JP6475317B2 - SOLID ELECTROLYTE COMPOSITION, BATTERY ELECTRODE SHEET AND METHOD FOR MANUFACTURING SAME - Google Patents

Description

  The present disclosure relates to a solid electrolyte composition, a battery electrode sheet and a manufacturing method thereof, and an all-solid secondary battery and a manufacturing method thereof.

  An electrolyte solution is used for the lithium ion battery. Attempts are being made to replace the electrolytic solution with a solid electrolyte and to make all the constituent materials solid to form an all-solid secondary battery. Among these, safety is an advantage of the technology using an inorganic solid electrolyte. A flammable material such as a carbonate-based solvent is used as a medium for the electrolytic solution used in the lithium ion secondary battery. Although various safety measures have been taken in the past, it cannot be said that there is no risk of problems during overcharging, and further consideration for safety is desired. An all-solid-state secondary battery made of an inorganic compound capable of making the electrolyte nonflammable is positioned as one of the measures for improving safety.

  A further advantage of the all-solid-state secondary battery is that it is suitable for increasing the energy density by stacking electrodes. Specifically, a battery having a structure in which an electrode and an electrolyte are directly arranged in series can be obtained. At this time, since the metal package for sealing the battery cell, the copper wire and the bus bar for connecting the battery cell can be omitted, the energy density of the battery is greatly increased. In addition, good compatibility with the positive electrode material capable of increasing the potential is also mentioned as an advantage.

Due to the above-mentioned advantages, the development of a next-generation lithium ion secondary battery has been vigorously advanced (for example, NEDO Technology Development Organization, Fuel Cell / Hydrogen Technology Development Department, Energy Storage Technology Development Office “NEDO”). Next-generation automotive storage battery technology development roadmap 2008 "(June 2009)).
On the other hand, an inorganic all-solid secondary battery has a disadvantage because the electrolyte is a hard solid. For example, the interfacial resistance between the solid particles and between the solid particles and the current collector is increased. In order to improve this, an acrylic binder, a fluorine-containing binder, a rubber binder such as butadiene, or the like may be used (see, for example, Japanese Patent Application Laid-Open No. 2012-212552).

  In addition, when forming an electrolyte layer or the like using solid electrolyte particles, vinylidene fluoride is used as a binder from the viewpoints of formability of the electrolyte layer, etc., ion conductivity and strength of the electrode layer, battery output, and binding force at the positive electrode. Techniques using a fluororesin such as (VDF) -hexafluoropropylene (HFP) copolymer have been proposed (for example, JP 2012-204114 A, JP 2013-114966 A, JP 2014-7138 A). No. publication).

In addition to the above, as an example of another binder for improving the cycle characteristics of the battery, the soft segment has a structure in which a polyalkylene ether diol and an organic diisocyanate are added, and the hard segment has a structure in which an organic diisocyanate and an organic diamine are added. There is a disclosure relating to a binder for an electrode including a polyurethane urea resin (see, for example, JP 2013-097906 A).
Furthermore, an electrode containing a polyurethane water dispersion comprising a polyisocyanate, a compound having two or more active hydrogen groups, a compound having one or more active hydrogen groups and a hydrophilic group, and an alkoxysilane derivative (chain extender) (For example, refer to Unexamined-Japanese-Patent No. 2014-191942) and it is supposed that it is excellent in a softness | flexibility and the binding property with respect to a collector.

  As a technique for improving the binding property between particles in each layer, it is disclosed to use a binder made of a particulate polymer containing a surfactant having a polyoxyethylene chain (for example, JP-A-2013-2003). 8611). In addition, a positive electrode with excellent ion conductivity and the like is manufactured by mixing a powdered binder selected from polytetrafluoroethylene, polyethylene, and polypropylene into the positive electrode active material without using a solvent to prevent the deterioration of the solid electrolyte. The technique to do is disclosed (for example, refer to JP2012-99315A). As examples of the particulate or powdery polymer, polyurethane fine particles whose surface is coated with polyurea colloidal particles are also known (see, for example, JP-A-7-97425).

As described above, conventionally, various studies have been made to improve the performance of an all-solid battery using a solid electrolyte. However, since the battery structure includes a solid electrolyte, the binding property between an electrode and an adjacent layer such as an electrolyte layer or the adhesion between particles in each layer still tends to be insufficient. On the other hand, in a composition containing a solid electrolyte and a binder, even if the binding property or adhesion can be improved, the electrolyte may be coated with a polymer to impair ion conductivity. For example, among the above-described conventional techniques, in JP 2012-204114 A, JP 2013-114966 A, JP 2014-7138 A, and JP 2013-097906 A, resins such as polyurethane urea are particles. Since it is not a polymer in the form of powder or powder, the surface of the solid electrolyte is easily coated with the polymer, and the ionic conductivity between the electrode active material and the solid electrolyte is significantly impaired. Further, the invention described in Japanese Patent Application Laid-Open No. 2014-191942 is used for an electrode of a secondary battery provided with an electrolytic solution in which polyurethane is dispersed in water, and is less likely to be covered with an electrolyte, but dislikes moisture. Application to all-solid-state secondary batteries is difficult. On the other hand, in JP2013-8611A and JP2012-99315A, a technique using a particulate or powdered polymer is proposed, but the electrode active material and the powder can be used without using a dispersion solvent. Since they are mixed, there is a problem that the desired binding property or adhesion cannot be ensured because the mixing tends to be uneven.
For this reason, the interfacial resistance between solid particles or between layers does not decrease, and the ionic conductivity necessary to enhance battery characteristics cannot be ensured at present. Further, insufficient strength of the electrode containing the solid electrolyte or the electrolyte layer itself, and interface peeling that gradually occurs due to long-term use are also one of the reasons that the ionic conductivity cannot be stably maintained. The decrease in ionic conductivity due to the high interface resistance directly affects battery characteristics such as battery voltage.
In the conventional technology as described above, it is difficult to meet the demand for higher battery performance, and there is a demand for improvement in battery performance including long-term cycle characteristics.

  The present disclosure has been made in view of the above, and does not depend on the application of external force, adhesion between solid particles, or between layers containing solid particles or between a layer containing solid particles and a current collector during battery production, etc. A solid electrolyte composition having excellent binding properties and low interface resistance, a battery electrode sheet that exhibits good binding properties regardless of the application of external force, a method for producing the same, and a high voltage It is an object of the present invention to provide an all-solid secondary battery having a long cycle life and a method for producing the same, and to achieve these objects.

Specific means for solving the problems include the following aspects.
<1> First particles having at least one of a polyurethane structure and a polyurea structure, and a plurality of first particles having a particle diameter smaller than that of the first particles and covering the surface of the first particles having a polyurea structure. A solid electrolyte composition containing organic particles (A) having two particles, and an inorganic solid electrolyte (B) having conductivity of ions of metals belonging to Group 1 or Group 2 of the periodic table. .
<2> The second particle is the solid electrolyte composition according to <1>, which has a long-chain alkyl group having 6 or more carbon atoms.
<3> The solid electrolyte composition according to <1> or <2>, in which the first particles have a hard segment and a soft segment.
<4> The solid electrolyte composition according to any one of <1> to <3>, wherein the organic particles (A) have a volume average particle diameter of 0.1 μm to 100 μm.

<5> The solid electrolyte composition according to any one of <1> to <4>, wherein the glass transition temperature of the first particles is higher than the glass transition temperature of the second particles.
<6> The solid electrolyte composition according to any one of <1> to <5>, wherein the glass transition temperature of the first particles is less than 50 ° C., and the glass transition temperature of the second particles is less than 0 ° C. It is a thing.
<7> The solid electrolyte composition according to any one of <1> to <6>, wherein the inorganic solid electrolyte (B) is a sulfide-based inorganic solid electrolyte.
<8> The solid electrolyte composition according to any one of <1> to <6>, wherein the inorganic solid electrolyte (B) is an oxide-based inorganic solid electrolyte.
<9> The content of the organic particles (A) is 0.01 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the inorganic solid electrolyte (B), and any one of <1> to <8> The solid electrolyte composition described in 1.
<10> Further, the dispersion medium (C) has a ratio of 10% by mass to 1000% by mass with respect to the inorganic solid electrolyte (B), and at least one of the dispersion media (C) is a hydrocarbon solvent. It is a solid electrolyte composition as described in any one of>-<9>.
<11> The solid electrolyte composition according to any one of <1> to <10>, wherein the organic particles (A) have a volume average particle diameter of 0.5 μm to 25 μm.

  <12> At least an isocyanate compound, a diol compound having a long-chain alkyl group having 6 or more carbon atoms, and an amine compound are reacted, and a structural part solvated with a hydrocarbon-based solvent and a structural part that is not solvated Preparing an emulsion by dispersing the second particles, the second particles, the isocyanate compound, and at least one of a diol compound and a diamine compound in a hydrocarbon solvent, A step of preparing organic particles (A) in which the surface of the first particles is covered with a plurality of second particles by subjecting the suspension to a polycondensation reaction, organic particles (A), and periodic table first And a step of mixing an inorganic solid electrolyte (B) having conductivity of ions of metals belonging to Group 2 or Group 2. A method for producing a solid electrolyte composition.

<13> A battery electrode having a current collector and a solid electrolyte-containing layer disposed on the current collector using the solid electrolyte composition according to any one of <1> to <11> It is a sheet.
<14> a positive electrode active material layer, a negative electrode active material layer, and an inorganic solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, the positive electrode active material layer, the negative electrode active material layer, And at least 1 layer of an inorganic solid electrolyte layer is a battery electrode sheet as described in <13> which is a solid electrolyte content layer.
<15> By the manufacturing method of the electrode sheet for batteries which has the process of providing the solid electrolyte composition as described in any one of <1>-<11> on a collector, and forming a solid electrolyte content layer. is there.
<16> a current collector, a positive electrode active material layer, a negative electrode active material layer, an inorganic solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer, a positive electrode active material layer, At least one of the negative electrode active material layer and the inorganic solid electrolyte layer includes a first particle having at least one of a polyurethane structure and a polyurea structure, a particle diameter smaller than the first particle, and a polyurea structure. A plurality of second particles covering the surface of the first particles, and an organic particle (A), and an inorganic having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table It is an all-solid-state secondary battery containing a solid electrolyte (B).
<17> An all-solid secondary battery comprising the battery electrode sheet according to <13> or <14>.
<18> A method for producing an all-solid secondary battery, comprising producing an all-solid secondary battery using the battery electrode sheet according to <13> or <14>.
<19> A step of producing a battery electrode sheet by applying the solid electrolyte composition according to any one of <1> to <11> on a current collector and forming a solid electrolyte-containing layer. It is a manufacturing method of the all-solid-state secondary battery which has.

According to the present disclosure, regardless of the application of external force, the adhesion between the solid particles, or the binding between the layer containing the solid particles or the layer containing the solid particles and the current collector in the battery production, etc. In addition, a solid electrolyte composition having low interface resistance is provided.
Moreover, according to this indication, the battery electrode sheet which expresses favorable binding property without depending on the provision of external force, and its manufacturing method are provided.
Furthermore, according to the present disclosure, an all-solid secondary battery having a high voltage and a long cycle life and a method for manufacturing the same are provided.

FIG. 1 is a schematic cross-sectional view schematically showing second particles having a polyurea structure. FIG. 2 is a scanning electron microscope (SEM) photograph showing the appearance of polyurethane particles (1), which are organic particles synthesized in the examples. FIG. 3 is a schematic cross-sectional view schematically showing the structure of organic particles in which core particles are coated with second particles having a polyurea structure. FIG. 4 is a DSC curve obtained by differential scanning calorimetry (DSC) measurement of polyurethane particles (1), which are organic particles synthesized in the examples. FIG. 5 is a schematic cross-sectional view schematically showing an all solid state secondary battery according to an embodiment of the present invention. FIG. 6 is a side sectional view schematically showing the test apparatus used in the examples.

  Hereinafter, the solid electrolyte composition of the present disclosure, the battery electrode sheet and the manufacturing method thereof, and the all-solid secondary battery and the manufacturing method thereof will be described in detail.

  “Composition” refers to a mixture in which two or more components are mixed. However, the composition may be substantially uniform, and may be partially aggregated or unevenly distributed as long as a desired effect is achieved.

  In addition, when there are a plurality of substituents or linking groups indicated by a specific code, or when a plurality of substituents etc. (same definition of the number of substituents) are specified simultaneously or alternatively, each substituent etc. They may be the same or different from each other. When a plurality of substituents and the like are close to each other, they may be bonded to each other or condensed to form a ring.

  In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

<Solid electrolyte composition>
The solid electrolyte composition according to an embodiment of the present invention includes first particles having at least one of a polyurethane structure and a polyurea structure (hereinafter referred to as “polyurethane particles”, “polyurea particles” or “polyurethane urea particles”, or “ Core particle)) and a plurality of second particles (hereinafter also referred to as “polyurea colloid particles”) having a particle diameter smaller than that of the polyurethane particles and having a polyurea structure and covering the surface of the polyurethane particles. And an inorganic solid electrolyte (B) having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table. The solid electrolyte composition of one embodiment of the present invention may further contain an active material, and may contain other components such as a dispersion medium and a lithium salt as necessary.

Conventionally, an all-solid secondary battery using an inorganic solid electrolyte such as Li _x La _y TiO ₃ (LLT) or Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ) has been known, and physical external force is applied during manufacturing. In addition, binding properties between particles or between layers have been secured by press bonding. However, due to poor binding properties between solid particles, between layers containing solid particles, or between a layer containing solid particles and a current collector during battery production, there are various situations such as usage status, usage environment, or aging. As a result, peeling easily occurs. As a result, there has been a problem that the interfacial resistance is increased and a desired battery voltage cannot be obtained. In addition, when peeling occurs between solid particles or an interface such as an interlayer, it is difficult to stably maintain cycle characteristics over a long period of time.
Under such circumstances, in the present embodiment, the polymer component is made by including organic particles in which the surface of core particles such as polyurethane is covered with polyurea colloidal particles having a polyurea structure together with an inorganic solid electrolyte. Is contained in the form of particles, the inorganic solid electrolyte is not completely included in the polymer film, and a state in which the solid electrolyte and the active material or the electrode or the adjacent layer are connected by dots can be formed. it can.
This ensures good binding between solid particles, between layers containing solid particles, or between layers containing solid particles and current collectors during battery production, while keeping ionic conductivity low by keeping the interface resistance low. It can be made. In addition, since the form of the organic particles is a structure in which the core particles are covered with polyurea colloidal particles having a polyurea structure, the elasticity derived from the core particles prevents the deterioration of cycle characteristics associated with the expansion and contraction of the active material or the like. . In addition, due to the flexibility derived from the polyurea colloidal particles having a polyurea structure present on the core particle surface, between solid particles, between layers containing solid particles, or between layers containing solid particles and current collectors during battery production, etc. , Adhesion is improved and interfacial adhesion is improved. The flexibility derived from the polyurea colloidal particles becomes more prominent when it has a flexible long-chain alkyl group.
Therefore, in this embodiment, interfacial peeling between solid particles, between layers containing solid particles, or between a layer containing solid particles and a current collector during battery production is suppressed, and a good battery voltage can be obtained over a long period of time. The cycle characteristics can be stably maintained.

-Organic particles (A)-
A solid electrolyte composition according to an embodiment of the present invention includes a first particle (polyurethane particle, polyurea particle, or polyurethane urea particle) having at least one of a polyurethane structure and a polyurea structure, and particles that are more than the first particles. It contains at least one organic particle having a plurality of second particles (polyurea colloidal particles) having a small diameter and having a polyurea structure and covering the surface of the first particles. By using such specific organic particles, the inorganic solid electrolyte is connected to the active material and the like to ensure adhesion, while the inorganic solid electrolyte is not completely encapsulated by the polymer film. Therefore, it is possible to obtain the effects of maintaining the adhesion between the solid particles, the binding property between the layers including the solid particles, and the like, and suppressing the interface resistance low.
The first particle refers to a part of the organic particle (A) that is covered with the second particle having a polyurea structure, and is hereinafter referred to as a polyurethane particle, a polyurea particle, or a polyurethane urea particle. Or core particles.

The organic particles are synthesized by emulsion polymerization of an isocyanate compound and a compound having active hydrogen in a hydrocarbon solvent in the presence of polyurea colloid particles as an emulsifier. As a specific method, for example, it can be synthesized according to the description in JP-A-7-97425.
The organic particles thus obtained have a particle structure in which the surfaces of the core particles (polyurethane particles, polyurea particles, or polyurethane urea particles) 23 are covered with polyurea colloidal particles 24, as shown in FIG. .

The method for synthesizing the organic particles will be described more specifically.
The organic particles are, for example, (1) synthesis of lipophilic diol (synthesis of dispersant), (2) synthesis of second particles (polyurea colloid particles) using lipophilic diol (dispersant), (3) Three-step operation of emulsion polymerization of organic particles (A) containing the first particles (polyurethane particles, polyurea particles, or polyurethane polyurea particles) inside, using two particles (polyurea colloid particles) as an emulsifying dispersant It is formed through. In the operation (1), for example, a commercially available lipophilic diol may be prepared, and the operation of synthesizing the lipophilic diol may be omitted.
As a specific example, a diol compound (lipophilic diol) having a long chain alkyl group having 6 or more carbon atoms is prepared, and at least an isocyanate compound, a diol compound having a long chain alkyl group having 6 or more carbon atoms, and an amine And reacting the compound to prepare second particles containing a hydrocarbon solvent and a solvated structural portion and a non-solvated structural portion, the prepared second particles, an isocyanate compound, a diol compound, and At least one of the diamine compounds is dispersed in a hydrocarbon solvent to prepare an emulsion, and the emulsion is subjected to a polycondensation reaction (emulsion polymerization reaction). It is good also as the synthesis method which provided the process (henceforth the process of preparing organic particle (A)) which prepares the organic particle (A) covered with the particle | grains.
In the step of preparing the organic particles (A), the generation of the first particles and the preparation of the organic particles (A) that cover the surfaces of the generated first particles with a plurality of second particles are performed.
Thus, when a diol compound having a long-chain alkyl group having 6 or more carbon atoms is used, second particles having a long-chain alkyl group having 6 or more carbon atoms can be obtained. Thereby, the adhesiveness is further improved.

Hereinafter, the operations (1) to (3) will be described.
(1) Synthesis of lipophilic diol First, a diol monomer having a hydrophobic group having an affinity for a hydrocarbon solvent (preferably a diol compound having a long-chain alkyl group having 6 or more carbon atoms) and a hydroxyl group The monomer is oligomerized or polymerized by various polymerization methods (radical polymerization, cationic polymerization, polycondensation, etc.). The oligomer or polymer formed at this time is a lipophilic oligomer or polymer having a hydrophobic group having an affinity for the hydrocarbon solvent and soluble in the hydrocarbon solvent.
As for the weight average molecular weight of the oligomer or polymer obtained here, the range of 500-2000 is preferable.

(2) Synthesis of second particles (polyurea colloidal particles) using lipophilic diol Next, a lipophilic oligomer or polymer having a hydrophobic group having affinity for a hydrocarbon solvent is added in the presence of the hydrocarbon solvent. A polyurethane prepolymer having an isocyanate group remaining at the terminal is synthesized by reacting with an isocyanate compound. When an amine compound is added to this to synthesize polyurethane polyurea, colloidal particulate polyurea (polyurea colloidal particles) is formed. This polyurea colloidal particle is presumed to have a structure in which the lipophilic group is directed to the outside of the particle, and the agglomerated part formed by hydrogen bonding with polyurea is directed to the inside of the particle.
The size of the polyurea colloidal particles is preferably 0.01 μm to 1 μm in terms of volume average particle diameter. The polyurea particles contain residual isocyanate groups.
In the polyurea colloidal particles, the hydrophobic group (preferably a long-chain alkyl group having 6 or more carbon atoms) is a structural part that solvates with a hydrocarbon solvent, and the polyurea structure (aggregated part formed by hydrogen bonding with polyurea) is It is a structural part that does not solvate with a hydrocarbon solvent. Hydrophobic groups, particularly long-chain alkyl groups having 6 or more carbon atoms, contribute to improved adhesion by solvation with hydrocarbon solvents.

(3) Emulsion polymerization of organic particles (A) containing the first particles (polyurethane particles, polyurea particles, or polyurethane polyurea particles) inside, using the second particles (polyurea colloid particles) as an emulsifying dispersant [3 .1 When the core particles are polyurethane]
Monomers (for example, isocyanate compounds, diol compounds, etc.) generally used in polyurethane synthesis to form polyurethane core particles using colloidal particulate polyurea colloidal particles obtained as described in (2) above as emulsifiers Is strongly dispersed in a hydrocarbon solvent, an emulsion is obtained. By subjecting the obtained emulsion to a polycondensation reaction, a polyurethane core particle (first particle having a polyurethane structure) and a polyurea structure having a particle diameter smaller than the core particle covering the surface of the core particle are formed. Organic particles having the polyurea colloid particles (second particles having a polyurea structure) are formed.
[3.2 When the core particles are polyurea]
Monomers (for example, isocyanate compounds, diamine compounds, etc.) generally used for polyurea synthesis to form polyurea core particles using colloidal polyurea colloidal particles obtained as described in (2) above as emulsifiers Is strongly dispersed in a hydrocarbon solvent, an emulsion is obtained. By subjecting the obtained emulsion to a polycondensation reaction, polyurea core particles (first particles having a polyurea structure) and a polyurea structure having a particle diameter smaller than the core particles covering the surface of the core particles are formed. Organic particles having the polyurea colloid particles (second particles having a polyurea structure) are formed.
[3.3 When the core particles are polyurethane urea]
The polyurethane urea core particles have a polyurethane structure and a polyurea structure in the core part.
Monomers (for example, isocyanate compounds, diol compounds) generally used for polyurethane urea synthesis to form polyurethane urea core particles using colloidal particulate polyurea colloid particles obtained as described in (2) above as emulsifiers , Diamine compounds, etc.) are strongly dispersed in a hydrocarbon solvent to obtain an emulsion. By subjecting the obtained emulsion to a polycondensation reaction, core particles made of polyurethane urea (first particles having a polyurethane urea structure) and polyurea covering the surface of the core particles and having a particle diameter smaller than that of the core particles Organic particles having polyurea colloidal particles having a structure (second particles having a polyurea structure) are formed.

The organic particles may be dried and used in the form of a powder, or may be used in the form of a dispersion dispersed in a solvent. The solvent is preferably a hydrocarbon solvent.
Details of the hydrocarbon solvent will be described later.

  The organic particles can be obtained by the above-described method. Preferably, a hydrocarbon solvent containing polyurea colloid particles dispersed therein is charged into a jacket-type synthesis kettle equipped with a stirrer or an emulsifier, and in this, an isocyanate compound and an activity A method of synthesizing organic particles by adding an inert medium solution of a compound having hydrogen and emulsifying and reacting the charged raw materials, and an isocyanate compound and a compound having active hydrogen separately in the presence of polyurea colloid particles. And a method of emulsifying in a hydrocarbon solvent and reacting with each other using an emulsion.

In the emulsion polymerization in the preparation of the organic particles (A), it is effective to make the second particles, the isocyanate and the compound having active hydrogen an emulsion while applying strong shearing. In addition to the above, the stirrer capable of applying a strong shear includes a homogenizer (for example, a high-pressure homogenizer, a rotary homogenizer, an ultrasonic homogenizer, etc.), a mill (for example, a bead mill, a ball mill, a tower mill, a three roll mill), a mixer (for example, a planetary unit). A Lee mixer, a disper mixer, a hensil mixer, a kneader, a Claire mix, a self-revolving mixer (agitating and defoaming machine)) and the like are suitable. In particular, a rotary homogenizer, an ultrasonic homogenizer, and a ball mill are more preferable, and a rotary homogenizer is more preferable.
As a shear rate, 8000 rpm to 50000 rpm is preferable, and 10,000 rpm to 35000 rpm is more preferable.
In the emulsification process, the number of agitators used is not limited to one, and a plurality of agitators may be used.
Further, a polymerization reaction may be performed during the emulsification treatment, or after the emulsification treatment, the emulsion may be heated and aged to be polymerized.

-First particles having at least one of a polyurethane structure and a polyurea structure-
The organic particles (A) have first particles (polyurethane particles, polyurea particles, or polyurethane urea particles) having at least one of a polyurethane structure and a polyurea structure as core particles forming the core part (center part). ing.

  Examples of isocyanate compounds used for the synthesis of polyurethane particles include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylene diisocyanate, metaxylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,6-hexane diisocyanate, 1,6. -Hexanediol diisocyanate, lysine diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or -2,6-)-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate And those having two isocyanate groups such as trimethylhexamethylene diisocyanate and dimer acid diisocyanate.

Moreover, the polyfunctional isocyanate compound which has several isocyanate group which made said isocyanate compound the isocyanurate body, the burette body, the adduct body, or the polymeric body is also mentioned.
Examples of the polyfunctional isocyanate compound include 4,4 ′, 4 ″ -triphenylmethane triisocyanate, 2,4-tolylene diisocyanate cyclic trimer, 2,6-tolylene diisocyanate cyclic trimer, 2 , 4- and 2,6-tolylene diisocyanate cyclic trimer, diphenylmethane-4,4'-diisocyanate trimer, 3 moles diphenylmethane-4,4'-diisocyanate and 1 mole of triisocyanate Reaction product of methylolpropane, reaction product of 3 moles of 2,4-tolylene diisocyanate and 1 mole of trimethylolpropane, 3 moles of 2,6-tolylene diisocyanate and 1 mole of trimethylolpropane Reaction product, reaction product of 3 moles of 2,4-tolylene diisocyanate and 1 mole of trimethylolethane, 3 Reaction product of 2,6-tolylene diisocyanate with 1 mol of trimethylol ethane, reaction product of 3 mol of 2,4- and 2,6-tolylene diisocyanate with 1 mol of trimethylol propane, etc. , And these polyisocyanates with methanol, ethanol, phenol, cresol, ε-caprolactam, methyl ethyl ketone oxime, acetone oxime, N, N-dimethylhydroxyamine, diethyl malonate, acetylacetone, etc. The compound etc. which carried out addition reaction of the compound which has an individual, and one part or all part of the isocyanate group of an isocyanate compound are mentioned.

  Examples of compounds having active hydrogen used for the synthesis of polyurethane particles include water, polyol compounds (diol compounds such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, octanediol, Ethylene glycol, propylene glycol, neopentyl glycol, hexanetriol, glycerin, trimethylolpropane, pentaerythritol, triethanolamine, sorbitol, polypropylene glycol, polyethylene glycol, polyethylene adipate, polybutylene adipate, polytetramethylene glycol, 1,4- Benzenethiol, polyhexamethylene adipate, poly-ε-caprolactone, polyhexamethylene carbonate, polypropylene glycol bis 2-aminop Pills ether).

  Examples of the compound having active hydrogen used for the synthesis of polyurea particles include amine compounds. Examples of the amine compound include ethylenediamine, propanediamine, 1,4-butanediamine, 1,6-hexanediamine, 2,2′-oxy (ethylamine), isophoronediamine, polyethyletherdiamine (for example, Jeffamine ED-600). , Jeffamine ED-900, Jeffamine ED-2003 (manufactured by Huntsman), etc.), polypropyl ether diamine (for example, Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-2010, Jeffamine D-4000 (manufactured by Huntsman) and the like), polybutyl ether diamine, polyethyleneimine, and the like.

  Polyurethane urea particles can be synthesized using a mixture of the above polyol compound and amine compound as a compound having active hydrogen.

  The compound having active hydrogen may be used alone, or any compound that reacts with an isocyanate compound, such as a mixture or copolymer obtained by mixing or copolymerizing two or more of them, can be used.

There is no restriction | limiting in particular in synthesis | combination temperature, Preferably it is 0 to 120 degreeC.
The amount of the polyurea colloidal particles used in the synthesis of the organic particles is preferably in the range of 5 parts by mass or more and preferably 95 parts by mass or less per 100 parts by mass of the isocyanate compound and the compound having active hydrogen. Among them, more preferably 10 parts by weight to 80 parts by weight, and still more preferably 20 parts by weight to 50 parts by weight. When the amount of the polyurea colloidal particles is 5 parts by weight or more, the emulsification reaction of the raw material used for the synthesis of polyurethane. Progresses well, makes it difficult for large agglomerates of polyurethane particles to occur during the synthesis process, and makes it easier to obtain the desired fine polymer dispersion. On the other hand, when the amount of the polyurea colloidal particles is 80 parts by mass or less, the emulsification reaction of the raw material used for the synthesis of polyurethane proceeds well, and a dispersion of polyurethane particles can be produced. It is hard to be a quantity.

  The concentration of the isocyanate compound and the compound having active hydrogen in the hydrocarbon solvent is preferably low in that it is easy to obtain a small particle size, and from the viewpoint of productivity, 100 parts by mass of the hydrocarbon solvent, 5 mass parts-70 mass parts are more preferable, More preferably, they are 10 mass parts-50 mass parts.

  In the present specification, the term “polyurethane” includes thermoplastic polyurethane, crosslinked polyurethane, thermoplastic urethane prepolymer, crosslinked urethane prepolymer, and poly (urethane-urea).

  Polyurethane has a hard segment and a soft segment by a combination of an isocyanate compound and a compound having active hydrogen. Therefore, it affects the mechanical properties of the polyurethane particles, and further affects the battery performance when an all-solid secondary battery is produced.

  Hereinafter, the hard segment, the soft segment, and the third component other than the hard segment and the soft segment will be described in detail.

(Hard segment)
The hard segment preferably has a skeleton that forms intermolecular pseudo-crosslinks through hydrogen bonds. Moreover, a hard segment points out that the glass transition temperature (Tg) of the compound which forms a hard segment is high, and Tg is 100 degreeC or more. The hard segment preferably has at least one bond selected from an amide bond, a urea bond, a urethane bond, and an imide bond, and more preferably has a urethane bond. When it has a urethane bond as a hard segment, it is preferable to have a structural part including a urethane bond formed from, for example, a diisocyanate compound and a diol compound having 6 or less carbon atoms. The hard segment is more preferably selected from the following group I.

“*” In the structure represents a binding site.
R ¹¹ and R ¹² are each independently an alkylene group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), a cycloalkylene group (preferably having 5 to 22 carbon atoms, 6 to 14 are more preferable, and 6 to 10 are particularly preferable), an arylene group (the number of carbon atoms is preferably 6 to 22, more preferably 6 to 14, and particularly preferably 6 to 10), or an alkylene group and a cycloalkylene group. The linking group is a combination of at least two selected from the group of an arylene group. Preferred examples of the linking group for R ¹¹ and R ¹² include a group represented by the following formula (M).
In addition, a formula (I-1) and a formula (I-2) will become a urethane group or a urea group by connecting with an oxygen atom or an imino group (NR < ^N >) in the coupling | bond part "*". ^RN represents a hydrogen atom or an alkyl group, preferably a hydrogen atom, a methyl group, or an ethyl group.
Furthermore, the hydrogen atom of the NH group in each formula may be substituted with an arbitrary substituent T. Examples of the substituent T substituted with N include a methyl group, an ethyl group, a halogen atom, and a cyano group.

In formula (M), X represents a single bond or an alkylene group having 1 to 4 carbon atoms. Examples of the alkylene group for X include —CH ₂ —, —C (CH ₃ ) ₂ — and the like. “*” Represents a binding site.

In Formula (I-3) and Formula (I-4), R ¹³ is an alkyl group (the number of carbon atoms is preferably 1-12, more preferably 1-6, and particularly preferably 1-3), an alkenyl group (carbon). The number is preferably 2 to 12, more preferably 2 to 6, and particularly preferably 2 to 3, and an aryl group (the number of carbon atoms is preferably 6 to 22, more preferably 6 to 14, and particularly preferably 6 to 10). An aralkyl group (7 to 23 carbon atoms are preferable, 7 to 15 carbon atoms are more preferable, and 7 to 11 carbon atoms are particularly preferable).
In the formula (I-3), the main chain ethylene group may be optionally substituted with a substituent (such as a methyl group, an ethyl group, a propyl group, a halogen atom, or a hydroxy group).
Here, R ¹³ may form a ring. For example, in Formula (I-4), R ¹³ may be bonded to N to form a pyrrolidone ring substituted at the N position.
In formulas (I-3) and (I-4), the ethylene group of the main chain may have a substituent T. Examples of the substituent T include a methyl group, an ethyl group, a halogen atom, and a cyano group. Further, an arbitrary linking group may be interposed between the ethylene group of the main chain and the CO group or NH group of the substituent. Examples of the substituent that substitutes ^N include the example of RN.

In the formula (I-5), R ¹⁴ represents an aromatic or aliphatic tetravalent linking group. R ¹⁴ is preferably a linking group represented by any one of the following formulas (i) to (iii).

In the formula, X ¹ represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group having 1 to 6 carbon atoms (methylene group, ethylene group, propylene _{group), - SO 2 -, -} S -, - CO-, or -O- is preferable. Among these, the above alkylene group is more preferable. L represents an alkenylene group (for example, —CH═CH—) or an alkylene group (for example, —CH ₂ —, —CH ₂ CH ₂ —). R ^X and R ^Y each independently represent a hydrogen atom or a substituent (for example, the above-described substituent T). * Represents a binding site with a carbonyl group.

(Soft segment)
The soft segment refers to a compound having a low glass transition temperature (Tg) and a Tg of 50 ° C. or lower of the compound forming the soft segment. The soft segment preferably has at least one selected from a polyalkylene oxide chain (a polyethylene oxide chain and a polypropylene oxide chain are preferable), a polycarbonate chain, a polyester chain, and a silicone chain.
The soft segment may be a group derived from an ester compound having a structural portion derived from a diol compound by adding a diol compound to an ester compound such as dodecyl methacrylate. In this case, the weight average molecular weight of the diol compound is preferably 600 or more, more preferably 800 or more and 5000 or less, from the viewpoint of imparting appropriate rubber stretchability.
Of the soft segments, groups selected from the following group II are preferred.

“*” In each structure represents a binding site.
In formulas (II-1) to (II-5), R ²¹ represents a hydrogen atom or an alkyl group (the number of carbon atoms is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 3). .

R ²² represents a monovalent substituent having a weight average molecular weight of 200 or more and 200,000 or less, having a polyalkylene oxide chain (a polyethylene oxide chain or a polypropylene oxide chain is preferred), a polycarbonate chain, or a polyester chain. The weight average molecular weight of the substituent represented by R ²² is preferably 500 or more, more preferably 700 or more, and still more preferably 1,000 or more. Further, the weight average molecular weight is preferably 100,000 or less, and more preferably 10,000 or less.
R ²² preferably has an alkyl group at the terminal (C1 is preferably 1-12, more preferably 1-6). The alkyl group is not only a hydrocarbon group, but also an ether group (—O—), a thioether group (—S—), a carbonyl group (> C═O), an imino group (> NR) in the alkyl group. ^N )). R ²² may have a heteroatom-containing group or a carbon-carbon unsaturated group defined in the third component described later. The NR ^N, examples of the ^{R N} and the like.

R ²³ is a linking group having a weight average molecular weight of 200 or more and 200,000 or less, which contains a polyalkylene oxide chain (preferably a polyethylene oxide chain or a polypropylene oxide chain), a polycarbonate chain, or a polyester chain. The weight average molecular weight of the linking group represented by R ²³ is preferably 500 or more, more preferably 700 or more, and still more preferably 1000 or more. The weight average molecular weight is preferably 100,000 or less, and more preferably 10,000 or less.
R ²³ preferably has an alkyl group at the terminal (C1 is preferably 1-12, more preferably 1-6). Further, the alkyl group may have an ether group (—O—), a thioether group (—S—), a carbonyl group (> C═O), or an imino group (> NR ^N ). ^RN represents a hydrogen atom or an alkyl group, preferably a hydrogen atom, a methyl group, or an ethyl group.
R ²³ may have a heteroatom-containing group or a carbon-carbon unsaturated group defined in the third component described later.

The weight average molecular weights of R ²² and R ²³ are obtained as polystyrene equivalent values by measuring the monomers before being incorporated into the polymer by gel permeation chromatography (GPC) under the following conditions. The calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A -2500 "," A-1000 ", and" n-propylbenzene ".
<Condition>
GPC: HLC (registered trademark) -8020 GPC (manufactured by Tosoh Corporation)
Column: G3000HXL and G2000HXL
-Eluent: THF (tetrahydrofuran), chloroform, NMP (N-methyl-2-pyrrolidone), m-cresol / chloroform (manufactured by Shonan Wako Pure Chemical Industries, Ltd.) can be selected. Used ・ Sample concentration: 0.45% by mass
・ Flow rate: 1 mL / min
Sample injection volume: 10 μl
・ Measurement temperature: 23 ℃
・ Uses differential refractometer (RI) detector

The ratio of the hard segment component and the soft segment component of the polyurethane forming the core particle of the organic particles is preferably in the following range.
The content ratio of the hard segment component is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 70 mol% or more in the whole polyurethane. The content ratio of the hard segment component is preferably 99 mol% or less, more preferably 90 mol% or less, and still more preferably 80 mol% or less.
The content ratio of the soft segment component is preferably 1 mol% or more, more preferably 2 mol% or more, and further preferably 5 mol% or more in the whole polyurethane. The content ratio of the soft segment component is preferably 50 mol% or less, more preferably 30 mol% or less, and further preferably 20 mol% or less.
Moreover, 1 mol or more is preferable, as for the molar ratio of the soft segment component with respect to 100 mol of hard segment components, 10 mol or more is more preferable, and 50 mol or more is further more preferable. The molar ratio of the soft segment component is preferably 1000 mol or less, more preferably 500 mol or less, and even more preferably 100 mol or less.

  By adjusting the hard segment component and the soft segment component in the above range, the polyurethane particles can achieve more excellent effects by reducing the interface resistance and maintaining the interface resistance in the all-solid secondary battery.

(Third component)
The polyurethane particles (core particles) may contain a third component other than the hard segment component and the soft segment component.
The polyurethane particles (core particles) preferably have a repeating unit having a hetero atom-containing group as a third component. As a hetero atom-containing group, an alcoholic hydroxyl group (hydroxyalkyl group: the number of carbon atoms is preferably 1-6, more preferably 1-3), a phenolic hydroxyl group (hydroxyphenyl group), a mercapto group, a carboxy group, It preferably has at least one selected from a sulfo group, a sulfonamide group, a phosphate group, a cyano group, an amino group, a zwitterion-containing group, a metal hydroxide group, and a metal alkoxide group.

Here, the amino group is represented by ^-NR _{N 2,} ^{R N} has the same meaning as ^{R N} of the imino groups (> NR ^N), and the preferred range is also the same. The zwitterion-containing group is a group having a betaine structure (the number of carbon atoms is preferably 1 to 12, and more preferably 1 to 6). Examples of the cation moiety include quaternary ammonium, sulfonium, and phosphonium. Rate, sulfonate. Examples of the metal hydroxide group include a hydroxylsilyl group and a hydroxyl titanyl group. Examples of the metal alkoxide group include an alkoxysilyl group (carbon number is preferably 1-12, more preferably 1-6) and an alkoxy titanyl group (carbon number is preferably 1-12, more preferably 1-6). More specific examples include a trimethoxysilyl group, a methyldimethoxysilyl group, a triethoxysilyl group, a methyldiethoxysilyl group, and a trimethoxytitanyl group.

  The repeating unit having a hetero atom-containing group is preferably 0 mol% to 30 mol% in the whole polyurethane. By incorporating a repeating unit having a heteroatom-containing group into polyurethane, the conductivity of lithium ions is improved, and the adhesion is improved by interaction with the inorganic solid electrolyte.

  The core particles (polyurethane particles, polyurea particles, or polyurethane urea particles) also preferably have a carbon-carbon unsaturated group as the third component. Examples of the carbon-carbon unsaturated group include a group containing a carbon-carbon double bond or a carbon-carbon triple bond. Examples of the group containing a carbon-carbon double bond include an acryl group, a methacryl group, a vinyl group, an allyl group, and a maleimide group. Examples of the group containing a carbon-carbon triple bond include a terminal ethynyl group, an internal ethynyl group, and a propargyl group.

  The group having a carbon-carbon unsaturated group is more preferably a group represented by the following formula (1) or formula (2).

“*” In the formula represents a binding site.
In formula (1) and formula (2), R ¹ and R ⁵ each independently represents an oxygen atom or an imino group (> NR ^N ). ^RN represents a hydrogen atom or an alkyl group (C1-C12 is preferable, 1-6 are more preferable, and 1-3 are more preferable). R ^{2 to} R ⁴ and R ^{6 to} R ¹⁰ each independently represent a hydrogen atom or an alkyl group (the carbon number is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 3).

  It is preferable that the repeating unit having a carbon-carbon unsaturated group is contained in the range of 0 mol% to 30 mol% with respect to the entire polyurethane, polyurea particles, or polyurethane urea particles. By incorporating the repeating unit having a carbon-carbon unsaturated group into polyurethane, polyurea, or polyurethane urea forming the core particle, adhesion is improved by chemical bonding with the inorganic solid electrolyte.

  The third component may be present in either the hard segment component or the soft segment component in the polyurethane, polyurea, or polyurethane urea forming the core particle. Further, it may exist as a side chain of the polymer or may exist at the end of the main chain of the polymer.

The hydrocarbon solvent used for the reaction between the isocyanate compound and the compound having active hydrogen and forming the continuous phase of the dispersion of the organic particles (A) to be produced is the first particles to be produced (polyurethane, polyurea or polyurethane). Those which are substantially poor solvents for urea and do not have active hydrogen are preferred.
Examples of hydrocarbon solvents include pentane, hexane, heptane, octane, decane, petroleum ether, petroleum benzine, ligroin, petroleum spirit, cyclohexane, methylcyclohexane, toluene, xylene, mesitylene hydrocarbons, dimethylpolysiloxane, etc. An inert liquid is mentioned. The hydrocarbon solvents may be used alone or as a mixture of two or more.

The hydrocarbon solvent may be the same as the solvent used for the second particles having the polyurea structure described below, or may be different from the solvent used for the second particles.
Moreover, when producing | generating 1st particle | grains using 2 or more types of hydrocarbon type solvents, it may emulsion-polymerize using the mixed solvent mixed beforehand before emulsion polymerization, and can dissolve an isocyanate compound. A first solvent and a second solvent capable of dissolving a compound having active hydrogen are prepared in advance, and one of them is mixed while stirring strongly, and a polymerization reaction is performed simultaneously with emulsification; As a result, the first particles may be dispersed in two or more mixed solvents. In this case, the polyurea colloidal particles (second particles) are preferably dispersed in the first solvent.

The hydrocarbon solvent preferably has a boiling point of 220 ° C. or less from the viewpoint of separability and productivity from polyurethane, polyurea or polyurethane urea synthesized with the hydrocarbon solvent.
The synthesis of polyurethane particles, polyurea particles, or polyurethane urea particles can optionally be carried out at a low temperature by using a catalyst. From the work surface, a reaction temperature of 0 ° C. or higher, preferably 20 ° C. or higher is more preferable. Is preferably carried out at a reaction temperature of 40 ° C. or higher.

The glass transition temperature (Tg) of the first particles of the organic particles is preferably higher than the glass transition temperature (Tg) of the second particles described later from the viewpoint of imparting rubber elasticity to the particles.
The glass transition temperature of the first particles is preferably less than 50 ° C, and more preferably less than 30 ° C. When the glass transition temperature is less than 50 ° C., it is suitable for favorably maintaining the shape of the core particle while imparting elasticity to the core particle. The glass transition temperature is preferably more than 0 ° C., more preferably 10 ° C. or more. When the glass transition temperature is higher than 0 ° C., elasticity is imparted to the core particles, and deterioration of cycle characteristics due to expansion or contraction of the active material or the like is prevented.

The glass transition temperature (Tg) is a value measured under the following conditions using a differential scanning calorimeter “X-DSC7000” (manufactured by SII Nanotechnology). The measurement is performed twice for the same sample, and the second measurement result is adopted.
<Condition>
・ Atmosphere in measurement chamber: Nitrogen (50 mL / min)
・ Raising rate: 5 ° C / min
Measurement start temperature: -100 ° C
-Measurement end temperature: 200 ° C
・ Sample pan: Aluminum pan ・ Measurement sample mass: 5 mg
-Calculation of Tg: Tg was calculated by rounding off the decimal point of the intermediate temperature between the lowering start point and the lowering end point of the DSC chart.

-Second particles having a polyurea structure-
The organic particles (A) have a plurality of second particles (polyurea colloid particles) having a polyurea structure on the surface of the core particles.
The second particles are obtained as colloidal polyurea particles during the synthesis process, and are used as an emulsifier during the synthesis of the organic particles (A).

  As shown in FIG. 1, the polyurea colloid particles in the solvent have a structure in which a lipophilic part 21 such as a long-chain alkyl group having 6 or more carbon atoms is bonded to the urea hydrogen bond part 22 in a colloidal state. Is presumed to be formed. Regarding the control of the particle size of the polyurea colloidal particles, the size of the whole particle including the structural part that solvates with the hydrocarbon solvent and the urea domain that is the non-solvated structural part, the structural part that solvates with the hydrocarbon solvent. And the urea domain, which is a structural portion that does not solvate, can be controlled.

The polyurea colloidal particles have a structural part (solvated part) that is solvated with respect to the hydrocarbon solvent and a structural part that is not solvated (non-solvated part). The polyurea colloidal particles are preferably particles having a long-chain alkyl group having 6 or more carbon atoms. Such particles can be obtained, for example, by reacting a diol compound having a long-chain alkyl group having 6 or more carbon atoms (so-called lipophilic diol), an isocyanate compound, and an amine compound in a non-aqueous medium. . That is, a structural portion solvated with a hydrocarbon solvent such as a long-chain alkyl group having 6 or more carbon atoms can be imparted to the particles. In place of the lipophilic diol and the isocyanate compound, a terminal NCO prepolymer comprising these compounds may be reacted.
On the other hand, as the reaction proceeds, hydrogen bonds between urea bonds form insoluble urea domains in the medium, and at the same time, hydrophobic long-chain alkyl groups of lipophilic diols are solvated in the medium. The polyurea colloidal particles are prevented from becoming enormous due to aggregation of non-soluble urea domains, and stable polyurea colloidal particles can be easily obtained.

  The structure that solvates with the hydrocarbon solvent that forms the polyurea colloidal particles exists in the outermost layer of the organic particles (A). It is also preferable to have a carbon-carbon unsaturated bond in the structure solvated with a hydrocarbon solvent for the purpose of binding the organic particles (A) to other particles. Specifically, it is preferable that the long-chain alkyl group having 6 or more carbon atoms has a carbon-carbon unsaturated bond, and further it does not have a polar group. Examples of such a substituent include a vinyl group, an allyl group, and an ethynyl group.

The volume average particle diameter of the non-solvated portion of the second particle is preferably in the range of 0.01 μm to 1.0 μm, and more preferably in the range of 0.05 μm to 0.5 μm.
The volume average particle diameter is a value measured with a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA).

  Furthermore, the lipophilic diol has low crystallinity in a non-aqueous medium, and the polymer chain mainly composed of the lipophilic diol can move freely to some extent in the process of polymerization, which occurs as the reaction proceeds. Separation of the non-soluble crystalline portion and the soluble non-crystalline portion is easily performed. Aggregates (urea hydrogen bond portions 22 in FIG. 1) formed by hydrogen bonds between urea bonds correspond to non-soluble crystal parts, and are formed as urea domains having the non-soluble crystal parts as the center of the particles. Hydrophobic groups (for example, long-chain alkyl groups having 6 or more carbon atoms) solvated around the non-soluble crystal portion are regularly oriented toward the outside of the particles (lipophilic portion 21 in FIG. 1). This is a fundamentally different action from the surfactant in the known method for producing colloidal particles obtained by polymerization under conventional micelles.

The method for producing polyurea colloidal particles will be described more specifically.
First, a lipophilic diol and an isocyanate compound are reacted in a non-aqueous medium or without a solvent to synthesize a prepolymer having an isocyanate group (NCO group). Next, the synthesized prepolymer is charged into a jacket-type synthesis kettle equipped with a stirrer, and a hydrocarbon solvent (inert liquid) is added to adjust the concentration so that the concentration becomes 5 mass% to 70 mass%. . While stirring this solution, a solution of an amine compound adjusted to a concentration of 2% by mass to 20% by mass in advance is gradually added and reacted to produce polyurea colloidal particles by polyureaization reaction.

In addition to the above method, the method of adding the amine compound solution may be a method of adding a prepolymer or a prepolymer solution to the amine solution.
The synthesis temperature at the time of polymer synthesis is not particularly limited, and is preferably 30 ° C to 120 ° C. In the synthesis of the polymer, the reaction concentration, temperature, stirrer form, stirring power, amine solution and prepolymer or addition rate of the solution are not particularly limited, but the reaction between the amine compound and the isocyanate group of the prepolymer is fast, It is preferable to control the reaction so that a rapid reaction is not performed.

The lipophilic diol used for the production of the polyurea colloidal particles is a polyol having a functional group of 2 or less, and a preferred molecular weight is 700 or more and less than 5000. However, the lipophilic diol is not limited to this. Specific examples of the lipophilic diol include about 2 fats and oils by a method of alcoholyzing various fats and oils with a lower alcohol or glycol, a method of partially saponifying fats and oils, a method of esterifying a hydroxyl group-containing fatty acid with glycols, etc. Those containing the following hydroxyl groups, or J.I. H. SAUNDERS, K.A. C. Examples include oil-modified polyols, terminal alcohol-modified acrylic resins, terminal alcohol-modified polyesters, and the like described in FRISCH's POLYURETHANES, CHEMISTRY ANDTECHNOLOGY PART1, Chemistry (p. 48-53, 1962).
Among the above, examples of the hydroxyl group-containing fatty acid include ricinoleic acid, 12-hydroxystearic acid, castor oil fatty acid, hydrogenated castor oil fatty acid, and the like.
Examples of the terminal alcohol-modified acrylic resin include a polymer of a long-chain alkyl (meth) acrylate using thioglycerol as a chain transfer agent. As the long-chain alkyl (meth) acrylate, one or more alkyl (meth) acrylates having 6 to 30 carbon atoms are suitable, and more preferably 8 to 25 carbon atoms (most preferably carbon number). 10 to less than 20) alkyl (meth) acrylate. Specific examples include hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (Meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, stearyl (meth) acrylate, benzyl methacrylate and the like can be mentioned.

The reaction between the lipophilic diol and the isocyanate compound is carried out so that the number of isocyanate groups (NCO) relative to the number of hydroxyl groups (OH) satisfies the condition shown in the following formula 1, and the molecular weight of the solvated prepolymer chain is adjusted. To do.
1 <“NCO / OH” ≦ 2 (Formula 1)
The molecular weight of the prepolymer chain thus synthesized is not particularly limited, and a preferred range is about 500 to 15000.

  As the isocyanate compound, all known isocyanate compounds can be applied, and particularly preferably aliphatic such as hexamethylene diisocyanate, water-added toluene diisocyanate (water-added TDI), water-added diphenylmethane diisocyanate (water-added MDI), isophorodiisocyanate or the like. It is an alicyclic diisocyanate compound.

As the non-aqueous medium used for producing the polyurea colloidal particles, any non-aqueous solvent that dissolves the lipophilic diol, the diisocyanate compound, and the amine compound, which are raw materials, and does not have active hydrogen can be used. Particularly preferred non-aqueous media are hydrocarbon solvents such as hexane, heptane, octane, decane, cyclohexane, toluene, and xylene.
A non-aqueous medium may be used individually by 1 type, and may mix 2 or more types.
In the present disclosure, “dissolution” includes both dissolution at normal temperature and high temperature.

  Examples of amine compounds used for the production of polyurea colloidal particles include ethylenediamine, diaminopropane, diaminobutane, hexamethylenediamine, trimethylhexamethylenediamine, N-aminoethylpiperazine, bis-aminopropylpiperazine, polyoxypropylenediamine, 4, 4-diaminodicyclohexylmethane, isophoronediamine, thiourea, methyliminobispropylamine and the like can be mentioned. An amine compound may be used individually by 1 type, and may be used as a mixture which mixed 2 or more types.

  The type, use amount and use ratio of the lipophilic diol, isocyanate compound, amine compound and the resulting prepolymer used in the production of the polyurea colloid particles are the size and stability of the polyurea colloid particles in the solvent used. Determined for control purposes. That is, the polyurea colloidal particles are formed by urea domains (crystal parts) that are not solvated in the non-aqueous medium, and polymer chains that extend from the urea domain and are solvated in the non-aqueous medium.

The nature of the polyurea colloidal particles depends on the size of the urea domains of the polyurea colloidal particles and the size and morphology of the solvated polymer chains.
The polyurea colloidal particles formed of the urea domain, the hydrocarbon solvent, and the solvating structural part (polymer chain) are obtained as a polyurea colloid dispersion liquid stably dispersed in a non-aqueous medium. The volume average particle diameter of the urea domain in the polyurea colloidal particles in the dispersion is usually 0.01 μm to 1.0 μm. The molecular weight of one of the structural parts (polymer chains) solvated with the hydrocarbon solvent is about 500-15000.
The mass ratio of urea domain to polymer chain (urea domain (urea bond or amine compound) / polymer chain) is preferably in the range of 0.5 to 30. If the ratio of urea bonds is at least the lower limit of the above range, non-solvating urea domains in the polyurea colloid particles are likely to be formed, and the polyurea colloid particles are difficult to dissolve in a non-aqueous medium. Easy to generate. On the other hand, if the ratio of urea bonds is less than or equal to the upper limit of the above range, the urea domain does not become too large, the stability of the resulting polyurea colloid particles is maintained, and aggregation of the polyurea colloid particles is suppressed.
The particle diameter in the dispersion of polyurea colloidal particles represents the diameter (length A in FIG. 1) of the urea domain (particulate crystal portion shown in FIG. 1).

  As described above, the dispersion of the polyurea colloidal particles looks from blue opalescence to yellowish opalescence due to light confusion. A solution obtained by drying and solidifying a dispersion of polyurea colloidal particles can be easily redispersed in a hydrocarbon solvent having a relatively low dissolving power to obtain a dispersion of polyurea colloidal particles having an arbitrary concentration. In addition, when the polyurea colloidal particle dispersion is dried and solidified, it is almost soluble in polar solvents such as dimethylformamide, formamide, cymethyl sulfoxide, methyl ethyl ketone, and butyl acetate, and has low solubility as described above. By adding and mixing an appropriate amount of a non-aqueous solvent, urea bonds in the polymer are precipitated and crystallized to form urea domains that are not solvated, whereby a polyurea colloidal dispersion can be obtained.

  In order to produce a dispersion of polyurea colloidal particles controlled to a stable dispersion state, as shown in FIG. 1, a structure portion (polymer chain) solvated with a nonaqueous solvent (particularly a hydrocarbon solvent), a solvent, It is desirable that the urea domain, which is a structure part (crystal part) that is not summed, is clearly phase-separated. In order to clearly separate the phases, it is necessary to manufacture so that a non-aqueous solvent (particularly a hydrocarbon solvent) and a solvated structure part and a non-solvated structure part (crystal part) are not mixed with urea domains. is important. For this purpose, a synthesis condition is required in which the non-aqueous solvent (particularly hydrocarbon solvent) and the solvated structural part and the urea domain, which is a non-solvated structural part, can be easily separated in the synthesis process.

The synthesis of the polyurea colloidal particles gives better results as the concentrations of both the prepolymer solution having an NCO group and the amine compound solution are lower and the addition rate of adding the other solution to one solution is slower. For the stirring, propeller mixer stirring is sufficient. Further, when the concentration of the raw material solution is high or when the addition rate of the solution is high, it is preferable to synthesize while mixing with a high shearing force by using a homogenizer or the like. The reaction temperature is determined by the type of the non-aqueous solvent used and the solubility of the urea domain in the non-aqueous solvent, and the preferred temperature is 30 ° C. to 120 ° C. in that the synthesis can be easily controlled. However, the temperature is not particularly limited to the above range.
The formation of the urea domain may be a method of forming in the synthesis process, or a method of forming the urea domain in the cooling process of the one synthesized at a high temperature.

The important factors in the polyurea colloidal particles are the type and concentration of the surface groups of the particles, and further the dispersibility and the dispersed particle size in an inert liquid. That is, the action of the polyurea colloidal particles as an emulsifier is as follows: a water-in-oil (W / O) type emulsifier in which water droplets are dispersed in oil; Depending on the correlation between the strength of hydrophilicity and hydrophobicity of the isocyanate compound and the compound having active hydrogen, and the inert liquid.
As a result of adding consideration to these conditions, it is possible to control the particle size of the polyurethane particles by adjusting the amount of polyurea colloid particles added to the polyisocyanate compound and the compound having active hydrogen. The larger the amount added in the range, the smaller the particle size, and the smaller the amount, the larger the particle size.

The glass transition temperature of the second particles of the organic particles gives flexibility and adherence between the solid particles, between the layers containing the solid particles, or between the layer containing the solid particles and the current collector during battery production. It is preferable that it is lower than the glass transition temperature of the first particles described above from the viewpoint of improving the interface adhesion.
The glass transition temperature of the second particles is preferably less than 0 ° C, and more preferably less than -20 ° C. When the glass transition temperature is less than 0 ° C., a flexible structural portion (preferably a long-chain alkyl moiety) is imparted to the surface of the core particle, and adhesion is improved. The glass transition temperature of the second particles is preferably −100 ° C. or higher, more preferably −70 ° C. or higher. When the glass transition temperature is −70 ° C. or higher, handleability is easily maintained.
The glass transition temperature (Tg) is a value measured by the same method as described above.

A solid electrolyte composition can be obtained by adding an inorganic solid electrolyte to an organic particle dispersion containing organic particles obtained from the raw materials as described above.
In addition, as described above, organic particles can also be obtained by separating a hydrocarbon solvent under a normal pressure or a reduced pressure from a dispersion of organic particles obtained from a raw material. A solid electrolyte composition can also be obtained by redispersing organic particles in a dispersion medium and adding an inorganic solid electrolyte thereto.

As an apparatus used for particle formation, known apparatuses such as a spray dryer, a vacuum dryer with a filtration device, a vacuum dryer with a stirring device, and a shelf dryer can be used.
The preferred drying temperature is influenced by the vapor pressure of the inert liquid, the softening temperature of the polyurethane particles, the particle size, etc., but is preferably 40 ° C. to 80 ° C. under reduced pressure.

The organic particles produced as described above are preferably spherical. Being a true sphere can be grasped by magnifying the shape of the particulate crystal portion shown in FIG. The true sphere indicates a sphere, and includes not only a case where the sphere is a perfect sphere but also a case where the sphere is a substantially sphere that can be grasped at a glance.
The volume average particle diameter of the organic particles is preferably in the range of 0.1 μm to 100 μm, and more preferably in the range of 0.5 μm to 25 μm.
The volume average particle diameter is a value measured with a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA).
The volume average particle size depends on the emulsification type of the synthetic kettle (propeller type, vertical type, homogenizer, spiral band type, etc.) and the magnitude of the stirring force, but in particular a compound having an isocyanate compound and active hydrogen in a non-aqueous solvent It is influenced by the concentration of polyurea, the type of polyurea colloidal particles and the amount added.
The mechanical stirring or shearing force for emulsifying the isocyanate compound and the compound having active hydrogen is determined in the initial stage of emulsification. The stronger the mechanical stirring or shearing force, the smaller the particle size of the dispersion. Subsequent stirring and shearing forces do not have a significant effect, and if the mechanical stirring or shearing force is too strong, aggregation of the dispersions may be promoted.

  The content of the organic particles in the solid electrolyte composition is preferably 0.01 parts by mass or more and 0.1 parts by mass with respect to 100 parts by mass of the inorganic solid electrolyte (including this when an active material is used). More preferably, it is more than 0.5 part by weight. Further, the content of the organic particles is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less.

The content of the organic particles in the solid electrolyte composition is preferably 0.01% by mass or more and more preferably 0.1% by mass or more with respect to the solid content of the solid electrolyte composition. Preferably, it is 0.5 mass% or more. Further, the content of the organic particles is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less.
When the content of the organic particles is within the above range, the binding property of the inorganic solid electrolyte and the effect of suppressing the interface resistance can be further improved.

  In addition to the specific organic particles described above, other binders and various additives may be used in combination in the solid electrolyte composition.

-Inorganic solid electrolyte (B)-
The solid electrolyte composition of one embodiment of the present invention contains at least one inorganic solid electrolyte. The inorganic solid electrolyte is not particularly limited as long as it has conductivity of ions of metals belonging to Group 1 or Group 2 of the periodic table, and generally does not have electron conductivity.
The inorganic solid electrolyte refers to an inorganic solid electrolyte, and the solid electrolyte is a solid that can move ions inside the electrolyte.

Since inorganic solid electrolytes do not contain organic substances (that is, carbon atoms), they are represented by organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), etc. It is clearly distinguished from the organic electrolyte salt).
Further, since the inorganic solid electrolyte is solid in a steady state, the cation and the anion are not dissociated or released, and the inorganic electrolyte salt (LiPF ₆ , LiBF ₄ , LiFSI, LiCl, etc.) are also clearly distinguished.

  The inorganic solid electrolyte having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table can be appropriately selected from solid electrolyte materials commonly used in the field of secondary batteries using solid electrolytes. . Preferred examples of the inorganic solid electrolyte include (i) a sulfide-based inorganic solid electrolyte and (ii) an oxide-based inorganic solid electrolyte.

(I) Sulfide-based inorganic solid electrolyte The sulfide-based inorganic solid electrolyte contains sulfur (S) and has conductivity of ions of metals belonging to Group 1 or Group 2 of the periodic table. Should be selected. The sulfide-based inorganic solid electrolyte may have an electronic insulating property.
Examples of the sulfide-based inorganic solid electrolyte include a lithium ion conductive inorganic solid electrolyte having a composition represented by the following formula (1).
_{Li a M b P c S d} A e ··· (1)
In the formula (1), M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, and Ge. Among these, M is preferably B, Sn, Si, Al and Ge, and more preferably Sn, Al and Ge. A represents I, Br, Cl or F, I and Br are preferred, and I is particularly preferred.
a, b, c, d and e each independently represent a composition ratio of each element, and a: b: c: d: e is 1-12: 0 to 1: 1: 2 to 12: 0. 5 is satisfied.
Furthermore, a is preferably 1 to 9, and more preferably 1.5 to 4. b is preferably 0 to 0.5. d is preferably 3 to 7, and more preferably 3.25 to 4.5. e is preferably from 0 to 3, and more preferably from 0 to 2.

  In the formula (1), the composition ratio of Li, M, P and S is preferably b = e = 0. That is, an inorganic solid electrolyte of lithium / phosphorous sulfide type (hereinafter also referred to as Li / P / S type) is preferable. More preferable composition ratios of Li, M, P and S are b = e = 0, and the composition ratios of a, c and d (a: c: d) are a: c: d = 1 to 9: 1: 3 to 7, more preferably b = e = 0 and a: c: d = 1.5 to 4: 1: 3.25 to 4.5.

  The composition ratio of each element in the formula (1) can be controlled by adjusting the blending amount of the raw material compound when producing the sulfide-based inorganic solid electrolyte as described below.

  The sulfide-based inorganic solid electrolyte may be amorphous (glass), crystallized (glass ceramics), or only partially crystallized. Among these, Li / P / S glass and Li / P / S glass ceramic are preferable.

Among sulfide-based inorganic solid electrolytes, glass-like sulfide-based inorganic solid electrolytes are preferable, glass-ceramic sulfide-based inorganic solid electrolytes are preferable, because lithium ion conductivity is excellent. A phosphide-based glass-ceramic solid electrolyte is preferred.
The “glass ceramics-like sulfide-based inorganic solid electrolyte” refers to a sulfide-based inorganic solid electrolyte having a structure in which a part of an amorphous structure is crystallized.
The lithium-phosphorous sulfide-based electrolyte includes [1] lithium sulfide (Li ₂ S) and diphosphorus pentasulfide (P ₂ S ₅ ), [2] lithium sulfide and at least one of elemental phosphorus and elemental sulfur, or [3]. It can be produced by the reaction of lithium sulfide, diphosphorus pentasulfide, simple phosphorus and simple sulfur.

The ratio of Li ₂ S to P ₂ S _{5 in the} Li / P / S glass and Li / P / S glass ceramic is a molar ratio of Li ₂ S: P ₂ S ₅ , preferably 65:35 to 35:35. 85:15, more preferably 68:32 to 75:25. By setting the ratio of Li ₂ S to P ₂ S ₅ within this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity can be preferably 1 × 10 ⁻⁴ S / cm or more, and more preferably 1 × 10 ⁻³ S / cm or more. The upper limit is not particularly limited, but is practically 1 × 10 ⁻¹ or less.

Specific examples of the compound include a solid electrolyte using a raw material composition containing Li ₂ S and a sulfide of an element belonging to Group 13 to Group 15.
Specifically, Li ₂ S / P ₂ S ₅ , Li ₂ S / LiI / P ₂ S ₅ , Li ₂ S / LiI / Li ₂ O / P ₂ S ₅ , Li ₂ S / LiBr / P ₂ S ₅ Li ₂ S / Li ₂ O / P ₂ S ₅ , Li ₂ S / Li ₃ PO ₄ / P ₂ S ₅ , Li ₂ S / P ₂ S ₅ / P ₂ O ₅ , Li ₂ S / P ₂ S ₅ / SiS ₂ , Li ₂ S / P ₂ S ₅ / SnS, Li ₂ S / P ₂ S ₅ / Al ₂ S ₃ , Li ₂ S / GeS ₂ , Li ₂ S / GeS ₂ / ZnS, Li ₂ S / Ga ₂ S ₃ , Li ₂ S / GeS ₂ / Ga ₂ S ₃ , Li ₂ S / GeS ₂ / P ₂ S ₅ , Li ₂ S / GeS ₂ / Sb ₂ S ₅ , Li ₂ S / GeS ₂ / Al ₂ S _{3, Li 2 S / SiS 2} , Li 2 S / Al 2 S 3, Li 2 S / SiS 2 / Al _{S 3, Li 2 S / SiS} 2 / P 2 S 5, Li 2 S / SiS 2 / P 2 S 5 / LiI, Li 2 S / SiS 2 / LiI, Li 2 S / SiS 2 / Li 4 SiO 4, Examples include Li ₂ S / SiS ₂ / Li ₃ PO ₄ , Li ₁₀ GeP ₂ S _{12, and the} like. Among them, Li ₂ S / P ₂ S ₅ , Li ₂ S / GeS ₂ / Ga ₂ S ₃ , Li ₂ S / LiI / P ₂ S ₅ , Li ₂ S / LiI / Li ₂ O / P ₂ S ₅ , Li ₂ S / GeS ₂ / P ₂ S ₅ , Li ₂ S / SiS ₂ / P ₂ S ₅ , Li ₂ S / SiS ₂ / Li ₄ SiO ₄ , Li ₂ S / SiS ₂ / Li ₃ PO _4, Li ₂ A solid electrolyte composed of S / Li ₃ PO ₄ / P ₂ S ₅ , Li ₂ S / GeS ₂ / P ₂ S ₅ , and Li ₁₀ GeP ₂ S ₁₂ is preferable. A raw material composition selected from the crystalline raw material composition and the amorphous raw material composition as described above is preferable because it has high lithium ion conductivity.

  Examples of a method for synthesizing a sulfide solid electrolyte material using the raw material composition as described above include an amorphization method. Examples of the amorphization method include a mechanical milling method and a melt quenching method, and among them, the mechanical milling method is preferable. The mechanical milling method is preferable in that processing at normal temperature is possible and the manufacturing process can be simplified.

(Ii) Oxide-based inorganic solid electrolyte An oxide-based inorganic solid electrolyte contains oxygen (O) and has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table. Just choose. The oxide-based inorganic solid electrolyte may have an electronic insulating property.

Specific compound _examples, Li _x La y TiO ₃ [x = 0.3~0.7, y = 0.3~0.7] _{(LLT), Li x La y} Zr z M m O n ( M is at least one element selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, x satisfies 5 ≦ x ≦ 10, and y satisfies 1 ≦ y ≦. 4 was filled, z satisfies 1 ≦ z ≦ 4, m satisfies 0 ≦ z ≦ 2, n satisfies _{5 ≦ x ≦ 20.),} Li x B y M z O n (M is C, S , Al, Si, Ga, Ge, In, and Sn, x satisfies 0 ≦ x ≦ 5, y satisfies 0 ≦ y ≦ 1, and z satisfies 0 ≦ z ≦ 1. the filled, n represents satisfy _{0 ≦ x ≦ 6.),} Li x (Al, Ga) y (Ti, Ge) z Si a P m O n ( where, 1 ≦ x ≦ 3,0 ≦ y 1,0 ≦ z ≦ 2,0 ≦ a ≦ 1,1 ≦ m ≦ 7,3 ≦ n ≦ 13), Li (3-2x) M x DO (x is a number from 0 to 0.1, M represents a divalent metal atom, D represents a halogen atom or a combination of two or more halogen atoms), Li _x Si _y O _z (1 ≦ x ≦ 5, 0 <y ≦ 3, 1 ≦ z) ≦ 10), Li _x S _y O _z (1 ≦ x ≦ 3, 0 <y ≦ 2, 1 ≦ z ≦ 10), Li ₃ BO ₃ —Li ₂ SO ₄ , Li ₂ O—B ₂ O ₃ —P ₂ O ₅ , Li ₂ O—SiO ₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _{(4-3 / 2w)} N _w (w is w <1), LISICON (Lithium super ionic conductor) type crystal structure _Li 3.5 _Zn 0.25 GeO ₄ having, having a perovskite crystal structure _{La 0.55 Li 0.35 TiO 3, NASICON} (Natrium super ionic conductor) type LiTi ₂ P ₃ O ₁₂ having a crystal _{structure, Li 1 + x + y (} Al, Ga) x (Ti, Ge) 2-x Si y P 3 _-y O ₁₂ (where, 0 ≦ x ≦ 1,0 ≦ y ≦ 1), Li 7 La 3 Zr 2 O 12 or the like having a garnet-type crystal structure.
A phosphorus compound containing Li, P and O is also desirable. For example, lithium phosphate (Li ₃ PO ₄ ), LiPON obtained by substituting part of oxygen of lithium phosphate with nitrogen, LiPOD (D is Ti, V, And at least one selected from Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, Au, and the like.
LiAON (A is at least one selected from Si, B, Ge, Al, C, Ga and the like) and the like can also be preferably used.

Among _them, Li _x La y TiO ₃ [x = 0.3~0.7, y = 0.3~0.7] _{(LLT), Li x La y} Zr z M m O n (M is Al, Mg, It is at least one element of Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, x satisfies 5 ≦ x ≦ 10, y satisfies 1 ≦ y ≦ 4, and z is 1 ≦ z ≦ 4, m satisfies 0 ≦ z ≦ 2, n satisfies 5 ≦ x ≦ 20), Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ), Li ₃ BO ₃ , Li ₃ BO _{3 -Li 2 SO 4, Li x} (Al, Ga) y (Ti, Ge) z Si a P m O n ( where, 1 ≦ x ≦ 3,0 ≦ y ≦ 1,0 ≦ z ≦ 2,0 ≦ a ≦ 1, 1 ≦ m ≦ 7, 3 ≦ n ≦ 13) are preferred. These may be used alone or in combination of two or more.

The ionic conductivity of the oxide-based inorganic solid electrolyte is preferably 1 × 10 ⁻⁶ S / cm or more, more preferably 5 × 10 ⁻⁶ S / cm or more, and 1 × 10 ⁻⁵ S. / Cm or more is particularly preferable.

The ion conductivity is measured in the film thickness direction by measuring AC impedance at a voltage amplitude of 5 mV and a frequency of 1 MHz to 1 Hz using a 1255 BF REQUENCY RESPONSE ANALYZER (manufactured by SOLARTRON) for a solid electrolyte layer formed with a predetermined thickness. Is a value (mS / cm) calculated by the following formula. The measurement is performed in a constant temperature bath at 30 ° C.
Ionic conductivity = 1000 × layer thickness (cm) / (resistance (Ω) × layer area (cm ² ))

Among these, it is preferable to use a sulfide-based or oxide-based inorganic solid electrolyte.
Inorganic solid electrolytes generally have a higher hardness and are likely to cause an increase in interfacial resistance in all solid state secondary batteries. Therefore, by using a composition using specific organic particles as described above, one embodiment of the present invention is used. The effect by appears more prominently.

  In the solid electrolyte composition, one inorganic solid electrolyte may be used alone, or two or more inorganic solid electrolytes may be used in combination.

The inorganic solid electrolyte may be used in the form of particles. In this case, the volume average particle diameter of the inorganic solid electrolyte is not particularly limited and is preferably 0.01 μm or more, more preferably 0.1 μm or more. Further, the volume average particle size of the inorganic solid electrolyte is preferably 100 μm or less, and more preferably 50 μm or less.
The volume average particle diameter is a value measured with a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA).

The concentration of the inorganic solid electrolyte in the solid electrolyte composition is preferably 5% by mass or more in 100% by mass of the solid component in consideration of both the battery performance and the effect of reducing and maintaining the interface resistance. It is more preferably 10% by mass or more, and particularly preferably 20% by mass or more. From the same viewpoint, the concentration of the inorganic solid electrolyte is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and particularly preferably 99.0% by mass or less.
However, when using an inorganic solid electrolyte with a positive electrode active material or a negative electrode active material, it is preferable that the sum total is the said density | concentration range.

-Dispersion medium (C)-
The solid electrolyte composition may contain a dispersion medium in which each of the above components is dispersed.
Examples of the dispersion medium include hydrocarbon solvents.
Examples of hydrocarbon solvents include pentane, hexane, heptane, octane, decane, petroleum ether, petroleum benzine, ligroin, petroleum spirit, cyclohexane, methylcyclohexane, toluene, xylene and other hydrocarbons, dimethylpolysiloxane, and other inert solvents. Liquid.
In addition, alcohol compound solvents, ether compound solvents, amide compound solvents, ketone compound solvents, aromatic compound solvents, aliphatic compound solvents, nitrile compound solvents, and the like are also preferable dispersion media.

Examples of the alcohol compound solvent include methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol, Examples include 2-methyl-2,4-pentanediol, 1,3-butanediol, 1,4-butanediol and the like.
Examples of the ether compound solvent include alkylene glycol (diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol and the like), alkylene glycol alkyl ether (ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, Propylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, etc.), dimethyl ether, diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, dimethoxyethane, 1, 4 Dioxane.

Examples of the amide compound solvent include N, N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε-caprolactam, formamide, N -Methylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide and the like.
Examples of the ketone compound solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, diisopropyl ketone, diisobutyl ketone, and cyclohexanone.
Examples of the aromatic compound solvent include benzene, toluene, xylene, chlorobenzene, dichlorobenzene, and the like.
Examples of the aliphatic compound solvent include hexane, heptane, octane, decane, dodecane, and the like.
Examples of the nitrile compound solvent include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile and the like.

  Among these, it is preferable to use an ether compound solvent, a ketone compound solvent, an aromatic compound solvent, or an aliphatic compound solvent, and it is more preferable to use an aromatic compound solvent or an aliphatic compound solvent. In the present disclosure, since it is preferable that the organic particles maintain their shape as particles in the solid electrolyte composition, a solvent having low solubility in the organic particles or a solvent that does not dissolve the organic particles is preferable. From this viewpoint, an aliphatic compound solvent is most preferable.

The dispersion medium preferably has a boiling point of 50 ° C. or higher, more preferably 80 ° C. or higher, under normal pressure (1 atm). The boiling point under normal pressure (1 atm) is preferably 250 ° C. or lower, and more preferably 220 ° C. or lower.
A dispersion medium may be used individually by 1 type, and may be used in combination of 2 or more type.
The ratio of the dispersion medium to the inorganic solid electrolyte (B) is preferably in the range of 10% by mass to 1000% by mass, and more preferably 30% by mass to 200% by mass from the viewpoint of appropriate dispersion stability and coating viscosity. A range is preferred.
Further, the content of the dispersion medium in the solid electrolyte composition can be set to an arbitrary amount in consideration of the balance between the viscosity of the solid electrolyte composition and the drying load. Generally, it is preferable that content in the solid electrolyte composition of a dispersion medium is 20 mass%-99 mass% with respect to the total mass of a solid electrolyte composition.

(Lithium salt (E))
The solid electrolyte composition may contain a lithium salt as long as the effect of the embodiment of the present invention is not impaired. As the lithium salt, a lithium salt generally used in a secondary battery can be suitably used, and specific examples thereof include the following compounds.

(L-1) Inorganic lithium salt:
For example, inorganic fluoride salts such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ ; perhalogenates such as LiClO ₄ , LiBrO ₄ , LiIO ₄ ; inorganic chloride salts such as LiAlCl ₄ .
(L-2) Fluorine-containing organic lithium salt:
For example, perfluoroalkane sulfonates such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ( Perfluoroalkanesulfonylimide salts such as C ₄ F ₉ SO ₂ ); perfluoroalkanesulfonylmethide salts such as LiC (CF ₃ SO ₂ ) ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [ PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₃ ) ₃ ], Li [PF ₅ (CF ₂ CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₂ CF ₃ ) ₃ ], etc.
(L-3) Oxalatoborate salt:
For example, lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.

Among the above, lithium salts include LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , Li (Rf ¹ SO ₃ ), LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN ( Rf ¹ SO ₂ ) (Rf ² SO ₂ ) is preferred, LiPF ₆ , LiBF ₄ , LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) More preferred is a lithium imide salt such as.
Rf ¹ and Rf ² each independently represent a perfluoroalkyl group, and examples thereof include CF ₃ , CF ₃ CF ₂ , and C ₄ F ₉ .

The preparation of the solid electrolyte composition includes the steps of preparing the organic particles (A) as described above, the prepared organic particles (A), and ions of metals belonging to Group 1 or Group 2 of the periodic table. And a step of mixing the conductive inorganic solid electrolyte (B).
Mixing is not limited in the method, for example, a homogenizer (for example, a high-pressure homogenizer, a rotary homogenizer, an ultrasonic homogenizer, etc.), a mill (for example, a bead mill, a ball mill, a tower mill, a three roll mill), a mixer (for example, a planetary mixer, A disper mixer, a hensil mixer, a kneader, a CLEARMIX, a self-revolving mixer (stirring deaerator), etc. can be used.
For mixing, a dispersion medium used for dispersing the object to be dispersed, such as beads or balls, may be used. For example, known beads such as glass beads and zirconia beads can be appropriately selected.
Moreover, when mixing an organic particle (A) and an inorganic solid electrolyte (B), you may mix an organic particle (A) and an inorganic solid electrolyte (B) with a dispersion medium, and mix using a dispersion medium.

(Positive electrode active material)
Next, the positive electrode active material used for the positive electrode composition of the all solid state secondary battery will be described.
The positive electrode active material is preferably one that can reversibly insert and release lithium ions. There is no restriction | limiting in particular as a material of a positive electrode active material, The element etc. which can be combined with Li, such as transition metal oxide or sulfur, may be sufficient. Among them, as the positive electrode active material, it is preferable to use a transition metal oxide, and a transition metal having a transition metal element M ^a (one or more elements selected from Co, Ni, Fe, Mn, Cu, and V). Oxides are more preferred. Transition metal oxides include mixed elements M ^b (metals other than lithium, elements of Group 1 (Ia) of the periodic table, elements of Group 2 (IIa), Al, Ga, In, Ge, and Sn. , Pb, Sb, Bi, Si, P, B, etc.) may be mixed.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt structure, (MB) a transition metal oxide having a spinel structure, (MC) a lithium-containing transition metal phosphate compound, (MD And lithium-containing transition metal halide phosphate compounds, (ME) lithium-containing transition metal silicate compounds, and the like.

(MA) Transition metal oxide having a layered rock salt structure As specific examples of the transition metal oxide having a layered rock salt structure, LiCoO ₂ (lithium cobaltate [LCO]), LiNi ₂ O ₂ (lithium nickelate), LiNi _0.85 Co _0.10 Al _0.05 O ₂ (nickel cobalt lithium aluminum oxide [NCA]), LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (nickel manganese lithium cobalt oxide [NMC]), LiNi _0.5 Mn _0.5 O ₂ (lithium manganese nickelate) may be mentioned.
(MB) Transition metal oxide having a spinel structure As specific examples of the transition metal oxide having a spinel structure, LiCoMnO _4, Li ₂ FeMn ₃ O ₈ , Li ₂ CuMn ₃ O ₈ , Li ₂ CrMn ₃ O _{8 ,} Li ₂ NiMn ₃ O ₈ .
(MC) Lithium-containing transition metal phosphate compound Examples of the lithium-containing transition metal phosphate compound include olivine-type phosphate iron salts such as LiFePO ₄ and Li ₃ Fe ₂ (PO ₄ ) ₃ , and pyrroline such as LiFeP ₂ O _7. Examples thereof include iron phosphates, cobalt phosphates such as LiCoPO ₄ , and monoclinic Nasicon type vanadium phosphate salts such as Li ₃ V ₂ (PO ₄ ) ₃ (vanadium lithium phosphate).
(MD) as the lithium-containing transition metal halogenated phosphoric acid compound containing lithium transition metal halogenated phosphate compound, for _example, Li 2 FePO ₄ fluorophosphate iron salt such as _F, Li 2 MnPO ₄ F fluoride such as phosphorus Examples thereof include cobalt phosphates such as an acid manganese salt and Li ₂ CoPO ₄ F.
(ME) Lithium-containing transition metal silicate compound Examples of the lithium-containing transition metal silicate compound include Li ₂ FeSiO ₄ , Li ₂ MnSiO ₄ , and Li ₂ CoSiO ₄ .

The volume average particle diameter (sphere conversion average particle diameter) of the positive electrode active material used in the all-solid secondary battery is not particularly limited, and is preferably 0.1 μm to 50 μm.
In order to adjust the positive electrode active material to a predetermined particle diameter, a conventionally known pulverizer or classifier may be used. You may use the positive electrode active material obtained by the baking method, after wash | cleaning with water, acidic aqueous solution, alkaline aqueous solution, and an organic solvent.
The volume average particle diameter (sphere conversion average particle diameter) of the positive electrode active material is a value measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA).

  There is no restriction | limiting in particular in the density | concentration of a positive electrode active material, 10 mass%-90 mass% are preferable with respect to 100 mass% of solid components of the composition for positive electrodes, and 20 mass%-80 mass% are more preferable.

  A positive electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, you may make a positive electrode active material layer contain a conductive support agent as needed.

(Negative electrode active material)
Next, the negative electrode active material used for the negative electrode composition of the all-solid-state secondary battery will be described.
As the negative electrode active material, those capable of reversibly inserting and releasing lithium ions are preferable. The material of the negative electrode active material is not particularly limited, and is a carbonaceous material, a metal oxide such as tin oxide and silicon oxide, a metal composite oxide, a lithium simple substance, a lithium alloy such as a lithium aluminum alloy, and Sn, Si, In Examples thereof include metals that can form alloys with lithium.
Among these, a carbonaceous material or a lithium composite oxide is preferable from the viewpoint of reliability. The metal composite oxide is preferable because it can occlude and release lithium.
The material of the negative electrode active material is not particularly limited, but preferably contains at least one of titanium and lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.

  The carbonaceous material used as the negative electrode active material is a material substantially composed of carbon, for example, petroleum pitch, natural graphite, artificial graphite such as vapor-grown graphite, carbon black such as acetylene black, and PAN-based materials. Examples thereof include carbonaceous materials obtained by firing various synthetic resins such as resins and furfuryl alcohol resins. The carbonaceous material further includes various types such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA-based carbon fiber, lignin carbon fiber, glassy carbon fiber, and activated carbon fiber. Examples thereof include carbon fibers, mesophase microspheres, graphite whiskers, and flat graphite.

  Carbonaceous materials can be divided into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. The carbonaceous material preferably has an interplanar spacing, density, and crystallite size described in JP-A-62-222066, JP-A-2-6856, and JP-A-3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, and the like. It can also be used.

  As the metal oxide and metal composite oxide used as the negative electrode active material, an amorphous oxide is particularly preferable, and chalcogenite which is a reaction product of a metal element and a group 16 element of the periodic table is more preferable. . “Amorphous” means a material having a broad scattering band having an apex in a region of 20 ° or more and 40 ° or less as a 2θ value by an X-ray diffraction method using CuKα rays. You may have. Of the crystalline diffraction lines seen from 40 ° to 70 ° in 2θ value, the strongest intensity is 100 times the diffraction line intensity at the apex of the broad scattering band seen from 20 ° to 40 ° in 2θ value. The ratio is preferably 5 or less, more preferably 5 times or less, and particularly preferably no crystalline diffraction line.

Among the compound group consisting of an amorphous oxide and a chalcogenide, an amorphous oxide of a metalloid element and a chalcogenide are more preferable, and elements of Group 13 (IIIB) to Group 15 (VB) of the periodic table, aluminum One selected from the group consisting of (Al), gallium (Ga), silicon (Si), tin (Sn), germanium (Ge), lead (Pb), antimony (Sb), and bismuth (Bi), or Al , Ga, Si, Sn, Ge, Pb, Sb, and Bi oxides selected from the group consisting of two or more, and chalcogenides are particularly preferable.
Specific examples of preferable amorphous oxides and chalcogenides include Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb _2. O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , SnSiS ₃ And composite oxides of these and lithium oxide (for example, Li ₂ SnO ₂ ) are preferable.

The average particle diameter of the negative electrode active material is preferably 0.1 μm to 60 μm.
In order to make the negative electrode active material have a predetermined particle diameter, a conventionally known pulverizer or classifier may be used. For example, a mortar, ball mill, sand mill, vibration ball mill, satellite ball mill, planetary ball mill, swirling airflow type A jet mill, a sieve, etc. are suitable. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle diameter, classification is preferably performed. There is no restriction | limiting in particular as a classification method, A sieve, an air classifier, etc. can be used as needed. As a classification method, either a dry method or a wet method can be applied.
The average particle diameter of the negative electrode active material is a value measured by the same method as the above-described method for measuring the volume average particle diameter of the positive electrode active material.

When an amorphous oxide centered on Sn, Si, Ge is used as the negative electrode active material, the negative electrode active material used in combination with the amorphous oxide centered on Sn, Si, Ge is lithium ion or lithium A carbon material capable of inserting and extracting metal, lithium, a lithium alloy, and a metal capable of forming an alloy with lithium are preferable.
Especially, it is preferable that at least 1 sort (s) of the active material represented by a following formula (A) is included.
Si _x M _(1-x) Formula (A)

In the formula (A), x represents a number of 0.01 or more and less than 1, and means a mole fraction. x is preferably 0.1 or more and less than 1, more preferably 0.1 or more and 0.99 or less, further preferably 0.2 or more and 0.98 or less, and particularly preferably 0.3 or more and 0.95 or less.
M is a chalcogen element, a metalloid element, an alkali metal element, an alkaline earth metal element or a transition metal element, or a chalcogen element, a metalloid element, an alkali metal element, an alkaline earth metal element, and a transition metal element Represents a combination of a plurality of elements selected from

M includes chalcogen elements such as oxygen (O), sulfur (S), and selenium (Se), metalloid elements such as boron (B) and germanium (Ge), and alkalis such as lithium (Li) and sodium (Na). Metal elements, alkaline earth metal elements such as magnesium (Mg), calcium (Ca), titanium (Ti), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), It is preferably selected from the group consisting of transition metal elements such as copper (Cu). Further, a combination of two or more elements selected from the above group may be used.
Among these, M is preferably a chalcogen element or a transition metal element, and more preferably a transition metal element. Among the transition metal elements, the first transition metal element is preferable, Ti, V, Mn, Fe, Co, Ni, and Cu are more preferable, and Ti, Mn, Fe, Co, and Ni are particularly preferable.

The negative electrode active material also preferably contains titanium (Ti). Specifically, for example, Li ₄ Ti ₅ O ₁₂ is excellent in rapid charge / discharge characteristics because it has a small volume fluctuation at the time of occlusion / release of lithium ions, can suppress deterioration of the electrode, and can improve battery life. This is preferable.

Although the density | concentration of a negative electrode active material is not specifically limited, It is preferable that it is 10 mass%-80 mass% with respect to the solid component of a solid electrolyte composition, and it is more preferable that it is 20 mass%-70 mass%.
A negative electrode active material may be used individually by 1 type, or may be used in combination of 2 or more type.

  Moreover, you may make a negative electrode active material layer contain a conductive support agent as needed.

The surfaces of the positive electrode active material and the negative electrode active material may be surface-coated with another metal oxide.
Examples of the surface coating agent include metal oxides that contain Ti, Nb, Ta, W, Zr, Si, and the like and may further contain Li.

Examples of the surface coating method include the following methods, which can be used as appropriate.
As an example in which the surface of the positive electrode active material is coated, a positive electrode active material having a coating portion formed by coating the surface of a positive electrode active material that is an oxide with a lithium niobate compound can be given. This positive electrode active material is disclosed in Japanese Patent Application Laid-Open No. 2010-225309 and non-patent literature (Narumi Ohta et al., “LiNbO ₃ -coated LiCoO ₂ as cathode material for solid-state lithium secondary material 7 1486-1490).
Further, (In the formula, X, Co, represents Mn or Ni, Y and Z each independently represent an integer from 1 to 10.) Lithium metal oxide _Li Y XO _Z covers the surface of the active material is Examples of the coating material include titanate spinel, tantalum oxide, niobium oxide, and the like. Specific examples include Li ₄ Ti ₅ O ₁₂ , LiTaO ₃ , LiNbO ₃ , LiAlO ₂ , Li ₂ ZrO ₃ , Li ₂ WO ₄ , Li ₂ TiO as described in JP-A-2008-103280. ₃ , Li ₂ B ₄ O ₇ , Li ₃ PO ₄ , Li ₂ MoO ₄ , LiBO _{2 and the} like.
Japanese Unexamined Patent Application Publication No. 2008-027581 describes an electrode material that has been surface-treated with at least one of sulfur and phosphorus as an electrode material for an all-solid-state secondary battery.
Further, as described in JP-A No. 2001-052733, lithium chloride may be supported on the surface of the positive electrode active material that is an oxide.

<Battery electrode sheet>
The battery electrode sheet of one embodiment of the present invention has a current collector and a solid electrolyte-containing layer disposed on the current collector using the solid electrolyte composition of the present disclosure. The battery electrode sheet includes a current collector, a positive electrode active material layer, a negative electrode active material layer, and an inorganic solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer. An embodiment in which the above-described solid electrolyte-containing layer is applied to at least one of the active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer is preferable.
In the battery electrode sheet of one embodiment of the present invention, since the solid electrolyte layer is formed using the solid electrolyte composition of the present disclosure, not only the resistance of the solid electrolyte layer itself is low, but also the solid electrolyte layer and The binding property between the electric bodies is high, and the interface resistance can be kept low. Thereby, when a secondary battery is produced, it is possible to maintain good cycle characteristics over a long period of time.

  In the battery electrode sheet, any one of the positive electrode active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer may be disposed using the solid electrolyte composition described above. Among them, the aspect in which the positive electrode active material layer is disposed using the above-described solid electrolyte composition, or all the layers of the positive electrode active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer are as described above. In the embodiment in which the solid electrolyte composition is used, the resistance of the solid electrolyte layer itself is low, the binding property between the solid electrolyte layer and the current collector is high, and the interface resistance can be kept low.

The structure of the battery electrode sheet according to one embodiment of the present invention may be, for example, a laminated structure of a positive electrode side current collector (for example, metal foil) / solid electrolyte layer / negative electrode side current collector (for example, metal foil). 5, positive electrode side current collector (for example, metal foil) 5 / positive electrode active material layer 4 / solid electrolyte layer 3 / negative electrode active material layer 2 / negative electrode side current collector (for example, metal foil) 1 A laminated structure may be used.
For example, in the latter structure, when the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer are formed using the solid electrolyte composition of the present disclosure, the resistance of each layer itself is suppressed to a low level. High binding properties at each interface between the positive electrode active material layer and the negative electrode active material layer and the current collector, the interface between the positive electrode active material layer and the solid electrolyte layer, and the interface between the solid electrolyte layer and the negative electrode active material layer, and the interface resistance Can be kept low. Thereby, excellent cycle characteristics are developed over a long period of time.

The details of the solid electrolyte layer and the solid electrolyte composition are as described above, and the positive electrode active material layer and the negative electrode active material layer can be suitably formed using the solid electrolyte composition described above. .
The solid electrolyte composition of one embodiment of the present invention is suitably used as a molding material for a negative electrode active material layer, a positive electrode active material layer, and a solid electrolyte layer, and among them, it is preferably used for molding a solid electrolyte layer.

(Current collector)
The current collector functions as an electrode when an all-solid secondary battery is produced, and is generally arranged as a positive electrode and a negative electrode. As the current collector as the positive electrode and the negative electrode, an electron conductor that does not cause a chemical change is preferably used.

  The positive electrode current collector is preferably a metal material such as aluminum, stainless steel, nickel, titanium, or a composite material obtained by treating the surface of aluminum or stainless steel with carbon, nickel, titanium, or silver. Is more preferable.

  As the current collector of the negative electrode, aluminum, copper, stainless steel, nickel or titanium is preferable, and aluminum, copper or copper alloy is more preferable.

  The shape of the current collector is usually preferably a film shape, a sheet shape, or a foil. Further, the shape of the current collector may be a net, a punched body, a lath body, a porous body, a foamed body, a molded body of a fiber group, or the like.

  There is no restriction | limiting in particular as thickness of a collector, 1 micrometer-500 micrometers are preferable. Further, the surface of the current collector may be provided with irregularities by performing a surface treatment.

~ Method for producing battery electrode sheet ~
The battery electrode sheet of one embodiment of the present invention may be produced by a known method, and preferably, the solid electrolyte composition of the present disclosure is applied onto a current collector to form a solid electrolyte-containing layer. It is produced by a method having steps.

Specifically, a solid electrolyte composition is applied by, for example, a known method such as a coating method on, for example, a metal foil serving as a current collector, and a film of the solid electrolyte composition is formed to produce a battery electrode sheet It may be a method to do.
For example, a battery electrode sheet can be more suitably produced by the method described below.
First, a metal foil that is a positive electrode current collector is prepared, a composition that becomes a positive electrode material is applied on the metal foil, and then dried to produce a positive electrode sheet having a positive electrode active material layer. Next, the solid electrolyte composition is applied onto the positive electrode active material layer of the positive electrode sheet and further dried to form a solid electrolyte layer. On the formed solid electrolyte layer, a composition to be a negative electrode material is further applied and dried to form a negative electrode active material layer. Thereafter, a current collector (metal foil) on the negative electrode side is overlaid on the negative electrode active material layer. In this manner, an all-solid secondary battery in which the solid electrolyte layer is sandwiched between the positive electrode active material layer and the negative electrode active material layer can be manufactured.
In addition, what is necessary is just to use the apply | coating method which apply | coats said each composition by a conventional method.
The composition for forming the positive electrode active material layer, the composition for forming the solid electrolyte layer (solid electrolyte composition), and the composition for forming the negative electrode active material layer are subjected to a drying treatment for each application of each composition. It may be applied, or a dry treatment may be applied collectively after each composition is applied in multiple layers.

  There is no restriction | limiting in particular in drying temperature, 30 degreeC or more is preferable and 60 degreeC or more is more preferable. The drying temperature is preferably 300 ° C. or lower, and more preferably 250 ° C. or lower. By heating and drying in the above temperature range, when the dispersion medium is contained, the dispersion medium is removed, and a solid state laminated structure can be obtained.

  As described above, when an all-solid secondary battery is manufactured, the binding property of each interface in the laminated structure of the positive electrode active material layer / solid electrolyte layer / negative electrode active material layer is improved, and excellent ion conduction is achieved even under no pressure. Sex can be secured.

<All-solid secondary battery>
The all-solid-state secondary battery of one embodiment of the present invention includes at least the battery electrode sheet of the present disclosure. Since the all-solid-state secondary battery of one embodiment of the present invention includes the battery electrode sheet of one embodiment of the present invention, it has excellent cycle characteristics.
Hereinafter, with reference to FIG. 5, the all-solid-state secondary battery which concerns on one Embodiment is demonstrated. FIG. 5 is a cross-sectional view schematically showing an all solid state secondary battery (lithium ion secondary battery) according to a preferred embodiment of the present invention.

The all-solid-state secondary battery 10 according to this embodiment includes a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5 stacked in this order as viewed from the negative electrode side. It has the structure. Each layer is in contact with each other and is in a good binding state. Therefore, even if it is used for a long period of time, it is difficult to peel off and the cycle characteristics of the secondary battery can be maintained well.
By having the above laminated structure, at the time of charging, electrons (e ⁻ ) are supplied to the negative electrode side, and lithium ions (Li ⁺ ) are accumulated. On the other hand, at the time of discharge, lithium ions (Li ⁺ ) accumulated in the negative electrode are returned to the positive electrode side, and electrons are supplied to the working part 6.
In the all-solid-state secondary battery 10 shown in FIG. 5, a light bulb is attached to the operating part 6 and lights up at the time of discharging.

  The thicknesses of the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 are not particularly limited, but are preferably 10 μm to 1000 μm, more preferably 100 μm to 500 μm, in consideration of general battery dimensions.

-Production of all-solid-state secondary batteries-
The all-solid-state secondary battery may be produced by a conventional method, and is preferably produced by a method having a step of applying the solid electrolyte composition of the present disclosure onto a current collector to form a solid electrolyte-containing layer. The
Specifically, similarly to the production of the battery electrode sheet described above, a process for forming a solid electrolyte-containing layer is provided to produce the battery electrode sheet, and then the battery electrode sheet is formed as shown in FIG. A disk-shaped electrode sheet 15 is cut out into a disk shape having a desired size (for example, 14.5 mm in diameter), and the disk-shaped electrode sheet 15 is placed in, for example, a stainless steel 2032 type coin case 14 and tightened with a necessary pressure. A type all-solid-state secondary battery 13 can be produced. For example, as shown in FIG. 6, the necessary pressure is applied by sandwiching a coin case 14 in which a disc-shaped electrode sheet 15 is placed between an upper support plate 11 and a lower support plate 12 and tightening with a pressurizing screw S. Also good.
Moreover, an all-solid-state secondary battery can also be produced using the battery electrode sheet described above.

-Applications of all-solid-state secondary batteries-
The all solid state secondary battery can be applied to various uses. The application mode of the all-solid-state secondary battery is not particularly limited. For example, when it is installed in an electronic device, a notebook computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy Terminal, Mobile Fax, Mobile Copy, Mobile Printer, Headphone Stereo, Video Movie, LCD TV, Handy Cleaner, Portable CD, Mini Disc, Electric Shaver, Walkie Talkie, Electronic Notebook, Calculator, Memory Card, Portable Tape Recorder, Radio, Backup Power Supply And memory cards.
Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders).
Furthermore, it can be used for various military uses, space use, or in combination with solar cells.

In particular, it is preferably applied to applications that require high capacity and high rate discharge characteristics. For example, in power storage facilities and the like that are expected to increase in capacity, higher safety is required, and further compatibility with battery performance is required. Moreover, in an electric vehicle or the like, an application in which a high-capacity secondary battery is mounted and charging is performed every day at home is assumed, and further safety against overcharging is required.
According to the present disclosure, excellent binding properties between solid particles and between layers, and rotational resistance is kept low, so that a stable battery voltage can be obtained in various usage modes, and excellent cycle characteristics according to usage modes. Can be expressed.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. However, the embodiments of the present invention are not limited to the following examples unless they exceed the gist of the present invention. Unless otherwise specified, “part” is based on mass.

<Synthesis of organic particles>
-Synthesis of polyurethane particles (1)-
(1) Synthesis of terminal diol lipophilic polymer 20 mL of methyl ethyl ketone was charged in a 500 mL three-necked flask and heated at 75 ° C. under a nitrogen stream. On the other hand, 70 g of dodecyl methacrylate (carbon number of alkyl part: 12, manufactured by Wako Pure Chemical Industries, Ltd.) and 110 g of methyl ethyl ketone were charged into a 500 mL graduated cylinder and stirred well. To this, 2.9 g of thioglycerol (manufactured by Wako Pure Chemical Industries, Ltd.) and 3.2 g of radical polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) were added as chain transfer agents and further stirred. . The obtained monomer solution was dropped into a 500 mL three-necked flask over 2 hours to initiate radical polymerization. Furthermore, after completion of the dropwise addition, heating and stirring were continued at 75 ° C. for 6 hours. The obtained polymerization solution was concentrated under reduced pressure, and methyl ethyl ketone was distilled off, and then dissolved in heptane. Terminal diol-modified polydodecyl methacrylate (Ab-1) [carbon number of alkyl moiety: 12; terminal diol lipophilic polymer] 292 g of a 25% by weight heptane solution was obtained.
The weight average molecular weight of the obtained polymer was 3200. The weight average molecular weight was measured by the following method.

(2) Synthesis of polyurea colloidal particles (Aa-1) 1 liter of a terminal diol-modified polydodecyl methacrylate (Ab-1; a diol compound having a long-chain alkyl group having 6 or more carbon atoms) with a mass of 25% by weight of heptane In addition to the three-necked flask of (L), it was diluted with 110 g of heptane. To this, 11.1 g of isophorone diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.1 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd .; catalyst) were added and stirred at 75 ° C. for 5 hours. Thereafter, a diluted solution of 125 g of heptane of 0.4 g of isophoronediamine (amine compound) was dropped over 1 hour. The polymer solution changed from a transparent solution to a pale yellow fluorescent color 10 minutes after the start of dropping. This shows that a urea colloid is formed. The reaction solution was cooled to room temperature to obtain 506 g of a 15 mass% heptane solution of polyurea colloidal particles (Aa-1) [second particles having a polyurea structure].
In the polyurea colloidal particles (Aa-1), the dodecyl group of the terminal diol-modified polydodecyl methacrylate is a structural part that solvates with heptane (hydrocarbon solvent), and the polyurea structure is a structural part that does not solvate with heptane. is there.
The weight average molecular weight of the polyurea of the polyurea colloidal particles (Aa-1) was 9,600. The weight average molecular weight was measured by the following method.

(3) Synthesis of polyurethane particles (1) In a 50 mL sample bottle, 2.6 g of dicyclohexylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.42 g of 1,4-butanediol (manufactured by Wako Pure Chemical Industries, Ltd.), 0.28 g of 2,2-bis (hydroxymethyl) butanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2.9 g of Kuraray polyol P-1020 (manufactured by Kuraray Co., Ltd.) were added. To this was added 15.7 g of a 15 mass% heptane solution of polyurea colloidal particles (Aa-1), and the mixture was dispersed with a homogenizer for 30 minutes while heating at 50 ° C. During this time, the mixture became fine particles and became a light orange slurry. The obtained slurry was quickly put into a 100 mL three-necked flask that had been stirred at 80 ° C. and a rotation speed of 400 rpm in advance, and 0.1 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd .; catalyst) was added thereto at 80 ° C. for 3 hours. Stir with heating. The slurry became a white emulsion. From this, it is presumed that polyurethane particles were formed. The white emulsion slurry was cooled to obtain a 40 mass% heptane dispersion of polyurethane particles (1) [organic particles (A)].

A scanning electron microscope (SEM) photograph of the obtained polyurethane particles (1) is shown in FIG.
The polyurethane particles had a weight average molecular weight of 18100 and a volume average particle diameter of 12 μm. The weight average molecular weight and the volume average particle diameter were measured by the following methods.
Furthermore, the result of having measured the glass transition temperature (Tg) of a polyurethane particle (1) is shown in FIG. Tg was measured by the following method. FIG. 4 shows a DSC curve obtained by differential scanning calorimetry (DSC) measurement of the polyurethane particles (1). As a result of DSC measurement, as shown in FIG. 4, two points of −44.7 ° C. and 56.2 ° C. were observed. From this, it is presumed that polyurethane particles in which polyurea colloid particles (Aa-1; second particles having a polyurea structure) are urethane-bonded are formed on polyurethane core particles (first particles having a polyurethane structure). . Of the two Tg's, the Tg on the low temperature side is the Tg of the polyurea colloidal particles, and the Tg on the high temperature side is the Tg of the polyurethane core particles.

~ Measurement of weight average molecular weight ~
The weight average molecular weight was measured as a polystyrene equivalent value by gel permeation chromatograph (GPC) under the following conditions. The same applies to the weight average molecular weights of other exemplary compounds synthesized below. The calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, It produced from eight samples of "A-2500", "A-1000", and "n-propylbenzene".
<Condition>
GPC: HLC (registered trademark) -8020 GPC (manufactured by Tosoh Corporation)
Column: G3000HXL and G2000HXL
-Eluent: THF (tetrahydrofuran), chloroform, NMP (N-methyl-2-pyrrolidone), m-cresol / chloroform (manufactured by Shonan Wako Pure Chemical Industries, Ltd.) can be selected. Used ・ Sample concentration: 0.45% by mass
・ Flow rate: 1 mL / min
Sample injection volume: 10 μl
・ Measurement temperature: 23 ℃
・ Uses differential refractometer (RI) detector

~ Measurement of volume average particle diameter ~
The volume average particle size was measured by a light scattering method using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA).

~ Measurement of Tg ~
The glass transition temperature (Tg) of the polyurethane particles is measured under the following conditions using a differential scanning calorimeter “X-DSC7000” (manufactured by SII Nanotechnology) for the polymer obtained by drying the polymer dispersion. did. The measurement was performed twice for the same sample, and the second measurement result was adopted.
<Condition>
・ Atmosphere in measurement chamber: Nitrogen (50 mL / min)
・ Raising rate: 5 ° C / min
Measurement start temperature: -100 ° C
-Measurement end temperature: 200 ° C
・ Sample pan: Aluminum pan ・ Measurement sample mass: 5 mg
-Calculation of Tg: Tg was calculated by rounding off the decimal point of the intermediate temperature between the lowering start point and the lowering end point of the DSC chart.

-Synthesis of polyurethane particles (2) to (6)-
In the synthesis of the polyurethane particles (1), the polyurethane particles (2) to (6) were synthesized in the same manner as the synthesis of the polyurethane particles (1) except that the following points were changed. In each polyurethane particle, the Tg on the low temperature side is the Tg of the polyurea colloid particles, and the Tg on the high temperature side is the Tg of the terminal diol-modified polydodecyl methacrylate.
-Polyurethane particles (2):
Dodecyl methacrylate was changed to stearyl methacrylate (carbon number of alkyl site: 18).
The weight average molecular weight was 32300, and the volume average particle diameter was 15 μm. Further, two glass transition temperatures of −67.2 ° C. and 42 ° C. were observed.
-Polyurethane particles (3):
Isophorone diisocyanate was changed to 1,6-hexanediol diisocyanate.
The weight average molecular weight was 22300, and the volume average particle diameter was 23 μm. Two glass transition temperatures, −54.5 ° C. and 42 ° C., were observed.
-Polyurethane particles (4):
Dicyclohexylmethane diisocyanate was changed to 4,4′-diphenylmethane diisocyanate.
The weight average molecular weight was 58500, and the volume average particle diameter was 18 μm. Two glass transition temperatures, −46.5 ° C. and 75 ° C., were observed.
-Polyurethane particles (5):
Dicyclohexylmethane diisocyanate was changed to isophorone diisocyanate and 1,6-hexane diisocyanate (isophorone diisocyanate / 1,6-hexane diisocyanate = 2/1; mass ratio).
The weight average molecular weight was 34,000, and the volume average particle diameter was 9 μm. Two glass transition temperatures, −46.5 ° C. and −9.3 ° C., were observed.
-Polyurethane particles (6):
2,2-bis (hydroxymethyl) butanoic acid was converted into 2,2-bis (hydroxymethyl) propionic acid and Blemmer GLM (manufactured by NOF Corporation) (2,2-bis (hydroxymethyl) propionic acid / Blemmer GLM). = 20/80; mass ratio).
The weight average molecular weight was 48900, and the volume average particle diameter was 7 μm. Two glass transition temperatures, −46.5 ° C. and 35 ° C., were observed.

-Synthesis of polyurea particles (7)-
A mixed solution obtained by adding 1.8 g of dicyclohexylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 22.0 g of the above-mentioned “15 wt% heptane solution of polyurea colloidal particles (Aa-1)” to a 50 mL sample bottle. Was dispersed at an internal temperature of 5 ° C. for 10 minutes using the following homogenizer. While continuing the dispersing operation with a homogenizer, 0.42 g of 1,6-hexanediamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 2.9 g of polypropylene glycol bis 2-aminopropyl ether (manufactured by Aldrich) were applied to this mixed solution for 5 minutes. Added dropwise. During this time, the mixed solution generated heat, and the internal temperature rose from 5 ° C to 12 ° C. When stirring was continued for 30 minutes at room temperature, a white emulsion slurry was obtained. From this, it was estimated that polyurea particles were formed.
Next, the white emulsion slurry was cooled to obtain a 40 mass% heptane dispersion of polyurea particles (7) [organic particles (A)].
The polyurea particles (7) had a weight average molecular weight of 32,000 and a volume average particle size of 3 μm. Two glass transition temperatures, −46.5 ° C. and −20 ° C., were observed.
<Homogenizer>
-Homogenizer body: T10basic ULTRA TURRAX (manufactured by IKA)
-Homogenizer shaft: S10N 8G shaft generator (manufactured by IKA)

-Synthesis of polyurethane urea particles (8)-
In a 50 mL sample bottle, 1.8 g of 4,4′-diphenylmethane diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.), 0.5 g of Blemmer GLM (manufactured by NOF Corporation), and the “polyurea colloidal particles (Aa- 1) of 15% by mass heptane solution ”(25.2 g) was added and dispersed at an internal temperature of 60 ° C. for 10 minutes using the following homogenizer. While continuing the dispersing operation with the homogenizer, 0.1 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.) was added, and the mixture was heated and stirred at 60 ° C. for 3 hours. In this way, polyurethane prepolymer core particles were produced.
Subsequently, while continuing the homogenizer dispersion, the mixed solution was returned to room temperature, and then 2.2 g of Jeffamine ED-900 (polyethyl ether diamine, manufactured by Huntsman) was added dropwise over 5 minutes. During this time, the mixed solution generated heat, and the internal temperature rose from 25 ° C. to 30 ° C. When dispersion was continued for 30 minutes at room temperature using a homogenizer, a white emulsion slurry was obtained. From this, it was estimated that polyurethane urea particles were formed.
Next, the white emulsion slurry was cooled to obtain a 40 mass% heptane dispersion of polyurethane urea particles (8) [organic particles (A)].
The weight average molecular weight of polyurethane urea in the polyurethane urea particles (8) was 45000, and the volume average particle diameter was 6 μm. Two glass transition temperatures, −46.5 ° C. and −25 ° C., were observed.
<Homogenizer>
-Homogenizer body: T10basic ULTRA TURRAX (manufactured by IKA)
-Homogenizer shaft: S10N 8G shaft generator (manufactured by IKA)

Further, the water content of each of the polyurethane particles and the polyurea particles synthesized above was measured by measuring the water content (g) in the sample by the Karl Fischer method using the polymer after vacuum drying at 80 ° C. It was calculated by dividing g) by the sample mass (g).
The water content of the polymer was 100 ppm or less.

<Synthesis of sulfide-based inorganic solid electrolyte>
-Synthesis of Li / P / S glass-
Non-patent literature (T. Ohtomo, A. Hayashi, M. Tatsumisago, Y. Tsuchida, S. Hama, K. Kawamoto, Journal of Power Sources, 233, (2013), pp23) 235 and A. Hayashi, S. Hama, H. Morimoto, M. Tatsumisago, T. Minami, Chem. Lett., (2001), pp 872-873) were used to synthesize Li / P / S glasses. .

Specifically, in a glove box under an argon atmosphere (dew point −70 ° C.), 2.42 g of lithium sulfide (Li ₂ S, manufactured by Aldrich, purity> 99.98%) and diphosphorus pentasulfide (P ₂ S _5, Aldrich Co., purity> 99%) 3.90 g were weighed, charged into an agate mortar, using an agate pestle and mixed for 5 minutes. The mixing ratio of Li ₂ S and _P 2 _{S 5} (molar _{ratio; = Li 2 S: P 2} S 5) is 75: was 25.
After putting 66 pieces of zirconia beads having a diameter of 5 mm into a zirconia 45 mL container (manufactured by Fritsch), the whole amount of the above mixture of lithium sulfide and diphosphorus pentasulfide was introduced, and the container was completely sealed under an argon atmosphere. . This container is set on a planetary ball mill P-7 (manufactured by Fritsch), mechanical milling is performed at a temperature of 25 ° C. and a rotation speed of 510 rpm for 20 hours, and yellow powder Li / P / S glass (sulfide-based inorganic solid electrolyte) Hereinafter, abbreviated as “Li / P / S”.) 6.20 g was obtained.

(Examples 1-12, Comparative Examples 1-4)
-Preparation of solid electrolyte composition-
(1) Preparation of Solid Electrolyte Composition (K-1) Into a 45 mL zirconia container (manufactured by Fritsch), 180 pieces of zirconia beads having a diameter of 5 mm were introduced, and an inorganic solid electrolyte LLZ (Li ₇ La ₃ Zr ₂ O ₁₂ ( (Average particle size: 5.06 μm), 9.0 g manufactured by Toshima Seisakusho Co., Ltd., 0.75 g (solid content 0.3 g) of 40 mass% heptane dispersion of polyurethane particles (1) synthesized above, and dispersion medium As (C), 15.0 g of toluene was added. Thereafter, this container was set on a planetary ball mill P-7 (manufactured by Fritsch), and stirring was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm to prepare a solid electrolyte composition (K-1).

(2) Preparation of Solid Electrolyte Composition (K-2) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and 9.0 g of the Li / P / S glass synthesized above. 0.75 g (solid content: 0.3 g) of a 40% by mass heptane dispersion of the polyurethane particles (1) synthesized above and 15.0 g of heptane as a dispersion medium were added. Thereafter, this container was set on a planetary ball mill P-7 (manufactured by Fritsch), and stirring was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm to prepare a solid electrolyte composition (K-2).

(3) Preparation of solid electrolyte compositions (K-3) to (K-10) and (HK-1) to (HK-3) In preparation of solid electrolyte compositions (K-1) or (K-2) The solid electrolyte composition was the same as the solid electrolyte composition (K-1) or (K-2) except that the organic particles (A) and the inorganic solid electrolyte (B) were changed as shown in Table 1. (K-3) to (K-10) and (HK-1) to (HK-3) were prepared. In addition, solid electrolyte composition (K-1)-(K-10) is a solid electrolyte composition used as an Example, and solid electrolyte composition (HK-1)-(HK-3) is a solid for comparison. It is an electrolyte composition.

The notation shown in Table 1 is shown below.
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle size: 5.06 μm, manufactured by Toshima Seisakusho)
Li / P / S: Li / P / S glass synthesized as above Polypropylene particles: Syxen (polyolefin emulsion), manufactured by Sumitomo Seika Co., Ltd.))
-Acrylic particles: Chemisnow MX-500 (acrylic latex particles), manufactured by Soken Chemical Co., Ltd.

-Preparation of composition for positive electrode of secondary battery-
(1) Preparation of composition for positive electrode (U-1) 180 zirconia beads having a diameter of 5 mm were placed in a 45 mL container (manufactured by Fritsch) made of zirconia, and an inorganic solid electrolyte LLZ (Li ₇ La ₃ Zr ₂ O ₁₂ ( (Average particle diameter 5.06 μm), 2.7 g (manufactured by Toshima Seisakusho), 0.75 g (solid content 0.3 g) of 40 mass% heptane dispersion of polyurethane particles (1) synthesized above, and as a dispersion medium 12.3 g of toluene was charged. This container was set in a planetary ball mill P-7 (manufactured by Fritsch), and machine dispersion was continued for 2 hours under the conditions of a temperature of 25 ° C. and a rotation speed of 300 rpm. Thereafter, 7.0 g of lithium cobalt oxide (LCO, manufactured by Nippon Kagaku Kogyo Co., Ltd.) as an active material is put into the container, and this container is set again on the planetary ball mill P-7, at a temperature of 25 ° C. and a rotation speed of 100 rpm. Mixing continued for 15 minutes. In this way, a positive electrode composition (U-1) was prepared.

(2) Preparation of positive electrode composition (U-2) 180 zirconia beads having a diameter of 5 mm were placed in a 45 mL container (manufactured by Fritsch) made of zirconia, and 2.7 g of the Li / P / S glass synthesized above. Then, 0.75 g (solid content 0.3 g) of 40 mass% heptane dispersion of the polyurethane particles (1) synthesized above and 12.3 g of heptane as a dispersion medium were added. This container was set in a planetary ball mill P-7 (manufactured by Fritsch), and mixing was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. Thereafter, 7.0 g of lithium nickel manganese cobaltate (NMC, manufactured by Nippon Kagaku Kogyo Co., Ltd.) as an active material was put into the container, and this container was set in the planetary ball mill P-7 again. Mixing continued at 15 minutes. In this way, a positive electrode composition (U-2) was prepared.

(3) Preparation of positive electrode compositions (U-3) to (U-10) and (HU-1) to (HU-2) In the same manner as the positive electrode composition (U-1), the positive electrode composition was prepared. A product (U-3) was prepared. Also, positive electrode compositions (U-4) to (U-10) and (HU-1) to (HU-2) were prepared in the same manner as the positive electrode composition (U-2).
The positive electrode compositions (U-1) to (U-10) are examples of positive electrode compositions, and the positive electrode compositions (HU-1) to (HU-2) are for comparative positive electrodes. It is a composition.

The notation shown in Table 2 is shown below.
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle size: 5.06 μm, manufactured by Toshima Seisakusho)
-Li / P / S: Li / P / S glass synthesized above-Polypropylene particles: Syxen (polyolefin emulsion), manufactured by Sumitomo Seika Co., Ltd.)
Acrylic particles: Chemisnow MX-500 (acrylic latex particles), manufactured by Soken Chemical Co., Ltd. LCO: LiCoO ₂ [lithium cobaltate]
NMC: Li (Ni _1/3 Mn _1/3 Co _1/3 ) O ₂ [lithium nickel manganese cobaltate]

-Preparation of secondary battery negative electrode composition-
(1) Preparation of composition for negative electrode (S-1) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and an inorganic solid electrolyte LLZ (Li ₇ La ₃ Zr ₂ O ₁₂ ( (Average particle diameter 5.06 μm), manufactured by Toshima Seisakusho Co., Ltd.) 5.0 g, polyurethane particles (1) synthesized above, 1.25 g of a 40% by weight heptane dispersion (solid content 0.5 g), and a dispersion medium 12.3 g of toluene was charged. This container was set in a planetary ball mill P-7 (manufactured by Fritsch), and mechanical dispersion was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. Thereafter, 7.0 g of acetylene black as an active material was put into a container, and this container was set again on the planetary ball mill P-7, and mixing was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 100 rpm. In this way, a negative electrode composition (S-1) was prepared.

(2) Preparation of composition for negative electrode (S-2) Into a 45 mL container (manufactured by Fritsch) made of zirconia, 180 pieces of zirconia beads having a diameter of 5 mm were charged, and 5.0 g of the Li / P / S glass synthesized above. 1.25 g of a 40 mass% heptane dispersion of the polyurethane particles (1) synthesized above (solid content 0.5 g) and 12.3 g of heptane as a dispersion medium were charged, and this container was put into a planetary ball mill P-7 (Fritsch). And mixing was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. Thereafter, 7.0 g of acetylene black was added as an active material, and this container was set on the planetary ball mill P-7 again, and mixing was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 200 rpm. In this way, a negative electrode composition (S-2) was prepared.

(3) Preparation of negative electrode compositions (S-3) to (S-10) and (HS-1) to (HS-2) In the same manner as the negative electrode composition (S-1), the positive electrode composition was prepared. A product (S-3) was prepared. Moreover, the composition for positive electrodes (S-4)-(S-10) and (HS-1)-(HS-2) were prepared by the method similar to the composition for negative electrodes (S-2).
The negative electrode compositions (S-1) to (S-10) are examples of negative electrode compositions, and the negative electrode compositions (HS-1) to (HS-2) are for comparative negative electrodes. It is a composition.

The notation shown in Table 3 is shown below.
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle size 5.06 μm, manufactured by Toshima Seisakusho)
-Li / P / S: Li / P / S glass synthesized above-Polypropylene particles: Syxen (polyolefin emulsion), manufactured by Sumitomo Seika Co., Ltd.)
・ Acrylic particles: Chemisnow MX-500 (acrylic latex particles), manufactured by Soken Chemical Co., Ltd. ・ AB: Acetylene black

-Production of positive electrode sheet for secondary battery-
The clearance for the secondary battery positive electrode composition (U-2, U-4 to U-10 and HU-1 to HU-2) manufactured above can be adjusted on an aluminum foil (current collector) having a thickness of 20 μm. After coating with a suitable applicator and heating at 80 ° C. for 1 hour, the coating solvent was dried by further heating at 110 ° C. for 1 hour. Then, using a heat press machine, it heated and pressurized so that it might become arbitrary density, and obtained the 150-micrometer-thick positive electrode sheet for secondary batteries which has a laminated structure of a positive electrode active material layer / aluminum foil.

-Production of electrode sheet for all solid state secondary battery-
On the positive electrode active material layer of the positive electrode sheet for a secondary battery obtained above, the solid electrolyte compositions (K-2, K-6 to K-10 and HK-1 to HK-3) prepared above were used. It was coated with an applicator with adjustable clearance, heated at 80 ° C. for 1 hour, and further heated at 110 ° C. for 1 hour to form a solid electrolyte layer having a thickness of 50 μm. Then, the composition for secondary battery negative electrodes (S-2, S-4 to S-10 and HS-1 to HS-2) prepared above was further applied on the solid electrolyte layer after drying, and 80 ° C. And then heated at 110 ° C. for 1 hour to form a negative electrode active material layer having a thickness of 100 μm. A 20 μm thick copper foil (current collector on the negative electrode side) is placed on the negative electrode active material layer, and heated and heated using a heat press so that the solid electrolyte layer and the negative electrode active material layer have an arbitrary density. The electrode sheet for an all-solid secondary battery shown in Table 4 was produced.
FIG. 5 shows the layer structure of the electrode sheet for an all-solid-state secondary battery. The electrode sheet for an all-solid-state secondary battery is a laminated structure of a current collector (aluminum foil) / negative electrode active material layer / solid electrolyte layer / secondary battery positive electrode sheet (positive electrode active material layer / current collector (aluminum foil)). have.
Each of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer has a thickness described in Table 4. The thickness of the positive electrode active material layer does not include the current collector thickness of 20 μm.

-Manufacture of all-solid-state secondary batteries-
The electrode sheet for the all-solid-state secondary battery manufactured above is cut into a disk shape having a diameter of 14.5 mm, and is placed in a stainless steel 2032 type coin case incorporating a spacer and a washer as shown in FIG. And tightened with a force of 8 Newton (N) to produce an all-solid-state secondary battery.

<Evaluation>
The following evaluation was performed with respect to the all-solid-state secondary battery electrode sheets and all-solid-state secondary batteries of Examples and Comparative Examples prepared above. The evaluation results are shown in Table 4.

-1. Battery voltage
The battery voltage of the all-solid-state secondary battery produced above was measured by a charge / discharge evaluation apparatus “TOSCAT-3000” manufactured by Toyo System Co., Ltd.
Charging was performed until the battery voltage reached 4.2 V at a current density of 2 A / m ^2. After reaching 4.2 V, constant voltage charging was performed until the current density was less than 0.2 A / m ² . Discharging was performed at a current density of 2 A / m ² until the battery voltage reached 3.0V. This was repeated three times as one cycle, and the battery voltage after 5 mAh / g discharge in the third cycle was read and evaluated according to the following criteria. Ranks A to B are acceptable levels.
<Evaluation criteria>
A: The battery voltage is 4.0 V or higher.
B: The battery voltage is 3.9 V or more and less than 4.0 V.
C: The battery voltage is 3.8V or more and less than 3.9V.
D: The battery voltage is less than 3.8V.

-2. Cycle characteristics
The cycle characteristics of the all-solid-state secondary battery produced above were measured with a charge / discharge evaluation apparatus “TOSCAT-3000” manufactured by Toyo System Co., Ltd.
Charging / discharging was performed under the same conditions as in “1. Battery voltage” above. The discharge capacity at the third cycle was set to 100, and the following criteria were evaluated from the number of cycles when the discharge capacity was less than 80. Ranks A to B are acceptable levels.
<Evaluation criteria>
A: The number of cycles is 50 or more.
B: The number of cycles is 40 times or more and less than 50 times.
C: The number of cycles is 30 times or more and less than 40 times.
D: The number of cycles is less than 30.

-3. Peeling-
With respect to the electrode sheet for an all-solid-state secondary battery produced as described above, each layer is cut so that 100 lattices are formed for each of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer of the positive electrode sheet. A tape peeling test was conducted to attach a tape (model number: 405, manufactured by Nichiban Co., Ltd.) to the surface of each layer with a cut, and peel the tape at a constant speed in the direction along the layer surface (direction of 180 degrees). It was. After the test, the presence or absence of peeling of each layer was evaluated according to the following evaluation criteria, and used as an index for evaluating adhesion or binding. Ranks A to B are acceptable levels.
<Evaluation criteria>
A: There is no peeled lattice (0).
B: 1 or more and less than 10 lattices are peeled off.
C: The number of peeled lattices is 10 or more and less than 20.
D: There are 20 or more peeled lattices.

  As shown in Table 4, in the examples, in at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer, the surface of the polyurethane particle is an organic particle covered with particles having a polyurea structure. By containing particles, the adhesion between the current collector and the positive electrode active material layer and between the current collector and the negative electrode active material layer is good, and each layer interface of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer The adhesiveness was also good, and the effect of reducing the interfacial resistance between the solid particles and between the respective layers was also noticeable. Therefore, the battery voltage and the cycle characteristics could be maintained satisfactorily while maintaining the voltage.

The entire disclosures of Japanese Patent Application No. 2015-223101 and Japanese Application No. 2015-039451 are incorporated herein by reference.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims (17)

A first particle having at least one of a polyurethane structure and a polyurea structure; and a plurality of second particles covering a surface of the first particle having a particle diameter smaller than that of the first particle and having a polyurea structure. And organic particles (A) having, and
Inorganic solid electrolyte having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table (B)
Contain,
The second particle has a long-chain alkyl group having 6 or more carbon atoms,
The solid electrolyte composition , wherein the glass transition temperature of the first particles is higher than the glass transition temperature of the second particles . The solid electrolyte composition according to claim 1, wherein the first particles have a hard segment and a soft segment. 3. The solid electrolyte composition according to claim 1, wherein the organic particles (A) have a volume average particle diameter of 0.1 μm to 100 μm. The glass transition temperature of the first particles is less than 50 ° C., the solid electrolyte composition according to any one of claims 1 to 3 the glass transition temperature of the second particles is less than 0 ℃ . The solid electrolyte composition according to any one of claims 1 to 4 , wherein the inorganic solid electrolyte (B) is a sulfide-based inorganic solid electrolyte. The solid electrolyte composition according to any one of claims 1 to 4 , wherein the inorganic solid electrolyte (B) is an oxide-based inorganic solid electrolyte. The content of the organic particles (A) is, with respect to the inorganic solid electrolyte (B) 100 parts by weight, to any one of claims 1 to 6 or less 20 parts by mass or more 0.01 part by weight The solid electrolyte composition described. Furthermore, the dispersion medium (C) has a ratio of 10% by mass to 1000% by mass with respect to the inorganic solid electrolyte (B), and at least one of the dispersion media (C) is a hydrocarbon solvent. The solid electrolyte composition according to claim 7 . The volume average particle diameter of the organic particles (A) is a solid electrolyte composition according to any one of claims 1 to 8 is 0.5Myuemu～25myuemu. At least a reaction part comprising an isocyanate compound, a diol compound having a long-chain alkyl group having 6 or more carbon atoms, and an amine compound to react with a hydrocarbon solvent and a solvated structure part and a non-solvated structure part. Preparing a particle of 2;
The second particles, the isocyanate compound, and at least one of a diol compound and a diamine compound are dispersed in a hydrocarbon solvent to prepare an emulsion, and the emulsion is subjected to a polycondensation reaction. A step of preparing organic particles (A) in which the surface of one particle is covered with a plurality of the second particles;
Mixing the organic particles (A) with an inorganic solid electrolyte (B) having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table;
I have a,
The second particle has a long-chain alkyl group having 6 or more carbon atoms,
The method for producing a solid electrolyte composition , wherein the glass transition temperature of the first particles is higher than the glass transition temperature of the second particles . Current collector and, battery electrode sheet having a solid electrolyte containing layer disposed on the current collector by using a solid electrolyte composition according to any one of claims 1 to 9. A positive electrode active material layer, a negative electrode active material layer, and an inorganic solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer,
The battery electrode sheet according to claim 11 , wherein at least one of the positive electrode active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer is the solid electrolyte-containing layer. The solid electrolyte composition according to any one of claims 1 to 9 was dispensed on the current collector, the production method of the battery electrode sheet having a step of forming a solid electrolyte containing layer. A current collector, a positive electrode active material layer, a negative electrode active material layer, and an inorganic solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer;
At least one of the positive electrode active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer,
A first particle having at least one of a polyurethane structure and a polyurea structure; and a plurality of second particles covering a surface of the first particle having a particle diameter smaller than that of the first particle and having a polyurea structure. And organic particles (A) having, and
Inorganic solid electrolyte having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table (B)
Contain,
The second particle has a long-chain alkyl group having 6 or more carbon atoms,
The all-solid-state secondary battery in which the glass transition temperature of the first particles is higher than the glass transition temperature of the second particles . All-solid secondary battery including an electrode sheet for a battery according to claim 1 1 or claim 1 2. Claim 1 1 or Claim 1 2 method for manufacturing an all solid state secondary battery of manufacturing an all-solid secondary battery using the electrode sheet for a battery according to. An all solid having a step of producing a battery electrode sheet by applying the solid electrolyte composition according to any one of claims 1 to 9 onto a current collector and forming a solid electrolyte-containing layer. A method for manufacturing a secondary battery.