JP2015153459A - Electrode sheet, all-solid lithium ion battery, and method of manufacturing electrode sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode sheet capable of achieving a large area and reduction in film thickness while suppressing missing of an electrode material and cracking of a surface and having excellent ion conductivity.SOLUTION: An electrode sheet 100 includes: a sheet-like porous base material 101; an adhesive 104; and an electrode material 105. The adhesive 104 is attached to the surface of a skeleton part 103 surrounding a void 102 of the porous base material 101. Moreover, the electrode material 105 contains a solid electrolyte material and an electrode active material and is filled into the inside of the void 102 of the porous base material 101.

Description

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

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

An electrolyte solution containing a flammable organic solvent is used in a lithium ion battery currently on the market. 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 to make the battery completely solid does not use a flammable organic solvent in the battery. It is considered that the manufacturing cost and productivity are excellent.
In such all solid-state lithium ion batteries, an electrode sheet mainly containing an electrode active material and a solid electrolyte material is used as an electrode. Patent Documents 1 and 2 below describe examples of such electrode sheets.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-40218) discloses a lithium metal having a porous metal sheet having a three-dimensional network structure and an inorganic solid electrolyte inserted into pores of the porous metal sheet. A battery electrode material sheet is described.

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

JP 2010-40218 A JP 2008-103258 A

According to the study by the present inventors, it is clear that when the electrode sheet as described in Patent Documents 1 and 2 is thinned, the electrode material is lost 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 lost or the surface is cracked, the lithium ion conductivity of the obtained electrode sheet is greatly reduced.

  The inventors of the present invention have made extensive studies on the structure of an electrode in order to provide an electrode sheet that can be increased in area and thickness while suppressing loss of electrode material and cracks on the surface, and has excellent ion conductivity. . As a result, the electrode material containing the solid electrolyte material and the electrode active material is filled into the voids of the porous substrate to which the adhesive is attached, thereby preventing the electrode material from being lost and cracking of the surface. The inventors have found that it is possible to reduce the thickness and form a thin film, and have reached the present invention.

That is, according to the present invention,
A sheet-like porous substrate;
An adhesive attached to the surface of the skeleton part surrounding at least the voids of the porous substrate;
An electrode material containing a solid electrolyte material and an electrode active material and filled in the voids of the porous substrate;
An electrode sheet is provided.

Furthermore, 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 constituted by the electrode sheet is provided.

Furthermore, according to the present invention,
A manufacturing method for manufacturing the electrode sheet,
Forming an adhesive layer on at least one surface of the sheet-like porous substrate; and
Forming an electrode material layer by attaching an electrode material on the pressure-sensitive adhesive layer, and obtaining a laminate in which the porous substrate, 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 attached to the surface of the skeleton surrounding the voids of the porous substrate, and the voids of the porous substrate are Filling the electrode material constituting the electrode material layer;
A method for producing an electrode sheet comprising

Furthermore, according to the present invention,
A manufacturing method for manufacturing the electrode sheet,
A step of preparing a sheet-like porous substrate and an adhesive;
Coating the pressure-sensitive adhesive on the surface of the skeleton surrounding the voids of the porous substrate;
Filling the electrode material into the voids of the porous substrate;
A method for producing an electrode sheet comprising

  According to the present invention, it is possible to provide an electrode sheet that can be increased in area and thickness while suppressing loss of electrode material and cracking of the surface, and excellent in ion conductivity.

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

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate. Moreover, the figure is a schematic diagram and does not necessarily match the actual dimensional ratio. In addition, unless otherwise indicated, "to" represents the following from the above.

FIG. 1 is a cross-sectional view schematically showing an example of the structure of an electrode sheet 100 according to an embodiment of the present invention.
The electrode sheet 100 includes a sheet-like porous substrate 101, an adhesive 104, and an electrode material 105. The adhesive 104 is attached to the surface of the skeleton 103 surrounding at least the void 102 of the porous substrate 101. The electrode material 105 includes a solid electrolyte material and an electrode active material, and is filled in the voids 102 of the porous substrate 101.

The electrode sheet 100 which concerns on this embodiment is used for the positive electrode layer or negative electrode layer which comprises an all-solid-type lithium ion battery, for example.
As an example of the all solid-state lithium ion battery to which the electrode sheet 100 according to the present embodiment is applied, a battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked in this order can be given. In this case, at least one of the positive electrode layer and the negative electrode layer is constituted by the electrode sheet 100.

A conventional electrode for an all-solid-state lithium ion battery is produced by press-molding an electrode material containing an electrode active material and a solid electrolyte at a high pressure, and then pressing the press-molded body and the current collector layer at a high pressure. It was. However, according to the study by the present inventors, it was difficult to increase the area of the electrode produced by such a method, and the industrial productivity was inferior. Further, when the film thickness is reduced, the electrode material is lost and the surface is cracked, and it is difficult to keep the shape of the electrode sheet constant.
In addition, according to the study by the present inventors, the electrode sheet as described in Patent Documents 1 and 2 also loses electrode material or cracks on the surface when the film is thinned, and the shape of the electrode sheet is constant. It was revealed that it was difficult to keep
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 lost or the surface is cracked, the lithium ion conductivity of the obtained electrode sheet is greatly reduced.
Based on the above knowledge, the present inventors provide an electrode sheet that can be increased in area and thickness while suppressing loss of electrode material and cracking of the surface, and has excellent ion conductivity. The structure of this was studied earnestly. As a result, the electrode material containing the solid electrolyte material and the electrode active material is filled into the voids of the porous substrate to which the adhesive is attached, thereby preventing the electrode material from being lost and cracking of the surface. The inventors have found that it is possible to reduce the thickness and thin the film, and have reached the present invention.

In the electrode sheet 100 according to this embodiment, the electrode material 105 is stably held in the voids 102 of the porous substrate 101 by the adhesive 104 attached to the skeleton 103 of the porous substrate 101. Therefore, even if the electrode sheet 100 is increased in area and thickness, the electrode material 105 can be stably held in the gap 102 of the porous substrate 101. As a result, the electrode material 105 is lost or the electrode sheet is lost. 100 cracks on the surface can be suppressed. Moreover, since the electrode sheet 100 can be made thin, the impedance of the electrode sheet 100 can be reduced, and as a result, the charge / discharge characteristics of the obtained all solid-state lithium ion battery can be further improved.
Furthermore, since the electrode material 105 can be stably held in the voids 102 of the porous substrate 101, the content of the binder contained in the electrode material 105 can be reduced. Thereby, 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 interface 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 increased in area and thickness while suppressing the loss of electrode material and cracks on the surface, and is excellent in lithium ion conductivity. Moreover, the charge / discharge characteristic of the obtained all-solid-state lithium ion battery can be improved by using the electrode sheet 100 excellent in lithium ion conductivity. In the present embodiment, the charge / discharge characteristics of the all solid-state lithium ion battery refer to 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-like porous substrate 101, an adhesive 104, and an electrode material 105. The adhesive 104 is attached to the surface of the skeleton 103 surrounding at least the void 102 of the porous substrate 101. The electrode material 105 includes a solid electrolyte material and an electrode active material, and is filled in the voids 102 of the porous substrate 101.

  In the electrode sheet 100, at least a part of the electrode material 105 is preferably attached to the adhesive 104. Accordingly, the electrode sheet 100 can be increased in area and thickness while further suppressing the loss of the electrode material 105 and the cracks on the surface of the electrode sheet 100. Moreover, the impedance of the electrode sheet 100 can be reduced by reducing the thickness of the electrode sheet 100. 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. For example, the electrode sheet 100 can be rectangular.
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, 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 electrode sheet 100 is equal to or greater than the above lower limit value, the loss of the electrode material 105 and the cracks on the surface of the electrode sheet 100 can be further suppressed. Moreover, the impedance of the electrode sheet 100 can be further reduced as the thickness of the electrode sheet 100 is not more than the above upper limit value. 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, and more preferably 40% by mass or more and 70% by mass when the entire electrode sheet 100 is 100% by mass. It is as follows. When the filling amount of the electrode material 105 is equal to or less than the above upper limit value, the loss of the electrode material 105 and the cracks on the surface of the electrode sheet 100 can be further suppressed. Further, when the filling amount of the electrode material 105 is equal to or more than the above lower limit value, an all-solid-state lithium ion battery more excellent in 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, and more preferably 15% by mass or more and 50% by mass when the entire 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 number of electrode materials 105 that can be filled in the voids 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 pressure-sensitive adhesive 104 is equal to or more than the above lower limit value, it is possible to realize an increase in area and thickness of the electrode sheet 100 while further suppressing loss of the electrode material 105 and cracks on the surface of the electrode sheet 100. . Moreover, the impedance of the electrode sheet 100 can be reduced by reducing the thickness of the electrode sheet 100. As a result, the charge / discharge characteristics of the obtained all solid-state lithium ion battery can be improved.

Even if the electrode sheet 100 according to the present embodiment does not use an electrolytic solution, when the positive electrode active material is Li ₁₄ MoS ₉ at room temperature, 1.5 × 10 ⁻⁴ S · cm ⁻¹ or more, LiMn ₂ O ₄ High lithium ion conductivity corresponding to 50% or more of the ionic conductivity of a powder press-molded body usually carried out, 2.5 × 10 ⁻⁶ S · cm ⁻¹ or more.
Here, the lithium ion conductivity is such that the electrode sheet is composed only of a positive electrode active material, an adhesive, and a porous substrate, and is 27.0 ° C., an applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz. It is lithium ion conductivity by the alternating current impedance method in measurement conditions.
In addition, the electrode sheet 100 according to the present embodiment can have a large area, and even when the thickness is 50 μm or less, the electrode material 105 is not easily lost or the surface is hardly cracked.
Therefore, the electrode sheet 100 according to this embodiment is extremely useful as an electrode sheet for a lithium ion battery.

  Hereinafter, each structure of the electrode sheet 100 which concerns on this embodiment is demonstrated.

<Sheet porous substrate>
The porous substrate 101 according to the present embodiment has a sheet shape, and can sufficiently fill the gap 102 with the electrode material 105. Examples of the form of the porous substrate 101 include a woven fabric, a nonwoven fabric, a mesh cloth, a porous membrane, an expanded sheet, and a punching sheet. Among these, a nonwoven 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.

  The material constituting the porous substrate 101 includes nylon, polyester such as polyethylene terephthalate (PET), polyethylene, polypropylene, polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, Resin materials such as polyvinylidene chloride, polyvinyl chloride, polyurethane, vinylon, polybenzimidazole, polyimide, polyphenylene sulfite, polyether ether ketone, cellulose, acrylic resin; natural fibers such as hemp, wood pulp, cotton linter; iron, Examples thereof include metal materials such as aluminum, titanium, nickel and stainless steel; inorganic materials such as glass and carbon.

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

Further, 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. Since the electrode material 105 that can be filled in the voids 102 can be increased when the porosity is equal to or higher than the above lower limit value, the discharge capacity density of the obtained all solid-state lithium ion battery can be improved.
Moreover, since the mechanical strength of the porous base material 101 can be improved and the holding power of the electrode material 105 can be improved when the porosity is not more than the above upper limit value, the resulting electrode sheet 100 can be made thinner. can do.
Here, the porosity means the ratio of the total volume of the voids in the total volume of the porous substrate 101. That is, the porosity is represented by (1−volume of constituent material in porous substrate / volume of porous substrate) × 100 (%).

Further, 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, 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 can easily flow into the porous base material 101, and the electrode material 105 can be filled in the void 102 with high density. Therefore, the contact resistance between the particles of the electrode material 105 is reduced, and the discharge capacity density of the obtained all solid-state lithium ion battery can be improved. Moreover, since the mechanical strength of the porous base material 101 can be improved and the holding power of the electrode material 105 can be improved when the air permeability is not more than the above upper limit value, the resulting electrode sheet 100 can be made thinner. can do.
Here, the air permeability of the porous substrate 101 can be measured according to JIS L1096-A (Fragile 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. Since the mechanical strength of the porous base material 101 can be improved as the thickness of the porous base material 101 is more than the said lower limit, the mechanical strength of the electrode sheet 100 obtained can be improved. Further, the holding force of the electrode material 105 can be improved.
Moreover, the impedance of the electrode sheet 100 obtained can be reduced further as the thickness of the porous base material 101 is below the said upper limit. 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 this embodiment adheres to the surface of the skeleton 103 of the porous substrate 101 and can attach the electrode material 105. The adhesive 104 preferably includes, for example, a resin that exhibits adhesiveness (hereinafter also referred to as an adhesive resin), and from the viewpoint of improving the electronic 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 included, the conductive fine particles are preferably 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 this specification, “(meth) acryl” is a generic term for acrylic and methacrylic.

  In this embodiment, the (meth) acrylic thermoplastic resin is a thermoplastic resin containing a (meth) acrylic acid ester unit. For example, a (meth) acrylic acid ester homopolymer, two or more ( Examples include a copolymer of (meth) acrylic acid ester, a copolymer of (meth) acrylic acid ester and a vinyl monomer having an unsaturated bond copolymerizable therewith.

  Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and tert-butyl (meth) acrylate. Cyclohexyl (meth) 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 Glycol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth ) 2-hydroxypropyl acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydro (meth) acrylate Cypentyl, 6-hydroxyhexyl (meth) acrylate, 3-hydroxy-3-methylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2- [ (Meth) acryloyloxy] ethyl-2-hydroxyethylphthalic acid, 2-[(meth) acryloyloxy] ethyl-2-hydroxypropylphthalic acid and the like.

  Examples of the vinyl monomer having an unsaturated bond copolymerizable with the (meth) acrylic acid ester include (meth) acrylic acid, maleic anhydride, maleimide derivatives, (meth) acrylonitrile, N-vinylpyrrolidone, N -Acryloylmorpholine, N-vinylcaprolactone, N-vinylpiperidine, N-vinylformamide, N-vinylacetamide, styrene, indene, 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 cinnamate, and derivatives thereof. The above (meth) acrylic acid ester and the vinyl monomer having an unsaturated bond copolymerizable with the (meth) acrylic acid ester may be used alone or in combination of two or more.

  From the viewpoint of improving the dispersibility of the conductive fine particles, the content of the (meth) acrylic ester unit contained in the (meth) acrylic thermoplastic resin is 100% by mass of the entire (meth) acrylic thermoplastic resin. When it is, it is 20 to 100 mass%, More preferably, it is 50 to 100 mass%, More preferably, it is 80 to 100 mass%.

  Examples of the silicone resin include polydimethylsiloxane.

  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, and polyisobutylene rubber.

  The content of the adhesive resin contained in the adhesive 104 according to this embodiment is preferably 80% by mass or more and 99.5% by mass or less, more preferably 100% by mass when the entire adhesive 104 is 100% by mass. It is 90 mass% or more and 99.9 mass% or less. When the content of the adhesive resin is within the above range, the balance between the adhesion between the porous substrate 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 includes, as necessary, cross-linking agents such as isocyanate compounds, acid anhydrides, amine compounds, epoxy compounds, metal chelates, aziridine compounds, and melamine compounds; rosin resins, terpene resins, It may further contain a tackifier resin such as petroleum resin, coumarone-indene resin, phenol resin, xylene resin, styrene resin; silane coupling agent; solid electrolyte material described later.
When tackifying resin is included in the pressure-sensitive adhesive 104 according to this embodiment, the initial tack and the adhesive force 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. For example, gold, silver, platinum, nickel, copper, cobalt, molybdenum, antimony, iron Metal particles such as chromium, alloy particles such as aluminum / magnesium alloy, aluminum / nickel alloy, etc. Metal oxide particles such as tin oxide and indium oxide; Metal particles such as nickel are coated with noble metals such as gold, silver, and platinum Non-conductive particles such as glass, ceramic, plastic, etc .; particles in which gold, silver, platinum, nickel, copper, cobalt, molybdenum, antimony, iron, chrome, etc. are coated; carbon particles, and the like.

The average particle diameter d ₅₀ in the weight-based particle size distribution by the laser diffraction / scattering particle size distribution measurement method of the conductive fine particles according to this embodiment is preferably 0.5 μm or more and 50 μm or less, 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 handling properties of the conductive fine particles and improve the electronic 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 entire pressure-sensitive adhesive 104 is 100% by mass. It is 10 mass% or less. When the content of the conductive fine particles is within the above range, the balance between the adhesion between the porous substrate 101 and the electrode material 105 and the electronic conductivity of the pressure-sensitive adhesive 104 is excellent.

Although the manufacturing method of the adhesive 104 which concerns on this embodiment is not specifically limited, For example, it can manufacture by the following methods.
First, a mixture containing appropriate amounts of the above-mentioned adhesive resin, and, if necessary, the above-mentioned crosslinking agent, the above-mentioned tackifier resin, the above-mentioned silane coupling agent, and the above-mentioned solid electrolyte material is heated and melted. Next, if necessary, the conductive fine particles can be added to the hot melt and mixed to be uniformly dispersed.

<Electrode material>
The electrode material 105 according to this embodiment includes an electrode active material and a solid electrolyte material as essential components.
When the electrode sheet 100 is used for a positive electrode layer constituting an all solid state lithium ion battery, the electrode material 105 includes a positive electrode active material and a solid electrolyte material, and includes a conductive additive, a binder, and the like as necessary. .
Further, when the electrode sheet 100 is used for a negative electrode layer constituting an all-solid-state lithium ion battery, the electrode material 105 includes a negative electrode active material and a solid electrolyte material, and includes a conductive aid, a binder, and the like as necessary. It is out.

(Positive electrode active material)
The positive electrode active material is not particularly limited as long as it is a material having a high electron conductivity so that lithium ions can be reversibly released and occluded and can easily transport electrons, and can be used for a positive electrode layer of an all-solid-state lithium ion battery. In general, a 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 complex oxides; polyaniline, polypyrrole and other highly conductive materials Molecules; sulfides such as Li ₂ S, CuS, Li—Cu—S compounds, TiS ₂ , FeS, MoS ₂ , and Li—Mo—S compounds; a mixture of sulfur and carbon; These positive electrode active materials may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the shape of the positive electrode active material include particles.
Further, 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.
The average particle size d ₅₀ of the positive electrode active material to be in the above range, it is possible while maintaining good handling properties, to produce a more dense positive electrode layer.

(Negative electrode active material)
The negative electrode active material is not particularly limited as long as it has a high electron conductivity so that lithium ions can be reversibly released and occluded and electron transport can be easily performed, and can be used for the negative electrode layer of an all-solid-state lithium ion battery. Generally known negative electrode active materials can be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin charcoal, carbon fiber, activated carbon, hard carbon, soft carbon; tin, tin alloy, silicon, silicon alloy, gallium, gallium alloy, indium, indium alloy, aluminum, aluminum Examples include alloy materials mainly composed of alloys; conductive polymers such as polyacene, polyacetylene, and polypyrrole; metal lithium; lithium titanium composite oxide (for example, Li ₄ Ti ₅ O ₁₂ ). These negative electrode active materials may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the shape of the negative electrode active material include particulates.
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 by the laser diffraction scattering type 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.
The average particle size d ₅₀ of the negative electrode active material to be in the above range, while maintaining good handling properties, it can be manufactured more density of the negative electrode.

(Solid electrolyte material)
The solid electrolyte material is not particularly limited as long as it has ion conductivity and insulating properties, but those generally used for all solid-state lithium ion batteries can be used. For example, a sulfide solid electrolyte material, an oxide solid electrolyte material, and the like can be given. Among these, a sulfide solid electrolyte material is preferable. Thereby, the interface 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 _{2 materials, Li 2 S-SnS 2 -P} 2 S 5 -SiS 2 materials, and the like. Among these, Li ₂ S—P ₂ S ₅ material is preferable because lithium ion conductivity is excellent and the manufacturing method is simple.
These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, Li ₂ S—P ₂ S ₅ material is preferable because it is excellent in lithium ion conductivity and has stability that does not cause decomposition in a wide voltage range.

Examples of the shape of the solid electrolyte material include a particulate shape. 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 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.
The average particle size d ₅₀ of the solid electrolyte material to be in the above range, while maintaining good handling properties, 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 additive 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 a normal conductive auxiliary agent that can be used for an all-solid-state lithium ion battery. For example, carbon black such as acetylene black and ketjen black; carbon fiber; vapor grown carbon fiber; Graphite powder; carbon materials such as carbon nanotubes may be mentioned. These conductive aids 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 include a binder, but the content of the binder is usually less than 0.5% by mass when the entire electrode material 105 is 100% by mass. , Preferably it is 0.1 mass% or less, More preferably, it is 0.05 mass% or less. Further, the electrode material 105 according to this embodiment further preferably does not substantially contain a binder, and particularly preferably does not contain a binder.
Thereby, 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 interface 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.
“Substantially free of binder” means that it may be contained to the extent that the effects of the present invention are not impaired. Further, the adhesive resin derived from the adhesive 104 existing in the vicinity of the interface between the electrode material 105 and the adhesive 104 is excluded from the “binder in the electrode material 105”.

  The binder refers to a binder generally used for lithium ion batteries in order to bind electrode active materials to each other and electrode active materials and a current collector. For example, polyvinyl alcohol, polyacrylic Examples thereof include aqueous binders such as acid, 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 substrate 101 by the adhesive 104 attached to the skeleton 103 of the porous substrate 101. Therefore, even if the binder content is less than or less than the above upper limit value, the electrode material 105 according to this embodiment can be stably held in the voids 102 of the porous substrate 101. As a result, it is possible to realize an increase in area and thickness of the electrode sheet 100 while suppressing the loss of the electrode material 105 and the cracks on the surface of the electrode sheet 100.
Moreover, since the electrode material 105 which concerns on this embodiment can make the binder which is nonionic conductivity below or below the said upper limit, it can reduce the interface contact resistance of the electrode sheet 100 obtained. 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 this embodiment, the content of the electrode active material is preferably 25% by mass or more and 50% by mass or less, more preferably 30% by mass or more and 40% by mass or less. In the electrode material 105 according to this embodiment, the content of the solid electrolyte material is preferably 25% by mass or more and 60% by mass or less, more preferably 30% by mass or more and 50% by mass or less. In the electrode material 105 according to this embodiment, the content of the conductive auxiliary 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.

(Method for preparing electrode material)
The electrode material 105 can be prepared, for example, by mixing an electrode active material, a solid electrolyte material, and, if necessary, a conductive additive, a binder, a thickener, a solvent, and the like with a mixer.
A known mixer such as a ball mill or a planetary mixer can be used as the mixer, and is not particularly limited. The mixing method is not particularly limited, and can be performed according to a known method.

[Method for producing electrode sheet]
Below, the manufacturing method of the electrode sheet 100 which concerns on this embodiment is demonstrated.
2-5 is sectional drawing which showed typically an example of the manufacturing method of the electrode sheet 100 of embodiment which concerns on this invention.
The manufacturing method of 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) Step of forming the pressure-sensitive adhesive layer 104a on at least one surface of the sheet-like porous substrate 101 (FIGS. 2A and 2B)
(2) A laminate in which the electrode material 105 is formed on the adhesive layer 104a to form the electrode material layer 105a, and the porous base material 101, the adhesive layer 104a, and the electrode material layer 105a are laminated in this order. Step of obtaining 150 (FIG. 2C)
(3) By pressing the obtained laminate 150, the adhesive 104 constituting the adhesive layer 104 a is attached to the surface of the skeleton 103 surrounding the void 102 of the porous substrate 101, and the porous substrate 101. Step of filling the electrode material 105 constituting the electrode material layer 105a into the gap 102 (FIGS. 3D and 3E)

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

  The thickness of the pressure-sensitive adhesive layer 104a according to this embodiment is appropriately determined in consideration of the porosity of the porous substrate 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 less.

  Examples of the sheet-like pressure-sensitive adhesive layer 104a include “baseless double-sided tape” and “conductive baseless pressure-sensitive adhesive tape” manufactured by Teraoka Seisakusho.

Next, (2) the electrode material layer 105a is formed on the pressure-sensitive adhesive layer 104a to form the electrode material layer 105a, and the porous substrate 101, the pressure-sensitive adhesive layer 104a, and the electrode material layer 105a are laminated in this order. A laminated body 150 is obtained.
A method for attaching the electrode material 105 on 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 in an inert atmosphere, Can be dispersed in a dispersion to form a slurry, and the slurry is applied onto the pressure-sensitive adhesive layer 104a and dried. As the 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 make the electrode material 105 uniform on the pressure-sensitive adhesive layer 104a, a guide having a predetermined height is placed on the pressure-sensitive adhesive layer 104a, and the powder of the electrode material 105 is placed so as to fill the opening of the guide. It is also possible to adhere on the adhesive layer 104a.
For example, the electrode material 105 is applied onto the guide using a squeegee, and the electrode material 105 is adhered to the adhesive layer 104a by filling the opening of the guide with the powder of the electrode material 105. Next, by removing the guide, the electrode material layer 105a having a uniform thickness is formed on the pressure-sensitive adhesive layer 104a.
Alternatively, the guide material may be filled with powder of the electrode material 105 in advance and the guide may be stacked on the adhesive layer 104a.
For example, a guide filled with powder of the electrode material 105 is stacked on the adhesive layer 104a, and the electrode material 105 filled in the opening of the guide is dropped onto the adhesive layer 104a by applying a weak vibration. Next, 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, a metal or resin porous plate, woven fabric, nonwoven fabric, mesh, etc. Is mentioned.
Due to the adhesiveness of the pressure-sensitive adhesive layer 104a, the electrode material 105 adheres onto the pressure-sensitive adhesive layer 104a, and the electrode material layer 105a is obtained.

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

  The manufacturing method of this electrode sheet 100 uses a simple apparatus and is excellent in productivity. Moreover, the thickness of the electrode sheet 100 obtained can be easily adjusted by adjusting the thickness of the sheet-like porous base material 101, the adhesive layer 104a, and the electrode material layer 105a. Furthermore, since the steps (1) to (3) can be performed continuously, the electrode sheet 100 can be continuously produced, and the electrode sheet 100 can be increased in area. Therefore, according to the manufacturing method of this electrode sheet 100, the electrode sheet 100 can be easily increased in area and thinned, and the productivity of the electrode sheet 100 can be improved.

Next, the manufacturing method of the electrode sheet 100 which consists of the process of following (4)-(6) is demonstrated.
(4) Step of preparing a sheet-like porous substrate 101 and an adhesive 104 (FIG. 4A)
(5) Step of coating the surface of the skeleton 103 surrounding the void 102 of the porous substrate 101 with the adhesive 104 (FIG. 4B)
(6) Step of filling the electrode material 105 into the gap 102 of the porous base material 101 (FIGS. 4C, 5D, and 5E)

  First, (4) a sheet-like porous substrate 101 and an adhesive 104 are prepared.

Next, (5) the adhesive 104 is coated on the surface of the skeleton 103 surrounding the void 102 of the porous substrate 101. The method of coating the pressure-sensitive adhesive 104 is not particularly limited, but the pressure-sensitive adhesive 104 is dissolved or dispersed in a solvent to form a liquid, and then the liquid is applied on the porous substrate 101 to penetrate the liquid into the gap 102. For example, and drying. As a method for 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 103 surrounding the void 102 of the porous substrate 101.

Subsequently, (6) the electrode material 105 is filled into the voids 102 of the porous substrate 101. The method of filling the electrode material 105 is not particularly limited. For example, a method of directly supplying the powder of the electrode material 105 into the void 102 of the porous substrate 101 in the air or in an inert atmosphere, or the electrode material 105 In a dispersion, and then the slurry is applied onto the porous substrate 101, and the slurry is infiltrated into the voids 102 and dried. As the 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 voids 102 of the porous substrate 101.

  As a method for directly supplying the powder of the electrode material 105 into the void 102 of the porous substrate 101 in the air or in an inert atmosphere, the electrode material 105 is powder-coated on the porous substrate 101 and a squeegee is used. Thus, a method of filling the electrode material 105 into the gap 102 while removing excess powder on the porous substrate 101 can be used.

Subsequently, by pressurizing as necessary, the gap 102 is filled with the electrode material 105 adhering to the surface of the porous substrate 101 without being filled in the gap 102.
The method for pressurizing the electrode sheet 100 is not particularly limited, and for example, a roll press or the like can be used. Thereby, it can pressurize continuously and the productivity of the electrode sheet 100 can be improved.
Moreover, the pressure which pressurizes the said laminated body 150 is 40 MPa or more and 500 MPa or less, for example.

  The manufacturing method of this electrode sheet 100 uses a simple apparatus and is excellent in productivity. Moreover, the thickness of the electrode sheet 100 obtained can be easily adjusted by adjusting the thickness of the sheet-like porous base material 101, the coating amount of the adhesive 104, and the usage amount of the electrode material 105. Furthermore, since the steps (5) to (6) can be performed continuously, the electrode sheet 100 can be continuously produced, and the electrode sheet 100 can be increased in area. Therefore, according to the manufacturing method of this electrode sheet 100, the electrode sheet 100 can be easily increased in area and thinned, and the productivity of the electrode sheet 100 can be improved.

In the manufacturing method of the electrode sheet 100 according to the present embodiment, when the void volume of the porous substrate 101 is A and the volume of the adhesive 104 is B, it is defined as [(A−B) / A] × 100. The remaining 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 substrate is X and the porosity is Y, the void volume A of the porous substrate 101 can be calculated by X × Y / 100. Further, the volume B of the adhesive 104 can be calculated from the density and mass of the adhesive 104. Alternatively, the volume of the pressure-sensitive adhesive layer 104a can be set as the volume B of the pressure-sensitive adhesive 104 as it is.
When the residual porosity is equal to or higher than the above lower limit value, the electrode material 105 that can be filled in the voids 102 can be increased, so that the discharge capacity density of the obtained all-solid-state lithium ion battery can be improved. Moreover, the retention strength of the electrode material 105 can be improved as the residual porosity is below the above upper limit.
The remaining porosity can be adjusted by adjusting the amount of the pressure-sensitive adhesive 104 used, the porosity of the porous substrate 101, and the like. For example, when the amount of the pressure-sensitive adhesive 104 used is constant, the residual porosity increases as the porous substrate 101 having a higher porosity is used. On the other hand, when the porous substrate 101 having the same porosity is used, the remaining porosity becomes smaller as the amount of the pressure-sensitive adhesive 104 used is increased.

[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.

  The all-solid-state lithium ion battery 200 according to this embodiment includes a positive electrode layer 201, a solid electrolyte layer 205, and a negative electrode layer 203 that are stacked in this order. At least one of the positive electrode layer 201 and the negative electrode layer 203 is constituted by the electrode sheet 100 according to the present embodiment.

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

(Positive electrode layer)
The positive electrode layer 201 of the present embodiment is preferably configured by the electrode sheet 100 according to the present embodiment.
The positive electrode layer 201 may be provided with a current collector on one surface. It does not specifically limit as a collector, The normal collector which can be used for all-solid-state lithium ion batteries, such as aluminum foil, can be used.

  The positive electrode layer 201 of the present embodiment may be pressed as 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 this embodiment is not particularly limited, and is preferably constituted by the electrode sheet 100 according to this embodiment.
The negative electrode layer 203 may be provided with a current collector on one surface. It does not specifically limit as a collector, The normal collector which can be used for all solid-type lithium ion batteries, such as copper foil, can be used.

  The negative electrode layer 203 of this 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 using a 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, what was mentioned as a solid electrolyte material included in the electrode material 105 mentioned 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 a desired insulating property can be obtained. For example, the range is from 10% by volume to 100% by volume. Among these, it is preferable that it exists in the range of 50 volume% or more and 100 volume% or less.

  In addition, the thickness of the solid electrolyte layer 205 of the present embodiment is, for example, preferably in the range of 0.1 μm to 1000 μm, and more preferably in the range of 0.1 μm to 300 μm.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these. In Examples and Comparative Examples, “mAh / g” indicates the discharge capacity density per 1 g of the positive electrode active material.

[1] Measuring Method First, measuring methods in the following examples and comparative examples will be described.

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

(2) Measurement of lithium ion conductivity Lithium ion conductivity was measured by an AC impedance method on the positive electrode active material sheets obtained in the examples and comparative examples.
Lithium ion conductivity was measured using a potentiostat / galvanostat SP-300 manufactured by Hokuto Denko Corporation. The sample size 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 the electrode was a Li foil.

(3) Charge / Discharge Test The positive electrode sheet of φ14 mm obtained in Examples and Comparative Examples was attached to the adhesive surface of a conductive aluminum foil adhesive tape (manufactured by Teraoka Seisakusho, φ14 mm) to obtain a positive electrode.
Subsequently, a solid electrolyte material (Li ₁₁ P ₃ S ₁₂ , 100 mg) was preliminarily pressed at 83 MPa using a pressing jig. Thereafter, it was placed on the positive electrode and further press molded at 250 MPa for 10 minutes to form a solid electrolyte layer on the positive electrode.
Moreover, the positive electrode obtained by the said method, the solid electrolyte layer, and the indium foil (phi = 14mm, t = 0.5mm) which are negative electrodes were laminated | stacked in this order, and the all-solid-state type lithium ion battery was produced. 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 / discharging was performed 10 times under the discharge conditions. However, since the potential window of the oxide positive electrode active material shifts to the high voltage side, the end-of-charge voltage was 3.6 V and the end-of-discharge voltage was 2.4 V.
Here, the discharge capacity change rate [%] was the 10th discharge capacity when the first discharge capacity was 100%. Table 1 shows the results obtained for the discharge capacity density and discharge capacity change rate for the positive electrode material.

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

(1) Positive electrode active material (Li ₁₄ MoS ₉ )
Under an argon atmosphere, an Al ₂ O ₃ ball mill pot with an internal volume of 400 mL was charged with MoS ₂ (Wako Pure Chemical Industries, 665 mg, 4.2 mmol) and Li ₂ S (Alfa Aesar, 1335 mg, 19.1 mmol). Was added, and 500 g of ZrO ₂ balls having a diameter of 10 mm were added, and the Al ₂ O ₃ ball mill pot was sealed.
Next, the 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 with a mortar and classified with 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 (manufactured by Kanto Chemical Co., 1650 mg, 19.0 mmol) and Li ₂ CO ₃ (manufactured by Kanto Chemical Co., 350 mg, 4.7 mmol) were weighed and added to an Al ₂ O ₃ ball mill pot having an internal volume of 400 mL. 500 g of ZrO ₂ balls having a diameter of 10 mm were placed, and the Al ₂ O ₃ ball mill pot was sealed.
Next, the Al ₂ O ₃ ball mill pot was placed on a ball mill turntable and treated at 120 rpm for 1 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 with a mortar and classified with 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 produced by the following procedure.
First, in a glove box in a nitrogen atmosphere, 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.). The Li foil started to change to black purple from the opening of the mesh, and all the Li foil changed to black purple Li ₃ N by leaving it at room temperature for 24 hours. 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 the solid electrolyte material.
Subsequently, 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%). Mix in agate mortar for 20 minutes. Next, 2 g of the mixed powder was weighed and put into an Al ₂ O ₃ ball mill pot (internal volume 400 mL) together with 500 g of φ10 mm ZrO ₂ balls, and mixed and ground at 120 rpm for 200 hours. The powder after mixing and pulverization was placed in a carbon boat and heat-treated in an argon stream at 330 ° C. for 2 hours to obtain Li ₁₁ P ₃ S ₁₂ .

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

(5) Adhesive The following were used as the adhesive.
-Adhesive sheet: (Teraoka Seisakusho, 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, Li ₁₄ MoS ₉ which is a positive electrode active material was filled in an opening of a PTFE mesh (CFC Industries, F3261-05, 18 mesh equivalent). The obtained PTFE mesh filled with Li ₁₄ MoS ₉ was overlaid on the pressure-sensitive adhesive sheet provided on one surface of the porous substrate 1 and then filled with the PTFE mesh by applying weak vibration. Li ₁₄ MoS ₉ was dropped on 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. Next, the obtained laminate was pressed at a pressure of 320 MPa. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet adhered to the surface of the skeleton part of the porous substrate 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 attached to the surface of the skeleton part of the porous substrate 1.
The obtained positive electrode active material sheet was measured for ionic conductivity. The obtained results are shown in Table 1. In addition, since it is difficult to measure the ionic conductivity in a state where the conductive assistant is mixed, the ionic conductivity was measured only with the positive electrode active material.

Subsequently, 0.308 g of Li ₁₄ MoS ₉ as the positive electrode active material, 0.308 g of acetylene black as the conductive auxiliary agent, 0.385 g of Li ₁₁ P ₃ S ₁₂ as the solid electrolyte material, and mortar For 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), and 500 g of φ10 mm ZrO ₂ balls were added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot was an argon atmosphere.
Next, the 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. Moreover, the positive electrode material was filled in the opening part of the mesh made from PTFE (CFC Industries, F3261-05, thickness 0.7mm, 100mm x 100mm, 18 mesh equivalent). After the obtained PTFE mesh filled with the positive electrode material is stacked on the pressure-sensitive adhesive sheet, the positive electrode material filled in the PTFE mesh is dropped on the pressure-sensitive adhesive sheet by applying a weak vibration, and the positive electrode material layer 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. Next, the obtained laminate was pressed at a pressure of 320 MPa. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet adhered to the surface of the skeleton part of the porous substrate 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 part of the porous substrate 1.
In the obtained positive electrode sheet, the lack of the positive electrode material and the crack of the surface did not occur. The thickness of the positive electrode sheet was 29 μm.
A φ14 mm positive electrode sheet was cut out from the obtained 100 mm × 100 mm positive electrode sheet, and the charge / discharge test described above was performed. The obtained results are shown in Table 1.

<Example 2>
The porous substrate 1 was cut into 100 mm × 100 mm, and an adhesive spray was sprayed on both surfaces of the porous substrate 1 to coat the surface of the porous substrate 1 with the adhesive. Here, the amount of the pressure-sensitive adhesive spray used was 0.0819 cm ³ . Further, Li ₁₄ MoS ₉ which is a positive electrode active material was filled in an opening of a PTFE mesh (CFC Industries, F3261-05, 18 mesh equivalent). The obtained PTFE mesh filled with Li ₁₄ MoS ₉ was layered on the porous substrate 1 coated with an adhesive, and a porous group coated with the adhesive with Li ₁₄ MoS ₉ by applying weak vibration. It was dropped on the material 1.
Next, the PTFE mesh was removed and pressed at a pressure of 320 MPa. The pressure-sensitive adhesive adhered to the surface of the skeleton part of the porous substrate 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 attached to the surface of the skeleton part of the porous substrate 1.
The obtained positive electrode active material sheet was measured for ionic conductivity. The obtained results are shown in Table 1.

Subsequently, 0.308 g of Li ₁₄ MoS ₉ as the positive electrode active material, 0.308 g of acetylene black as the conductive auxiliary agent, 0.385 g of Li ₁₁ P ₃ S ₁₂ as the solid electrolyte material, and mortar For 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), and 500 g of φ10 mm ZrO ₂ balls were added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot was an argon atmosphere.
Next, the 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 spray was sprayed on both surfaces of the porous substrate 1 to coat the surface of the porous substrate 1 with the adhesive. A positive electrode material was filled in an opening of a PTFE mesh (CFC Industries, F3261-05, thickness 0.7 mm, 100 mm × 100 mm, equivalent to 18 mesh). After the PTFE mesh filled with the obtained positive electrode material is stacked on the porous substrate 1 coated with the adhesive, vibration is given by striking with a stick, and the positive electrode material filled in the PTFE mesh is removed. It was dropped on the porous substrate 1 coated with an adhesive.
Next, the PTFE mesh was removed and pressed at a pressure of 320 MPa. The pressure-sensitive adhesive adhered to the surface of the skeleton part of the porous substrate 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 part of the porous substrate 1.
In the obtained positive electrode sheet, the lack of the positive electrode material and the crack of the surface did not occur. The thickness of the positive electrode sheet was 26 μm.
A φ14 mm positive electrode sheet was cut out from the obtained 100 mm × 100 mm positive electrode sheet, and the charge / discharge test described above was performed. The obtained results are shown in Table 1.

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

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

<Comparative Example 1>
Except not using an adhesive, the positive electrode active material sheet and the positive electrode sheet were respectively produced in the same manner as in Example 1, and the ionic conductivity measurement and the charge / discharge test were performed, respectively. The obtained results are shown in Table 1.

<Comparative Example 2>
A positive electrode active material sheet and a positive electrode in the same manner as in Comparative Example 1 except that a binder (PTFE dispersion, manufactured by Asahi Glass Fluoropolymers, Inc., CD123) was mixed at 0.5% by mass with respect to 100% by mass of the positive electrode material. Sheets were prepared, and ion conductivity measurements and charge / discharge tests were performed. The obtained results 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 100% by mass.

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

<Comparative Example 4>
A positive electrode active material sheet and a positive electrode in the same manner as in Comparative Example 3 except that a binder (PTFE dispersion, manufactured by Asahi Glass Fluoropolymers, Inc., CD123) was mixed at 0.5% by mass with respect to 100% by mass of the positive electrode material. Sheets were prepared, and ion conductivity measurements and charge / discharge tests were performed. The obtained results 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 100% by mass.

<Comparative Example 5>
Li ₁₄ MoS ₉ as a positive electrode active material was pressed at a pressure of 320 MPa to produce a positive electrode active material sheet having a thickness of 301 μm.
The obtained positive electrode active material sheet was measured for ionic conductivity. The obtained results are shown in Table 1.

Subsequently, 0.308 g of Li ₁₄ MoS ₉ as the positive electrode active material, 0.308 g of acetylene black as the conductive auxiliary agent, 0.385 g of Li ₁₁ P ₃ S ₁₂ as the solid electrolyte material, and mortar For 5 minutes.
The obtained mixture was added to an Al ₂ O ₃ ball mill pot (internal volume 400 mL), and 500 g of φ10 mm ZrO ₂ balls were added, and the Al ₂ O ₃ ball mill pot was sealed. The inside of the Al ₂ O ₃ ball mill pot was an argon atmosphere.
Next, the 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 produce a positive electrode sheet having a thickness of 301 μm. In the obtained positive electrode sheet, the lack of the positive electrode material and the crack of the surface occurred. A φ14 mm positive electrode sheet was cut out from the obtained 100 mm × 100 mm positive electrode sheet, and the charge / discharge test described above was performed. The obtained results are shown in Table 1.

The positive electrode sheets obtained in Examples 1 to 4 were free of positive electrode material and cracked on the surface. Furthermore, the all-solid-state lithium ion batteries using the positive electrode sheets obtained in Examples 1 to 4 had high discharge capacity and change rate of discharge capacity, and were excellent in charge / discharge characteristics.
On the other hand, in the positive electrode sheets of Comparative Examples 1, 3, and 5 that did not use an adhesive, the positive electrode material was missing or the surface was cracked. Moreover, the all-solid-state lithium ion battery using such a positive electrode sheet has a low discharge capacity and a change rate of the discharge capacity, and is inferior in charge / discharge characteristics.
Further, since the positive electrode sheets of Comparative Examples 2 and 4 were added with a binder, there was no missing of the positive electrode material or cracking of the surface. 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 change rate of discharge capacity, and is inferior in charge / discharge characteristics.

DESCRIPTION OF SYMBOLS 100 Electrode sheet 101 Porous base material 102 Cavity 103 Skeletal part 104 Adhesive 104a Adhesive layer 105 Electrode material 105a Electrode material layer 150 Laminate 200 All-solid-state lithium ion battery 201 Positive electrode layer 203 Negative electrode layer 205 Solid electrolyte layer

Claims (13)

A sheet-like porous substrate;
An adhesive attached to the surface of the skeleton surrounding at least the voids of the porous substrate; and
An electrode material containing a solid electrolyte material and an electrode active material and filled in the voids of the porous substrate;
An electrode sheet comprising: The electrode sheet according to claim 1,
An electrode sheet in which at least a part of the electrode material adheres to the 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,
The electrode sheet whose filling amount of the electrode material is 15% by mass or more and 85% by mass or less when the entire electrode sheet is 100% by mass. In the electrode sheet according to any one of claims 1 to 4,
The electrode sheet whose content of the binder in the said electrode material is less than 0.5 mass% when the whole said electrode material is 100 mass%. In the electrode sheet according to any one of claims 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. In the electrode sheet according to any one of claims 1 to 6,
The electrode sheet, wherein the porous substrate is a nonwoven fabric. In the electrode sheet according to any one of claims 1 to 7,
The porous sheet is an electrode sheet having electronic conductivity. In the electrode sheet according to any one of claims 1 to 8,
An electrode sheet having a porosity of the porous substrate of 50% or more and 95% or less. 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 constituted by the electrode sheet according to any one of claims 1 to 9. A manufacturing method for manufacturing the electrode sheet according to any one of claims 1 to 9,
Forming an adhesive layer on at least one surface of the sheet-like porous substrate; and
Forming an electrode material layer by attaching an electrode material on the pressure-sensitive adhesive layer, and obtaining 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 attached to the surface of the skeleton surrounding the voids of the porous substrate, and the voids in the porous substrate are Filling the electrode material constituting the electrode material layer;
The manufacturing method of the electrode sheet containing this. A manufacturing method for manufacturing the electrode sheet according to any one of claims 1 to 9,
A step of preparing a sheet-like porous substrate and an adhesive;
Coating the pressure-sensitive adhesive on the surface of the skeleton surrounding the voids of the porous substrate;
Filling an electrode material into the voids of the porous substrate;
The manufacturing method of the electrode sheet containing this. It is a manufacturing method of the electrode sheet according to claim 11 or 12,
When the void volume of the porous substrate is A and the volume of the adhesive is B,
The manufacturing method of the electrode sheet whose remaining void ratio defined by [(A-B) / A] x100 is 10% or more and 90% or less.

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