JP2015164116A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device which is arranged to be able to exhibit a high electromotive force and superior charge and discharge characteristics by enhancement of the electrical conductivity of an electrode active material layer, and which enables the reduction in worsening of these characteristics owing to the repetition of charge and discharge.SOLUTION: A power storage device according to the present invention comprises: laminates arranged laminating bipolar electrodes through solid electrolytic layers. The bipolar electrodes each have a conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer, provided that one of the first and second active material layers serves as a positive electrode active material layer, and the other serves as a negative electrode active material layer; and the solid electrolytic layers. The solid electrolytic layer includes silver ion conducting solid electrolyte.

Description

  The present invention relates to an electricity storage device. In detail, it is related with the electrical storage device using the solid electrolyte containing a silver electrolyte.

  A power storage device mounted on a moving body such as an automobile or an aircraft is always exposed to vibration and impact during operation of the moving body, and therefore requires a high degree of impact resistance. In addition to the impact resistance similar to the above, the electricity storage device used for the operation of implantable medical devices represented by pacemakers can be downsized, and the possibility of liquid leakage is as low as possible. It is required that the charge / discharge characteristics do not deteriorate even when bent.

  An electricity storage device using a solid electrolyte is expected to satisfy the above-described requirements, and research is ongoing. For example, Patent Document 1 discloses a lithium primary battery and a lithium ion secondary battery having a solid electrolyte obtained by firing a molded body containing lithium ion conductive glass ceramics. In Patent Document 2, an attempt is made to improve the electrical conductivity of the active material layer by controlling the ratio of the particle size of the electrolyte particles contained in the active material layer to the particle size of the active material particles within a certain range. ing.

JP 2007-134305 A International Publication No. 2013/021843

  However, the battery obtained by the technique of Patent Document 1 has insufficient electromotive force and charge / discharge characteristics because the electric conductivity of the electrode active material layer is low. On the other hand, according to the technique of Patent Document 2, although there is a certain effect in improving the electrical conductivity of the active material layer, the obtained electricity storage device deteriorates due to repeated charge and discharge, for example, It could not withstand actual use as a lithium ion secondary battery.

  Therefore, some aspects according to the present invention can achieve high electromotive force and excellent charge / discharge characteristics by improving the electrical conductivity of the electrode active material layer by solving at least a part of the above problems. It is an object of the present invention to provide an electricity storage device that can reduce deterioration of these characteristics due to repeated charge and discharge.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the electricity storage device according to the present invention is:
A conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer, wherein the first active material layer and the first active material layer A bipolar electrode in which one of the two active material layers functions as a positive electrode active material layer and the other as a negative electrode active material layer;
A solid electrolyte layer;
Including a plurality of laminates in which the bipolar electrode is laminated via the solid electrolyte layer,
The solid electrolyte layer contains a silver ion conductive solid electrolyte.

[Application Example 2]
In the electricity storage device of Application Example 1,
The first active material layer and the second active material layer may contain the same active material.

[Application Example 3]
One aspect of the electricity storage device according to the present invention is:
A conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer, wherein the first active material layer and the first active material layer A bipolar electrode in which one of the two active material layers functions as a positive electrode active material layer and the other as a negative electrode active material layer;
A solid electrolyte layer;
Including a plurality of laminates in which the bipolar electrode is laminated via the solid electrolyte layer,
When the thickness of the first active material layer is T1 and the thickness of the second active material layer is T2, the value of T1 / T2 is 0.8 to 1.2.

[Application Example 4]
In the electricity storage device of Application Example 3,
The first active material layer and the second active material layer may contain the same active material.

[Application Example 5]
In the electricity storage device of Application Example 3 or Application Example 4,
The solid electrolyte layer may contain a silver ion conductive solid electrolyte.

[Application Example 6]
In the electricity storage device of any one of Application Examples 1 to 5,
There may be one or more conductive layers, and at least one of them may contain a polymer.

[Application Example 7]
In the electricity storage device of Application Example 6,
The polymer may be a thermoplastic elastomer.

[Application Example 8]
In the electricity storage device of Application Example 6 or Application Example 7,
The conductive layer containing the polymer may contain 10 to 95% by mass of the polymer.

[Application Example 9]
In the electricity storage device of any one of Application Example 6 to Application Example 8,
The polymer may include a repeating unit derived from styrene and a repeating unit derived from butadiene.

  According to the electricity storage device of the present invention, by improving the electrical conductivity of the electrode active material layer, high electromotive force and excellent charge / discharge characteristics can be exhibited, and deterioration of these characteristics due to repeated charge / discharge is reduced. it can.

It is sectional drawing which shows typically the electrical storage device which concerns on this Embodiment. It is a top view which shows one usage pattern of the electrical storage device which concerns on this Embodiment. It is a conceptual diagram which shows one usage pattern of the electrical storage device which concerns on this Embodiment. It is a conceptual diagram which shows one usage pattern of the electrical storage device which concerns on this Embodiment. It is a conceptual diagram which shows the usage pattern which utilizes the electrical storage device which concerns on this Embodiment as a heat sink.

  Hereinafter, preferred embodiments according to the present invention will be described in detail. It should be understood that the present invention is not limited to only the embodiments described below, and includes various modifications that are implemented without departing from the scope of the present invention.

1. Electric storage device 1.1. Structure and Features of Power Storage Device An power storage device according to an embodiment of the present invention is formed on a conductive layer, a first active material layer formed on one surface of the conductive layer, and the other surface of the conductive layer. A bipolar electrode that functions as a positive electrode active material layer and the other as a negative electrode active material layer, a solid electrolyte layer, and a second active material layer , And a structure including a plurality of laminated bodies in which the bipolar electrodes are laminated via the solid electrolyte layer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing an electricity storage device according to an embodiment of the present invention. As shown in FIG. 1, the electricity storage device 100 includes a conductive layer 10, a first active material layer 12 formed on one surface of the conductive layer 10, and a second active material formed on the other surface of the conductive layer 10. A bipolar electrode 16 having the layer 14 and a solid electrolyte layer 18 are provided. The power storage device 100 shown in FIG. 1 is a laminate in which the basic structure sandwiched by the solid electrolyte layer 18 so that the bipolar electrode 16 is in contact with the first active material layer 12 and the second active material layer 14 is repeated. . In an electricity storage device composed only of this basic structure, a sufficient voltage cannot be obtained. Therefore, it is necessary to provide an electricity storage device in which a plurality of such basic structures are stacked. A sufficient voltage can be obtained by forming an electricity storage device in which a plurality of basic structures are stacked. However, in the electricity storage device according to the present embodiment, it is necessary that a conductive layer exists on the outermost surface of a stacked body in which a plurality of basic structures are stacked. The conductive layer 10 has a function as a so-called current collector.

  Further, when the solid electrolyte layer contains a silver ion conductive solid electrolyte, the laminate can produce an electricity storage device having an arbitrary capacity by cutting the laminate into an arbitrary shape and size. it can. That is, the capacity can be freely controlled according to the divided area. When a laminate having a conventional solid electrolyte layer is cut, the solid electrolyte layer is easily collapsed or the interface is peeled off at the time of cutting, and the yield is reduced due to a short circuit. However, according to the solid electrolyte layer containing the silver ion conductive solid electrolyte, such a problem hardly occurs and it can be cut out with a high yield.

  When one or more conductive layers are present, at least one of the conductive layers contains a polymer, whereby the adhesion of the laminate can be improved. Therefore, when the laminate is cut into arbitrary shapes and sizes, peeling of each layer (occurrence of defective products) can be suppressed by adding a polymer to at least one of the conductive layers. , Improve the yield. The polymer contained in the conductive layer will be described later.

  The electricity storage device according to the present embodiment may have a structure in which the stacked body is covered with an exterior body. The said exterior body has a function which accommodates the said laminated body, prevents the short circuit between positive and negative electrodes, and prevents the penetration | invasion of the water | moisture content inside a laminated body.

As the exterior body, it is preferable to use a laminate film. For example, the laminate film preferably has a structure in which a metal layer is sandwiched between a first resin layer and a second resin layer. Examples of the material of the resin constituting the first resin layer include polyethylene terephthalate resin, polytetrafluoroethylene resin, and polyamide resin. Examples of the resin material constituting the second resin layer include ethylene vinyl acetate copolymer resins, olefin resins (eg, polyethylene, polypropylene, etc.), polylactide resins, polyglycolide resins, polycaprolactone resins, poly ( Saccharide) -based resins, poly (ethylene oxide) -based resins, poly (ethylene glycol) -based resins, and the like, and copolymers thereof. Examples of the metal species constituting the metal layer include aluminum and stainless steel. The preferred thickness of each layer is, for example, as follows.
First resin layer: preferably 10 to 100 μm, more preferably 20 to 50 μm
Second resin layer: preferably 10 to 100 μm, more preferably 20 to 50 μm
Metal layer: preferably 10 to 200 μm, more preferably 50 to 100 μm

  When the electricity storage device according to the present embodiment has a solid electrolyte layer containing a silver ion conductive solid electrolyte that is resistant to humidity, it is a case where charging / discharging is performed in the atmosphere without an exterior body. Can be charged and discharged well.

1.2. Hereinafter, each configuration of the electricity storage device according to the present embodiment will be described in detail.

1.2.1. Bipolar electrode The bipolar electrode used in the present embodiment includes a conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer. One of the first active material layer and the second active material layer functions as a positive electrode active material layer, and the other functions as a negative electrode active material layer.

1.2.1.1. Conductive layer The material of the conductive layer is not particularly limited as long as it has electronic conductivity. Examples of the material for the conductive layer include a metal material and a carbon material.

  Examples of the metal material include Cu, Ni, V, Au, Pt, Al, Mg, Fe, Ti, Co, Zn, Ge, In, Li, Ni, Ta, and one or more of these. Examples thereof include alloys. Among these, it is preferable to use Al, Al alloy, Cu, Cu alloy or stainless steel. As said carbon material, a carbon fiber nonwoven fabric, a carbon fiber woven fabric, a graphene sheet, a carbon sheet etc. are mentioned, for example.

  The conductive layer may be formed by depositing the above metal material or carbon material on a suitable substrate. Examples of the substrate include polyamide, polyimide, polyethylene terephthalate, polyphenylene sulfide, polypropylene, glass, and silicon.

  As the conductive layer used in this embodiment, a metal material is preferably used, and the metal material is more preferably used in the form of a metal foil, an etching metal foil, an expanded metal, or the like.

  Although the thickness of a conductive layer is not specifically limited, For example, it is preferable to set it as the range of 0.5-50 micrometers. In the case where a metal layer or a carbon material deposited on a substrate is used as the conductive layer, the above thickness is a numerical value including the thickness of the substrate.

  As a conductive layer, from the viewpoint of obtaining a device with high yield and excellent flexibility and charge / discharge cycle characteristics by relaxing the stress generated inside the device when the device is bent or expanded or contracted, It is desirable to include. Such a polymer is preferably a thermoplastic elastomer because it can impart excellent elasticity to the conductive layer at room temperature. The glass transition temperature (Tg) of the thermoplastic elastomer is preferably −80 ° C. to + 250 ° C., more preferably −75 ° C. to + 130 ° C., and further preferably −70 ° C. to + 10 ° C.

  Examples of the thermoplastic elastomer include a styrene-butadiene elastomer, a styrene-isoprene elastomer, a polyolefin elastomer, a vinyl chloride elastomer, a polyester elastomer, a polyurethane elastomer, and a nylon elastomer. Among these, polyolefin elastomer, styrene-butadiene elastomer, styrene-ethylene-styrene elastomer, styrene-ethylene-butadiene-styrene elastomer, polyamide-polyether-polyamide elastomer, polyamide-polyether elastomer, polyester- It is preferable to use one or more selected from the group consisting of polyether-based elastomers, polyurethane-polyester-based elastomers, polyester-polyether-polyester-based elastomers, and polyurethane-polyester-polyurethane-based elastomers, and repetition derived from styrene. A styrene-butadiene elastomer having a unit and a repeating unit derived from butadiene is more preferable. In the present specification, “elastomer” is a concept including a polymer in which an elastomer is modified by hydrogenation.

  The amount of the polymer in the conductive layer is preferably 10 to 95% by mass, more preferably 30 to 90% by mass, and particularly preferably 40 to 85% by mass. When the content ratio of the polymer in the conductive layer is in the above range, stress relaxation can be effectively performed when stress is generated inside the device, and it is effective that cracking and peeling occur inside the device. It can suppress and it can suppress more that the yield and characteristic of a device fall.

1.2.1.2. 1st active material layer and 2nd active material layer The 1st active material layer and 2nd active material layer (henceforth a "electrode active material layer" hereafter) used by this Embodiment are (A) electrolyte It can be produced from a composition containing at least particles and (B) active material particles (hereinafter also simply referred to as “composition”). The electrode active material layer may be directly formed on the above-described conductive layer, or may be formed on the surface of the substrate sheet and then transferred onto the conductive layer. In the latter case, as the base sheet, for example, a sheet made of PET, polyolefin, fluororesin, or the like can be used.

  In order to form an electrode active material layer on the surface of a conductive layer or a substrate sheet, for example, a coating film is formed by applying the composition on the surface of the conductive layer or the substrate sheet, and then dispersed from the formed coating film. Depending on the method of removing the medium. Press coating may optionally be performed on the coating film after the dispersion medium is removed.

  In the above application, for example, a doctor blade method, a reverse roll method, a comma bar method, a gravure method, an air knife method, or the like can be applied. The dispersion medium can be removed by a method in which the coating film formed by coating is allowed to stand at a predetermined temperature for a predetermined time. The temperature at this time is preferably 20 to 250 ° C., more preferably 50 to 150 ° C .; the time is preferably 1 to 120 minutes, and more preferably 5 to 60 minutes.

In order to press the coated film after the dispersion medium is removed, an appropriate processing machine such as a high pressure super press, a soft calendar, or a one-ton press can be used. The conditions for the press working can be appropriately set according to the processing machine to be used and a desired relative density (described later).

  The electrode active material layer thus formed preferably has a thickness of 0.1 to 1,000 μm, and more preferably 40 to 150 μm. When the same type of electrode active material layer is used for the positive electrode and the negative electrode, and the positive and negative electrodes are produced by the difference in film thickness, the film thickness for the positive electrode is preferably 0.1 to 500 μm, The film thickness for the negative electrode is preferably 0.1 to 500 μm, more preferably 20 to 120 μm.

  The ratio T1 / T2 is preferably 0.8 to 1.2 when the thickness of the first active material layer is T1 and the thickness of the second active material layer is T2. By setting the ratio of the thickness of the first active material layer and the second active material layer in the above range, the first active material layer formed on both surfaces of the current collector is changed in volume by charging and discharging. Therefore, the bipolar electrode can be prevented from warping or deforming in accordance with the volume change of the active material layer accompanying charge / discharge. When the value of the ratio T1 / T2 is 0.8 to 1.2, the active material contains at least Ag and V, and the composition ratio of Ag to V in the active material is 0.35 to 0.20. As a result, the above-described effects are more remarkably exhibited.

Density of the electrode active material layer is preferably 1.0~15g / cm ^3, more preferably 1.5~12g / cm ^3. The relative density of the electrode active material layer is preferably in the range of 70 to 99.99%, and more preferably in the range of 80 to 99.9%. The relative density of the electrode active material layer can be obtained by dividing the actual density of the electrode active material layer by the theoretical density of the electrode active material layer. The theoretical density of the electrode active material layer can be obtained by multiplying the solid composition specific gravity by the solid composition volume fraction.

  Hereinafter, the components contained in the composition used for producing the electrode active material layer will be described in detail.

<(A) Electrolyte particles>
The composition used in the present embodiment contains (A) electrolyte particles. (A) As electrolyte particle, it is preferable to use the solid electrolyte material which is an inorganic compound which has ion conductivity. Examples of the ion species to be conducted include metal ions such as lithium ions and silver ions.

Examples of the lithium ion conductive solid electrolyte material include an amorphous oxide solid electrolyte material containing lithium atoms, an amorphous sulfide solid electrolyte material containing lithium atoms, and a crystalline solid containing lithium atoms Examples include electrolyte materials. Examples of the amorphous oxide-based solid electrolyte material containing lithium atoms include Li ₂ O—B ₂ O ₃ —P ₂ O ₅ , Li ₂ O—SiO ₂ , Li ₂ O—B ₂ O ₃ , Li ₂ O—B ₂ O ₃ —ZnO and the like can be mentioned. Examples of the amorphous sulfide-based solid electrolyte material containing lithium atoms include Li ₂ S—SiS ₂ , LiI—Li ₂ S—SiS ₂ , LiI—Li ₂ S—P ₂ S ₅ , and LiI—Li _{2. S-B 2 S 3, Li} 3 PO 4 -Li 2 S-Si 2 S, Li 3 PO 4 -Li 2 S-SiS 2, Li 3 PO 4 -Li 2 S-SiS, LiI-Li 2 S-P _{2 O 5, LiI-Li 3} PO 4 -P 2 S 5, Li 2 S-P 2 S 5 , and the like. The crystalline solid electrolyte material containing the lithium atom, for example _{LiI, LiI-Al 2 O 3} , Li 3 N, Li 3 N-LiI-LiOH, Li 1 + x Al x Ti 2 -x (PO 4) 3 ( 0 ≦ x ≦ 2), Li _{1 + x + y} A _x Ti _2−x Si _y P _3−y O1 ₂ (A = Al or Ga; 0 ≦ x ≦ 0.4; 0 <y ≦ 0.6), [(A _1/2 Li _1/2 ) _1-x B _x ] TiO ₃ (A = La, Pr, Nd or Sm; B = Sr or Ba; 0 ≦ x ≦ 0.5), Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _{(4-3 / 2x)} N _x
(X <1), Li _3.6 Si _0.6 P _0.4 O _{4 and the} like.

Examples of silver ion conductive solid electrolyte materials include MAg ₄ I ₅ (M = Rb or K), Ag ₆ I ₄ WO ₄ , 5AgI-3Ag ₂ O-2V ₂ O ₅ , 4AgI-Ag ₂ O-V _{2. O 5, 3AgI-Ag 4 SiO} 4, AgI-Ag 2 O-2B 2 O 3, AgI-Ag 2 O-MoO 3, AgI-Ag 2 O-WO 3 -B 2 O 3, AgI-Ag 2 O- _{CrO 3, AgI-Ag 2 O} -P 2 O 5, AgCl-Ag 2 WO 4, AgBr-Ag 2 WO 4 , and the like. Of these, Ag ₆ I ₄ WO ₄ is preferred because of its high stability to moisture, oxygen and high temperature.

  (A) The median diameter (Da) of the electrolyte particles is preferably 10 to 50 μm, and more preferably 20 to 45 μm. (A) The ionic conductivity of the electrolyte particles is considered to be higher on the surface than on the inside. Therefore, by using the (A) electrolyte particles in the above particle size range, the surface area contributing to ionic conductivity can be set to an appropriate value, the above-described conductive path is ensured, and the migration resistance of metal ions is reduced. It is also preferable because it can be used.

<(B) Active material particles>
The composition used in the present embodiment contains (B) active material particles. The active material particles (B) are preferably active material materials that can occlude and release metal ions. The metal ion species to be occluded / released is preferably the same as the ion species ion-conducted by the (A) electrolyte particles, and examples thereof include lithium ions and silver ions.

Examples of the active material that absorbs and releases lithium ions include metal-based active materials containing lithium atoms, oxide-based active materials containing lithium atoms, sulfide-based active materials containing lithium atoms, and lithium cobalt nitride. Examples thereof include system active materials. Examples of the metal-based active material containing lithium atoms include lithium metal and lithium alloys (for example, at least one selected from the group consisting of LiM, M = Sn, Si, Al, Ge, Sb, and P). It is done. Examples of the oxide-based active material containing lithium atoms include lithium cobaltate (Li _(1-x) CoO ₂ , x = 0 to 0.5), lithium nickelate (Li _(1-x) NiO ₂ , x = 0-0.5), LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , lithium manganate (LiMn ₂ O ₄ ), Li _{1 + x} Mn _{2- xy My} O ₄ (M = Al 1 or more selected from the group consisting of Mg, Co, Fe, Ni and Zn; 0 ≦ x + y ≦ 2), Li _x Co _y Sn _z O ₂ (where x, y and z are each 0.05 ≦ x ≦ 1.1, 0.85 ≦ y ≦ 1, 0.001 ≦ z ≦ 0.1), Li _(1-x) Co _(1-y) Ni _y O ₂ (0.5 <x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1), lithium titanate, lithium phosphate (LiMPO ₄ , M = Fe, Mn, Co, and one selected from the group consisting of Co and Ni), lithium silicon oxide, and the like. Examples of the sulfide-based active material containing lithium atoms include titanium sulfide (TiS ₂ ).

Examples of the active material that occludes / releases silver ions include silver metal, silver chevrel compound, vanadium pentoxide-silver compound (Ag _x V ₂ O ₅ , x = 0.9 to 0.1). In particular, when x = 0.7 to 0.4, the volume change accompanying the charge / discharge of the active material contained in the first active material layer and the second active material layer is changed to the first formed on both surfaces of the current collector. Since it can suppress on both surfaces of the 1 active material layer and the 2nd active material layer, it can suppress that a bipolar electrode warps or deform | transforms according to the volume change of the active material layer accompanying charging / discharging. .

Examples of the active material that absorbs and releases both lithium ions and silver ions include, for example, an alloy-based active material that does not contain any lithium atom or silver atom, an oxide-based active material that does not contain any lithium atom or silver atom, Sulfide-based active materials containing neither lithium atoms nor silver atoms, metal halide active materials containing neither lithium atoms nor silver atoms, carbon-based active materials, conductive polymer-based active materials, fluorine compounds, etc. Can be mentioned. Examples of the alloy containing neither lithium nor silver are selected from the group consisting of MgM (at least one selected from the group consisting of M = Sn, Ge and Sb) and NSb (N = In, Cu and Mn). At least one). Examples of the oxide active material containing neither lithium atom nor silver atom include vanadium oxide (V ₂ O ₅ ), molybdenum oxide (MoO ₃ ), MnO ₂ , MoO ₃ , V ₂ O ₅ , and V ₆ O. ₁₃ , Fe ₂ O ₃ , Fe ₃ O ₄ , tin oxide and the like. Examples of the sulfide-based active material containing neither lithium atom nor silver atom include TiS ₂ , TiS ₃ , MoS ₃ , FeS _{2 and the} like. Examples of the metal halide active material containing neither lithium atom nor silver atom include CuF ₂ and NiF ₂ . Examples of the carbon-based active material include carbon fluoride, graphite, hard carbon, vapor-grown carbon fiber, PAN-based carbon fiber, and pitch-based carbon fiber. Examples of the conductive polymer active material include polyacetylene and poly-p-phenylene.

  The active material particles (B) used in the present embodiment are not clearly distinguished as positive electrode active material particles and negative electrode active material particles. The same type of active material particles may be used for positive and negative electrodes, or different types of active material particles may be used. When the same kind of active material particles is used for positive and negative electrodes, the positive and negative electrode films may be used with the same film thickness, or may be used with a difference in film thickness. When different types of active material particles are used for positive and negative electrodes, an electrode made of a material having a higher Fermi rank is used for the positive electrode.

  (B) The median diameter (Da) of the active material particles is preferably 5 to 100 μm, and more preferably 15 to 50 μm. By using the active material particles (B) in the above particle size range, the effect of improving the electron path formation of the active material by increasing the particle size and the required diffusion distance of the metal ions responsible for charge in the active material by reducing the particle size Since both effect balances, such as a reduction effect, become favorable, electronic resistance and ionic resistance are reduced, which is preferable.

<Other additives>
The electrode active material layer used in the present embodiment is prepared from a composition containing (A) electrolyte particles and (B) active material particles as essential components as described above. Depending on the above, other components other than these may be contained. Examples of other components include a dispersion medium, a binder, an electrode deterioration preventing agent, and a conductive aid.

-Dispersion medium When the composition is in the form of a slurry for producing an electrode active material layer, the dispersion medium that can be used for such an electrode slurry includes (A) electrolyte particles and (B) active material particles. It is preferable to use a nonpolar liquid organic medium from the viewpoints of stably dispersing and suppressing these alterations as much as possible.

  Examples of the nonpolar liquid organic medium include aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. Examples of the aliphatic hydrocarbon include hexane, heptane, octane, decane, and dodecane. Examples of the alicyclic hydrocarbon include cyclohexane, cycloheptane, cyclooctane, cyclodecane, and cyclododecane. Examples of the aromatic hydrocarbon include toluene, xylene, mesitylene, cumene and the like. These nonpolar liquid organic media may be used alone or in combination of two or more.

-Binder In the composition used in the present embodiment, the binding between (A) the electrolyte particles and (B) the active material particles and between these and the conductive layer is strengthened, From the viewpoint of imparting flexibility, a binder can be added.

  Examples of such a binder include celluloses such as methyl cellulose (MC), carboxymethyl cellulose (CMC), and ethyl cellulose (EC); polyvinyl alcohol, polyacrylate, polyalkylene oxide (for example, polyethylene oxide), and polyvinylidene fluoride. Fluoropolymers such as (PVDF), polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP); (meth) acrylic acid ester (co) polymer, styrene- (meth) Acrylate ester copolymer, styrene-butadiene copolymer, hydrogenated product of styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene, hydrogenated product of polybutadiene, polyolefin, poly Mick acid, polyimide, polylactic acid, chitin, chitosan and the like, can be used a known material as a binder in the electrode slurry.

  The binder is made of the material as described above, and its glass transition temperature (Tg) is preferably −80 ° C. to + 250 ° C., more preferably −75 ° C. to + 130 ° C., and further preferably −70 ° C. to + 10 ° C. It is preferable to be an elastomer. In particular, at least one selected from the group consisting of polyolefin elastomers, styrene-ethylene elastomers, styrene-butadiene elastomers, polyamide-polyether elastomers, polyester-polyether elastomers, and polyurethane-polyester elastomers. It is preferable to use it.

-Electrode degradation preventive agent When the electrode active material layer used in the present embodiment contains a binder as described above, the electrode degradation preventive agent prevents degradation of the binder, active material, and electrolyte, Therefore, it can be used to prevent deterioration of the active material sheet.

  As such an electrode deterioration preventing agent, for example, a maleimide compound can be preferably used, and specific examples include compounds represented by the following general formulas (1) and (2).

（上記式（１）中のＸ^１は、フェニル基、ヒドロキシフェニル基、カルボキシフェニル基、ニトロフェニル基、メトキシフェニル基、エトキシフェニル基、炭素数１〜５のアルキル基、炭素数１〜５のアルケニル基もしくはシクロヘキシル基であるか、あるいは炭素数１〜５のアルキル基を有するアルキルフェニル基であり；
上記式（２）中のＸ^２は、１，６−へキシレン基、フェニレン基もしくは３−メチル−１，２−フェニレン基であるか、あるいは下記式

（上記式中のＹは、酸素原子、メチレン基または−ＳＯ_２−である。）で表される２価の基である。）

(X ¹ in the above formula (1) is a phenyl group, a hydroxyphenyl group, a carboxyphenyl group, a nitrophenyl group, a methoxyphenyl group, an ethoxyphenyl group, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. An alkenyl group or a cyclohexyl group, or an alkylphenyl group having an alkyl group having 1 to 5 carbon atoms;
X ² in the above formula (2) is 1,6-hexylene group, phenylene group or 3-methyl-1,2-phenylene group, or the following formula

(Y in the above formula is an oxygen atom, a methylene group or —SO ₂ —). )

  When the electrode deterioration preventing agent is in a solid state, it is preferably used in a powder state having a median diameter of 100 μm or less, preferably 0.001 to 10 μm.

-Conductive auxiliary agent As a conductive auxiliary agent, a carbon material, a metal (however, except lithium and silver), etc. can be used. Examples of the carbon material include carbon black such as acetylene black. Examples of the metal include nickel. The conductive assistant is preferably used in a powder state having a median diameter of 100 μm or less, preferably 0.001 to 50 μm.

<Content ratio of each component>
The preferable content rate of each component in the composition used by this Embodiment is as follows, respectively.
-Use ratio of (A) electrolyte particles and (B) active material particles: (A) As a ratio (Ma / Mb) between the mass (Ma) of the electrolyte particles and the mass (Mb) of the (B) active material particles, Preferably 70/30 to 1/99, more preferably 50/50 to 5/95
Binder: preferably 30% by volume or less, more preferably 20-1% by volume, based on the total amount of the composition
-Electrode deterioration preventing agent: preferably 80 parts by mass or less, more preferably 50-1 part by mass with respect to 100 parts by mass of the binder-Conductive auxiliary agent: (B) preferably with respect to 100 parts by mass of the active material particles Is 20 parts by mass or less, more preferably 1 to 15 parts by mass. Dispersion medium: solid content concentration in the composition (the ratio of the total mass of components other than the dispersion medium in the composition to the total mass of the composition) As, preferably 5 to 90% by mass, more preferably 10 to 80% by mass

1.2.2. Solid electrolyte layer The solid electrolyte layer used in the present embodiment preferably contains a silver ion conductive solid electrolyte. When the solid electrolyte layer contains a silver ion conductive solid electrolyte, an electric storage device having an arbitrary capacity can be manufactured by dividing the laminate into an arbitrary shape and size. That is, the capacity can be freely controlled according to the divided area. When a laminate having a conventional solid electrolyte layer is cut, the solid electrolyte layer is easily collapsed or the interface is peeled off at the time of cutting, and the yield is reduced due to a short circuit. However, a solid electrolyte layer containing a silver ion conductive solid electrolyte is unlikely to cause such a problem and can be cut out with a high yield.

  In addition, since the silver ion conductive solid electrolyte is very resistant to humidity, even when the power storage device according to the present embodiment is charged and discharged in the air without an outer package, it can be charged and discharged satisfactorily. It becomes.

The shape of the solid electrolyte layer can be, for example, a thin film or a powder compact. The thickness of the solid electrolyte layer is preferably 0.1 to 1000 μm, more preferably 1 to 100 μm.
m.

As the silver ion conductive solid electrolyte material, for example _MAg 4 _I 5 (M = Rb or _{K), Ag 6 I 4 WO} 4, 5AgI-3Ag 2 O-2V 2 O 5, 4AgI-Ag 2 O-V 2 _{O 5, 3AgI-Ag 4 SiO} 4, AgI-Ag 2 O-2B 2 O 3, AgI-Ag 2 O-MoO 3, AgI-Ag 2 O-WO 3 -B 2 O 3, AgI-Ag 2 O- _{CrO 3, AgI-Ag 2 O} -P 2 O 5, AgCl-Ag 2 WO 4, AgBr-Ag 2 WO 4 , and the like. Of these, Ag ₆ I ₄ WO ₄ is preferred because of its high stability to moisture, oxygen and high temperature.

  The solid electrolyte layer may be composed only of the silver ion conductive solid electrolyte material, or may contain other components other than the silver ion conductive solid electrolyte material. Examples of other components include non-woven fabric, woven fabric, and net-like body.

  The network can be used for the purpose of reinforcing the mechanical strength of the solid electrolyte layer. Examples of the network include a polymer film made porous by processing such as stretching. In the case of using the network, the solid electrolyte layer is filled with the solid electrolyte and other components (excluding the network) in the openings of the network, and the upper and lower sides of the network after the filling have a thickness of 5 to 5. It can be set as the structure pinched | interposed by the solid electrolyte layer of about 25 micrometers. The opening ratio of the mesh body is preferably in the range of 15% to 65%. Here, the aperture ratio is defined by the ratio (percentage) of the area of the total opening per unit area of the mesh body. If the aperture ratio is less than 15%, the conductivity of the solid electrolyte layer may be small, and if the aperture ratio exceeds 65%, the strength of the solid electrolyte layer may be insufficient.

The thickness of the mesh body is preferably 10 to 150 μm, and the average area per opening of the mesh body is preferably 1.6 × 10 ⁻³ mm ^{2 to} 9 × 10 ⁻² mm ^2. . Moreover, it is preferable that the width | variety between adjacent opening parts is 20 micrometers-120 micrometers. Basis weight of the case of the nonwoven fabric ^is preferably ^{5g / m 2 ~50g / m 2} .

  Examples of the material constituting the net-like body include nylon 6, nylon 66, polypropylene, polyethylene, polyester, and the like.

  The content ratio of the silver ion conductive solid electrolyte material in the solid electrolyte layer is preferably 80% by mass or more, and more preferably 85% by mass or more.

1.3. Method for Manufacturing Power Storage Device The method for manufacturing the power storage device according to the present embodiment is not particularly limited as long as it has the above structure. The electricity storage device according to the present embodiment can be manufactured, for example, by the following method. That is, it is a method of laminating each layer so as to be the above-described laminated body, and sealing the obtained laminated body with an exterior body. After laminating each layer to form a laminate, the laminate may be thermally compressed using a hot press or the like.

  The electricity storage device manufactured in this manner has high electromotive force and excellent charge / discharge characteristics, and the electromotive force and charge / discharge characteristics are not deteriorated even by repeated charge / discharge.

1.4. Shape of power storage device and method of use The shape of the power storage device according to the present embodiment is not particularly limited as long as it has the above structure. The shape of the electricity storage device according to the present embodiment can be an appropriate shape such as a coin shape, a button shape, a sheet shape, a cylindrical shape, a square shape, or a flat shape. In addition, since the electricity storage device according to the present embodiment does not use an electrolytic solution, after manufacturing the laminated structure, the shape can be freely processed by cutting, drilling, bending, and the like according to the mounting method. it can.

  FIG. 2 is a plan view showing one usage pattern of the electricity storage device according to the present embodiment. In the example of FIG. 2, an image in the case where the power storage device according to the present embodiment is applied to the space of the mounting substrate 26 in which the protrusions 22 a, 22 b, 22 c, 22 d such as capacitors or sensors are formed on the substrate 20. Represents. As shown in FIG. 2, the power storage device 101 can cut a part corresponding to the protrusions 22 a, 22 b, 22 c, and 22 d formed on the mounting substrate 26, or make a hole. Then, by bonding the power storage device 101 to the mounting substrate 26, the space occupied by the power storage device can be reduced, and space saving can be realized.

  FIG. 3 is a conceptual diagram showing one usage pattern of the electricity storage device according to the present embodiment. In the example of FIG. 3, an image in the case where the power storage device according to the present embodiment is applied to the recess 32 of the mounting substrate 30 is illustrated. As shown in FIG. 3, the space occupied by the electricity storage device can be reduced by fitting the electricity storage device 102 in which the convex portion is formed by cutting into the recess 32 of the mounting substrate 30, thereby saving space. Can be realized.

  FIG. 4 is a conceptual diagram showing one usage pattern of the electricity storage device according to the present embodiment. In the example of FIG. 4, an image in the case where the power storage device according to the present embodiment is applied to the space 42 of the mounting substrate 40 is shown. The electricity storage device according to this embodiment can be bent as described above. Therefore, as shown in FIGS. 4A and 4B, the space occupied by the electricity storage device can be reduced by bending the electricity storage device 103 and fitting it into the space 42 of the mounting substrate 40. Thus, space saving can be realized.

  Furthermore, since the electricity storage device according to the present embodiment is all solid, the thermal conductivity is greatly improved as compared with an electricity storage device using an electrolytic solution. Further, since there is no danger of gas generation due to thermal decomposition of the electrolytic solution, the heat resistance is greatly improved. For this reason, it can utilize also as a heat sink for cooling a heat generating body.

  FIG. 5 is a conceptual diagram showing a usage pattern in which the electricity storage device according to the present embodiment is used as a heat sink. In the example illustrated in FIG. 5A, the plurality of power storage devices 104 are arranged substantially vertically with respect to the base 50. On the other hand, in the example shown in FIG. 5B, the power storage device 104 in the vicinity of the center of the base 50 is erected substantially perpendicular to the base 50, and the peripheral power storage device 104 is curved toward the outer peripheral direction. is set up. With such a structure, it is considered that the heat dissipation effect can be expressed more effectively. By using the power storage device according to the present embodiment as a heat sink, it is not necessary to separately install a heat sink for the purpose of heat dissipation, and a reduction in space can be achieved.

  For example, by using the power storage device according to the present embodiment as a heat sink of an electrothermal element that converts thermal energy into electric energy by the Seebeck effect, etc., not only can the generated power be stored, but also the heat dissipation effect can be improved. Power generation efficiency can be improved.

  In addition, since the electricity storage device according to the present embodiment is all solid, durability against mechanical shock and vibration is greatly improved as compared to an electricity storage device using an electrolytic solution. For this reason, it can be suitably used for a device that requires impact resistance such as vibration power generation. Note that the heat resistance and high mechanical strength of the electricity storage device according to the present embodiment can also be used as a panel reinforcing material for solar cells.

2. EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. “Part” and “%” in Examples and Comparative Examples are based on mass unless otherwise specified.

2.1. Preparation of Electrolyte Particles and Active Material Particles For the preparation of each particle described below, the necessary amount for subsequent use was ensured by repeating the following operations on the scale described below as necessary.

(1) Preparation of electrolyte particles 1
Using an uniaxial automatic mortar (manufactured by Nissho Science Co., Ltd., model number “ANM-1000”), 50 g of Ag ₆ I ₄ WO ₄ (manufactured by Nippon Inorganic Chemical Industries, Ltd., purity 98%) as electrolyte particles Electrolytic particles (Ag ₆ I ₄ WO ₄ ) were obtained by pulverizing in the atmosphere at 25 ° C. and 50% RH for 1 hour at 120 rpm. The electrolyte particles obtained in this way are indicated as “Ag ₆ I ₄ WO ₄ ” in Table 1.

(2) Preparation of electrolyte particles 2
In a glove box controlled to have a dew point of −80 ° C. or lower under an argon atmosphere, 28 g of Si (manufactured by High Purity Chemical Laboratory, Inc., purity 99.99%) and S (high purity chemical research) Each crystal powder of 64 g (purity 99.999%) together with zirconia balls is placed in a zirconia container and treated for 160 hours using a planetary ball mill apparatus (manufactured by Fritsch, model number “P-5”), and SiS ₂ was prepared.

Subsequently, in a glove box controlled to have a dew point of −80 ° C. or lower under an argon atmosphere, SiS ₂ prepared above and Li ₂ S having the same number of moles as that of Li ₂ S (manufactured by Furuuchi Chemical Co., Ltd., purity: 99. 9%) of powder is mixed and mixed so as to be 50 g in total, and pulverized for 1 hour under the condition of 120 rpm using a uniaxial automatic mortar (manufactured by Nippon Ceramics Co., Ltd., model number “ANM-1000”). By processing, Li ₂ S—SiS ₂ electrolyte particles (Li ₂ S—SiS ₂ ) were obtained. The electrolyte particles obtained in this way are indicated as “Li ₂ S—SiS ₂ ” in Table 1.

(3) Preparation of active material particles 1
Using an uniaxial automatic mortar (manufactured by Nippon Ceramics Co., Ltd., model number “ANM-1000”), Ag _0.7 V ₂ O ₅ (manufactured by Nippon Inorganic Chemical Co., Ltd., purity 98%) as active material particles ) The active material particles (Ag _0.7 V ₂ O ₅ ) were obtained by pulverizing 50 g in the atmosphere at 25 ° C. and 50% RH under the condition of 120 rpm for 1 hour. The active material particles thus obtained are represented as “Ag _0.7 V ₂ O ₅ ” in Table 1.

(4) Preparation of active material particles 2
Using an uniaxial automatic mortar (manufactured by Nippon Ceramics Co., Ltd., model number “ANM-1000”), Ag _0.6 V ₂ O ₅ (manufactured by Nippon Inorganic Chemical Industry Co., Ltd., purity 98%) as active material particles ICP analysis value Ag / V = 0.29) 50 g of active material particles (Ag _0.58 V ₂₎ by pulverizing in the atmosphere at 25 ° C. and 50% RH under the condition of 120 rpm for 1 hour. O ₅₎ was obtained. The active material particles obtained in this way are indicated as “Ag _0.58 V ₂ O ₅ ” in Table 1.

(5) Preparation of active material particles 3
Using an uniaxial automatic mortar (manufactured by Nissho Science Co., Ltd., model number “ANM-1000”), 50 g of LiCoO ₂ (manufactured by Hayashi Kasei Co., Ltd., purity 99%) as active material particles in the atmosphere Active material particles (LiCoO ₂ ) were obtained by grinding for 1 hour under conditions of 120 rpm in an environment of 50 ° C. and 50% RH. The active material particles thus obtained are shown in Table 1 as “L
iCoO ₂ ”.

(6) Preparation of active material particles 4
Using an uniaxial automatic mortar (manufactured by Nissho Science Co., Ltd., model number “ANM-1000”), 50 g of graphite (manufactured by Hitachi Chemical Co., Ltd.) as active material particles was added to the atmosphere at 25 ° C. and 50% RH. Then, active material particles were obtained by grinding for 1 hour under the condition of 120 rpm. The active material particles obtained in this way are indicated as “C” in Table 1.

2.2. Production of active material sheet (1) Production of active material sheet 1
The electrolyte obtained in the above-mentioned “(1) Preparation of electrolyte particles 1” in a polypropylene light-shielding bottle (manufactured by Sun Platec Co., Ltd.) having a capacity of 100 mL in an argon atmosphere glove box controlled at a dew point of −90 ° C. or lower. 37 g of particles, 37 g of active material particles obtained in “(3) Preparation of active material particles 1” or “(4) Preparation of active material particles 2”, 0.2 g of 4,4′-bismaleimide diphenylmethane, styrene Mixing 0.3 g of butadiene elastomer (trade name “TR2000” manufactured by JSR Corporation), 2 g of styrene-ethylene-butadiene elastomer (trade name “G1652” manufactured by Kraton Polymer Japan Co., Ltd.) and 23.5 g of toluene. did.

  In a 100 mL polypropylene light-shielding bottle (manufactured by Sun Platec Co., Ltd.), the total amount (100 g) of the mixture obtained above and 30 g of zirconia balls having a diameter of 5 mm were charged, and the bottle was sealed. The bottle after sealing was attached to a paint shaker (manufactured by Toyo Seiki Seisakusho) and mixed in the atmosphere at 25 ° C. and 50% RH for 1.5 hours. Subsequently, the zirconia ball | bowl was isolate | separated using stainless steel # 80 sieve (JISZ8801), and the slurry for active material sheets of 76.5 mass% of solid content concentration was obtained.

  The obtained slurry for an active material sheet was applied onto a coating film (manufactured by Yasuda Seiki Seisakusho, model number “No. 542”) on a PET film having a thickness of 38 μm (manufactured by Teijin DuPont Films, model number “A71”). -AB ") in the atmosphere at 25 [deg.] C. and 50% RH in an environment of 500 [mu] m and uniformly coated by the doctor blade method to form a film.

  The deposited PET film was heated in an explosion-proof oven (manufactured by Enomoto Kasei Co., Ltd., model number “HT220S”) in the atmosphere at 80 ° C. for 0.5 hours to distill off the solvent. An active material sheet having a thickness of 100 μm was produced by peeling.

(2) Production of active material sheet 2
An active material sheet having a thickness of 85 μm was obtained in the same manner as in “(1) Preparation of active material sheet 1” except that the doctor blade used was 420 μm.

(3) Production of active material sheet 3
The electrolyte particles used were Li ₂ S—SiS ₂ obtained in “(2) Preparation of electrolyte particles 2”, and the active material particles used were LiCoO ₂ obtained in “(5) Preparation of active material particles 3”. Except for the above, an active material sheet having a thickness of 100 μm was obtained in the same manner as in “(1) Production of active material sheet 1”.

(4) Production of active material sheet 4
The electrolyte particles to be used are Li ₂ S—SiS ₂ obtained in “(2) Preparation of electrolyte particles 2”, and the active material particles to be used are graphite obtained in “(6) Preparation 4 of active material particles”. Except for the above, an active material sheet having a thickness of 100 μm was obtained in the same manner as in “(1) Production of active material sheet 1”.

2.3. Preparation of electrolyte sheet (1) Preparation of electrolyte sheet 1
The electrolyte prepared in the above-mentioned “(1) Preparation of electrolyte particles 1” in a 100 mL polypropylene light-shielding bottle (manufactured by Sun Platec Co., Ltd.) in an argon atmosphere glove box whose atmosphere is controlled to a dew point of −90 ° C. or less. 56 g of particles, 4 g of 4,4′-bismaleimide diphenylmethane, 1 g of a styrene-butadiene elastomer (manufactured by JSR Corporation, trade name “TR2000”), a styrene-butadiene elastomer (manufactured by Kraton Polymer Japan Co., Ltd., trade name “ G1652 ") and 4 g of toluene were mixed.

  In a 100 mL polypropylene light-shielding bottle (manufactured by Sun Platec Co., Ltd.), the total amount (100 g) of the mixture obtained above and 30 g of zirconia balls having a diameter of 5 mm were charged, and the bottle was sealed. The bottle after sealing was attached to a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and mixed in the atmosphere at 25 ° C. and 50% RH for 1.5 hours. Subsequently, the zirconia ball | bowl was isolate | separated using stainless steel # 80 sieve (JISZ8801), and the slurry for electrolyte sheets of 65 mass% of solid content concentration was obtained.

  The obtained slurry for an electrolyte sheet was applied onto a coating film (manufactured by Yasuda Seiki Seisakusho Co., Ltd., model number “No. 542”) on a PET film having a thickness of 38 μm (manufactured by Teijin DuPont Films, model number “A71”). AB ”) in the atmosphere at 25 ° C. and 50% RH, and uniformly coated by the doctor blade method under the conditions of a coating gap of 170 μm and a coating speed of 5.8 cm / second.

  The formed PET film is heated in an explosion-proof oven (Enomoto Kasei Co., Ltd., model number “HT220S”) in the atmosphere at 80 ° C. for 0.5 hours to distill off the solvent, and the PET film is removed. An electrolyte sheet having a thickness of 60 μm was produced by peeling from above.

(2) Production of electrolyte sheet 2
An electrolyte sheet was obtained in the same manner as in “(1) Preparation of electrolyte sheet 1” except that the electrolyte particles used were Li ₂ S—SiS ₂ obtained in “(2) Preparation of electrolyte particles 2”. .

2.4. Production of conductive sheet (1) Production of conductive sheet 1
In a 100 mL polypropylene light-shielding bottle (manufactured by Sun Platec Co., Ltd.), 1.25 g of Ketjen Black EC (manufactured by Ketjen Black International, specific gravity 1.6 g / cm ³ ), styrene-butadiene elastomer (Clayton polymer) Made in Japan, trade name “G1652”, specific gravity 0.9 g / cm ³ ) 2.5 g, toluene 22.6 g and zirconia balls 30 g having a diameter of 5 mm were charged, and the bottle was sealed. The bottle after sealing was attached to a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and mixed in the atmosphere at 25 ° C. and 50% RH for 1.5 hours. Subsequently, the slurry for electrically conductive sheets was obtained by isolate | separating a zirconia ball | bowl using stainless steel # 80 sieve (JISZ8801).

  The obtained slurry for a conductive sheet was applied to a coating film (manufactured by Yasuda Seiki Seisakusho, model number “No. 542”) on a PET film (made by Teijin DuPont Films, model number “A71”) having a thickness of 38 μm. AB ”) in the atmosphere at 25 ° C. and 50% RH, and uniformly coated by a doctor blade method under the conditions of a coating gap of 100 μm and a coating speed of 5.8 cm / second.

The deposited PET film is made into an explosion-proof oven (Enomoto Kasei Co., Ltd., model number “HT22”).
0S ") in the atmosphere at 80 ° C. for 0.5 hours to distill off the solvent, and peel off from the PET film, thereby containing a conductive sheet having a thickness of 9 μm containing 67% by mass of the polymer. Was made. The conductive sheet thus obtained was indicated as “carbon sheet A” in the table.

(2) Production of conductive sheet 2
Except for the addition amount of ketjen black of 0.7 g and the addition amount of styrene-butadiene elastomer (made by Kraton Polymer Japan Co., Ltd., trade name “G1652”) of 3.05 g, the above “(1) conductive sheet” In the same manner as in “Production 1”, a conductive sheet containing 81% by mass of a polymer was obtained. The conductive sheet thus obtained is represented as “carbon sheet B” in the table.

(3) Production of conductive sheet 3
Except that the addition amount of ketjen black was 2 g and the addition amount of styrene-butadiene elastomer (product name “G1652” manufactured by Kraton Polymer Japan Co., Ltd.) was 1.75 g, the above “(1) Production of conductive sheet” In the same manner as in “1”, a conductive sheet containing 47% by mass of a polymer was obtained. The conductive sheet thus obtained was represented as “carbon sheet C” in the table.

(4) Production of conductive sheet 4
Except that the addition amount of ketjen black was 2.75 g and the addition amount of styrene-butadiene elastomer (made by Kraton Polymer Japan Co., Ltd., trade name “G1652”) was 1 g, the above “(1) Production of conductive sheet” In the same manner as in “1”, a conductive sheet containing 27% by mass of a polymer was obtained. The conductive sheet thus obtained is represented as “carbon sheet D” in the table.

2.5. Production of electricity storage device (1) Example 1
_Ag 0.7 _V 2 _{O 5} and _Ag 6 _{I 4} WO 4 active material sheet (100 [mu] m) 1 sheet prepared by using as the first active material layer (active material layer), _Ag 6 _I 4 WO as a solid electrolyte layer electrolyte one sheet produced with _4, the active material was prepared using the _Ag 0.7 _V 2 _{O 5} and _Ag 6 _I 4 WO ₄ as the second active material layer (negative electrode active material layer) sheet (100 [mu] m) 2 The sheets were stacked in order and sandwiched between 6 mm thick SUS plates. Then, the first active material layer, the solid electrolyte layer, and the second active material layer are removed by performing a hot press for 10 minutes at 175 ° C. and 400 kg / cm ² using an AS ONE hot press machine and removing the SUS plate. The laminated body laminated | stacked in order of these was obtained.

Next, the laminate was cut into four 80 mm square pieces. Four cut laminates and 18 μm thick copper foil cut into 80 mm square are used as the conductive layer, and the conductive layer, second active material layer, solid electrolyte layer, and first active material layer are sequentially formed from the outermost part. In the state where the laminated body and the conductive sheet were alternately laminated, pressurization was performed for 10 minutes under the press conditions of 175 ° C. and 400 kg / cm ² to produce an electricity storage device composed of the laminated body and the copper foil conductive sheet.

(2) Example 2
An electricity storage device was obtained in the same manner as in Example 1 except that an aluminum foil having a thickness of 30 μm was used as the conductive layer.

(3) Example 3
An electricity storage device in the same manner as in Example 1 above, except that a sheet laminated in the order of carbon sheet A (thickness 9 μm), copper foil (thickness 18 μm), and carbon sheet A (thickness 9 μm) was used as the conductive layer. Got.

(4) Example 4
An electricity storage device was obtained in the same manner as in Example 3 except that the thickness of the copper foil was 25 μm.

(5) Example 5
An electricity storage device was obtained in the same manner as in Example 3 except that the thickness of the copper foil was 10 μm.

(6) Example 6
An electricity storage device was obtained in the same manner as in Example 1 except that carbon sheet A (thickness 9 μm) was used as the conductive layer.

(7) Example 7
An electricity storage device was obtained in the same manner as in Example 1 except that carbon sheet B (thickness 9 μm) was used as the conductive layer.

(8) Example 8
An electricity storage device was obtained in the same manner as in Example 1 except that carbon sheet C (thickness 9 μm) was used as the conductive layer.

(9) Example 9
An electricity storage device was obtained in the same manner as in Example 1 except that carbon sheet D (thickness 9 μm) was used as the conductive layer.

(10) Example 10
An electricity storage device was obtained in the same manner as in Example 6, except that the number of cut laminates used in Example 6 was 2 and the number of carbon sheets A used was 3.

(11) Example 11
An electricity storage device was obtained in the same manner as in Example 6 except that the number of used laminates in Example 6 was 8 and the number of carbon sheets A used was 9.

(12) Example 12
_{Ag 0.58} V ₂ O ₅ and _Ag 6 _{I 4} WO 4 active material sheet (100 [mu] m) 1 sheet prepared by using as the first active material layer (active material layer), _Ag 6 _I 4 WO as a solid electrolyte layer ₄ electrolyte single sheets produced using the active material sheets produced using _{Ag 0.58} V ₂ O ₅ and _Ag 6 _I 4 WO ₄ as the second active material layer (negative electrode active material layer) (100 [mu] m) 1 The sheets were stacked in order and sandwiched between 6 mm thick SUS plates. Then, the first active material layer, the solid electrolyte layer, and the second active material layer are removed by performing a hot press for 10 minutes at 175 ° C. and 400 kg / cm ² using an AS ONE hot press machine and removing the SUS plate. The laminated body laminated | stacked in order of these was obtained.

Next, the laminate was cut into four 80 mm square pieces. A sheet obtained by laminating four cut-out laminates, and a carbon sheet A (thickness 9 μm), copper foil (thickness 18 μm), and carbon sheet A (thickness 9 μm) separately cut into 80 mm squares as a conductive layer In a state in which the laminate and the conductive sheet are alternately laminated so that the conductive layer, the second active material layer, the solid electrolyte layer, and the first active material layer are arranged in this order from the outermost part, 175 ° C., 400 kg / cm ² Pressurization was performed under pressing conditions for 10 minutes to produce an electricity storage device composed of a laminate and a copper foil conductive sheet.

(13) Example 13
An electricity storage device was obtained in the same manner as in Example 12 except that carbon sheet A (thickness 9 μm) was used as the conductive layer.

(14) Example 14
Active material sheet (85 μm) produced using Ag _0.58 V ₂ O ₅ and Ag ₆ I ₄ WO ₄ as the second active material layer (negative electrode active material layer) (“(2) Production of active material sheet 2” A power storage device was manufactured in the same manner as in Example 13 except that one active material sheet manufactured in step 1 was used.

(15) Example 15
Active material sheet (85 μm) produced using Ag _0.58 V ₂ O ₅ and Ag ₆ I ₄ WO ₄ as the first active material layer (positive electrode active material layer) (“(2) Production of active material sheet 2” A power storage device was manufactured in the same manner as in Example 13 except that one active material sheet manufactured in step 1 was used.

(16) Comparative Example 1
_Two active material sheets manufactured using LiCoO ₂ as the first active material sheet (positive electrode active material sheet) on the SUS plate (the active material sheet prepared in “(2) Preparation of active material sheet 3”), One electrolyte sheet manufactured using Li ₂ S—SiS ₂ as the electrolyte sheet, and an active material sheet manufactured using graphite as the second active material sheet (negative electrode active material sheet) (“(3) Production of Active Material Sheet” Active material sheet prepared in step 4)) and one SUS plate are laminated in order, and the first active material sheet is subjected to hot pressing for 10 minutes at 175 ° C. and 400 kg / cm ² using an ASONE hot press. Then, a laminate including a lithium electrolyte in the order of the electrolyte sheet and the second active material sheet was obtained. An electricity storage device was obtained in the same manner as in Example 1 except that the laminate containing the silver electrolyte in Example 1 was changed to the laminate containing the lithium electrolyte.

(17) Comparative Example 2
An electricity storage device was obtained in the same manner as in Example 2 except that the laminate containing the silver electrolyte in Example 2 was changed to a laminate containing the lithium electrolyte produced in Comparative Example 1.

(18) Comparative Example 3
An electricity storage device was obtained in the same manner as in Example 1 except that the number of used laminates in Example 1 was one and the number of copper foils was two.

2.6. Evaluation of electricity storage device <Evaluation of initial discharge characteristics>
Azwan copper foil adhesive tape 831S was attached to the outermost part of the manufactured electricity storage device as an extraction tab. The charge / discharge characteristics of the electricity storage device were evaluated in a constant temperature bath at 25 ° C. and 50% RH. Each power storage device was subjected to constant current charging (hereinafter referred to as “CC charging”) at a charge cutoff voltage shown in Table 1 and a current density of 0.1 mA / cm ² . Further, initial discharge evaluation was performed by performing constant current discharge (hereinafter referred to as “CC discharge”) at a cutoff voltage shown in Table 1 and a current density of 0.1 mA / cm ² . The initial discharge capacity and the average discharge voltage are shown in Table 1 together with the discharge capacity at that time. It can be determined that the initial discharge capacity is preferably 0.1 mAh / cm ² or more, and more preferably 0.12 mAh / cm ² or more. As an average discharge voltage, 0.7V or more is good, and it can be judged that less than 0.7V is bad.

<Evaluation of capacity retention>
For each power storage device, CC charging was performed at the charge cutoff voltage shown in Table 1 and a current density of 0.1 mA / cm ² . Furthermore, CC discharge was performed at a cut-off voltage shown in Table 1 with a current density of 0.5 mA / cm ² . Subsequently, CC charging was performed on the electricity storage device at the charge cutoff voltage shown in Table 1 and a current density of 0.1 mA / cm ² . Furthermore, CC discharge was performed at a current density of 1.0 mA / cm ² . Each discharge capacity was defined as a high-speed discharge capacity. Capacity retention (%) = (high-speed discharge capacity / initial discharge capacity) × 100. 0.
It can be judged that the capacity retention at 5 mA / cm ² is 80% or more, and 90% or more is better. It can be judged that the capacity retention at 1.0 mA / cm ² is 50% or more and 75% or more is better.

<Evaluation of cycle maintenance ratio>
For each power storage device, CC charge / discharge cycle evaluation was performed at a current density of 0.1 mA / cm ² at the cut-off voltage shown in Table 1. The discharge capacity at the 200th time was defined as the cycle capacity, and the cycle retention ratio (%) = (cycle capacity / initial discharge capacity) × 100. It can be judged that the cycle maintenance ratio is 90% or higher and 95% or higher is better.

2.7. Evaluation Results Table 1 below shows the layer configuration of the electricity storage devices used in the examples and comparative examples, and the evaluation results.

The four-layer cell including a silver electrolyte using a metal foil as the conductive layer of Examples 1 and 2 had a good average discharge voltage of about 1.5 V, and had a generally good capacity retention rate and cycle maintenance rate. .

  The four-layer cell including a silver electrolyte using a metal foil and a carbon sheet as the conductive layer of Examples 3 to 5 has a particularly excellent cycle maintenance ratio in addition to the average discharge voltage being about 1.5V. there were. In the serially stacked cell, the conductive layer is sandwiched between the positive electrode and the negative electrode, and the positive electrode and the negative electrode are expanded and contracted in reverse during charge and discharge, so that a large shear load is applied to the conductive layer. In particular, it is considered that the electrode expansion and contraction when silver ions having a larger ion size than lithium or the like are deinserted into the active material is large. By using a carbon sheet containing a polymer that is flexible and capable of relaxing stress, the shear load on the current collecting layer peculiar to the series-stacked cell can be greatly relaxed, so that it is considered that a good cycle retention rate was obtained.

  The four-layer cell including a silver electrolyte using a carbon sheet as the conductive layer of Examples 6 to 9 has a particularly excellent capacity retention rate and cycle retention rate in addition to an average discharge voltage of about 1.5 V. Met. Although the detailed cause of the improvement in the capacity retention rate is unknown, it is presumed that a good capacity retention ratio was expressed by not including the metal foil because the interface resistance between the metal foil and the carbon sheet was high.

  The cells in which the number of stacks containing a silver electrolyte using a carbon sheet as a conductive layer in Examples 10 to 11 were particularly good in capacity retention rate, cycle retention rate, and bending evaluation, but the average discharge voltage was 0. It was a good value of 7V or more. From this result, it was found that there was no problem even if the number of layers was changed, and the voltage could be changed depending on the number of layers.

  In addition to the good average discharge voltage of about 1.5 V in Example 12, the cycle retention rate was particularly good. In the serially stacked cell, the conductive layer is sandwiched between the positive electrode and the negative electrode, and the positive electrode and the negative electrode are expanded and contracted in reverse during charge and discharge, so that a large shear load is applied to the conductive layer. In particular, it is considered that the electrode expansion and contraction when silver ions having a larger ion size than lithium or the like are deinserted into the active material is large. By using a carbon sheet containing a polymer that is flexible and capable of relaxing stress, the shear load on the current collecting layer peculiar to the series-stacked cell can be greatly relaxed, so that it is considered that a good cycle retention rate was obtained. In addition, since Example 12 uses only one negative electrode sheet, it has been found that although the device is thin, the capacity and cycle characteristics are good, and it is effective for thinning the battery and increasing the energy density. . In addition, since the same sheet is used for the positive electrode and the negative electrode, a laminate in which a first active material layer (positive electrode active material layer), a solid electrolyte layer, and a second active material layer (negative electrode active material layer) are stacked in this order is an object. In addition, an electricity storage device having a structure in which a stacked body and a conductive layer are stacked is also a target structure. Since the electricity storage device has a target structure electrochemically, it is not necessary to distinguish between the positive electrode and the negative electrode of the electricity storage device, and the management of the small electricity storage device after being finely cut out becomes easy. Moreover, there is no fear of reverse connection when mounting the electricity storage device, which is preferable. In addition, since the power storage device is a target in terms of physical structure, it is preferable that the power storage device is less likely to warp against a thermal history during manufacture or mounting of the power storage device. Furthermore, according to Examples 13-15, when the ratio of the thickness of a positive electrode active material sheet and a negative electrode active material sheet does not contain metal foil and exists in the range of 0.8-1.2, favorable charging / discharging characteristics are obtained. Was found to be obtained.

  On the other hand, the four-layer cell including the laminate including the lithium electrolytes of Comparative Examples 1 and 2 could not be discharged without being charged. In Comparative Example 1, it is presumed that at the time of charging, the copper foil existing on the contact surface of the positive electrode was dissolved and became unstable and could not be charged. In Comparative Example 2, it is presumed that charging was not possible because aluminum alloyed with Li on the negative electrode contact surface during charging.

  In Comparative Example 3, since the laminate was used as a single layer structure, the average voltage was as low as 0.4 V, and it was not suitable for practical use.

  The present invention is not limited to the above embodiment, and various modifications can be made. The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). The present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration. Furthermore, the present invention includes a configuration that achieves the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object. Furthermore, the present invention includes a configuration obtained by adding a known technique to the configuration described in the above embodiment.

DESCRIPTION OF SYMBOLS 10 ... Conductive layer, 12 ... 1st active material layer, 14 ... 2nd active material layer, 16 ... Bipolar electrode, 18 ... Solid electrolyte layer, 20 ... Board | substrate, 22a, 22b, 22c, 22d ... Protrusion, such as a capacitor | condenser or a sensor Thing, 26, 30, 40 ... mounting substrate, 32 ... recess, 42 ... space, 50 ... base, 100, 101, 102, 103, 104 ... power storage device

Claims (9)

A conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer, wherein the first active material layer and the first active material layer A bipolar electrode in which one of the two active material layers functions as a positive electrode active material layer and the other as a negative electrode active material layer;
A solid electrolyte layer;
Including a plurality of laminates in which the bipolar electrode is laminated via the solid electrolyte layer,
The electrical storage device, wherein the solid electrolyte layer contains a silver ion conductive solid electrolyte.   The electricity storage device according to claim 1, wherein the first active material layer and the second active material layer contain the same active material. A conductive layer, a first active material layer formed on one surface of the conductive layer, and a second active material layer formed on the other surface of the conductive layer, wherein the first active material layer and the first active material layer A bipolar electrode in which one of the two active material layers functions as a positive electrode active material layer and the other as a negative electrode active material layer;
A solid electrolyte layer;
Including a plurality of laminates in which the bipolar electrode is laminated via the solid electrolyte layer,
An electricity storage device in which the value of T1 / T2 is 0.8 to 1.2 when the thickness of the first active material layer is T1 and the thickness of the second active material layer is T2.   The electricity storage device according to claim 3, wherein the first active material layer and the second active material layer contain the same active material.   The power storage device according to claim 3 or 4, wherein the solid electrolyte layer contains a silver ion conductive solid electrolyte.   The electrical storage device according to any one of claims 1 to 5, wherein at least one conductive layer is present, and at least one of the conductive layers contains a polymer.   The electricity storage device according to claim 6, wherein the polymer is a thermoplastic elastomer.   The electricity storage device according to claim 6 or 7, wherein the conductive layer containing the polymer contains 10 to 95% by mass of the polymer.   The electricity storage device according to any one of claims 6 to 8, wherein the polymer includes a repeating unit derived from styrene and a repeating unit derived from butadiene.

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