JP6754850B2 - Electrode sheet, all-solid-state lithium-ion battery, and method for manufacturing electrode sheet - Google Patents

Description

The present invention relates to an electrode sheet, an all-solid-state lithium ion battery, and a method for manufacturing an electrode sheet.

Lithium-ion batteries are generally used as a power source for small portable devices such as mobile phones and laptop computers. Recently, in addition to small portable devices, lithium-ion batteries have begun to be used as power sources for electric vehicles and electric power storage.

Currently commercially available lithium ion batteries use an electrolytic solution containing a flammable organic solvent. On the other hand, a lithium-ion battery (hereinafter, also referred to as an all-solid-state lithium-ion battery) in which the electrolyte is changed to a solid electrolyte and the battery is completely solidified does not use a flammable organic solvent in the battery, and thus is a safety device. It is considered that the manufacturing cost and productivity are excellent.
In such an all-solid-state lithium-ion battery, an electrode sheet mainly containing an electrode active material and a solid electrolyte material is used as an electrode. The following Patent Documents 1 and 2 describe examples of such electrode sheets.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2010-40218) is characterized by having a porous metal sheet having a three-dimensional network structure and an inorganic solid electrolyte inserted into the pores of the porous metal sheet. The electrode material sheet for a battery is described.

Patent Document 2 (Japanese Patent Laid-Open No. 2008-103258) includes an electrode material and a support having a plurality of openings, and the electrode material has a continuous penetration structure in the thickness direction at the openings of the support.
An electrode sheet in which the support is made of glass and the aperture ratio of the support is 40 to 90% is described.

Japanese Unexamined Patent Publication No. 2010-40218 Japanese Unexamined Patent Publication No. 2008-103258

According to the studies by the present inventors, it has been clarified that when the electrode sheet as described in Patent Documents 1 and 2 is thinned, the electrode material is chipped or the surface of the electrode sheet is cracked. It was.
On the other hand, it has been clarified that when the electrode material contains a binder in order to prevent the electrode material from being chipped or cracked on the surface, the lithium ion conductivity of the obtained electrode sheet is significantly reduced.

The present inventors have diligently studied the structure of the electrode in order to provide an electrode sheet capable of increasing the area and thinning while suppressing chipping of the electrode material and cracking of the surface and having excellent ionic conductivity. .. As a result, the electrode material containing the solid electrolyte material and the electrode active material is filled in the voids of the porous base material to which the pressure-sensitive adhesive is attached, so that the large area of the electrode is suppressed while suppressing the loss of the electrode material and the cracking of the surface. We have found that thinning and thinning are possible, and have reached the present invention.

That is, according to the present invention.
A sheet-like porous substrate made of resin material, natural fiber, glass or carbon,
At least the adhesive adhering to the surface of the skeleton surrounding the voids of the porous substrate,
An electrode material containing a solid electrolyte material and an electrode active material and filled inside the voids of the porous substrate,
Bei to give a,
An electrode sheet is provided in which the content of the binder in the electrode material is less than 0.5% by mass when the total content of the electrode material is 100% by mass .

Further, according to the present invention
An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
An all-solid-state lithium ion battery in which at least one of the positive electrode layer and the negative electrode layer is composed of the electrode sheet is provided.

Further, according to the present invention
It is a manufacturing method for manufacturing the above electrode sheet, and is
A step of forming an adhesive layer on at least one surface of a sheet-like porous substrate, and
A step of forming an electrode material layer by adhering an electrode material on the pressure-sensitive adhesive layer to obtain a laminate in which the porous base material, the pressure-sensitive adhesive layer, and the electrode material layer are laminated in this order.
By pressurizing the obtained laminate, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is adhered to the surface of the skeleton portion surrounding the voids of the porous substrate, and the pressure-sensitive adhesive is contained in the voids of the porous substrate. The process of filling the electrode material constituting the electrode material layer and
A method for producing an electrode sheet including the above is provided.

Further, according to the present invention
It is a manufacturing method for manufacturing the above electrode sheet, and is
Sheet-shaped porous substrate, process of preparing adhesive, and
A step of coating the surface of the skeleton portion surrounding the voids of the porous substrate with the adhesive, and
The step of filling the electrode material in the voids of the porous substrate, and
A method for producing an electrode sheet including the above is provided.

According to the present invention, it is possible to provide an electrode sheet capable of increasing the area and thinning while suppressing chipping of the electrode material and cracking of the surface, and having excellent ionic conductivity.

It is sectional drawing which shows typically an example of the structure of the electrode sheet of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the manufacturing method of the electrode sheet of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the manufacturing method of the electrode sheet of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the manufacturing method of the electrode sheet of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the manufacturing method of the electrode sheet of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the structure of the all-solid-state lithium ion battery of embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by a common reference numeral, and description thereof will be omitted as appropriate. In addition, the figure is a schematic view and does not necessarily match the actual dimensional ratio. Unless otherwise specified, "~" represents the following from the above.

FIG. 1 is a cross-sectional view schematically showing an example of the structure of the electrode sheet 100 according to the embodiment of the present invention.
The electrode sheet 100 includes a sheet-shaped porous base material 101, an adhesive 104, and an electrode material 105. The pressure-sensitive adhesive 104 is attached to at least the surface of the skeleton portion 103 surrounding the voids 102 of the porous base material 101. Further, the electrode material 105 contains a solid electrolyte material and an electrode active material, and is filled inside the voids 102 of the porous base material 101.

The electrode sheet 100 according to the present embodiment is used, for example, as a positive electrode layer or a negative electrode layer constituting an all-solid-state lithium ion battery.
An example of an all-solid-state lithium-ion battery to which the electrode sheet 100 according to the present embodiment is applied includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer laminated in this order. In this case, at least one of the positive electrode layer and the negative electrode layer is composed of the electrode sheet 100.

Conventional electrodes for all-solid-state lithium-ion batteries are manufactured by press-molding an electrode material containing an electrode active material and a solid electrolyte at high pressure, and then pressing the press-molded body and the current collector layer at high pressure. It was. However, according to the study by the present inventors, it is difficult to increase the area of the electrode produced by such a method, and the industrial productivity is inferior. Further, when the thin film is formed, the electrode material is chipped and the surface is cracked, and it is difficult to keep the shape of the electrode sheet constant.
Further, according to the study by the present inventors, when the electrode sheet as described in Patent Documents 1 and 2 is thinned, the electrode material is chipped or the surface is cracked, and the shape of the electrode sheet is constant. It turned out to be difficult to keep in.
On the other hand, it has been clarified that when the electrode material contains a binder in order to prevent the electrode material from being chipped or cracked on the surface, the lithium ion conductivity of the obtained electrode sheet is significantly reduced.
Based on the above findings, the present inventors have provided an electrode sheet that can be made larger and thinner while suppressing chipping of the electrode material and cracks on the surface, and has excellent ionic conductivity. Diligently examined the structure of. As a result, the electrode material containing the solid electrolyte material and the electrode active material is filled in the voids of the porous base material to which the pressure-sensitive adhesive is attached, so that the large area of the electrode is suppressed while suppressing the loss of the electrode material and the cracking of the surface. We have found that thinning and thinning are possible, and have reached the present invention.

In the electrode sheet 100 according to the present embodiment, the electrode material 105 is stably held in the voids 102 of the porous base material 101 by the pressure-sensitive adhesive 104 adhering to the skeleton portion 103 of the porous base material 101. Therefore, even if the electrode sheet 100 is made larger and thinner, the electrode material 105 can be stably held in the voids 102 of the porous base material 101, and as a result, the electrode material 105 is missing or the electrode sheet is formed. It is possible to suppress cracks on the surface of 100. Further, since the electrode sheet 100 can be thinned, the impedance of the electrode sheet 100 can be lowered, and as a result, the charge / discharge characteristics of the obtained all-solid-state lithium ion battery can be further improved.
Further, since the electrode material 105 can be stably held in the void 102 of the porous base material 101, the content of the binder contained in the electrode material 105 can be reduced. As a result, the contact property between the electrode active material and the solid electrolyte material and the contact property between the solid electrolyte materials are improved, and the interfacial contact resistance of the electrode sheet 100 can be reduced. As a result, the lithium ion conductivity of the electrode sheet 100 can be improved.
From the above, the electrode sheet 100 according to the present embodiment can be made larger in area and thinner while suppressing chipping of the electrode material and cracks on the surface, and is excellent in lithium ion conductivity. Further, by using the electrode sheet 100 having excellent lithium ion conductivity, the charge / discharge characteristics of the obtained all-solid-state lithium ion battery can be improved. In the present embodiment, the charge / discharge characteristics of the all-solid-state lithium-ion battery refer to the discharge capacity density, output characteristics, cycle characteristics, and the like.

Hereinafter, the electrode sheet 100 and the all-solid-state lithium-ion battery 200 according to the present embodiment will be described in detail.

[Electrode sheet]
First, the electrode sheet 100 according to the present embodiment will be described.
The electrode sheet 100 includes a sheet-shaped porous base material 101, an adhesive 104, and an electrode material 105. The pressure-sensitive adhesive 104 is attached to at least the surface of the skeleton portion 103 surrounding the voids 102 of the porous base material 101. Further, the electrode material 105 contains a solid electrolyte material and an electrode active material, and is filled inside the voids 102 of the porous base material 101.

In the electrode sheet 100, it is preferable that at least a part of the electrode material 105 is attached to the pressure-sensitive adhesive 104. As a result, it is possible to realize a large area and a thin film of the electrode sheet 100 while further suppressing the loss of the electrode material 105 and the cracking on the surface of the electrode sheet 100. Further, by thinning the electrode sheet 100, the impedance of the electrode sheet 100 can be lowered. As a result, the charge / discharge characteristics of the obtained all-solid-state lithium-ion battery can be improved.

The planar shape of the electrode sheet 100 is not particularly limited and can be appropriately selected according to the shape of the solid electrolyte layer or the current collector layer, but can be, for example, a rectangle.
The thickness of the electrode sheet 100 is preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, still more preferably 20 μm or more and 100 μm or less, and particularly preferably 20 μm or more and 80 μm or less. When the thickness of the electrode sheet 100 is at least the above lower limit value, the chipping of the electrode material 105 and the cracking on the surface of the electrode sheet 100 can be further suppressed. Further, when the thickness of the electrode sheet 100 is not more than the above upper limit value, the impedance of the electrode sheet 100 can be further lowered. As a result, the charge / discharge characteristics of the obtained all-solid-state lithium-ion battery can be further improved.

In the electrode sheet 100, the filling amount of the electrode material 105 is preferably 15% by mass or more and 85% by mass or less, more preferably 40% by mass or more and 70% by mass, when the whole of the electrode sheet 100 is 100% by mass. It is as follows. When the filling amount of the electrode material 105 is not more than the above upper limit value, the lack of the electrode material 105 and the cracking on the surface of the electrode sheet 100 can be further suppressed. Further, when the filling amount of the electrode material 105 is not more than the above lower limit value, an all-solid-state lithium ion battery having a higher discharge capacity density can be obtained.

In the electrode sheet 100, the content of the pressure-sensitive adhesive 104 is preferably 5% by mass or more and 80% by mass or less, more preferably 15% by mass or more and 50% by mass, when the whole of the electrode sheet 100 is 100% by mass. It is as follows. When the content of the pressure-sensitive adhesive 104 is not more than the above upper limit value, the electrode material 105 that can be filled inside the void 102 can be increased, so that the discharge capacity density of the obtained all-solid-state lithium ion battery can be improved. Further, when the content of the adhesive 104 is not more than the above lower limit value, it is possible to realize a large area and a thin film of the electrode sheet 100 while further suppressing the lack of the electrode material 105 and the cracking on the surface of the electrode sheet 100. .. Further, by thinning the electrode sheet 100, the impedance of the electrode sheet 100 can be lowered. As a result, the charge / discharge characteristics of the obtained all-solid-state lithium-ion battery can be improved.

The electrode sheet 100 according to the present embodiment is 1.5 × 10 ^-4 S · cm ^-1 or more and LiMn ₂ O ₄ when the positive electrode active material is Li ₁₄ MoS ₉ at room temperature without using an electrolytic solution. , 2.5 × 10 ^-6 S · cm ^-1 or more, which is equivalent to 50% or more of the ion conductivity of a powder press-molded body which is usually carried out, and exhibits high lithium ion conductivity.
Here, the lithium ion conductivity is such that the electrode sheet is composed of only the positive electrode active material, the pressure-sensitive adhesive and the porous substrate, and has a temperature of 27.0 ° C., an applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz. Lithium ion conductivity by AC impedance method under measurement conditions.
Further, the electrode sheet 100 according to the present embodiment can have a large area, and even if the thickness is 50 μm or less, the electrode material 105 is less likely to be chipped or the surface is less likely to be cracked.
Therefore, the electrode sheet 100 according to the present embodiment is extremely useful as an electrode sheet for a lithium ion battery.

Hereinafter, each configuration of the electrode sheet 100 according to the present embodiment will be described.

<Sheet-shaped porous substrate>
The porous base material 101 according to the present embodiment is in the form of a sheet, and the electrode material 105 can be sufficiently filled in the void 102 thereof. Examples of the form of the porous base material 101 include woven fabrics, non-woven fabrics, mesh cloths, porous membranes, expanding sheets, punching sheets and the like. Among these, a non-woven fabric is preferable from the viewpoint of excellent holding power of the electrode material 105 and excellent surface smoothness of the obtained electrode sheet 100.

Examples of the material constituting the porous base material 101 include polyesters such as nylon and polyethylene terephthalate (PET), polyethylene, polypropylene, polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, polyvinylidene chloride, and the like. Resin materials such as polyvinylidene chloride, polyvinylidene chloride, polyurethane, vinylon, polybenzimidazole, polyimide, polyphenylene sulfide, polyether ether ketone, cellulose, acrylic resin; natural fibers such as hemp, wood pulp, cotton linter; iron, Metallic materials such as aluminum, titanium, nickel and stainless steel; inorganic materials such as glass and carbon can be mentioned.

Further, as the porous base material 101, one having electron conductivity is preferable. Thereby, the electron conductivity of the obtained electrode sheet 100 can be further improved. Examples of the porous base material 101 having electron conductivity include metal materials such as iron, aluminum, titanium, nickel, and stainless steel; those formed of carbon and the like.

The porosity of the porous substrate 101 is preferably 50% or more and 95% or less, and more preferably 70% or more and 90% or less. When the porosity is at least the above lower limit value, the electrode material 105 that can be filled inside the void 102 can be increased, so that the discharge capacity density of the obtained all-solid-state lithium ion battery can be improved.
Further, when the porosity is not more than the above upper limit value, the mechanical strength of the porous base material 101 can be improved and the holding power of the electrode material 105 can be improved, so that the obtained electrode sheet 100 can be further thinned. can do.
Here, the porosity means the ratio of the total volume of the voids to the total volume of the porous base material 101. That is, the porosity is represented by (1-volume of constituent material in porous substrate / volume of porous substrate) x 100 (%).

The air permeability of the porous substrate 101 is preferably 100 cm ³ / cm ² / sec or more and 400 cm ³ / cm ² / sec or less, and more preferably 150 cm ³ / cm ² / sec or more and 300 cm ³ / cm ² / sec or less. .. When the air permeability is equal to or higher than the above lower limit value, the powder of the electrode material 105 easily flows into the inside of the porous base material 101, and the electrode material 105 can be filled in the void 102 at a high density. Therefore, the contact resistance between the particles of the electrode material 105 can be reduced, and the discharge capacity density of the obtained all-solid-state lithium ion battery can be improved. Further, when the air permeability is not more than the above upper limit value, the mechanical strength of the porous base material 101 can be improved and the holding power of the electrode material 105 can be improved, so that the obtained electrode sheet 100 can be further thinned. can do.
Here, the air permeability of the porous base material 101 can be measured according to JIS L1096-A (Frazil method).

The thickness of the porous substrate 101 is preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, further preferably 20 μm or more and 100 μm or less, and particularly preferably 20 μm or more and 80 μm or less. When the thickness of the porous base material 101 is at least the above lower limit value, the mechanical strength of the porous base material 101 can be improved, so that the mechanical strength of the obtained electrode sheet 100 can be improved. In addition, the holding power of the electrode material 105 can be improved.
Further, when the thickness of the porous base material 101 is not more than the above upper limit value, the impedance of the obtained electrode sheet 100 can be further lowered. As a result, the charge / discharge characteristics of the obtained all-solid-state lithium-ion battery can be further improved.

<Adhesive>
The pressure-sensitive adhesive 104 according to the present embodiment can adhere to the surface of the skeleton portion 103 of the porous base material 101 and can adhere the electrode material 105. The adhesive 104 preferably contains, for example, a resin exhibiting adhesiveness (hereinafter, also referred to as an adhesive resin), and from the viewpoint of improving the electron conductivity of the electrode sheet 100, the adhesive resin and the conductive fine particles It is more preferable that it contains. When the adhesive resin and the conductive fine particles are contained, it is preferable that the conductive fine particles are dispersed in the pressure-sensitive adhesive 104.
Examples of the adhesive resin contained in the adhesive 104 include (meth) acrylic thermoplastic resins, silicone resins, urethane resins, polyvinyl ethers, and rubbers. Here, in the present specification, "(meth) acrylic" is a general term for acrylic and methacrylic.

In the present embodiment, the (meth) acrylic-based thermoplastic resin is a thermoplastic resin containing a (meth) acrylic acid ester unit, and is, for example, a copolymer of (meth) acrylic acid ester, or two or more kinds of (meth) acrylic acid ester homopolymers. Examples thereof include a copolymer of a (meth) acrylic acid ester, a copolymer of a (meth) acrylic acid ester and a vinyl monomer having an unsaturated bond capable of copolymerizing the same.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, isopropyl (meth) acrylic acid, n-butyl (meth) acrylic acid, and tert-butyl (meth) acrylic acid. , (Meta) cyclohexyl acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, (meth) Methoxyethyl acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hexanediol di (meth) acrylate, ethylene Glycoldi (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylpropanthry (meth) acrylate, penta Ellisritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid 3-Hydroxypropyl, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, (meth) acrylate 6-Hydroxyhexyl, 3-hydroxy-3-methylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl Examples thereof include -2-hydroxyethylphthalic acid and 2-[(meth) acrylicoyloxy] ethyl-2-hydroxypropylphthalic acid.

Examples of the vinyl monomer having an unsaturated bond copolymerizable with the above (meth) acrylic acid ester include (meth) acrylic acid, maleic anhydride, maleimide derivative, (meth) acrylonitrile, N-vinylpyrrolidone, and N. -Acryloylmorpholine, N-vinylcaprolactone, N-vinylpiperidin, N-vinylformamide, N-vinylacetamide, styrene, inden, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, Examples thereof include p-methoxystyrene, p-tert-butoxystyrene, divinylbenzene, butadiene, isoprene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl silicate and derivatives thereof. The vinyl monomer having an unsaturated bond copolymerizable with the (meth) acrylic acid ester and the (meth) acrylic acid ester may be used alone or in combination of two or more.

The content of the (meth) acrylic acid ester unit contained in the (meth) acrylic thermoplastic resin is 100% by mass as a whole of the (meth) acrylic thermoplastic resin from the viewpoint of improving the dispersibility of the conductive fine particles. When this is done, it is preferably 20% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.

Examples of the silicone resin include polydimethylsiloxane and the like.

Examples of the polyvinyl ether include polyvinyl methyl ether and polyvinyl ethyl ether.

Examples of the rubber include natural rubber, isoprene rubber, styrene-butadiene rubber, polyisobutylene rubber and the like.

The content of the adhesive resin contained in the pressure-sensitive adhesive 104 according to the present embodiment is preferably 80% by mass or more and 99.5% by mass or less, more preferably, when the total amount of the pressure-sensitive adhesive 104 is 100% by mass. It is 90% by mass or more and 99.9% by mass or less. When the content of the adhesive resin is within the above range, the balance between the adhesiveness between the porous base material 101 and the electrode material 105 and the electronic conductivity of the adhesive 104 is excellent.

The pressure-sensitive adhesive 104 according to the present embodiment is, if necessary, a cross-linking agent for isocyanate compounds, acid anhydrides, amine compounds, epoxy compounds, metal chelates, aziridine compounds, melamine compounds and the like; rosin-based resins, terpene-based resins, etc. Adhesion-imparting resins such as petroleum resin, kumaron-inden resin, phenol resin, xylene resin, and styrene resin; silane coupling agent; and solid electrolyte materials described later may be further contained.
When the pressure-sensitive adhesive 104 according to the present embodiment contains a pressure-sensitive adhesive resin, the initial tack and the pressure-sensitive adhesive strength can be easily adjusted.

The conductive fine particles contained in the pressure-sensitive adhesive 104 according to the present embodiment are not particularly limited as long as they are fine particles having electron conductivity, but for example, gold, silver, platinum, nickel, copper, cobalt, molybdenum, antimony, and iron. , Chromium and other metal particles; Aluminum / magnesium alloy, Aluminum / nickel alloy and other alloy particles; Tin oxide, indium oxide and other metal oxide particles; Nickel and other metal particles coated with precious metals such as gold, silver and platinum Particles; non-conductive particles such as glass, ceramic, and plastic coated with a metal such as gold, silver, platinum, nickel, copper, cobalt, molybdenum, antimony, iron, and chromium; carbon particles and the like.

The average particle size d ₅₀ in the weight-based particle size distribution measured by the laser diffraction / scattering type particle size distribution measurement method of the conductive fine particles according to the present embodiment is preferably 0.5 μm or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less. .. By setting the average particle diameter d ₅₀ within the above range, it is possible to maintain good handleability of the conductive fine particles and improve the electron conductivity of the pressure-sensitive adhesive 104.

The content of the conductive fine particles contained in the pressure-sensitive adhesive 104 is preferably 0.05% by mass or more and 20% by mass or less, more preferably 0.1% by mass, when the whole of the pressure-sensitive adhesive 104 is 100% by mass. It is 10% by mass or less. When the content of the conductive fine particles is within the above range, the balance between the adhesiveness between the porous base material 101 and the electrode material 105 and the electronic conductivity of the pressure-sensitive adhesive 104 is excellent.

The method for producing the pressure-sensitive adhesive 104 according to the present embodiment is not particularly limited, and for example, it can be produced by the following method.
First, a mixture containing the adhesive resin,, if necessary, the cross-linking agent, the tackifier resin, the silane coupling agent, and the solid electrolyte material in an appropriate amount is heated and melted. Then, if necessary, it can be obtained by adding the above-mentioned conductive fine particles to the thermal melt, mixing them, and uniformly dispersing them.

<Electrode material>
The electrode material 105 according to the present embodiment contains an electrode active material and a solid electrolyte material as essential components.
When the electrode sheet 100 is used for the positive electrode layer constituting the all-solid-state lithium ion battery, the electrode material 105 contains a positive electrode active material and a solid electrolyte material, and if necessary, a conductive auxiliary agent, a binder and the like. ..
Further, when the electrode sheet 100 is used for the negative electrode layer constituting the all-solid-state lithium ion battery, the electrode material 105 contains a negative electrode active material and a solid electrolyte material, and if necessary, contains a conductive auxiliary agent, a binder and the like. I'm out.

(Positive electrode active material)
The positive electrode active material is not particularly limited as long as it can reversibly release and occlude lithium ions and has high electron conductivity so that electron transport can be easily performed, and can be used for the positive electrode layer of an all-solid-state lithium ion battery. A generally known positive electrode active material can be used. For example, lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganese oxide (LiMn ₂ O ₄ ), solid solution oxide (Li ₂ MnO _3- LiMO ₂ (M = Co, Ni, etc.)). ), Lithium-manganese-nickel oxide (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ), olivine-type lithium phosphorus oxide (LiFePO ₄ ) and other composite oxides; polyaniline, polypyrrole, etc. with high conductivity _{molecule; Li 2 S, CuS, Li} -CuS _compounds, TiS _{2, FeS,} sulfides such as MoS 2, Li-MoS compound; a mixture of sulfur and carbon; or the like can be used. These positive electrode active materials may be used alone or in combination of two or more.

Examples of the shape of the positive electrode active material include particulate matter.
The particulate positive electrode active material of the present embodiment is not particularly limited, but the average particle size d ₅₀ in the weight-based particle size distribution by the laser diffraction / scattering type particle size distribution measurement method is preferably 0.5 μm or more and 20 μm or less. More preferably, it is 1 μm or more and 10 μm or less.
By setting the average particle size d ₅₀ of the positive electrode active material within the above range, good handleability can be maintained and a higher density positive electrode layer can be produced.

(Negative electrode active material)
The negative electrode active material is not particularly limited as long as it can reversibly release and occlude lithium ions and has high electron conductivity so that electron transport can be easily performed, and can be used for the negative electrode layer of an all-solid-state lithium ion battery. A generally known negative electrode active material can be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin coal, carbon fiber, activated carbon, hard carbon, soft carbon; tin, tin alloy, silicon, silicon alloy, gallium, gallium alloy, indium, indium alloy, aluminum, aluminum. Alloy-based materials mainly composed of alloys; conductive polymers such as polyacene, polyacetylene, and polypyrrole; metallic lithium; lithium titanium composite oxide (for example, Li ₄ Ti ₅ O ₁₂ ) and the like can be mentioned. These negative electrode active materials may be used alone or in combination of two or more.

Examples of the shape of the negative electrode active material include particulate matter.
The particulate negative electrode active material according to the present embodiment is not particularly limited, but the average particle size d ₅₀ in the weight-based particle size distribution measured by the laser diffraction / scattering particle size distribution measurement method is preferably 1 μm or more and 50 μm or less, more preferably. It is 5 μm or more and 30 μm or less.
By setting the average particle diameter d ₅₀ of the negative electrode active material within the above range, good handleability can be maintained and a higher density negative electrode can be produced.

(Solid electrolyte material)
The solid electrolyte material is not particularly limited as long as it has ionic conductivity and insulating property, but a material generally used for an all-solid-state lithium ion battery can be used. For example, a sulfide solid electrolyte material, an oxide solid electrolyte material, and the like can be mentioned. Among these, a sulfide solid electrolyte material is preferable. As a result, the interfacial resistance with the positive electrode active material is further reduced, and an all-solid-state lithium ion battery having excellent output characteristics can be obtained.

Examples of the solid electrolyte material include Li ₂ S-P ₂ S ₅ material, Li ₂ S-SiS ₂ material, Li ₂ S-GeS ₂ material, Li ₂ S-Al ₂ S ₃ material, and Li ₂ S-SiS ₂ -Li ₃ PO ₄ material, Li ₂ S-P ₂ S _5- GeS ₂ material, Li ₂ S-Li ₂ O-P ₂ S _5- SiS ₂ material, Li ₂ S-GeS _2- P ₂ S _5- SiS Examples thereof include ₂ materials, Li ₂ S-SnS _2- P ₂ S _5- SiS ₂ materials and the like. Among these, the Li ₂ SP ₂ S ₅ material is preferable because it has excellent lithium ion conductivity and the manufacturing method is simple.
These may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, the Li ₂ SP ₂ S ₅ material is preferable because it has excellent lithium ion conductivity and stability that does not cause decomposition in a wide voltage range.

Examples of the shape of the solid electrolyte material include particulate matter. The particulate solid electrolyte material of the present embodiment is not particularly limited, but the average particle size d ₅₀ in the weight-based particle size distribution measured by the laser diffraction / scattering type particle size distribution measurement method is preferably 1 μm or more and 20 μm or less, more preferably 1 μm. It is 10 μm or less.
By setting the average particle diameter d ₅₀ of the solid electrolyte material within the above range, good handleability can be maintained and the lithium ion conductivity of the electrode sheet 100 can be further improved.

(Conductive aid)
The electrode material 105 according to the present embodiment preferably contains a conductive auxiliary agent from the viewpoint of improving the electronic conductivity of the electrode sheet 100. The conductive auxiliary agent is not particularly limited as long as it is an ordinary conductive auxiliary agent that can be used in an all-solid-state lithium-ion battery, but for example, carbon black such as acetylene black and kechen black; carbon fiber; vapor phase carbon fiber; Graphite powder; examples include carbon materials such as carbon nanotubes. These conductive auxiliaries may be used alone or in combination of two or more.
Among these, carbon black having a small particle size and a low price is preferable.

(binder)
Further, the electrode material 105 according to the present embodiment may contain a binder, but the content of the binder is usually less than 0.5% by mass when the total amount of the electrode material 105 is 100% by mass. , It is preferably 0.1% by mass or less, and more preferably 0.05% by mass or less. Further, it is more preferable that the electrode material 105 according to the present embodiment substantially does not contain a binder, and it is particularly preferable that the electrode material 105 does not contain a binder.
As a result, the contact property between the electrode active material and the solid electrolyte material and the contact property between the solid electrolyte materials are improved, and the interfacial contact resistance of the electrode sheet 100 can be further reduced. As a result, the lithium ion conductivity of the electrode sheet 100 can be further improved.
In addition, "substantially free of binder" means that the binder may be contained to the extent that the effect of the present invention is not impaired. Further, the adhesive resin derived from the pressure-sensitive adhesive 104 existing in the vicinity of the interface between the electrode material 105 and the pressure-sensitive adhesive 104 is removed from the "binder in the electrode material 105".

The binder refers to a binder generally used in lithium ion batteries for binding electrode active materials and electrode active materials to a current collector, for example, polyvinyl alcohol or polyacrylic. Water-based binders such as acids, carboxymethyl cellulose, polytetrafluoroethylene fine particles, and styrene-butadiene rubber fine particles; solvent-based binders such as polytetrafluoroethylene, polyvinylidene fluoride, and polyimide.

The electrode material 105 according to the present embodiment is held in the void 102 of the porous base material 101 by the pressure-sensitive adhesive 104 adhering to the skeleton portion 103 of the porous base material 101. Therefore, even if the content of the binder is less than or less than the above upper limit value, the electrode material 105 according to the present embodiment can be stably held in the void 102 of the porous base material 101. As a result, it is possible to increase the area and thinn the electrode sheet 100 while suppressing the loss of the electrode material 105 and the cracking on the surface of the electrode sheet 100.
Further, in the electrode material 105 according to the present embodiment, since the binder having non-ionic conductivity can be less than or less than the above upper limit value, the interfacial contact resistance of the obtained electrode sheet 100 can be reduced. As a result, the lithium ion conductivity of the obtained electrode sheet 100 can be further improved.

(Mixing ratio of electrode material)
In the electrode material 105 according to the present embodiment, the content of the electrode active material is preferably 25% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 40% by mass or less. Further, in the electrode material 105 according to the present embodiment, the content of the solid electrolyte material is preferably 25% by mass or more and 60% by mass or less, and more preferably 30% by mass or more and 50% by mass or less. Further, in the electrode material 105 according to the present embodiment, the content of the conductive auxiliary agent is preferably 10% by mass or more and 45% by mass or less, and more preferably 15% by mass or more and 35% by mass or less.

(Preparation method of electrode material)
The electrode material 105 can be prepared, for example, by mixing an electrode active material, a solid electrolyte material, a conductive auxiliary agent, a binder, a thickener, a solvent, and the like, if necessary, with a mixer.
As the mixer, known ones such as a ball mill and a planetary mixer can be used, and the mixer is not particularly limited. The mixing method is not particularly limited, and the mixing method can be carried out according to a known method.

[Manufacturing method of electrode sheet]
Next, a method for manufacturing the electrode sheet 100 according to the present embodiment will be described.
2 to 5 are cross-sectional views schematically showing an example of a method for manufacturing the electrode sheet 100 according to the embodiment of the present invention.
The method for manufacturing the electrode sheet 100 according to the present embodiment includes the following steps (1) to (3) or the following steps (4) to (6).
First, a method for manufacturing the electrode sheet 100 including the steps (1) to (3) will be described.

(1) A step of forming an adhesive layer 104a on at least one surface of a sheet-shaped porous base material 101 (FIGS. 2A and 2B).
(2) An electrode material layer 105a is formed by adhering the electrode material 105 on the pressure-sensitive adhesive layer 104a, and the porous base material 101, the pressure-sensitive adhesive layer 104a, and the electrode material layer 105a are laminated in this order. Step of obtaining 150 (FIG. 2 (c))
(3) By pressurizing the obtained laminate 150, the pressure-sensitive adhesive 104 constituting the pressure-sensitive adhesive layer 104a is adhered to the surface of the skeleton portion 103 surrounding the voids 102 of the porous base material 101, and the porous base material 101 is attached. Step of filling the electrode material 105 constituting the electrode material layer 105a into the void 102 (FIGS. 3 (d) and 3 (e)).

First, (1) the pressure-sensitive adhesive layer 104a is formed on at least one surface of the sheet-shaped porous base material 101. The method for forming the pressure-sensitive adhesive layer 104a is not particularly limited, and examples thereof include a method of laminating a sheet-shaped pressure-sensitive adhesive layer 104a on a porous base material 101. According to this method, the pressure-sensitive adhesive layer 104a can be continuously formed on the porous base material 101.

The thickness of the pressure-sensitive adhesive layer 104a according to the present embodiment is appropriately determined in consideration of the porosity of the porous base material 101, the type of the electrode material 105, and the like, but is usually 5 μm or more and 50 μm or less, preferably 10 μm. It is 35 μm or more and 35 μm or less.

Examples of the sheet-shaped adhesive layer 104a include "baseless double-sided tape" and "conductive baseless adhesive tape" manufactured by Teraoka Seisakusho Co., Ltd.

Next, (2) the electrode material layer 105a is formed by adhering the electrode material 105 on the pressure-sensitive adhesive layer 104a, and the porous base material 101, the pressure-sensitive adhesive layer 104a, and the electrode material layer 105a are laminated in this order. The laminated body 150 is obtained.
The method of adhering the electrode material 105 onto the pressure-sensitive adhesive layer 104a is not particularly limited, but a method of directly supplying the powder of the electrode material 105 onto the pressure-sensitive adhesive layer 104a in the air or an inert atmosphere, or a method of directly supplying the powder of the electrode material 105 onto the pressure-sensitive adhesive layer 104a, or the electrode material 105. Is dispersed in a dispersion liquid to form a slurry, and the slurry is applied onto the pressure-sensitive adhesive layer 104a and dried. As a method for applying the slurry, generally known methods such as a doctor blade coating method, a dip coating method, a spray coating method, and a bar coater coating method can be used.
By these methods, the electrode material layer 105a can be continuously formed on the pressure-sensitive adhesive layer 104a.

Examples of the method of directly supplying the powder of the electrode material 105 onto the pressure-sensitive adhesive layer 104a in the air or in an inert atmosphere include a method of powder-coating the electrode material 105 on the pressure-sensitive adhesive layer 104a.
In order to align the electrode material 105 on the pressure-sensitive adhesive layer 104a to a uniform thickness, a guide having a predetermined height is placed on the pressure-sensitive adhesive layer 104a, and the powder of the electrode material 105 is applied so as to fill the opening of the guide. It is also possible to adhere it on the pressure-sensitive adhesive layer 104a.
For example, using a squeegee, the electrode material 105 is powder-coated on the guide, the opening of the guide is filled with the powder of the electrode material 105, and the electrode material 105 is adhered on the pressure-sensitive adhesive layer 104a. Then, by removing the guide, an electrode material layer 105a having a uniform thickness is formed on the pressure-sensitive adhesive layer 104a.
Alternatively, a method in which the opening of the guide is filled with the powder of the electrode material 105 in advance and the guide is superposed on the pressure-sensitive adhesive layer 104a may be used.
For example, the guide filled with the powder of the electrode material 105 is superposed on the pressure-sensitive adhesive layer 104a, and the electrode material 105 filled in the opening of the guide is dropped onto the pressure-sensitive adhesive layer 104a by applying a weak vibration. Then, by removing the guide, the electrode material layer 105a having a uniform thickness can be formed on the pressure-sensitive adhesive layer 104a.
Such a guide may be a structure made of metal or synthetic resin and having a large opening. For example, easily available guides include a porous plate made of metal or resin, a woven fabric, a non-woven fabric, a mesh, and the like. Can be mentioned.
Due to the adhesiveness of the pressure-sensitive adhesive layer 104a, the electrode material 105 adheres to the pressure-sensitive adhesive layer 104a to obtain the electrode material layer 105a.

Subsequently, (3) by pressurizing the obtained laminate 150, the pressure-sensitive adhesive 104 constituting the pressure-sensitive adhesive layer 104a is adhered to the surface of the skeleton portion 103 surrounding the voids 102 of the porous base material 101, and is porous. The electrode material 105 constituting the electrode material layer 105a is filled in the void 102 of the base material 101.
The method of pressurizing the laminated body 150 is not particularly limited, and for example, a roll press or the like can be used. As a result, the laminated body 150 can be continuously pressurized, and the productivity of the electrode sheet 100 can be improved.
The pressure for pressurizing the laminated body 150 is, for example, 40 MPa or more and 500 MPa or less.

The method for manufacturing the electrode sheet 100 is easy to use and has excellent productivity. Further, the thickness of the obtained electrode sheet 100 can be easily adjusted by adjusting the thicknesses of the sheet-shaped porous base material 101, the pressure-sensitive adhesive layer 104a, and the electrode material layer 105a. Further, since the steps (1) to (3) above can be continuously performed, the electrode sheet 100 can be continuously produced, and the area of the electrode sheet 100 can be increased. Therefore, according to this method of manufacturing the electrode sheet 100, the area of the electrode sheet 100 can be easily increased and the thickness of the electrode sheet 100 can be thinned, and the productivity of the electrode sheet 100 can be improved.

Next, a method for manufacturing the electrode sheet 100, which comprises the following steps (4) to (6), will be described.
(4) A step of preparing a sheet-shaped porous base material 101 and an adhesive 104 (FIG. 4 (a)).
(5) A step of coating the surface of the skeleton portion 103 surrounding the void 102 of the porous base material 101 with the pressure-sensitive adhesive 104 (FIG. 4 (b)).
(6) A step of filling the void 102 of the porous base material 101 with the electrode material 105 (FIGS. 4 (c), 5 (d), (e)).

First, (4) a sheet-shaped porous base material 101 and an adhesive 104 are prepared.

Next, (5) the surface of the skeleton portion 103 surrounding the void 102 of the porous base material 101 is coated with the pressure-sensitive adhesive 104. The method for coating the pressure-sensitive adhesive 104 is not particularly limited, but the pressure-sensitive adhesive 104 is dissolved or dispersed in a solvent to make it liquid, and then the liquid is applied onto the porous base material 101 and the liquid permeates into the voids 102. Examples thereof include a method of allowing and drying. As a method of applying the liquid onto the porous substrate 101, generally known methods such as a doctor blade coating method, a dip coating method, a spray coating method, and a bar coater coating method can be used.
By these methods, the pressure-sensitive adhesive 104 can be continuously coated on the surface of the skeleton portion 103 surrounding the voids 102 of the porous base material 101.

Subsequently, (6) the electrode material 105 is filled in the void 102 of the porous base material 101. The method of filling the electrode material 105 is not particularly limited, and for example, a method of directly supplying the powder of the electrode material 105 into the voids 102 of the porous substrate 101 in the air or in an inert atmosphere, or a method of filling the electrode material 105. Is dispersed in a dispersion liquid to form a slurry, and then the slurry is applied onto the porous substrate 101, and the slurry is allowed to permeate into the voids 102 to be dried. As a method for applying the slurry, generally known methods such as a doctor blade coating method, a dip coating method, a spray coating method, and a bar coater coating method can be used.
By these methods, the electrode material 105 can be continuously filled in the void 102 of the porous base material 101.

As a method of directly supplying the powder of the electrode material 105 into the void 102 of the porous base material 101 in the air or in an inert atmosphere, the electrode material 105 is powder-coated on the porous base material 101 and squeezed. A method of filling the void 102 with the electrode material 105 while removing excess powder on the porous substrate 101 can be mentioned.

Subsequently, if necessary, the void 102 is filled with the electrode material 105 that is not filled in the void 102 but is attached to the surface of the porous base material 101.
The method of pressurizing the electrode sheet 100 is not particularly limited, and for example, a roll press or the like can be used. As a result, the pressure can be continuously applied, and the productivity of the electrode sheet 100 can be improved.
The pressure for pressurizing the laminated body 150 is, for example, 40 MPa or more and 500 MPa or less.

The method for manufacturing the electrode sheet 100 is easy to use and has excellent productivity. Further, the thickness of the obtained electrode sheet 100 can be easily adjusted by adjusting the thickness of the sheet-shaped porous base material 101, the coating amount of the adhesive 104, and the amount of the electrode material 105 used. Further, since the steps (5) to (6) can be continuously performed, the electrode sheet 100 can be continuously produced, and the area of the electrode sheet 100 can be increased. Therefore, according to this method of manufacturing the electrode sheet 100, the area of the electrode sheet 100 can be easily increased and the thickness of the electrode sheet 100 can be thinned, and the productivity of the electrode sheet 100 can be improved.

In the method for producing the electrode sheet 100 according to the present embodiment, when the void volume of the porous base material 101 is A and the volume of the pressure-sensitive adhesive 104 is B, it is defined as [(AB) / A] × 100. The residual porosity is preferably 10% or more and 90% or less, and more preferably 15% or more and 90% or less. Here, when the volume of the porous base material is X and the porosity is Y, the void volume A of the porous base material 101 can be calculated by X × Y / 100. Further, the volume B of the pressure-sensitive adhesive 104 can be calculated from the density and mass of the pressure-sensitive adhesive 104. Alternatively, the volume of the pressure-sensitive adhesive layer 104a can be used as it is as the volume B of the pressure-sensitive adhesive 104.
When the residual porosity is at least the above lower limit value, the electrode material 105 that can be filled inside the void 102 can be increased, so that the discharge capacity density of the obtained all-solid-state lithium ion battery can be improved. Further, when the residual porosity is not more than the above upper limit value, the holding power of the electrode material 105 can be improved.
The residual porosity can be adjusted by adjusting the amount of the pressure-sensitive adhesive 104 used, the porosity of the porous base material 101, and the like. For example, when the amount of the pressure-sensitive adhesive 104 used is constant, the larger the porosity of the porous base material 101, the larger the residual porosity. On the other hand, when the porous base material 101 having the same porosity is used, the larger the amount of the pressure-sensitive adhesive 104 used, the smaller the residual porosity.

[All-solid-state lithium-ion battery]
Next, the all-solid-state lithium-ion battery 200 according to the present embodiment will be described. FIG. 6 is a cross-sectional view schematically showing an example of the structure of the all-solid-state lithium-ion battery according to the embodiment of the present invention. The all-solid-state lithium-ion battery 200 according to the present embodiment is a lithium-ion secondary battery, but may be a lithium-ion primary battery.

In the all-solid-state lithium-ion battery 200 according to the present embodiment, the positive electrode layer 201, the solid electrolyte layer 205, and the negative electrode layer 203 are laminated in this order. Then, at least one of the positive electrode layer 201 and the negative electrode layer 203 is composed of the electrode sheet 100 according to the present embodiment.

The all-solid-state lithium-ion battery 200 according to the present embodiment is manufactured according to a generally known method. For example, it is produced by forming a stack of a positive electrode layer 201, a solid electrolyte layer 205, and a negative electrode layer 203 into a cylindrical shape, a coin shape, a square shape, a film shape, or any other shape.

(Positive layer)
The positive electrode layer 201 of the present embodiment is preferably composed of the electrode sheet 100 according to the present embodiment.
The positive electrode layer 201 may be provided with a current collector on one surface. The current collector is not particularly limited, and a normal current collector that can be used for an all-solid-state lithium-ion battery such as an aluminum foil can be used.

The positive electrode layer 201 of the present embodiment may be pressed, if necessary, to adjust the density of the positive electrode layer 201. As a pressing method, a generally known method can be used.

(Negative electrode layer)
The negative electrode layer 203 of the present embodiment is not particularly limited, and is preferably composed of the electrode sheet 100 according to the present embodiment.
The negative electrode layer 203 may be provided with a current collector on one surface. The current collector is not particularly limited, and a normal current collector that can be used for an all-solid-state lithium-ion battery such as a copper foil can be used.

The negative electrode layer 203 of the present embodiment may be pressed as necessary to adjust the density of the negative electrode layer 203. As a pressing method, a generally known method can be used.

(Solid electrolyte layer)
The solid electrolyte layer 205 according to the present embodiment is a layer formed between the positive electrode layer 201 and the negative electrode layer 203 by the solid electrolyte material. The solid electrolyte material contained in the solid electrolyte layer 205 is not particularly limited as long as it has lithium ion conductivity, and generally known materials can be used. For example, those listed as the solid electrolyte material to be included in the electrode material 105 described above can be used.

The content of the solid electrolyte material in the solid electrolyte layer 205 according to the present embodiment is not particularly limited as long as the desired insulating property can be obtained, but is, for example, in the range of 10% by volume or more and 100% by volume or less. Of these, it is preferably in the range of 50% by volume or more and 100% by volume or less.

The thickness of the solid electrolyte layer 205 of the present embodiment is, for example, preferably in the range of 0.1 μm or more and 1000 μm or less, and more preferably in the range of 0.1 μm or more and 300 μm or less.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference form will be added.
<Additional notes>
(Appendix 1)
Sheet-shaped porous substrate and
At least the adhesive adhering to the surface of the skeleton surrounding the voids of the porous substrate, and
An electrode material containing a solid electrolyte material and an electrode active material and filled inside the voids of the porous substrate.
Electrode sheet with.
(Appendix 2)
In the electrode sheet described in Appendix 1,
An electrode sheet in which at least a part of the electrode material is attached to the pressure-sensitive adhesive.
(Appendix 3)
In the electrode sheet according to Appendix 1 or 2,
An electrode sheet having a thickness of 300 μm or less.
(Appendix 4)
In the electrode sheet according to any one of Appendix 1 to 3,
An electrode sheet in which the filling amount of the electrode material is 15% by mass or more and 85% by mass or less, assuming that the entire electrode sheet is 100% by mass.
(Appendix 5)
In the electrode sheet according to any one of Appendix 1 to 4,
An electrode sheet in which the content of the binder in the electrode material is less than 0.5% by mass when the total amount of the electrode material is 100% by mass.
(Appendix 6)
In the electrode sheet according to any one of Appendix 1 to 5,
An electrode sheet used for a positive electrode layer or a negative electrode layer constituting an all-solid-state lithium-ion battery.
(Appendix 7)
In the electrode sheet according to any one of Appendix 1 to 6,
The porous base material is an electrode sheet which is a non-woven fabric.
(Appendix 8)
In the electrode sheet according to any one of Appendix 1 to 7,
An electrode sheet in which the porous substrate has electron conductivity.
(Appendix 9)
In the electrode sheet according to any one of Appendix 1 to 8,
An electrode sheet having a porosity of 50% or more and 95% or less of the porous substrate.
(Appendix 10)
An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
An all-solid-state lithium-ion battery in which at least one of the positive electrode layer and the negative electrode layer is composed of the electrode sheet according to any one of Supplementary note 1 to 9.
(Appendix 11)
A manufacturing method for manufacturing the electrode sheet according to any one of Supplementary note 1 to 9.
A step of forming an adhesive layer on at least one surface of a sheet-like porous substrate, and
A step of forming an electrode material layer by adhering an electrode material on the pressure-sensitive adhesive layer to obtain a laminate in which the porous base material, the pressure-sensitive adhesive layer, and the electrode material layer are laminated in this order.
By pressurizing the obtained laminate, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is adhered to the surface of the skeleton portion surrounding the voids of the porous substrate, and the pressure-sensitive adhesive is contained in the voids of the porous substrate. The step of filling the electrode material constituting the electrode material layer and
A method for manufacturing an electrode sheet including.
(Appendix 12)
A manufacturing method for manufacturing the electrode sheet according to any one of Supplementary note 1 to 9.
Sheet-shaped porous substrate, process of preparing adhesive, and
A step of coating the surface of the skeleton portion surrounding the voids of the porous substrate with the adhesive,
A step of filling the voids of the porous substrate with an electrode material, and
A method for manufacturing an electrode sheet including.
(Appendix 13)
The method for manufacturing an electrode sheet according to Appendix 11 or 12.
When the void volume of the porous substrate is A and the volume of the pressure-sensitive adhesive is B,
[(AB) / A] A method for producing an electrode sheet in which the residual porosity defined by × 100 is 10% or more and 90% or less.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples and comparative examples, "mAh / g" indicates the discharge capacity density per 1 g of the positive electrode active material.

[1] Measurement method First, the measurement methods in the following examples and comparative examples will be described.

(1) Particle Size Distribution The particle size distribution of the positive electrode active material used in Examples and Comparative Examples was measured by a laser diffraction method using a laser diffraction scattering type particle size distribution measuring device (Mastersizer 3000 manufactured by Malvern). From the measurement results, the particle size (D ₅₀ , average particle size) at 50% cumulative in the weight-based cumulative distribution was determined for each positive electrode active material.

(2) Measurement of Lithium Ion Conductivity The positive electrode active material sheets obtained in Examples and Comparative Examples were measured for lithium ion conductivity by the AC impedance method.
For the measurement of lithium ion conductivity, a potentiostat / galvanostat SP-300 manufactured by Hokuto Denko Co., Ltd. was used. The size of the sample was φ9.5 mm, the thickness was about 0.05 mm, the measurement conditions were an applied voltage of 10 mV, a measurement temperature of 27.0 ° C., a measurement frequency range of 0.1 Hz to 7 MHz, and an electrode of Li foil.

(3) Charge / Discharge Test A positive electrode sheet having a diameter of 14 mm obtained in Examples and Comparative Examples was attached to an adhesive surface of a conductive aluminum foil adhesive tape (manufactured by Teraoka Seisakusho Co., Ltd., φ14 mm) to obtain a positive electrode.
Subsequently, the solid electrolyte material (Li ₁₁ P ₃ S ₁₂ , 100 mg) was pre-pressed at 83 MPa using a press jig. Then, it was placed on the positive electrode and press-molded at 250 MPa for 10 minutes to form a solid electrolyte layer on the positive electrode.
Further, the positive electrode, the solid electrolyte layer, and the indium foil (φ = 14 mm, t = 0.5 mm) as the negative electrode obtained by the above method were laminated in this order to prepare an all-solid-state lithium ion battery. Next, the all solid state lithium ion battery obtained was charged to a charge termination voltage 3.0V at a current density of 65μA / cm ^2, at a current density of 65μA / cm ^2, until the discharge cutoff potential 0.4V Charging and discharging were performed 10 times under the condition of discharging. However, since the potential window of the oxide positive electrode active material shifts to the high voltage side, the charge end voltage was set to 3.6 V and the discharge end voltage was set to 2.4 V.
Here, when the first discharge capacity is 100%, the tenth discharge capacity is defined as the discharge capacity change rate [%]. Table 1 shows the results obtained for the discharge capacity density and the discharge capacity change rate for the positive electrode material.

[2] Materials Next, the materials used in the following Examples and Comparative Examples will be described.

(1) Positive electrode active material (Li ₁₄ MoS ₉ )
In an argon atmosphere, MoS ₂ (manufactured by Wako Pure Chemical Industries, Ltd., 665 mg, 4.2 mmol) and Li ₂ S (manufactured by Alfa Aesar, 1335 mg, 19.1 mmol) were placed in a ball mill pot made of Al ₂ O ₃ having an internal volume of 400 mL. Was weighed and added, and 500 g of a ZrO ₂ ball having a diameter of 10 mm was further added, and an Al ₂ O ₃ ball mill pot was sealed.
Next, an Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for 4 days.
The obtained Li-Mo-S compound was pulverized in a mortar and classified by a sieve having an opening of 43 μm to obtain Li ₁₄ MoS ₉ having an average particle diameter d ₅₀ of 5 μm.

(2) Positive electrode active material (LiMn ₂ O ₄ )
MnO ₂ (Kanto Chemical Co., Ltd., 1650 mg, 19.0 mmol) and Li ₂ CO ₃ (Kanto Chemical Co., Ltd., 350 mg, 4.7 mmol) are weighed and added to an Al ₂ O ₃ ball mill pot having an internal volume of 400 mL. 500 g of φ10 mm ZrO ₂ balls were put in, and an Al ₂ O ₃ ball mill pot was sealed.
Next, an Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for one day.
The obtained mixture was heated at 750 ° C. for 24 hours in an air atmosphere using an electric furnace to obtain a Li-Mn-O compound. The Li-Mn-O compound was pulverized in a mortar and classified by a sieve having an opening of 43 μm to obtain LiMn ₂ O ₄ having an average particle diameter d ₅₀ of 5 μm.

(3) Production of Solid Electrolyte Material (Li ₁₁ P ₃ S ₁₂ ) Li ₂ S (manufactured by Alfa Aesar, purity 99.9%) and P ₂ S ₅ (reagent manufactured by Kanto Chemical Co., Inc.) were used as raw materials. Li ₃ N was prepared by the following procedure.
First, a stainless steel net (150 mesh) was pressure-bonded to Li foil (purity 99.8%, thickness 0.5 mm) manufactured by Honjo Metal Co., Ltd. in a glove box having a nitrogen atmosphere. The Li foil began to change to black-purple from the opening of the net, and when left as it was at room temperature for 24 hours, all of the Li foil changed to black-purple Li ₃ N. Li ₃ N was pulverized in an agate mortar and then sieved with a stainless steel sieve, and a powder of 25 μm or less was recovered and used as a raw material for a solid electrolyte material.
Next, each raw material was precisely weighed in an argon glove box so that Li ₂ S: P ₂ S ₅ : Li ₃ N = 67.5: 22.5: 10.0 (mol%), and these powders were added. It was mixed in an agate mortar for 20 minutes. Next, 2 g of the mixed powder was weighed, placed in an Al ₂ O ₃ ball mill pot (internal volume 400 mL) together with 500 g of a φ10 mm ZrO ₂ ball, and mixed and pulverized at 120 rpm for 200 hours. The powder after mixing and pulverization was placed in a carbon boat and heat-treated at 330 ° C. for 2 hours in an argon air stream to obtain Li ₁₁ P ₃ S ₁₂ .

(4) Porous base material The following were used as the porous base material.
Porous base material 1: Non-woven fabric (PET, Asahi Kasei, Silky Fine (registered trademark), WS7R02-05, thickness 22 μm, density 0.23 g / cm ³ , porosity 83%, air permeability> 300 cm ³ / cm ² / sec)
-Porosity base material 2: Non-woven fabric (natural fiber / PET / acrylic resin coating type, manufactured by Asahi Kasei Corporation, Silky Fine (registered trademark), WSKG12-10, thickness 46 μm, density 0.22 g / cm ³ , porosity 85% , Porosity> 300cm ³ / cm ² / sec)

(5) Adhesive The following adhesives were used.
-Adhesive sheet: (Teraoka Seisakusho Co., Ltd., baseless double-sided tape 7029 0.015, acrylic adhesive, thickness 15 μm)
・ Adhesive spray: (3M, spray glue 55, acrylic rubber)

<Example 1>
The porous substrate 1 was cut into 100 mm × 100 mm, and an adhesive sheet (100 mm × 100 mm) was attached to one surface of the porous substrate 1. Further, the opening of a PTFE mesh (Flon Industries, Ltd., F3261-05, equivalent to 18 mesh) was filled with Li ₁₄ MoS ₉ , which is a positive electrode active material. The obtained PTFE mesh filled with Li ₁₄ MoS ₉ was placed on an adhesive sheet provided on one surface of the porous substrate 1, and then weakly vibrated to fill the PTFE mesh. Li ₁₄ MoS ₉ was dropped onto the pressure-sensitive adhesive sheet to form a positive electrode material layer.
Next, the PTFE mesh was removed to obtain a laminate composed of the porous substrate 1, the pressure-sensitive adhesive sheet, and the positive electrode material layer. The resulting laminate was then pressed at a pressure of 320 MPa. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet adhered to the surface of the skeleton portion of the porous base material 1, and Li ₁₄ MoS ₉ penetrated from the upper surface to the lower surface so as to fill the remaining voids. At this time, a part of Li ₁₄ MoS ₉ was attached to the pressure-sensitive adhesive adhering to the surface of the skeleton portion of the porous base material 1.
The ionic conductivity of the obtained positive electrode active material sheet was measured. The results obtained are shown in Table 1. Since it is difficult to measure the ion conductivity in a state where the conductive additive is mixed, the ion conductivity was measured only with the positive electrode active material.

Next, 0.308 g of Li ₁₄ MoS ₉ which is a positive electrode active material, 0.308 g of acetylene black which is a conductive auxiliary agent, and 0.385 g of Li ₁₁ P ₃ S ₁₂ which is a solid electrolyte material are mortar and pestle. Was mixed for 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), 500 g of ZrO ₂ balls having a diameter of 10 mm was further added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot had an argon atmosphere.
Next, an Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for 24 hours to obtain a positive electrode material.
The porous substrate 1 was cut into 100 mm × 100 mm, and an adhesive sheet (100 mm × 100 mm) was attached to one surface of the porous substrate 1. Further, the opening of a PTFE mesh (manufactured by Freon Industries, Ltd., F3261-05, thickness 0.7 mm, 100 mm × 100 mm, equivalent to 18 mesh) was filled with a positive electrode material. The PTFE mesh filled with the obtained positive electrode material is placed on the pressure-sensitive adhesive sheet, and then a weak vibration is applied to drop the positive electrode material filled in the PTFE mesh onto the pressure-sensitive adhesive sheet to cause a positive electrode material layer. Was formed.
Next, the PTFE mesh was removed to obtain a laminate composed of the porous substrate 1, the pressure-sensitive adhesive sheet, and the positive electrode material layer. The resulting laminate was then pressed at a pressure of 320 MPa. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet adhered to the surface of the skeleton portion of the porous base material 1, and the positive electrode material penetrated from the upper surface to the lower surface so as to fill the remaining voids. At this time, a part of the positive electrode material was attached to the pressure-sensitive adhesive attached to the surface of the skeleton portion of the porous base material 1.
In the obtained positive electrode sheet, the positive electrode material was not chipped or the surface was not cracked. The thickness of the positive electrode sheet was 29 μm.
A positive electrode sheet having a diameter of 14 mm was cut out from the obtained positive electrode sheet having a size of 100 mm × 100 mm, and the charge / discharge test described above was performed. The results obtained are shown in Table 1.

<Example 2>
The porous base material 1 was cut into 100 mm × 100 mm, and an adhesive spray was sprayed on both sides of the porous base material 1, and the adhesive was coated on the surface of the skeleton portion of the porous base material 1. Here, the amount of the pressure-sensitive adhesive spray used was 0.0819 cm ³ . Further, the opening of a PTFE mesh (Flon Industries, Ltd., F3261-05, equivalent to 18 mesh) was filled with Li ₁₄ MoS ₉ , which is a positive electrode active material. A PTFE mesh filled with the obtained Li ₁₄ MoS ₉ is placed on a porous base material 1 coated with an adhesive, and a weak vibration is applied to coat the Li ₁₄ MoS ₉ with an adhesive-coated porous group. It was dropped on the material 1.
Then, the PTFE mesh was removed and pressed at a pressure of 320 MPa. The pressure-sensitive adhesive adhered to the surface of the skeleton portion of the porous base material 1, and Li ₁₄ MoS ₉ penetrated from the upper surface to the lower surface so as to fill the remaining voids. At this time, a part of Li ₁₄ MoS ₉ was attached to the pressure-sensitive adhesive adhering to the surface of the skeleton portion of the porous base material 1.
The ionic conductivity of the obtained positive electrode active material sheet was measured. The results obtained are shown in Table 1.

Next, 0.308 g of Li ₁₄ MoS ₉ which is a positive electrode active material, 0.308 g of acetylene black which is a conductive auxiliary agent, and 0.385 g of Li ₁₁ P ₃ S ₁₂ which is a solid electrolyte material are mortar and pestle. Was mixed for 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), 500 g of ZrO ₂ balls having a diameter of 10 mm was further added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot had an argon atmosphere.
Next, an Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for 24 hours to obtain a positive electrode material.
The porous base material 1 was cut into 100 mm × 100 mm, and an adhesive spray was sprayed on both sides of the porous base material 1, and the adhesive was coated on the surface of the skeleton portion of the porous base material 1. A positive electrode material was filled in the opening of a PTFE mesh (manufactured by Freon Industries, Ltd., F3261-05, thickness 0.7 mm, 100 mm × 100 mm, equivalent to 18 mesh). The PTFE mesh filled with the obtained positive electrode material is placed on the porous base material 1 coated with the adhesive, and then vibrated by poking with a stick to obtain the positive electrode material filled in the PTFE mesh. It was dropped onto the porous substrate 1 coated with the adhesive.
Then, the PTFE mesh was removed and pressed at a pressure of 320 MPa. The pressure-sensitive adhesive adhered to the surface of the skeleton portion of the porous base material 1, and the positive electrode material penetrated from the upper surface to the lower surface so as to fill the remaining voids. At this time, a part of the positive electrode material was attached to the pressure-sensitive adhesive adhering to the surface of the skeleton portion of the porous base material 1.
In the obtained positive electrode sheet, the positive electrode material was not chipped or the surface was not cracked. The thickness of the positive electrode sheet was 26 μm.
A positive electrode sheet having a diameter of 14 mm was cut out from the obtained positive electrode sheet having a size of 100 mm × 100 mm, and the charge / discharge test described above was performed. The results obtained are shown in Table 1.

<Example 3>
The positive electrode activity is the same as in Example 1 except that LiMn ₂ O ₄ is used instead of Li ₁₄ MoS ₉ as the positive electrode active material and the porous base material 2 is used instead of the porous base material 1 as the porous base material. A substance sheet and a positive electrode sheet were prepared, respectively, and the ion conductivity was measured and the charge / discharge test was performed. The results obtained are shown in Table 1.

<Example 4>
As in Example 2, LiMn ₂ O ₄ was used instead of Li ₁₄ MoS ₉ as the positive electrode active material, and the porous base material 2 was used instead of the porous base material 1 as the porous base material. A substance sheet and a positive electrode sheet were prepared, respectively, and the ion conductivity was measured and the charge / discharge test was performed. The results obtained are shown in Table 1.

<Comparative example 1>
A positive electrode active material sheet and a positive electrode sheet were prepared in the same manner as in Example 1 except that no adhesive was used, and the ion conductivity was measured and the charge / discharge test was performed respectively. The results obtained are shown in Table 1.

<Comparative example 2>
The positive electrode active material sheet and the positive electrode are the same as in Comparative Example 1 except that the binder (PTFE dispersion, manufactured by Asahi Glass Fluoropolymers, CD123) is blended so as to be 0.5% by mass with respect to 100% by mass of the positive electrode material. Each sheet was prepared, and the ion conductivity was measured and the charge / discharge test was performed. The results obtained are shown in Table 1. In the case of the positive electrode active material sheet, the total of the positive electrode active material and the binder was set to 100% by mass.

<Comparative example 3>
The positive electrode activity is the same as in Comparative Example 1 except that LiMn ₂ O ₄ is used instead of Li ₁₄ MoS ₉ as the positive electrode active material and the porous base material 2 is used instead of the porous base material 1 as the porous base material. A substance sheet and a positive electrode sheet were prepared, respectively, and the ion conductivity was measured and the charge / discharge test was performed. The results obtained are shown in Table 1.

<Comparative example 4>
The positive electrode active material sheet and the positive electrode are the same as in Comparative Example 3 except that the binder (PTFE dispersion, manufactured by Asahi Glass Fluoropolymers, CD123) is blended so as to be 0.5% by mass with respect to 100% by mass of the positive electrode material. Each sheet was prepared, and the ion conductivity was measured and the charge / discharge test was performed. The results obtained are shown in Table 1. In the case of the positive electrode active material sheet, the total of the positive electrode active material and the binder was set to 100% by mass.

<Comparative example 5>
Li ₁₄ MoS ₉ , which is a positive electrode active material, was pressed at a pressure of 320 MPa to prepare a positive electrode active material sheet having a thickness of 301 μm.
The ionic conductivity of the obtained positive electrode active material sheet was measured. The results obtained are shown in Table 1.

Next, 0.308 g of Li ₁₄ MoS ₉ which is a positive electrode active material, 0.308 g of acetylene black which is a conductive auxiliary agent, and 0.385 g of Li ₁₁ P ₃ S ₁₂ which is a solid electrolyte material are mortar and pestle. Was mixed for 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), 500 g of ZrO ₂ balls having a diameter of 10 mm was further added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot had an argon atmosphere.
Next, an Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for 24 hours to obtain a positive electrode material.
Next, the obtained positive electrode material was pressed at a pressure of 320 MPa to prepare a positive electrode sheet having a thickness of 301 μm. In the obtained positive electrode sheet, the positive electrode material was chipped and the surface was cracked. A positive electrode sheet having a diameter of 14 mm was cut out from the obtained positive electrode sheet having a size of 100 mm × 100 mm, and the charge / discharge test described above was performed. The results obtained are shown in Table 1.

The positive electrode sheets obtained in Examples 1 to 4 had no chipping of the positive electrode material or cracks on the surface. Further, the all-solid-state lithium-ion battery using the positive electrode sheets obtained in Examples 1 to 4 had a high discharge capacity and a high discharge capacity change rate, and was excellent in charge / discharge characteristics.
On the other hand, in the positive electrode sheets of Comparative Examples 1, 3 and 5 in which no adhesive was used, the positive electrode material was missing and the surface was cracked. Further, the all-solid-state lithium ion battery using such a positive electrode sheet has a low discharge capacity and a low discharge capacity change rate, and is inferior in charge / discharge characteristics.
Further, in the positive electrode sheets of Comparative Examples 2 and 4, since the binder was added, the positive electrode material was not missing or the surface was not cracked. However, the obtained positive electrode sheet had low ionic conductivity. The all-solid-state lithium-ion battery using such a positive electrode sheet has a low discharge capacity and a low discharge capacity change rate, and is inferior in charge / discharge characteristics.

100 Electrode sheet 101 Porous base material 102 Void 103 Skeleton part 104 Adhesive 104a Adhesive layer 105 Electrode material 105a Electrode material layer 150 Laminated body 200 All-solid-state lithium-ion battery 201 Positive electrode layer 203 Negative electrode layer 205 Solid electrolyte layer

Claims (12)

A sheet-like porous substrate made of resin material, natural fiber, glass or carbon,
At least the adhesive adhering to the surface of the skeleton surrounding the voids of the porous substrate, and
An electrode material containing a solid electrolyte material and an electrode active material and filled inside the voids of the porous substrate.
Bei to give a,
An electrode sheet in which the content of the binder in the electrode material is less than 0.5% by mass when the total amount of the electrode material is 100% by mass . In the electrode sheet according to claim 1,
An electrode sheet in which at least a part of the electrode material is attached to the pressure-sensitive adhesive. In the electrode sheet according to claim 1 or 2.
An electrode sheet having a thickness of 300 μm or less. In the electrode sheet according to any one of claims 1 to 3,
An electrode sheet in which the filling amount of the electrode material is 15% by mass or more and 85% by mass or less, assuming that the entire electrode sheet is 100% by mass. In the electrode sheet according to any one of claims 1 to 4 .
An electrode sheet used for a positive electrode layer or a negative electrode layer constituting an all-solid-state lithium-ion battery. In the electrode sheet according to any one of claims 1 to 5 ,
The porous base material is an electrode sheet which is a non-woven fabric. In the electrode sheet according to any one of claims 1 to 6 .
An electrode sheet in which the porous substrate has electron conductivity. In the electrode sheet according to any one of claims 1 to 7 .
An electrode sheet having a porosity of 50% or more and 95% or less of the porous substrate. An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
An all-solid-state lithium-ion battery in which at least one of the positive electrode layer and the negative electrode layer is composed of the electrode sheet according to any one of claims 1 to 8 . A manufacturing method for manufacturing the electrode sheet according to any one of claims 1 to 8 .
A step of forming an adhesive layer on at least one surface of a sheet-like porous substrate, and
A step of forming an electrode material layer by adhering an electrode material on the pressure-sensitive adhesive layer to obtain a laminate in which the porous base material, the pressure-sensitive adhesive layer, and the electrode material layer are laminated in this order.
By pressurizing the obtained laminate, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is adhered to the surface of the skeleton portion surrounding the voids of the porous base material, and the pressure-sensitive adhesive is contained in the voids of the porous base material. The step of filling the electrode material constituting the electrode material layer and
A method for manufacturing an electrode sheet including. A manufacturing method for manufacturing the electrode sheet according to any one of claims 1 to 8 .
Sheet-shaped porous substrate, process of preparing adhesive, and
A step of coating the surface of the skeleton portion surrounding the voids of the porous substrate with the adhesive,
A step of filling the voids of the porous substrate with an electrode material, and
A method for manufacturing an electrode sheet including. The method for manufacturing an electrode sheet according to claim 10 or 11 .
When the void volume of the porous substrate is A and the volume of the pressure-sensitive adhesive is B,
[(AB) / A] A method for producing an electrode sheet in which the residual porosity defined by × 100 is 10% or more and 90% or less.

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