JP2016207393A - Separator electrode assembly, manufacturing method of the same, and lithium battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator electrode assembly excellent in adhesion between a separator and a positive electrode, a manufacturing method of the same, and a lithium battery.SOLUTION: A separator electrode assembly 1 includes: a positive electrode collector 5; a positive electrode active material layer 6 provided on the positive electrode collector 5; a resin layer 3 provided on the positive electrode active material layer 6; and a separator 4, containing an inorganic oxide, provided on the resin layer 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a separator electrode assembly, a method for producing the same, and a lithium battery, and particularly relates to a separator electrode assembly, a method for producing a separator electrode assembly, and a lithium battery using the separator electrode assembly.

  Conventionally, lithium batteries such as lithium ion batteries and lithium metal batteries include, for example, a negative electrode including a negative electrode active material such as carbon or lithium metal, a positive electrode including a positive electrode active material such as lithium manganese composite oxide, and a porous polymer. And a separator.

  However, the porous polymer may be melted by a high temperature or easily broken by dendrite generated from lithium metal.

  Therefore, a separator electrode unit including an inorganic separator has been proposed for lithium batteries (see, for example, Patent Document 1 and Patent Document 2).

In the separator electrode units of Patent Document 1 and Patent Document 2, a positive electrode containing LiCoO ₂ as a positive electrode active material is first prepared, and then an inorganic separator is formed on the positive electrode by a sol-gel method. Specifically, a slurry containing Al ₂ O ₃ , alkoxysilane, and an organic solvent is applied to the positive electrode with a blade and heat-treated at a high temperature of 150 ° C. or 250 ° C.

JP 2006-505100 Gazette Special table 2008-517435 gazette

  However, in the manufacturing method of these patent documents, when laminating | stacking a separator on a positive electrode, the heat processing for evaporating an organic solvent at high temperature is implemented. Therefore, an expensive and large apparatus that enables high-temperature heat treatment and organic solvent recovery treatment is required, and the drying time becomes long. As a result, it is disadvantageous in industrial production.

  Therefore, an inorganic separator that can be produced by a dry method (for example, a dry spray method) that does not involve evaporation of an organic solvent is required.

  However, when the inorganic separator is formed on the positive electrode by adopting the dry method, there arises a problem that the adhesiveness between the inorganic separator and the positive electrode is lowered. Then, in the subsequent steps, that is, in the step of laminating the negative electrode on the separator, the step of sealing in the outer can, and the like, the inorganic separator and the negative electrode are easily separated, so that the handling property (handleability) is lowered.

  The objective of this invention is providing the separator electrode assembly with favorable adhesiveness of a separator and a positive electrode, its manufacturing method, and a lithium battery.

  The separator electrode assembly of the present invention includes an electrode current collector, an electrode active material layer provided on the electrode current collector, a resin layer provided on the electrode active material layer, and the resin layer. And a separator containing an inorganic oxide.

  In the separator electrode assembly of the present invention, it is preferable that the resin layer contains a hydrophilic resin.

  In the separator electrode assembly of the present invention, it is preferable that the hydrophilic resin is polyvinyl alcohol.

  In the separator electrode assembly of the present invention, it is preferable that the resin layer has a thickness of 10 nm to 1000 nm.

  In the separator electrode assembly of the present invention, it is preferable that the resin layer contains inorganic oxide particles.

  In the separator electrode assembly of the present invention, it is preferable that the inorganic oxide particles are at least one selected from the group consisting of silica particles, zirconia particles, alumina particles, and lithium aluminate particles.

  In the separator electrode assembly of the present invention, it is preferable that the separator is formed by an aerosol deposition method.

  In the separator electrode assembly of the present invention, it is preferable that the electrode current collector is a positive electrode current collector, and the electrode active material layer is a positive electrode active material layer.

  A lithium battery according to the present invention includes the above-described separator electrode assembly and a negative electrode provided on the separator and containing lithium.

  The separator electrode assembly manufacturing method of the present invention includes a step of preparing an electrode including an electrode current collector and an electrode active material layer, a step of providing a resin layer on the electrode active material layer, and Further, the method includes a step of providing a separator containing an inorganic oxide by a dry method.

  The separator electrode assembly of the present invention includes an electrode, a resin layer provided on the electrode, and a separator provided on the electrode. Therefore, the adhesiveness between the electrode and the separator is good. Therefore, it is easy to handle and facilitates subsequent battery manufacturing. Moreover, since a separator contains an inorganic oxide, it is excellent in heat resistance compared with an organic polymer separator. Furthermore, since it has high strength, it is possible to reduce damage to dendrites grown from lithium metal and the like due to charge / discharge, and the charge / discharge cycle is excellent.

  According to the method for producing a separator electrode assembly of the present invention, a separator electrode assembly having good adhesion between the electrode and the separator can be produced. In addition, since the separator is formed using a dry method that does not involve evaporation of the organic solvent, the environmental load can be reduced and the drying time can be shortened. Therefore, it is suitable for industrial production.

  The lithium battery of the present invention is excellent in heat resistance and charge / discharge cycle, and is suitable for industrial production.

FIG. 1 shows a side sectional view of an embodiment of a separator electrode assembly of the present invention. FIG. 2 shows a side sectional view of a lithium metal battery including the separator electrode assembly shown in FIG. FIG. 3 is a schematic configuration diagram of an aerosol deposition apparatus used in the method of manufacturing the separator electrode assembly shown in FIG. FIG. 4 is a schematic configuration diagram of a peeling test for peeling the separator of the example.

1. Separator electrode assembly
As shown in FIG. 1, one embodiment of a separator electrode assembly (hereinafter also referred to as “SEA”) 1 of the present invention is SEA 1 used for a lithium battery, specifically, a positive electrode 2, A resin layer 3 and a separator 4 are provided.

(Positive electrode)
The positive electrode 2 includes a positive electrode current collector 5 and a positive electrode active material layer 6.

  The positive electrode current collector 5 has only to be electronically conductive and can support the positive electrode active material layer 6, and examples thereof include metal foils such as aluminum foil, copper foil, nickel foil, and gold foil.

  The thickness of the positive electrode current collector 5 is, for example, 1 μm or more, preferably 10 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

  The positive electrode active material layer 6 is provided on the positive electrode current collector 5. Specifically, the positive electrode active material layer 6 is disposed on the positive electrode current collector 5 such that the lower surface of the positive electrode active material layer 6 is in contact with the upper surface of the positive electrode current collector 5.

  The positive electrode active material layer 6 is formed from a positive electrode composition. The positive electrode composition contains a positive electrode active material.

  The positive electrode active material is, for example, lithium-based composite oxides such as lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate, lithium manganese phosphate, lithium iron sulfate, and modified products thereof, such as metal sulfur And sulfur-based materials such as lithium sulfide and elemental sulfur. These can also be used individually by 1 type and can also use 2 or more types.

  From the viewpoint of conductivity, lithium-based composite oxides are preferable, and lithium cobaltate and lithium nickelate are more preferable.

  The shape of the positive electrode active material is not particularly limited as long as it is particulate (powder), and may be, for example, a bulk shape, a needle shape, a plate shape, or a layer shape. The bulk shape includes, for example, a spherical shape, a rectangular parallelepiped shape, a crushed shape, or a deformed shape thereof.

  The average particle diameter of the positive electrode active material is, for example, 0.1 μm or more, preferably 0.2 μm or more, and for example, 15 μm or less, preferably 8 μm or less.

In the present invention, the average particle diameter is a median diameter (D ₅₀ ), and is measured by, for example, a laser diffraction / scattering particle diameter distribution measuring apparatus (manufactured by Nikkiso Co., Ltd., Microtrac MT3000).

  The positive electrode composition can also contain additives such as a current collector and a binder.

  The current collector improves the conductivity of the positive electrode 2, and examples thereof include carbon materials and metal materials. Examples of the carbon material include graphite such as natural graphite and artificial graphite, carbon black such as acetylene black and ketjen black, and amorphous carbon such as needle coke. Examples of the metal material include copper and nickel. These can also be used individually by 1 type and can also use 2 or more types.

  Among these current collectors, carbon materials are preferable, and carbon black is more preferable.

  The content ratio of the current collector is, for example, 0.1 parts by mass or more, preferably 1 part by mass or more, for example, 20 parts by mass or less, preferably 15 parts by mass with respect to 100 parts by mass of the positive electrode active material. It is below mass parts.

  The binder is not particularly limited as long as it binds the positive electrode active material, and examples thereof include polymers such as polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polyvinyl acetate, styrene-butadiene rubber, acrylonitrile rubber, and carboxymethyl cellulose. These can also be used individually by 1 type and can also use 2 or more types.

  The content ratio of the binder is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 20 parts by mass or less, preferably 10 parts by mass or less with respect to 100 parts by mass of the positive electrode active material. is there.

  The positive electrode active material layer 6 is preferably a porous body.

  The porosity of the positive electrode active material layer 6 is, for example, 10% or more, preferably 20% or more, more preferably 35% or more, and for example, 80% or less, preferably 65% or less.

  The porosity is calculated by calculating the relative density ρ (= w / v) from the mass w and volume v (= width × length × thickness) of the measurement target (the positive electrode active material layer 6 etc.), and then calculating by the following formula. be able to.

Porosity = {1- (ρ / ρ ′)} × 100
Note that ρ ′ represents the theoretical density, and can be, for example, the density when a film having no voids is formed from the material to be measured.

  Thereby, the electrolyte solution 31 (after-mentioned) can be filled in the positive electrode active material layer 6, and it is excellent in ion conductivity.

  The thickness of the positive electrode active material layer 6 is, for example, 30 μm or more, preferably 50 μm or more, and for example, 200 μm or less, preferably 100 μm or less.

(Resin layer)
The resin layer 3 is provided on the positive electrode active material layer 6. Specifically, the resin layer 3 is such that the lower surface of the resin layer 3 is in contact with the upper surface of the positive electrode active material layer 6 and the upper surface of the resin layer 3 is in contact with the lower surface of the separator 4 (described later). 6 and a separator 4 (described later).

  The resin layer is formed from a resin composition containing a resin.

  Examples of the resin include hydrophilic resin, rubber, and acrylate polymer.

  The hydrophilic resin is a resin that dissolves in water or swells with water. For example, polyvinyl alcohol, polyacrylonitrile, cellulose resin (carboxymethyl cellulose, hydroxyethyl cellulose, lithium carboxymethyl cellulose, etc.), ethylene-vinyl acetate. A copolymer etc. are mentioned. These can also be used individually by 1 type and can also use 2 or more types. Preferably, polyvinyl alcohol and a cellulose resin are mentioned, More preferably, polyvinyl alcohol is mentioned.

  Examples of the rubber include natural rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber, styrene ethylene butadiene styrene rubber, styrene isoprene styrene rubber, styrene isobutylene rubber, isoprene rubber, polyisobutylene rubber, butyl rubber, Examples include acrylonitrile acrylamide rubber. These can also be used individually by 1 type and can also use 2 or more types. Preferably, a styrene-type elastomer is mentioned, More preferably, SBR is mentioned.

  The acrylic ester polymer is a polymer of (meth) acrylic ester. The (meth) acrylic acid ester is a methacrylic acid ester and / or an acrylic acid ester. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate Alkyl (meth) acrylates such as n-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. Chain or branched alkyl) esters. These can also be used individually by 1 type and can also use 2 or more types.

  Among these resins, hydrophilic resins and rubbers are preferably used from the viewpoint of improving adhesiveness and suppressing buffering of the separator 4 caused by volume change of the positive electrode active material layer 6. Furthermore, it is more preferable from the viewpoint of improving the film formation stability of the separator 4 when forming the separator 4 on the surface of the resin layer 3, and from the viewpoint of improving the stability of the SEA 1 by being bonded to the separator 4 uniformly and firmly. May be a hydrophilic resin, and more preferably polyvinyl alcohol.

  The weight average molecular weight Mw of the resin is, for example, 10,000 or more, preferably 50,000 or more, more preferably 100,000 or more, and for example, 1,000,000 or less, preferably 500,000 or less, more preferably 300,000 or less.

  By setting the weight average molecular weight of the resin in the above range, water absorption in the resin layer 3 can be suppressed, and deterioration of adhesiveness after storage in the air or in a wet atmosphere can be suppressed. Moreover, the softness | flexibility of the resin layer 3 can be improved, moderate flexibility can be provided to SEA1, and the handling of SEA1 can be improved further.

  In addition, a weight average molecular weight is measured by gel permeation chromatography (GPC), and is calculated | required by a standard polystyrene conversion value.

  The resin composition preferably contains inorganic oxide particles. Thereby, the adhesiveness of the positive electrode 2 and the separator 4 and the adhesiveness after storage can be improved more. Moreover, the resin layer stability at the time of abnormality of the battery cell 33, the ion conductivity at the time of electrolyte solution immersion, etc. can be made favorable.

  Examples of the inorganic oxide particles include silica particles, zirconia particles, alumina particles, and lithium aluminate particles. These can also be used individually by 1 type and can also use 2 or more types. Preferably, silica particles and alumina particles are used.

  The average particle diameter of the inorganic oxide particles is, for example, 1 nm or more, preferably 5 nm or more, and for example, 500 nm or less, preferably 50 nm or less.

  When the resin composition contains inorganic oxide particles, the content ratio of the inorganic oxide particles is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 50 parts by mass with respect to 100 parts by mass of the resin. For example, 500 parts by mass or less, preferably 150 parts by mass or less.

  The average particle diameter of the inorganic oxide particles can be measured using a field emission scanning electron microscope (Schottky Field Emission Electron Microscope SU 5000).

  The resin composition can also contain known additives as necessary.

  Preferably, the resin composition (that is, the resin layer) is made of only a resin or only of a resin and oxide particles.

  The thickness of the resin layer 3 is, for example, 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more, and, for example, 1000 nm or less, preferably 500 nm or less, more preferably 150 nm or less.

  By setting the thickness of the resin layer 3 in the above range, the polarization of the battery cell 33 during the charging cycle can be minimized. Further, the SEA 1 can be thinned while improving the adhesion between the positive electrode 2 and the separator 4. When forming the resin layer 3 using the resin containing liquid mentioned later, since drying time can be reduced significantly, it is excellent in industrial production.

  The thickness of the resin layer 3 is measured by observing a cross-sectional view of the resin layer 3 using a scanning electron microscope (“S-3400N”, manufactured by Hitachi High-Technologies Corporation).

(Separator)
The separator 4 is provided on the resin layer 3. Specifically, the separator 4 is disposed on the resin layer 3 such that the lower surface of the separator 4 is in contact with the upper surface of the resin layer 3.

  For example, the separator 4 contains an inorganic oxide, and preferably contains a porous body of an inorganic oxide. More preferably, the separator 4 is made of a porous body of an inorganic oxide. Thereby, it is excellent in heat resistance and intensity | strength.

  The separator 4 is preferably a ceramic layer formed into a porous layer by an AD method (described later) using an inorganic oxide as a material.

As the inorganic oxide, an ion conductive inorganic oxide is preferable. The ion conductive inorganic oxide is an inorganic oxide capable of conducting lithium ions, and specifically includes a lithium-based inorganic oxide, preferably a lithium-based phosphate compound. Examples of the lithium phosphate include a mixture of tetralithium silicate and lithium phosphate (Li ₄ SiO ₄ .Li ₃ PO ₄ ), lithium boron phosphate (Li _X BPO ₄ , where 0 <x ≦ 0 .2), lithium phosphate oxynitride (LiPON) and the like. These can also be used individually by 1 type and can also use 2 or more types. Preferably, a mixture of tetralithium silicate and lithium phosphate is used. Thereby, the lithium ion conductivity of the lithium metal battery 30 provided with SEA1 is improved, and battery characteristics such as battery capacity are excellent.

  The mixing ratio of tetralithium silicate and lithium phosphate is, for example, 10:90 to 90:10, preferably 30:70 to 70:30, by mass ratio as tetralithium silicate: lithium phosphate. .

The ion conductivity of the ion conductive inorganic oxide is, for example, 1 × 10 ⁻⁸ S / cm or more, preferably 1 × 10 ⁻⁷ S / cm or more, and for example, 1 × 10 ⁻¹ S / cm. cm or less. Ionic conductivity is measured by electrochemical impedance analysis (EIS). For example, an impedance / gain face analyzer (manufactured by Solartron Analytical) can be used.

  The ion conductive inorganic oxide is preferably formed in a particulate form. Specific examples of the particle shape include a bulk shape, a needle shape, a plate shape, and a layer shape. The bulk shape includes, for example, a spherical shape, a rectangular parallelepiped shape, a crushed shape, or a deformed shape thereof.

  The average particle diameter of the ion conductive inorganic oxide is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 10 μm or less, preferably 2.5 μm or less.

  The porosity of the separator 4 is, for example, 5% or more, preferably 8% or more, and for example, 85% or less, preferably 75% or less, more preferably 50% or less, and particularly preferably 30%. % Or less.

  The average pore diameter of the separator 4 is, for example, 1 nm or more, preferably 10 nm or more, and for example, 2000 nm or less, preferably 700 nm or less, more preferably 100 nm or less.

  For example, the average pore diameter is obtained by cutting the separator 4 in the thickness direction, observing an enlarged SEM image of the cut surface with a scanning electron microscope (SEM), and averaging the maximum pore diameter of the voids displayed in the SEM image. Value.

  The thickness of the separator 4 is, for example, 1 μm or more, preferably 2 μm or more, and for example, 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less.

  And according to this SEA1, since the resin layer 3 is interposed between the positive electrode 2 and the separator 4, the adhesiveness between the positive electrode 2 and the separator 4 is good. Therefore, handling properties (handling properties) are good. That is, when SEA1 is used, a battery made of lithium metal or the like can be easily manufactured.

  Moreover, since the separator 4 contains an inorganic oxide, compared with an organic polymer separator, it is excellent in heat resistance. Moreover, since it is high intensity | strength, the damage with respect to the dendrite generate | occur | produced from lithium metal etc. by charging / discharging can be reduced, and it is excellent in the charging / discharging cycle in a lithium secondary battery.

2. Lithium Battery A lithium metal battery 30 that is an embodiment of the lithium battery of the present invention includes, for example, SEA 1, a negative electrode 7, an electrolytic solution 31, and an exterior body 32 as shown in FIG. 2.

  The negative electrode 7 is provided on the separator 4 of the SEA 1 and includes a negative electrode current collector 9 and a negative electrode active material layer 8 provided therebelow. Specifically, the negative electrode 7 is disposed on the SEA 1 so that the lower surface of the negative electrode active material layer 8 is in contact with the upper surface of the separator 4.

  The negative electrode current collector 9 has only to have electronic conductivity and can support the negative electrode active material layer 8, and examples thereof include metal foils such as aluminum foil, copper foil, nickel foil, and gold foil.

  The thickness of the negative electrode current collector 9 is, for example, 0.1 μm or more, preferably 0.25 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

  The negative electrode active material layer 8 is formed on the lower surface of the negative electrode current collector 9 and contains lithium. Specifically, it is formed from, for example, lithium metal (Li), lithium alloy (for example, lithium aluminum alloy) or the like.

  The thickness of the negative electrode active material layer 8 is, for example, 0.05 μm or more, preferably 0.1 μm or more, and for example, 50 μm or less, preferably 35 μm or less.

  The SEA 1 (positive electrode 2, resin layer 3, separator 4) and negative electrode 7 constitute a battery cell 33.

  The exterior body 32 seals (accommodates) the battery cell 33 (that is, the positive electrode 2 / resin layer 3 / separator 4 / negative electrode 7) and the electrolyte 31 inside the exterior body 32.

  The exterior body 32 may be a known or commercially available product, and is composed of a sealed bag body such as a laminate film or a metal can.

  Examples of the layer forming the laminate film include metal layers such as aluminum, iron, copper, nickel, titanium, and stainless steel, metal oxide layers such as silicon oxide and aluminum oxide, polyethylene, polypropylene, polyethylene terephthalate, polyamide, and ABS resin. And a polymer layer. One of these layers can be used alone, or two or more layers can be used.

  Examples of the metal can material include aluminum, iron, copper, nickel, titanium, and stainless steel. These can also be used individually by 1 type and can also use 2 or more types.

  The electrolytic solution 31 is filled in the exterior body 32. Specifically, the electrolytic solution 31 is filled in the exterior body 32 so as to immerse the battery cell 33. More specifically, the electrolytic solution 31 penetrates into the inside (void) of the separator 4, and preferably penetrates into the inside (void) of the separator 4 and the positive electrode active material layer 6.

  The electrolyte solution 31 may be any liquid that can move lithium ions between the negative electrode 7 and the positive electrode 2, and examples thereof include electrolytes used in conventional lithium ion secondary batteries and lithium metal secondary batteries. It is done.

  The electrolytic solution 31 is, for example, a nonaqueous electrolytic solution, and preferably contains an organic solvent and an ionic electrolyte.

  Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, and chain carbonates such as methyl carbonate, methyl ethyl carbonate, and diethyl carbonate, such as tetrahydrofuran and 2-methyltetrahydrofuran. Furans such as γ-butyrolactone, 1,2-dimethoxyethane, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, acetonitrile, N, N-dimethylformamide Etc. These can also be used individually by 1 type and can also use 2 or more types.

  Preferably, a cyclic carbonate, a chain carbonate, etc. are mentioned, More preferably, combined use of a cyclic carbonate and a chain carbonate is mentioned.

An ionic electrolyte is used to improve ionic conductivity, and examples thereof include lithium salts. Examples of the lithium _{salt, LiPF 6, LiBF 4, LiAsF} 6, LiSiF 6, LiClO 4, LiB (C 6 H 5) 4, LiSbSO 3, LiCH 3 SO 3, LiCF 3 SO 3, LiC 4 F 9 SO 3 , Li (CF ₃ SO ₂ ) ₂ N, LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , LiCl, and the like. These can also be used individually by 1 type and can also use 2 or more types.

From the viewpoint of high ion conductivity, LiPF ₆ , Li (CF ₃ SO ₂ ) ₂ N, and the like are preferable.

  The content ratio of the lithium salt in the electrolytic solution 31 is, for example, 0.1 mol / L or more, preferably 0.4 mol / L or more, and for example, 10 mol / L or less, preferably 5 mol / L or less. .

  The electrolytic solution 31 preferably further contains an ionic liquid. Thereby, the safety of the lithium metal battery 30 is further improved.

  Examples of the ionic liquid include N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) imide, N-methyl-N-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, and 1-methyl-3-propyl. Examples include imidazolium bis (trifluoromethanesulfonyl) imide and 1-ethyl-3-butylimidazolium tetrafluoroborate. These can also be used individually by 1 type and can also use 2 or more types.

  When the electrolytic solution 31 contains an ionic liquid, the content ratio of the ionic liquid in the electrolytic solution 31 is, for example, 10% by volume or more, preferably 30% by volume or more, more preferably 40% by volume or more. For example, it is less than 100% by volume, preferably 60% by volume or less.

  The lithium metal battery 30 is excellent in heat resistance and charge / discharge cycle and is suitable for industrial production.

3. SEA Manufacturing Method SEA1 is, for example, a step of forming a positive electrode active material layer 6 on a positive electrode current collector 5 to obtain a positive electrode 2, a layer of resin layer 3 on the positive electrode active material layer 6 of the positive electrode 2, and a positive electrode resin It is manufactured by a laminate forming step for obtaining a layer laminate 34 and a SEA forming step for laminating the separator 4 on the resin layer 3 by a dry method.

  First, the positive electrode active material layer 6 is laminated on the positive electrode current collector 5 (positive electrode forming step).

  Specifically, the positive electrode slurry containing the positive electrode composition is applied to the upper surface of the positive electrode current collector 5.

  The positive electrode slurry is obtained by mixing the positive electrode composition and a solvent.

  Examples of the solvent contained in the positive electrode slurry include ketones such as acetone and methyl ethyl ketone, for example, N-methylpyrrolidone, in addition to the organic solvent described above. Examples of the solvent also include aqueous solvents such as water, for example, alcohols such as methanol, ethanol, propanol, and isopropanol. These can also be used individually by 1 type and can also use 2 or more types.

  Examples of the coating method include known methods such as doctor blade, roll coating, screen coating, and gravure coating.

The application amount is, for example, 3.5 to 50 mg / cm ^{2 based} on the positive electrode active material.

  Next, the positive electrode slurry is dried to form a coating film.

  If necessary, the coating film is compressed. Examples of the compression method include known methods, for example, a method of pressing the coating film with a roller, a flat plate or the like.

  Thereby, the positive electrode 2 provided with the positive electrode electrical power collector 5 and the positive electrode active material layer 6 which is provided on it and is a porous body is obtained.

  The positive electrode active material layer 6 can be formed by applying a slurry containing the positive electrode composition on the upper surface of the positive electrode current collector 5, but can also be formed by, for example, an aerosol deposition method described later. .

  Next, the resin layer 3 is laminated on the positive electrode active material layer 6 of the positive electrode 2.

  For example, the resin layer 3 is laminated by placing a resin-containing liquid on the upper surface of the positive electrode active material layer 6 and drying it.

  The resin-containing liquid is obtained by mixing a resin composition and a solvent.

  The resin content in the resin-containing liquid is, for example, 0.1% by mass or more, preferably 1% by mass or more, and for example, 20% by mass or less, preferably 10% by mass or less.

  Examples of the solvent contained in the resin-containing liquid include water-based solvents such as water and alcohols such as methanol, ethanol, propanol, and isopropanol. From the viewpoints of reducing environmental load and facility load, water is preferable.

  When a water-soluble resin is used as the resin, the resin-containing liquid is preferably an aqueous solution in which the resin is dissolved in water. Thereby, the thin and uniform resin layer 3 can be formed on the upper surface of the positive electrode active material layer 6 in a short time.

  When preparing an aqueous resin solution, if the resin is difficult to dissolve in water, the resin can be dissolved in water by stirring and heating as necessary. After the dissolution, water can be further added to the resin aqueous solution to obtain a diluted aqueous solution having the above-mentioned content ratio.

  Examples of the method for arranging the resin-containing liquid on the upper surface of the positive electrode active material layer 6 include a spraying method, a dipping method, and the above-described coating method. Preferably, a spraying method is used. Specifically, the spraying method is, for example. It is carried out using an atomizer such as a spray gun.

  A drying temperature is 100 degreeC or less, for example, Preferably, it is 80 degreeC or less, for example, 50 degreeC or more, Preferably, 60 degreeC or more is mentioned.

  The drying time is, for example, 1 minute or more, preferably 3 minutes or more, and for example, 60 minutes or less, preferably 20 minutes or less.

  Thereby, the positive electrode resin layer laminated body 34 provided with the positive electrode 2 and the resin layer 3 provided on it is obtained.

  Next, the separator 4 is laminated on the resin layer 3 of the positive electrode resin layer laminate 34 by a dry method (SEA formation step).

  The lamination method of the separator 4 is a dry method, and examples thereof include an aerosol deposition method, a dry spray method (cold spray method, hot spray method), a plasma spray method, and the like.

  Preferably, an aerosol deposition method (AD method / gas deposition method / gas deposition method) and a dry spray method are used, and more preferably, an AD method is used. Thereby, the separator 4 can be formed on the surface of the resin layer 3 with good adhesion.

  Hereinafter, a method of forming the separator 4 using the aerosol deposition method (hereinafter referred to as AD method) will be described.

  In order to form the separator 4 by the AD method, for example, an aerosol deposition apparatus 10 shown in FIG. 3 is used.

  The aerosol deposition apparatus 10 includes a film forming chamber 11, an aerosol chamber 12, and a carrier gas transport device 13.

  The film forming chamber 11 is a film forming chamber for forming the separator 4 on the surface of the positive electrode resin layer laminate 34 (specifically, the surface of the resin layer 3). A thermometer (not shown) for measuring the temperature and a pressure gauge (not shown) for measuring the pressure in the film forming chamber 11 are provided.

  The substrate holder 14 includes a support column 15, a pedestal 16, and a stage 17.

  In order to connect the pedestal 16 and the stage 17, the support column 15 is provided so as to penetrate the ceiling wall of the film formation chamber 11 and protrude downward (vertically in the vertical direction).

  The pedestal 16 is provided at one end (lower end) in the longitudinal direction of the support column 15 in order to hold and fix the positive electrode 2 in the film forming chamber 11.

  The stage 17 can move the positive electrode 2 in any direction (x direction (front-rear direction), y direction (left-right direction), z direction (up-down direction), and θ direction (rotation direction)) when the separator 4 is formed. In order to do this, it is provided on the upper surface of the ceiling wall of the film forming chamber 11 and is connected to the other longitudinal end (upper end) of the support column 15. Thereby, the stage 17 is connected to the pedestal 16 via the support column 15, and the pedestal 16 can be moved by the stage 17.

  A mechanical booster pump 18 and a rotary pump 19 are connected to the film forming chamber 11.

  The mechanical booster pump 18 and the rotary pump 19 depressurize the inside of the film forming chamber 11 and reduce the pressure inside the aerosol chamber 12 communicated with the film forming chamber 11 via a connecting pipe 20 (described later). 11 are sequentially connected.

  The aerosol chamber 12 is a reservoir for storing the material of the separator 4 (that is, inorganic oxide powder), and includes a vibration device 21 and a pressure gauge (not shown) for measuring the pressure in the aerosol chamber 12. ).

  The vibration device 21 is a device for vibrating the material of the aerosol chamber 12 and the separator 4 in the aerosol chamber 12, and a known shaker is used.

  In addition, a connecting tube 20 is connected to the aerosol chamber 12.

  The connecting pipe 20 is a pipe for transporting an aerosolized material (hereinafter referred to as aerosol) from the aerosol chamber 12 to the film forming chamber 11, and one end (upstream end) thereof is the aerosol chamber 12. And the other side of the film forming chamber 11 extends through the bottom wall toward the pedestal 16. In the film formation chamber 11, a film formation nozzle 22 is connected to the other end (downstream end) of the connecting pipe 20.

  The film forming nozzle 22 is an injection device for spraying aerosol onto the surface of the resin layer 3, and is arranged in the film forming chamber 11 so that the injection port faces the pedestal 16 on the upper side in the vertical direction. Specifically, the film formation nozzle 22 has an injection port at a predetermined interval (for example, 1 mm or more, preferably 20 mm or more) from the pedestal 16 (in particular, the surface of the resin layer 3 disposed on the pedestal 16). For example, 100 mm or less, preferably 80 mm or less). Thereby, the aerosol supplied from the aerosol chamber 12 can be sprayed onto the surface of the resin layer 3.

  The shape of the spray nozzle of the film forming nozzle 22 is not particularly limited, and is appropriately set according to the aerosol spray amount, spray range, and the like.

  A connecting pipe opening / closing valve 23 is interposed in the middle of the connecting pipe 20 in the flow direction. As the connection pipe on-off valve 23, for example, a known on-off valve such as an electromagnetic valve is used.

  The carrier gas transport device 13 includes a carrier gas cylinder 25.

  The carrier gas cylinder 25 is a cylinder that stores a carrier gas such as oxygen gas, helium gas, argon gas, nitrogen gas, and air gas, and is connected to the aerosol chamber 12 via a gas pipe 26.

  The gas pipe 26 is a pipe for transporting the carrier gas from the carrier gas cylinder 25 to the aerosol chamber 12, and its upstream end is connected to the carrier gas cylinder 25 and its downstream end is connected to the aerosol chamber 12. Has been.

  A gas flow meter 27 is interposed in the middle of the gas pipe 26 in the flow direction. The gas flow meter 27 is a device for adjusting the flow rate of the gas in the gas pipe 26 and detecting the flow rate, and is not particularly limited, and a known flow meter is used.

  Further, in the middle of the gas pipe 26 in the flow direction, a gas pipe opening / closing valve 28 is interposed downstream of the gas flow meter 27. As the gas pipe opening / closing valve 28, for example, a known opening / closing valve such as an electromagnetic valve is used.

  In order to form the separator 4 by using the aerosol deposition apparatus 10 as described above, first, the film forming nozzle 22 and the resin layer 3 of the positive electrode resin layer laminate 34 are arranged to face each other with an interval therebetween. Specifically, the positive electrode resin layer laminate 34 is arranged on the pedestal 16 so that the surface of the resin layer 3 faces the film forming nozzle 22 side (lower side).

  On the other hand, the material of the separator 4 (for example, an inorganic oxide powder) is put into the aerosol chamber 12.

  In addition, the material of the separator 4 can also be dried in advance before charging.

  The drying temperature is, for example, 50 to 150 ° C., and the drying time is, for example, 1 to 24 hours.

  Next, in this method, the gas pipe opening / closing valve 28 is closed, the connecting pipe opening / closing valve 23 is opened, and the mechanical booster pump 18 and the rotary pump 19 are driven, whereby the film forming chamber 11 and the aerosol chamber are driven. 12 is depressurized.

  The pressure in the film forming chamber 11 is, for example, 5 to 80 Pa, and the pressure in the aerosol chamber 12 is, for example, 5 to 80 Pa.

  Next, in this method, the material of the separator 4 is vibrated in the aerosol chamber 12 by the vibration device 21 and the gas pipe opening / closing valve 28 is opened to supply the carrier gas from the carrier gas cylinder 25 to the aerosol chamber 12. Thereby, the material of the separator 4 can be made into an aerosol, and the generated aerosol can be transported to the film forming nozzle 22 via the connecting pipe 20. At this time, the aerosol collides with the inner wall of the film forming nozzle 22 and is crushed to become particles having a smaller particle diameter.

  The flow rate of the carrier gas adjusted by the gas flow meter 27 is, for example, 0.1 L / min or more, preferably 3 L / min or more, and, for example, 80 L / min or less, preferably 50 L / min. It is as follows.

  Next, in this method, the crushed material particles are ejected from the ejection port of the film forming nozzle 22 toward the surface of the resin layer 3 (injection step).

  The pressure in the aerosol chamber 12 during aerosol injection is, for example, 50 to 80,000 Pa. The pressure in the film forming chamber 11 is, for example, 10 to 1000 Pa.

  Moreover, the temperature in the aerosol chamber 12 during aerosol injection is, for example, 0 to 50 ° C.

  In addition, during the aerosol injection, preferably, the stage 17 is appropriately moved to spray the aerosol evenly on the surface of the resin layer 3.

  In such a case, the moving speed of the stage 17 (that is, the moving speed of the film forming nozzle 22) is, for example, 0.1 to 50 mm / second.

  Thereby, the separator 4 can be formed on the surface (vertical direction lower side) of the resin layer 3. As a result, SEA1 including the positive electrode 2, the resin layer 3, and the separator 4 is obtained.

  And according to the manufacturing method of this SEA1, SEA1 with the favorable adhesiveness of the positive electrode 2 and the separator 4 can be manufactured. In addition, since the separator 4 is formed using a dry method that does not involve evaporation of the organic solvent, the environmental load can be reduced and the drying time can be shortened. Therefore, it is suitable for industrial production.

  In addition, according to a moving speed and the thickness of the separator 4, you may repeat and implement the said injection process in multiple times. The number of repetitions is preferably 1 to 10 times.

4). Manufacturing Method of Lithium Metal Battery The lithium metal battery 30 is manufactured by stacking the negative electrode 7 on the SEA 1 separator 4 to obtain a battery cell 33 and a sealing process for sealing the battery cell 33.

  First, the negative electrode 7 is laminated on the SEA 1 (cell formation step).

  The negative electrode 7 can be prepared by disposing the negative electrode current collector 9 on the negative electrode active material layer 8 by a known method.

  Subsequently, the negative electrode 7 is disposed on the SEA 1 by a known method so that the upper surface of the separator 4 is in contact with the lower surface of the negative electrode active material layer 8.

  Thereby, the battery cell 33 of positive electrode 2 / resin layer 3 / separator 4 / negative electrode 7 is obtained.

  Next, the positive electrode lead (not shown) is attached to the positive electrode current collector 5, and the negative electrode lead (not shown) is attached to the negative electrode current collector 9.

  Next, the battery cell 33 is sealed (sealing step).

  Specifically, the battery cell 33 is sealed so as to be wrapped by the exterior body 32.

  Further, when the battery cell 33 is sealed with the exterior body 32, the electrolytic solution 31 is supplied to the exterior body 32. Specifically, the electrolytic solution 31 is supplied to the exterior body 32 so that the electrolytic solution 31 sufficiently penetrates into each of the separator 4 and the positive electrode active material layer 6. Preferably, the internal voids of the separator 4 and the positive electrode active material layer 6 are filled with the electrolytic solution 31.

  Thereby, the lithium metal battery 30 is manufactured.

  According to the method for manufacturing the lithium metal battery 30, the positive electrode 2 and the separator 4 are firmly adhered, and the separator 4 is not separated from the positive electrode 2 in the subsequent steps. Therefore, the handling property (handling property) of SEA 1 in the negative electrode forming step and the sealing step is good, the negative electrode forming step and the sealing step can be smoothly performed, and the lithium metal battery 30 can be prepared in advance. it can.

Such a lithium metal battery 30 can be used as either a primary battery (disposable battery) or a secondary battery. For example, when LiCoO ₂ is used as the positive electrode active material layer 6 and used as a secondary battery, an electrochemical reaction represented by the following reaction formulas 1 to 3 occurs.

リチウム金属電池３０は、例えば、角型電池や円筒型電池などの巻回型電池として形成でき、また、積層型電池として形成することもできる。また、ボタン型電池、ピン型電池などとすることもできる。

The lithium metal battery 30 can be formed as a wound battery such as a prismatic battery or a cylindrical battery, or can be formed as a stacked battery. Moreover, it can also be set as a button type battery, a pin type battery, etc.

5. In the embodiment of FIG. 2, a lithium metal battery is formed using lithium metal or the like as the negative electrode active material, but the negative electrode active material and the positive electrode active material are not particularly limited. For example, a carbon material (for example, A lithium ion secondary battery can also be manufactured using graphite, amorphous carbon), metal oxide (for example, silicon oxide, tin oxide), or the like.

  In addition, a sodium ion secondary battery can be formed using a sodium metal oxide as the positive electrode active material and a carbon material as the negative electrode active material. Furthermore, a magnesium ion secondary battery can be obtained using a magnesium metal oxide as the positive electrode active material and a carbon material, magnesium metal, or the like as the negative electrode active material.

  In the SEA 1 of the embodiment of FIG. 1, the positive electrode 2 is described as an example of the electrode, the positive electrode current collector 5 as an example of the electrode current collector, and the positive electrode active material layer 6 as an example of the electrode active material layer. For example, although not shown, the negative electrode 7 can be used as an example of the electrode, the negative electrode current collector 9 can be used as an example of the electrode current collector, and the negative electrode active material layer 8 can be used as an example of the electrode active material layer.

  In this embodiment, the SEA 1 includes a negative electrode current collector 9, a negative electrode active material layer 8 provided on the negative electrode current collector 9, a resin layer 3 provided on the negative electrode active material layer 8, and a resin layer 3. And a separator 4 containing an inorganic oxide. That is, the resin layer 3 is laminated between the negative electrode active material layer 8 of the negative electrode 7 and the separator 4.

  This embodiment also has the same effects as the embodiment of FIG.

  Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example. The numerical values of the examples shown below can be substituted for the numerical values (that is, the upper limit value or the lower limit value) described in the embodiment. Specific numerical values such as blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and the corresponding blending ratio (content ratio) ), Physical property values, parameters, etc. The upper limit value (numerical value defined as “less than” or “less than”) or lower limit value (number defined as “greater than” or “exceeded”) may be substituted. it can.

Example 1
(Preparation of positive electrode)
90 parts by mass of LiCoO ₂ (average particle diameter (D ₅₀ ) 5 μm) as a positive electrode active material, 5 parts by mass of carbon powder as a conductive agent, 5 parts by mass of polyvinylidene fluoride as a binder, and 400 parts by mass of N-methylpyrrolidone (NMP) as a solvent. Mixing was performed to prepare a positive electrode composition slurry.

  The slurry was applied to one side of an aluminum foil (positive electrode current collector, thickness: 25 μm) by a doctor blade method and dried to prepare a coating film.

  Thereafter, the coating film was compressed with a compression roller to form a positive electrode active material layer having a thickness of 70 μm. The positive electrode active material layer was a porous body, and the porosity was 50%.

  This produced the positive electrode.

(Formation of resin layer)
5 g of PVA powder (polyvinyl alcohol, Mw 146000-186000, 99% hydrolysis, Sigma Aldrich) was mixed with 60 ml of water. The mixture was gradually heated to 95 ° C. with stirring, and then air-cooled to 60 ° C. with stirring to prepare 50 ml of a concentrated aqueous PVA solution.

  Next, 150 ml of water was added to the concentrated PVA aqueous solution, and PVA was uniformly dispersed using a multi ultrasonic cleaner (W-118, manufactured by Honda Electronics Co., Ltd.). Thereby, diluted PVA aqueous solution was prepared.

  A diluted PVA aqueous solution is sprayed on the surface of the positive electrode active material layer using a mini air spray gun (Air Brush E1307N, manufactured by Kiso Power Tool Co., Ltd.), dried at 55 ° C. for 5 minutes, and the resin layer made of PVA is formed into the positive electrode active material Formed on the surface of the layer. This obtained the positive electrode resin layer laminated body. The thickness of the resin layer was 100 nm.

(Formation of separator)
A separator was directly formed on the resin layer of the positive electrode resin layer laminate using the aerosol deposition method.

  Specifically, the aerosol deposition apparatus (carrier gas: air gas) shown in FIG. 3 was prepared, and the positive electrode was placed on the base of the substrate holder in the film forming chamber (22 ° C.).

  At this time, the distance between the spray nozzle and the surface of the resin layer was adjusted to 20 mm.

On the other hand, a lithium-based inorganic oxide (Li ₄ SiO ₄ .Li ₃ PO ₄ (50:50 wt%), average particle diameter (D ₅₀ ) 0.75 μm, ion conductivity 2 × 10 ⁻⁶ S / cm) is prepared. In a 500 mL glass aerosol chamber.

  Thereafter, the gas pipe open / close valve was closed, the connecting pipe open / close valve was opened, and the mechanical booster pump and the rotary pump were driven to reduce the pressure in the film forming chamber and the aerosol chamber to 50 Pa.

  Next, the gas flow rate was adjusted to 50 L / min with a gas flow meter, and the gas tube on-off valve was opened while the aerosol chamber was vibrated with a shaker. Thus, the powder mixture was aerosolized in the aerosol chamber, and the obtained aerosol was sprayed from the film forming nozzle.

  At this time, the pressure in the aerosol chamber was about 1000 to 50000 Pa, and the pressure in the film formation chamber was about 300 Pa.

  Then, the stage on which the positive electrode is fixed is moved in the xy direction at a moving speed of 5 mm / second by the stage of the substrate holder, and aerosol sprayed from the film forming nozzle is sprayed on the surface of the positive electrode active material layer. .

  Thereby, a separator (a porous body made of an ion conductive inorganic oxide) was formed on the surface of the resin layer to obtain a separator positive electrode assembly (SEA). The separator had a thickness of 7 μm, a porosity of 10%, and an average pore size of 20 nm.

Example 2
SEA was produced in the same manner as in Example 1 except that the formation of the resin layer was changed as follows.

(Formation of resin layer)
In the same manner as in Example 1, a concentrated PVA aqueous solution was prepared.

Next, 1 g of silica powder (SiO _2, fumed powder, average particle size 7 nm, manufactured by Sigma Aldrich) was mixed with 30 ml of water, and the silica was uniformly dispersed using a multi ultrasonic cleaner to prepare a silica solution.

  Next, the concentrated PVA aqueous solution and the silica solution were mixed at a volume ratio of 1: 3 (so that the mass ratio of PVA and silica was 1: 1), and stirred using a multi ultrasonic cleaner. Thereby, a silica-containing PVA aqueous solution was prepared.

  Next, a silica-containing PVA aqueous solution is sprayed on the surface of the positive electrode active material layer using a mini air spray gun, and dried at 55 ° C. for 5 minutes, and a resin layer (thickness 100 nm) made of silica and PVA is formed on the positive electrode active material layer. Formed.

Example 3
A resin layer (thickness: 100 nm) made of alumina and PVA was formed on the positive electrode active material layer using alumina powder (Al ₂ O ₃ , average particle diameter of 10 to 20 nm, manufactured by CIK Nanotech) instead of SiO ₂ powder. Except for the above, SEA was produced in the same manner as in Example 1.

Example 4
SEA was produced in the same manner as in Example 1 except that the formation of the resin layer was changed as follows.

(Formation of resin layer)
A diluted SBR aqueous solution was prepared by mixing water in an SBR aqueous solution (styrene butadiene rubber aqueous solution, “TRD2001”, solid content 48 mass%, manufactured by JSR) at a volume ratio of 1: 1.

  The diluted SBR aqueous solution was sprayed on the surface of the positive electrode active material layer using a mini air spray gun and dried at 55 ° C. for 5 minutes to form a resin layer (thickness: 100 nm) made of SBR on the positive electrode active material layer.

Example 5
SEA was produced in the same manner as in Example 1 except that the formation of the resin layer was changed as follows.

(Formation of resin layer)
1 g of silica powder (SiO _2, fumed powder, average particle diameter 7 nm, manufactured by Sigma Aldrich) was mixed with 20 ml of water, and silica was uniformly dispersed using a multi ultrasonic cleaner to prepare a silica solution.

  Next, an SBR aqueous solution (styrene butadiene rubber aqueous solution, TRD2001, solid content 48 mass%, manufactured by JSR) and a silica solution are mixed at a volume ratio of 1: 1 (the mass ratio of SBR and silica is 10: 1). ) And stirred using a multi-sonic cleaner. Thereby, a silica-containing SBR aqueous solution was prepared.

  Next, a silica-containing SBR aqueous solution is sprayed on the surface of the positive electrode active material layer using a mini air spray gun, and dried at 55 ° C. for 5 minutes, and a resin layer (thickness 100 nm) made of silica and SBR is used as the positive electrode active material layer. Formed.

Example 6
Instead of PVA powder (polyvinyl alcohol, Mw 14600-186000, 99% hydrolysis, Sigma Aldrich), PVA powder (polyvinyl alcohol, Mw 13,000-23000, 87-89% hydrolysis, Sigma Aldrich) was used, SEA was produced in the same manner as in Example 1 except that a resin layer (thickness: 100 nm) made of PVA was formed on the positive electrode active material layer.

Example 7
SEA was produced in the same manner as in Example 2 except that the thickness of the resin layer was 300 nm.

Example 8
SEA was produced in the same manner as in Example 2 except that the thickness of the resin layer was 400 nm.

Comparative Example 1
SEA was produced in the same manner as in Example 1 except that the resin layer was not formed.

Evaluation (1) Adhesiveness As shown in FIG. 4, SEA1 of each Example and Comparative Example was fixed to the base material 40 so that the separator 4 was on the upper side. Next, the pressure-sensitive adhesive tape (Kapton tape) 41 is lightly pressed downward, and one end side of the pressure-sensitive adhesive tape 41 is attached to the upper surface of the separator 4 and the base material 40, and then the other end side of the pressure-sensitive adhesive tape 41 is directed upward. It peeled off.

  A case where the separator was not separated from the positive electrode active material layer and the separator was not attached to the peeled adhesive tape at all was evaluated as ◎.

  The separator was not separated from the positive electrode active material layer, but the case where the end of the separator was very slightly attached to the peeled adhesive tape was evaluated as ◯.

  Although the separator did not separate from the positive electrode active material layer, the case where the separator was slightly adhered to the peeled adhesive tape was evaluated as Δ.

  When the separator separated from the positive electrode active material layer of the positive electrode, or when the majority of the separator was adhered to the peeled adhesive tape, it was evaluated as x.

  The results are shown in Table 1.

(2) Storage stability (adhesion after storage)
The SEA1 of each example and comparative example was left in the air for 2 hours. Thereafter, the above (1) evaluation of adhesiveness was performed.

  The results are shown in Table 1.

(3) Cell Polarization A lithium metal battery 30 (see FIG. 1) was produced using SEA produced in each example and comparative example.

  As the negative electrode 7 of the battery cell 33, a Li metal foil (thickness 50 μm) / Ni foil (thickness 30 μm) laminate was used. Moreover, the electrolyte solution 31 was prepared according to the following.

LiPF ₆ was dissolved in a mixed solution in which ethylene carbonate (EC) and dimethyl carbonate (DMC) were mixed at 50:50 (volume ratio) so as to be 2.0 mol / L to prepare an electrolyte-containing organic solvent. .

Lithium bistrifluoromethanesulfonimide (Li (CF ₃ SO ₂ ) to N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) imide (PP13-TFSI, ionic liquid) at 0.4 mol / L ₂ N; Li-TFSI) was dissolved to prepare an electrolyte-containing ionic liquid.

  An electrolyte solution was prepared by mixing an electrolyte-containing organic solvent and an electrolyte-containing ionic liquid at a volume ratio of 60:40.

  Using the modular electrochemical measurement system (ModuLab, manufactured by Solartoron Analytical), charge and discharge were performed on the produced lithium metal battery 30 for 1 to 2 seconds at 0.2 C under a galvanostat cycle. did. The cell voltage at the end of charging at that time and the cell voltage at the next discharge were measured. The internal resistance is calculated from a value obtained by dividing half of the voltage difference between the measured value at the end of charging and the measured value at the next discharge by the current value at the time of charging and discharging.

  When the voltage difference measured on the lithium metal battery 30 of the comparative example is 100%, the case where the voltage difference of the lithium metal battery 30 of each example is within 110% is evaluated as ◯, and the voltage difference exceeds 110% When the voltage difference was within 160%, it was evaluated as Δ, and when the voltage difference exceeded 160%, it was evaluated as x. The measured voltage difference corresponds to the internal polarization of the cell.

  The results are shown in Table 1.

(4) Stability of separator on the surface of the resin layer A plurality of examples and comparative examples were produced. At that time, when the separator was formed on the surface of the resin layer by the AD method, the case where a separator having a desired thickness could be formed (reproduced) without changing the conditions of the AD method was evaluated as ◯. A case where a separator having a desired thickness was formed (reproduced) by slightly changing the AD conditions and optimizing the conditions was evaluated as Δ. Even if the AD conditions were changed, the case where it was difficult to form (reproduce) a separator having a desired thickness was evaluated as x.

  The results are shown in Table 1.

1 SEA
2 Positive electrode 3 Resin layer 4 Separator 5 Positive electrode current collector 6 Positive electrode active material layer 7 Negative electrode

Claims (10)

An electrode current collector;
An electrode active material layer provided on the electrode current collector;
A resin layer provided on the electrode active material layer;
A separator electrode assembly, comprising: a separator provided on the resin layer and containing an inorganic oxide.   The separator electrode assembly according to claim 1, wherein the resin layer contains a hydrophilic resin.   The separator electrode assembly according to claim 2, wherein the hydrophilic resin is polyvinyl alcohol.   The separator electrode assembly according to any one of claims 1 to 3, wherein a thickness of the resin layer is 10 nm or more and 1000 nm or less.   The separator electrode assembly according to claim 1, wherein the resin layer contains inorganic oxide particles.   The separator electrode assembly according to claim 5, wherein the inorganic oxide particles are at least one selected from the group consisting of silica particles, zirconia particles, alumina particles, and lithium aluminate particles.   The separator electrode assembly according to any one of claims 1 to 6, wherein the separator is formed by an aerosol deposition method. The electrode current collector is a positive electrode current collector;
The separator electrode assembly according to any one of claims 1 to 7, wherein the electrode active material layer is a positive electrode active material layer. The separator electrode assembly according to claim 8,
A lithium battery provided on the separator and comprising a negative electrode containing lithium. Preparing an electrode comprising an electrode current collector and an electrode active material layer;
Providing a resin layer on the electrode active material layer; and
A method for producing a separator electrode assembly, comprising a step of providing a separator containing an inorganic oxide on the resin layer by a dry method.

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