying a dispersion containing a compound having a polymerizable site and a polymerization initiator or a catalyst, in which the compound having a polymerizable site is dissolved, followed by heating, or non-ionizing. A method of irradiating radiation, ionizing radiation, or infrared rays can be mentioned.

In the compound having a polymerizable site, the polymer site may be singular or multifunctional in the molecule. In addition, a polyfunctional polymerizable compound means a compound having two or more polymerizable groups. The polyfunctional polymerizable compound is not particularly limited as long as it can be polymerized by heating or irradiation with non-ionizing radiation, ionizing radiation, or infrared rays. Examples of polyfunctional polymerizable compounds include acrylate resins, methacrylate resins, urethane acrylate resins, vinyl ester resins, unsaturated polyesters, epoxy resins, oxetane resins, vinyl ethers, and resins utilizing en-thiol reactions. be done. Among these, acrylate resins, methacrylate resins, urethane acrylate resins, or vinyl ester resins are preferable from the viewpoint of productivity.

Materials constituting the polymer particles include, for example, polyvinylidene fluoride, acrylic resin, polyamide compound, polyimide compound, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene copolymer, nitrile-butadiene rubber (HNBR ), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethyl methacrylic acid (PMMA), polyethylene vinyl acetate (PEVA), polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, or poly butylene tephthalate and the like.

Examples of polymer compounds include polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol ( PEO), polymethyl methacrylic acid (PMMA), or polyethylene vinyl acetate (PEVA).

The mass ratio of the binder to the active material is preferably 10% or less, more preferably 5% or less. When the mass ratio of the binder to the active material is 10% or less, the binding strength at the time of electrode formation is improved without impairing the dischargeability.

<Second embodiment>
The second embodiment shows an example of an electrode having an electron insulating layer. FIG. 7 is a plan view illustrating electrodes according to the second embodiment. FIG. 8 is a cross-sectional view illustrating an electrode according to the second embodiment, showing a cross section along line BB of FIG.

As shown in FIGS. 7 and 8, the electrode 20 differs from the electrode 10 (see FIGS. 1 and 2) in that an electron insulating layer 21 is formed. It is preferable that the electron insulating layer 21 covers the entire upper surface and side surfaces of the electrode mixture layer 12 and that there is no portion of the electrode mixture layer 12 exposed from the electron insulating layer 21 .

On one surface 11a of the substrate 11, the uncoated portion 11n is annularly provided outside the outer peripheral portion 21p of the electronic insulating layer 21 in plan view. The uncoated portion 11n is a portion where one surface 11a of the substrate 11 is exposed without being covered with the electrode mixture layer 12 or the electronic insulating layer 21 . The portion indicated by the low-density dot pattern in FIG. 7 is the uncoated portion 11n.

(Laminate application of solid electrolyte or gel electrolyte, etc.)
FIG. 9 is a diagram illustrating an electrode manufacturing method according to the second embodiment. As shown in FIG. 4 or 5, after the positional information of the electrode mixture layer 12 is acquired by image recognition, a solid electrolyte is used to form the electron insulating layer 21 on the electrode mixture layer 12 as shown in FIG. Alternatively, an electrolyte liquid composition 21A containing a gel electrolyte is inkjet printed. At this time, the electrolyte liquid composition 21A is applied so as to cover the entire electrode mixture layer 12 (upper surface and side surfaces). The electrolyte liquid composition 21A becomes the electronic insulating layer 21 when dried. Note that the electrolyte liquid composition 21A is an example of a liquid composition that does not contain an active material but contains an electronic insulating layer forming material. The electronic insulating layer forming material is here a solid electrolyte or a gel electrolyte.

Further, as in the first embodiment, the substrate 11 is cut out at any position in the region where the electron insulating layer 21 is not formed (region where the electrolyte liquid composition 21A is not applied). As a result, as shown in FIGS. 7 and 8, in the electrode 20, the electrode mixture layer 12 can be prevented from being exposed, and the electrode end portion can prevent a short circuit inside the battery due to slipping of the active material or the like. structure is obtained.

(Electrolyte liquid composition)
As the electrolyte liquid composition 21A, for example, a liquid composition in which a solid electrolyte is dispersed in a dispersion medium can be used. The electrolyte liquid composition 21A may further contain a dispersant, a binder, or a monomer that becomes a polymer through a polymerization process, if necessary. The average particle size of the solid electrolyte is preferably 10 μm or less, more preferably 5 μm or less. When the average particle size of the solid electrolyte is 10 μm or less, the ejection stability and sedimentation resistance of the liquid composition are improved. d10 of the solid electrolyte is preferably 0.1 μm or more. When the d10 of the solid electrolyte is 0.1 μm or more, the storage stability of the liquid composition is improved.

The electrolyte liquid composition of the present embodiment may contain no solid electrolyte and may contain a gel electrolyte. A gel electrolyte includes a resin, a non-aqueous electrolyte, an ionic liquid, glyme, or an electrolyte salt, as described above. The viscosity of the liquid composition at 25° C. is preferably in the range of 3 mPa·s to 100 mPa·s. More preferably, it is 9 mPa·s or more and 50 mPa·s or less.

(Solid electrolyte or gel electrolyte)
(Ceramic solid electrolyte for lithium-ion secondary batteries)
As the electrolyte, a ceramic solid electrolyte such as an oxide or a sulfide, a gel electrolyte, or a composite electrolyte of ceramics and polymer can be used.

As oxides, LISICON type oxides such as γ-Li ₃ PO ₄ , Li ₃ BO ₄ , 0.75Li ₄ GeO ₄ -0.25Li ₂ ZnGeO ₄ solid solution, Li ₄ SiO ₄ -Zn ₂ SiO ₄ solid solution, Li Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ or Li _1.6 Al _0.6 Ge _0.8 Ti _0.6 which is ₄ GeO ₄ —Li ₃ VO ₄ solid solution, NASICON type oxide (PO ₄ ) ₃ , perovskite structure (Li,La)TiO ₃ , garnet oxides La ₅ Li ₃ Nb ₂ O ₁₂ , Li ₅ La ₃ TaO ₁₂ , or Li ₇ La ₃ Zr ₂ O ₁₂ is mentioned.

Sulfides include Li ₄ GeS ₄ —Li ₃ PS ₄ solid solution, Li ₄ SiS ₄ —Li ₃ PS ₄ solid solution, Li ₃ PS ₄ —Li ₂ S solid solution, Li ₂ SP ₂ S ₅ solid solution, Li ₂ S -SiS ₂ , Li ₁₀ GeP ₂ S ₁₂ , Argyrodite-type Li ₆ PS ₅ X (X=Cl, Br, I), or L ₇ P ₃ S ₁₁ crystals.

(Ceramic solid electrolyte for sodium-ion secondary batteries)
Examples of oxides include NASICON-type Na _1+x Zr ₂ Si _x P _3-x O ₁₂ (0≦x≦1) or β-alumina-type Na ₂ O-11Al ₂ O ₃ . Sulfides include Na ₂ SP ₂ S ₅ , Na ₃ PS ₄ , Na ₃ SbS ₄ , Na ₂ S—SiS ₂ , Na ₂ S—GeS ₂ and the like. Selenides include Na ₃ PSe ₄ and the like.

(gel electrolyte)
Gel electrolytes include resins and non-aqueous electrolytes, ionic liquids, glymes, or electrolyte salts. Resins for gel electrolytes include the polymers and polymerizable monomers used in the above binders.

The electrode liquid composition for printing the alignment mark 300 may be an electrode liquid composition containing a positive electrode active material, a negative electrode active material, a conductive material such as a conductive aid, or an insulating material such as a solid electrolyte or a semi-solid electrolyte. It may also be an electrode liquid composition part containing an elastic material. Considering adhesion to the electrode mixture layer due to falling off during cutting, printing with an electrode liquid composition made of an insulating material such as a solid electrolyte or a semi-solid electrolyte is more preferable from the viewpoint of safety.

(Non-aqueous electrolyte)
At least one of the above resins for a gel electrolyte and a non-aqueous electrolyte solution containing an electrolyte salt are mixed so that the weight ratio of the non-aqueous electrolyte solution to the resin is in the range of 50% or more and 2000% or less. The concentration of the electrolyte salt in the non-aqueous electrolyte can be appropriately selected depending on the purpose. It is preferably 2 mol/L to 4 mol/L. The non-aqueous electrolyte is not particularly limited and can be appropriately selected according to the purpose, but an aprotic organic solvent is preferred.

As the aprotic organic solvent, a carbonate-based organic solvent such as a chain carbonate or a cyclic carbonate can be used. Among these, chain carbonates are preferred because they have high dissolving power for electrolyte salts. Also, the aprotic organic solvent preferably has a low viscosity from the viewpoint of ejection stability.

Examples of chain carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and the like.

The content of the chain carbonate in the non-aqueous solvent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50% by mass or more. When the content of the chain carbonate in the non-aqueous solvent is 50% by mass or more, even if the solvent other than the chain carbonate is a cyclic substance with a high dielectric constant (for example, a cyclic carbonate or a cyclic ester), the cyclic substance content is reduced. Therefore, even if a non-aqueous electrolytic solution having a high concentration of 2 M or more is prepared, the viscosity of the non-aqueous electrolytic solution is lowered, and the penetration of the non-aqueous electrolytic solution into the electrode and ion diffusion are improved.

Examples of cyclic carbonates include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), and the like.

As the non-aqueous solvent other than the carbonate-based organic solvent, if necessary, an ester-based organic solvent such as a cyclic ester or a chain ester, an ether-based organic solvent such as a cyclic ether, or a chain ether may be used. can.

Cyclic esters include, for example, γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone, and the like.

Examples of chain esters include alkyl propionate, dialkyl malonate, alkyl acetate (methyl acetate (MA), ethyl acetate, etc.), or alkyl formate (methyl formate (MF), ethyl formate, etc.). etc.

Cyclic ethers include, for example, tetrahydrofuran, alkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, 1,4-dioxolane and the like.

Examples of chain ethers include 1,2-dimethoxyethane (DME), diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, and the like.

(ionic liquid)
For ionic liquids, the cationic species are at least Li ⁺ or Na ⁺ , BMP (1-butyl-1-methylpyrrolidinium), EMI (1-ethyl-3-methylimidazolium), and BMMI (1-butyl-2,3-dimethylimidazolium). The anionic species, including one, is TFSI (bis(trifluoromethanesulfonyl)imide) or FSI (bisfluorosulfonyl)imide.

(grime)
As the glyme, use triflyme (G3) or tetraglyme (G4) of R—O—(CHCHO) _n —R with n=3, 4, which generally forms a stable Lewis acid-base type 1:1 complex cation. can be done.

(electrolyte salt)
The electrolyte salt is not particularly limited as long as it has high ionic conductivity and is soluble in a non-aqueous solvent. The electrolyte salt preferably contains a halogen atom. Examples of cations constituting the electrolyte salt include lithium ions, sodium ions, and the like. Anions constituting the electrolyte salt include, for example, BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (FSO ₂ ) ₂ N ⁻ , or (CF ₃ SO ₂ ) ₃ C ^{− and} the like.

The _{lithium salt} is not particularly limited and can be appropriately selected depending _on the intended purpose. lithium trifluoromethosulfonate ( _LiCF3SO3 ) _, lithium bis(trifluoromethylsulfonyl)imide (LiN _{( CF3SO2} ) ₂ ), lithium ( _{bispentafluoroethylsulfonyl} ) or imide (LiN( _C2F5 SO ₂ ) ₂ ) and the like. Among these, LiPF ₆ is preferable from the point of ionic conductivity, and LiBF ₄ is preferable from the point of stability.

The sodium _salt is not particularly limited and can be appropriately selected depending _on the intended purpose. ₆ ), sodium trifluoromethosulfonate ( _NaCF3SO3 ), sodium _bis (trifluoromethylsulfonyl)imide (NaN( _CF3SO2 ) ₂ ), or sodium ( _{bispentafluoroethylsulfonyl} )imide (NaN(C ₂ F ₅ SO ₂ ) ₂ ) and the like. In addition, electrolyte salt may be used individually and may use 2 or more types together.

(Inorganic particles)
In addition, the gel electrolyte may contain inorganic particles. Examples of inorganic particles include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and γ-Li ₃ PO ₄ , Li ₃ BO ₄ and 0.75Li ₄ GeO ₄ − which are LISICON type oxides of oxide solid electrolyte materials. 0.25 Li ₂ ZnGeO ₄ solid solution, Li ₄ SiO ₄ -Zn ₂ SiO ₄ solid solution, Li ₄ GeO ₄ -Li ₃ VO ₄ solid solution, Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ or _{Li1.6Al0.6Ge0.8Ti0.6} ( _PO4 ) _{3 ,} perovskite structure ₍ Li _, La) _{TiO3 ,} garnet oxide _{La5Li3Nb 2} O ₁₂ , Li ₅ La ₃ TaO ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ and the like. At least one of these inorganic particles and the ionic liquid are mixed so that the weight ratio of the ionic liquid to the inorganic particles is in the range of 50% or more and 200% or less.

(Method for producing electrode liquid composition)
To prepare the electrode liquid composition, the active material is dispersed in the dispersion medium, the ionic liquid, the glyme, and the non-aqueous electrolyte. The average particle size of the active material is preferably 10 μm or less, more preferably 5 μm or less. When the average particle size of the active material is 10 μm or less, the ejection stability and sedimentation resistance of the electrode liquid composition are improved. The d10 of the active material is preferably 0.1 μm or more, more preferably 0.15 μm or more. When the d10 of the active material is 0.1 μm or more, the storage stability of the electrode liquid composition is improved. The electrode liquid composition of the first embodiment may further contain a conductive aid, a dispersant, a binder, a solid electrolyte, a gel electrolyte, or a monomer that becomes a gel electrolyte through a polymerization process, if necessary. The viscosity of the electrode liquid composition at 25° C. is preferably in the range of 3 mPa·s to 100 mPa·s. More preferably, it is 9 mPa·s or more and 50 mPa·s or less.

Here, the average particle size means a volume average particle size based on an effective diameter, and the average particle size is measured by, for example, a laser diffraction/scattering method or a dynamic light scattering method. In addition, the viscosity of the electrode liquid composition at 25° C. was determined by a B-type viscometer (cone plate type viscometer). Measured at 100 rpm with a CPA-40Z rotor installed.

(Formation of separator)
As shown in FIG. 4 or 5, after the position information of the electrode mixture layer 12 is acquired by image recognition, polymerization is possible to form the electron insulating layer 21 on the electrode mixture layer 12 as shown in FIG. An insulating layer liquid composition 21B containing a compound having moieties is inkjet printed. At this time, the insulating layer liquid composition 21B is applied so as to cover the entire electrode mixture layer 12 (upper surface and side surfaces). The insulating layer liquid composition 21B forms a crosslinkable structure by light irradiation or heat, and becomes the electronic insulating layer 21 when dried. The insulating layer liquid composition 21B is an example of a liquid composition that does not contain an active material but contains an electronic insulating layer forming material.

(Electron insulating layer forming material)
The polymerizable compound corresponds to a precursor of a resin for forming the electronic insulating layer 21, and is not particularly limited as long as it is a resin capable of forming a crosslinkable electronic insulating layer by light irradiation or heat. , acrylate resins, methacrylate resins, urethane acrylate resins, vinyl ester resins, unsaturated polyester resins, epoxy resins, oxetane resins, vinyl ethers, or resins utilizing ene-thiol reactions. Among these resins, acrylate resins, methacrylate resins, urethane acrylate resins, and vinyl ester resins, which are highly reactive and can easily form an electronic insulating layer by radical polymerization, are particularly preferable from the viewpoint of productivity.

The above resin can be obtained by preparing a mixture of a polymerizable monomer that can be cured by light or heat and a compound that generates radicals or acids by light or heat. In order to form the electronic insulating layer 21 by polymerization-induced phase separation, ink may be prepared by mixing the above mixture with porogen in advance.

The polymerizable compound has at least one radically polymerizable functional group. Examples thereof include monofunctional, difunctional, or trifunctional or higher radically polymerizable compounds, functional monomers, and radically polymerizable oligomers. Among these, difunctional or higher radically polymerizable compounds are particularly preferred.

Examples of monofunctional radically polymerizable compounds include 2-(2-ethoxyethoxy) ethyl acrylate, methoxypolyethylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, phenoxypolyethylene glycol acrylate, 2-acryloyloxyethyl succinate, 2- ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexylcarbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate , phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, or styrene monomer. These may be used individually by 1 type, or may use 2 or more types together.

Examples of bifunctional radically polymerizable compounds include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, 6-hexanediol dimethacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, neopentyl glycol diacrylate, or tricyclodecane dimethanol diacrylate etc. These may be used individually by 1 type, or may use 2 or more types together.

Trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, and trimethylolpropane triacrylate. Acrylates, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate, PO-modified glycerol triacrylate, tris(acryloxyethyl ) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol tri acrylates, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxy tetraacrylate, EO-modified phosphoric acid triacrylate, or 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, and the like. These may be used individually by 1 type, or may use 2 or more types together.

A photoradical generator can be used as the photopolymerization initiator. For example, photoradical polymerization initiators such as Michler's ketone and benzophenone known under the trade names of Irgacure and Darocure, more specific compounds include benzophenone, acetophenone derivatives such as α-hydroxy- or α-aminocetophenone, -aroyl-1,3-dioxolane, benzyl ketal, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, pp'-dichlorobenzophene, pp '-Bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzyl dimethyl ketal, tetramethylthiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, azobisisobutyronitrile, benzoin peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, methylbenzoyl Benzoin alkyl ethers and esters such as formate, zoin isopropyl ether, benzoin methyl ether, benzoin ethyl ether, ben ether, benzoin isobutyl ether, benzoin n-butyl ether, benzoin n-propyl, 1-hydroxy-cyclohexyl-phenyl- Ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethane-1- on, bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, bis(2,4,6- trimethylbenzoyl)-phenylphosphine oxide, 2-methyl-1[4-(methylthio)phenyl]-2-morifolinopropan-1-one, 2-hydroxy-2-methyl-1-phenyl-propane-1- On (Darocure 1173), bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2- Methyl-1-propan-1-one monoacyl Phosphine oxide, bisacylphosphine oxide or titanocene, fluorescene, anthraquinone, thioxanthone or xanthone, lophine dimer, trihalomethyl compound or dihalomethyl compound, active ester compound, organoboron compound, and the like are preferably used.

Furthermore, a photocrosslinkable radical generator such as a bisazide compound may be contained at the same time. Further, when the polymerization is carried out only by heat, a usual thermal polymerization initiator such as A (AIBN), which is a usual photoradical generator, can be used.

On the other hand, a similar function can be achieved by preparing a mixture of a photoacid generator that generates an acid upon irradiation with light and at least one monomer that polymerizes in the presence of an acid. When such a liquid ink is irradiated with light, the photoacid generator generates an acid, and this acid functions as a catalyst for the cross-linking reaction of the polymerizable compound.

Also, the generated acid diffuses within the ink layer. Moreover, the acid diffusion and the acid-catalyzed cross-linking reaction can be accelerated by heating, and unlike radical polymerization, the cross-linking reaction is not inhibited by the presence of oxygen. The obtained resin layer is also excellent in adhesion as compared with the radical polymerization system.

The polymerizable compound that crosslinks in the presence of an acid includes compounds having a cyclic ether group such as an epoxy group, an oxetane group, an oxolane group, acrylic or vinyl compounds having the above-described substituents on their side chains, carbonate compounds, low Monomers with a cationically polymerizable vinyl bond, such as molecular weight melamine compounds, vinyl ethers and vinylcarbazoles, styrene derivatives, alpha-methylstyrene derivatives, vinyl alcohol esters such as vinyl alcohol and acrylic and methacrylic ester compounds. use together.

Examples of photoacid generators that generate acids upon irradiation with light include onium salts, diazonium salts, quinonediazide compounds, organic halides, aromatic sulfonate compounds, bisulfone compounds, sulfonyl compounds, sulfonate compounds, sulfonium compounds, sulfamide compounds, Iodonium compounds, or sulfonyldiazomethane compounds, mixtures thereof, and the like can be used.

Among them, it is desirable to use an onium salt as the photoacid generator. Usable onium salts include, for example, fluoroborate anion, hexafluoroantimonate anion, hexafluoroarsenate anion, trifluoromethanesulfonate anion, paratoluenesulfonate anion, and diazonium salt with paranitrotoluenesulfonate anion as a counter ion, phosphonium salts, and sulfonium salts may be mentioned. Photoacid generators can also be used with halogenated triazine compounds.

The photoacid generator may optionally further contain a sensitizing dye. Sensitizing dyes include, for example, acridine compounds, benzoflavins, perylenes, anthracenes, and laser dyes.

The porogen is mixed to form vacancies in the electron insulating layer 21 after curing. The porogen is capable of dissolving the polymerizable monomer and the compound that generates radicals or acids by light or heat, and the process of polymerizing the polymerizable monomer and the compound that generates radicals or acids by light or heat. Any liquid substance that can cause phase separation can be selected.

Examples of porogens include ethylene glycols such as diethylene glycol monomethyl ether, ethylene glycol monobutyl ether and dipropylene glycol monomethyl ether, esters such as γ-butyrolactone and propylene carbonate, and amides such as NN dimethylacetamide.

Liquid substances having relatively large molecular weights, such as methyl tetradecanoate, methyl decanoate, methyl myristate, and tetradecane, also tend to function as porogens. In particular, many ethylene glycols have high boiling points. The phase separation mechanism is highly dependent on the porogen concentration for the structures formed. Therefore, by using the liquid substance, it is possible to form the electronic insulating layer 21 stably. Moreover, the porogen may be used alone or in combination of two or more.

Furthermore, as in the first embodiment, the substrate 11 is cut out at any position in the region where the electronic insulating layer 21 is not formed (region where the insulating layer liquid composition 21B is not applied). As a result, as shown in FIGS. 7 and 8, in the electrode 20, the electrode mixture layer 12 can be prevented from being exposed, and the electrode end portion can prevent a short circuit inside the battery due to slipping of the active material or the like. structure is obtained.

(Printing on current collector)
FIG. 11 is a plan view illustrating electrodes according to a modification of the second embodiment. FIG. 12 is a cross-sectional view illustrating an electrode according to a modification of the second embodiment, showing a cross section along line CC of FIG. When an insulating base material is used as the base material 11, it is necessary to form an electrically conductive layer 31 for current collection, like the electrode 30 shown in FIGS. A portion of the electrically conductive layer 31 is exposed at the edge of the electronic insulating layer 21 .

To form the electrically conductive layer 31, for example, metal nanoparticles or fibers of at least one of silver, copper, gold, nickel, and aluminum, or carbon nanotubes, or highly conductive carbon materials such as graphene, or titanium nitride, etc. A conductive liquid composition containing conductive ceramics is prepared.

Then, by inkjet printing, the above liquid composition is discharged onto the insulating substrate 11 to form the electrically conductive layer 31 . By inkjet printing, the electrically conductive layer 31 can be formed in any desired shape on any desired location on the substrate 11 .

The average particle size of the dispersion in the liquid composition for forming the electrically conductive layer is preferably 0.01 μm or more and 3 μm or less, and the viscosity of the liquid composition for forming the electrically conductive layer at 25° C. is 3 mPa·s or more and 18 mPa·s or less. is preferred.

When the average particle size of the dispersed particles in the liquid composition for forming the electrical conductive layer is 0.01 μm or more, the ejection stability of the liquid composition is stable, and when it is 3 μm or less, the storage stability of the liquid composition is improved. do. Further, when the viscosity at 25° C. of the liquid composition for forming the electrically conductive layer is in the range of 3 mPa·s to 18 mPa·s, the liquid composition is easily ejected as droplets, so that the ejection amount can be easily controlled.

After performing the printing process, the liquid composition can be fired by a firing method commonly used in the art. In the case of metal nanoparticles, they are more preferably dried and baked under a vacuum of 10 ⁻⁴ Pa or less, under a nitrogen atmosphere, or under an argon atmosphere in order to prevent oxidation. Light firing with a xenon flash lamp can also be used to enhance sinterability.

<Third embodiment>
The third embodiment shows an example of an electrode having electrode mixture layers on both sides of a substrate. FIG. 13 is a cross-sectional view illustrating an electrode according to the third embodiment; Note that the plan view of the electrode according to the third embodiment is the same as FIG.

As shown in FIG. 13, the electrode 40 differs from the electrode 10 (see FIGS. 1 and 2) in that an electrode mixture layer 42 is formed on the other surface 11b of the substrate 11. As shown in FIG. The electrode mixture layer 42 is formed, for example, at a position overlapping the electrode mixture layer 12 in plan view. The thickness of the electrode mixture layer 42 is, for example, the same as the thickness of the electrode mixture layer 12 .

On the other surface 11b of the substrate 11, the uncoated portion 11p is annularly provided outside the outer peripheral portion 42p of the electrode mixture layer 42 in plan view. The uncoated portion 11 p is a portion where the other surface 11 b of the base material 11 is exposed without being covered with the electrode mixture layer 42 . The uncoated portion 11p is formed, for example, at a position overlapping with the uncoated portion 11m in plan view.

(coating on both sides)
FIG. 14 is a diagram illustrating an electrode manufacturing method according to the third embodiment. After cutting out the base material 11 on which the electrode mixture layer 12 is formed as shown in FIG. 14A, the base material 11 is turned upside down as shown in FIG. is image-recognized by the image sensor 102B, the positional information of the electrode mixture layer 12 is acquired. Then, as shown in FIG. 14C, the electrode liquid composition containing the electrode mixture 42A is applied to the other surface 11b of the substrate 11 so as to overlap the position of the electrode mixture layer 12 in plan view. The electrode liquid composition containing the electrode mixture 42A can be applied using the inkjet head 101B in the same manner as the electrode liquid composition containing the electrode mixture 12A. The electrode liquid composition containing the electrode mixture 42A may have the same composition as the electrode liquid composition containing the electrode mixture 12A, or may have a different composition.

Note that the method of identifying the position of the base material 11 by recognizing the shape of the edge of the base material 11 with the image sensor 102B may be used in the case of single-sided coating. For example, when manufacturing the electrode 20 shown in FIG. The electrolyte liquid composition 21A or the insulating layer liquid composition 21B that is recognized by the image sensor 102B and covers the electrode mixture layer 12 may be applied.

(Bipolar type application)
In particular, a bipolar electrode can be formed by applying an electrode liquid composition containing the electrode mixture 42A having a polarity different from that of the electrode liquid composition containing the electrode mixture 12A. Alternatively, like an electrode 50 shown in FIG. 15, electronic insulating layers 21 and 51 covering the electrode mixture layers 12 and 42 may be formed on the one surface 11a and the other surface 11b of the substrate 11 .

On the other surface 11b of the substrate 11, the uncoated portion 11q is annularly provided outside the outer peripheral portion 51p of the electronic insulating layer 51 in plan view. The uncoated portion 11q is a portion where the other surface 11b of the substrate 11 is exposed without being covered with the electrode mixture layer 42 or the electronic insulating layer 51 . The uncoated portion 11q is formed, for example, at a position overlapping the uncoated portion 11n in plan view.

As shown in FIG. 16, the coating on the other surface 11b side is performed between the step of coating the substrate 11 with the electrode liquid composition containing the electrode mixture 12A and the step of cutting only the substrate 11. good too. In FIG. 16, the alignment mark 310 is a through hole formed in the base material 11 by laser processing. In this case, by recognizing the image of the alignment mark 310, the positional information of the electrode liquid composition containing the electrode mixture 12A can be obtained from the other surface 11b side of the substrate 11. FIG.

First, as shown in FIG. 16A, one surface 11a of the substrate 11 is coated with an electrode liquid composition containing the electrode mixture 12A. After that, as shown in FIG. 16(b), the substrate 11 is turned over, and the alignment mark 310 is image-recognized from the other surface 11b side of the substrate 11 by the image sensor 102B. read the location information of After that, as shown in FIG. 16(c), the inkjet head 101B applies the electrode liquid composition onto the other surface 11b of the base material 11 so as to overlap the application position of the electrode liquid composition containing the electrode mixture 12A in plan view. An electrode liquid composition containing the electrode compound material 42A is applied.

When the alignment mark can be visually recognized only from one surface 11a side of the base material 11, the alignment mark is image-recognized from the one surface 11a side of the base material 11, and the timing is adjusted from the conveying speed of the base material 11, and the other side is displayed. It is possible to apply an electrode liquid composition containing the electrode mixture 42A to the surface 11b of the .

(Electrode manufacturing equipment)
FIG. 17 is a schematic diagram illustrating an electrode manufacturing apparatus. As shown in FIG. 17, the electrode manufacturing apparatus 100A includes an inkjet head 101A, image sensors 102A and 102B, a conveyor belt 103, a laser head 104, a controller 130, an inkjet printing control board 140, and an image sensor controller. It has boards 150A and 150B and a laser processing control board 160 . Controller 130 can issue various commands to inkjet printing control board 140 , image sensor control boards 150 A and 150 B, and laser processing control board 160 .

The inkjet head 101A is an example of means for applying an electrode liquid composition containing an electrode mixture to any position on a substrate in any shape. The image sensors 102A and 102B are an example of means for acquiring positional information where the electrode liquid composition containing the electrode mixture is applied. The laser head 104 is an example of a means for cutting only the base material at an arbitrary position in the region excluding the electrode mixture region coated with the electrode liquid composition containing the electrode mixture, and cutting out the electrode in an arbitrary shape. The electrode manufacturing apparatus 100A controls an arbitrary position to apply the electrode liquid composition containing the electrode mixture, an arbitrary shape of the electrode liquid composition containing the electrode mixture, and an arbitrary position to cut the substrate by digital data. It is possible.

FIG. 18 is an example of a main hardware block diagram of the control device. As shown in FIG. 18 , in electrode manufacturing apparatus 100A, control device 130 has CPU 131 , ROM 132 , RAM 133 , NVRAM 134 , ASIC 135 , I/O 136 , and operation panel 137 .

The CPU 131 controls the entire electrode manufacturing apparatus 100A. The ROM 132 stores programs executed by the CPU 131 and other fixed data. The RAM 133 temporarily stores data related to electrode manufacturing. NVRAM 134 is a non-volatile memory for retaining data while the device is powered off. The ASIC 135 processes various signal processing for image data, image processing such as rearrangement, and input/output signals for controlling the entire apparatus. The I/O 136 is an interface for inputting/outputting signals with the inkjet printing control board 140, the image sensor control boards 150A and 150B, and the laser processing control board 160. FIG. The operation panel 137 inputs and displays necessary information to the control device 130 .

FIG. 19 is an example of a main functional block diagram of the control device. As shown in FIG. 19, the control device 130 has a head control section 1301, a sensor control section 1302, and a laser control section 1303 as functional blocks.

The head control unit 1301 issues a drive instruction to the inkjet printing control board 140 at the specified timing and the number of droplets under the given waveform data and the ejection conditions such as the ejection frequency. The sensor control unit 1302 issues commands to the image sensor control boards 150A and 150B and acquires necessary information including position information of the electrode liquid composition containing the electrode mixture from the image sensors 102A and 102B. The laser control unit 1303 controls the amount of emitted light necessary for cutting the base material 11, and scans the laser light based on the positional information of the electrode liquid composition containing the electrode mixture acquired by the sensor control unit 1302. command to the laser processing control board 160.

By using the electrode manufacturing apparatus 100A shown in FIGS. 17 to 19, the design can be changed by transferring digital data, electrodes of arbitrary shape can be formed by inkjet printing, and electrodes of arbitrary shape can be cut out by laser processing. Thus, the design data of the electrode shape is transferred from the control device 130 to the inkjet printing control board 140, the image sensor control boards 150A and 150B, and the laser processing control board 160, respectively. As a result, it is possible to switch to manufacturing electrodes of different designs without performing setup changes such as redesigning or exchanging masks and plates.

(Environment of coating process)
In addition, the liquid composition that serves as an electrode or electrolyte contains a material that reacts with moisture in the atmosphere to cause deterioration in performance. In particular, sulfide solid electrolytes are known to generate toxic hydrogen sulfide gas when reacting with moisture, requiring strict moisture control. An inert gas environment such as dry air, nitrogen, or argon with a low dew point is preferred in the process where these moisture-reactive materials are exposed. Application of the electrode liquid composition containing at least the electrode mixture is preferably carried out in an environment filled with dry air or an inert gas with a dew point of −40° C. or less. Moreover, it is more preferable that the environment filled with dry air or inert gas has a positive pressure with respect to the external environment.

According to the electrode manufacturing method according to the first embodiment and the like, a series of electrode manufacturing processes from application to electrode cutting can be controlled only by exchanging digital data, and remote operation is possible. For example, the electrode liquid composition containing the electrode mixture is applied in an environment filled with dry air or an inert gas with a dew point of −40° C. or less, and the electrode liquid composition containing the electrode mixture is maintained in this environment. It is possible to change the application position and application shape of the object.

For example, as shown in FIG. 20, performance and safety can be improved by locally controlling moisture only in a limited space 170 around the process of applying the liquid composition and cutting the substrate. It becomes possible to manufacture electrodes while ensuring. Therefore, it is possible to reduce the cost of production line stoppage and setup change due to design change, and the running cost of atmosphere control of the restricted space, thereby making it possible to manufacture electrodes at low cost.

Although the preferred embodiments and the like have been described in detail above, the present invention is not limited to the above-described embodiments and the like, and various modifications and substitutions can be made to the above-described embodiments and the like without departing from the scope of the claims. can be added.

10, 20, 30, 40, 50 electrode 11 substrate 11a one surface 11b of substrate 11 other surface 11c of substrate 11 position 11e end portions 11m, 11n, 11p, 11q of substrate 11 uncoated portion 12 , 42 electrode mixture layers 12A, 42A electrode mixture 12p outer peripheral portion 21 of electrode mixture layer 12 electron insulating layer 21A electrolyte liquid composition 21B insulating layer liquid composition 21p outer peripheral portion 31 of electron insulating layer 21 electrical conductive layer 42p electrode Outer peripheral portion 51p of composite material layer 42 Outer peripheral portions 100, 100A of electronic insulating layer 51 Electrode manufacturing devices 101A, 101B Inkjet heads 102A, 102B Image sensor 103 Conveyor belt 104 Laser head 104L Laser light 130 Control device 131 CPU
132 ROMs
133 RAM
134 NVRAM
135 ASICs
136 I/O
137 Operation panel 140 Inkjet printing control board 150A, 150B Image sensor control board 160 Laser processing control board 300, 310 Alignment mark 1301 Head control unit 1302 Sensor control unit 1303 Laser control unit

JP 2018-129222 A Patent No. 6432990 JP 2012-221912 A JP 2018-37143 A

Claims (15)

A first step of applying an electrode liquid composition containing an electrode mixture to an arbitrary position on a substrate in an arbitrary shape;
a second step of acquiring position information where the electrode liquid composition containing the electrode mixture is applied;
and a third step of cutting only the base material at an arbitrary position in the region excluding the electrode mixture region coated with the electrode liquid composition containing the electrode mixture, and cutting out the electrode in an arbitrary shape. An electrode manufacturing method characterized by: The arbitrary position for applying the electrode liquid composition containing the electrode mixture in the first to third steps, the arbitrary shape, and the arbitrary position for cutting the base material can be controlled by a control device. 2. The electrode manufacturing method according to claim 1, wherein: The control device is characterized in that the arbitrary position where the electrode liquid composition containing the electrode mixture is applied, the arbitrary shape, and the arbitrary position where the substrate is cut are controlled by digital data. The electrode manufacturing method according to claim 2. 4. The electrode manufacturing method according to claim 1, wherein in the first step, an electrode liquid composition containing the electrode mixture is discharged from a nozzle. 5. The electrode manufacturing method according to any one of claims 1 to 4, wherein in the third step, only the base material is cut with a laser beam. 6. The electrode manufacturing method according to any one of claims 1 to 5, wherein in the second step, the positional information is obtained by image recognition of the end shape of the electrode mixture region. In the second step, the positional information is obtained by image recognition of a mark formed by printing the electrode liquid composition containing the electrode mixture on a region other than the electrode mixture region. The electrode manufacturing method according to any one of claims 1 to 5. 6. The electrode manufacturing method according to any one of claims 1 to 5, wherein in the second step, the position information is obtained by image recognition of holes formed in the base material. 6. The position information is obtained by cutting the base material in an arbitrary shape and recognizing an image of an edge of the cut base material in the second step. 1. The electrode manufacturing method according to item 1. 10. The electrode manufacturing method according to any one of claims 1 to 9, wherein the substrate is a sheet metal foil or an insulating substrate. 10. The electrode manufacturing method according to any one of claims 1 to 9, wherein the base material is a strip-shaped metal foil or an insulating base material. In the first step, as the electrode liquid composition containing the electrode mixture, a liquid composition containing an active material is applied to form an electrode mixture layer,
After the first step, a liquid composition that does not contain the active material and contains an electronic insulating layer forming material is applied onto the electrode mixture layer, and the electrode mixture layer is coated on the electrode mixture layer. 12. The method for manufacturing an electrode according to any one of claims 1 to 11, comprising the step of forming an electronic insulating layer covering the entirety of the electrode. Between the first step and the second step, the substrate is turned over, and the electrode liquid composition containing the electrode mixture of the substrate is not coated at an arbitrary position on the surface of the substrate. 13. The electrode manufacturing method according to any one of claims 1 to 12, further comprising a step of applying an electrode liquid composition containing an electrode mixture. At least the first step is performed in an environment filled with dry air or an inert gas having a dew point of −40° C. or lower, and the position of applying the electrode liquid composition containing the electrode mixture while maintaining the environment. 14. The electrode manufacturing method according to any one of claims 1 to 13, wherein the coating shape can be changed. a first means for applying an electrode liquid composition containing an electrode mixture to an arbitrary position on a substrate in an arbitrary shape;
a second means for acquiring position information where the electrode liquid composition containing the electrode mixture is applied;
a third means for cutting only the base material at an arbitrary position in an area excluding the electrode mixture area coated with the electrode liquid composition containing the electrode mixture, and cutting out the electrode in an arbitrary shape;
a control device capable of controlling the arbitrary position for applying the electrode liquid composition containing the electrode mixture in the first to third means, the arbitrary shape, and the arbitrary position for cutting the base material; an electrode manufacturing apparatus comprising:

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