JP2016091809A - Intermediate layer raw material composition for capacitor air battery, electrode having intermediate layer including such raw material composition, and capacitor air battery including such electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor air battery having a novel structure in which a metal air battery and an electric double layer capacitor are combined together, and having a momentary discharge capacity and a high energy density.SOLUTION: A capacitor air battery comprises: an air electrode layer; an electrolyte layer; and a negative electrode layer including a covered negative electrode abutting against a first intermediate layer. The first intermediate layer is in contact with the electrolyte layer. The raw material composition of the intermediate layer includes a granular material including a carbon-based material. It is preferable that the granular material consists of particles having an average particle diameter of 0.02-500 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intermediate layer raw material composition for a capacitor air battery, an electrode having an intermediate layer containing the raw material composition, and a capacitor air battery including the electrode.

  Metal-air batteries that use metal as the negative electrode material and use oxygen in the air as the positive electrode active material do not require the positive electrode active material to be built into the battery, and fill the negative electrode active material in most of the space in the battery container. In principle, it has the highest energy density among chemical cells. Therefore, it can be expected to reduce the size and weight of the battery and increase the capacity.

  Like a fuel cell, a metal-air cell can supply energy by continuously reducing oxygen supplied from air at a porous air catalyst electrode. However, since the power output of metal-air batteries is limited by the low diffusion rate of oxygen in the porous air catalyst electrode, the instantaneous high power required for hybrid electric vehicles or electric vehicle applications There was a problem that the output could not be realized.

  On the other hand, a capacitor using an electrochemical double layer is suitable for instantaneous charging / discharging, and therefore, an electronic component for hybrid power storage composed of a secondary battery and an electric double layer capacitor was devised (patent) Reference 1). A hybrid battery in which a metal-air battery and an electric double layer capacitor are stacked and accommodated in the same container has been proposed (Patent Document 2). However, in any of the batteries, since the secondary battery and the electric double layer capacitor are separate, it has been difficult to further reduce the size and thickness of the battery and increase the capacity of the battery.

JP 2004-355823 A JP 2013-077744 A

  The present invention has been made in view of the above circumstances, and provides a capacitor air battery having a novel structure in which a metal air battery and an electric double layer capacitor are combined, and having an instantaneous discharge capacity and high energy density. With the goal. Moreover, it aims at providing the electrode which has an intermediate | middle layer raw material composition for manufacturing the said capacitor | condenser air battery, and the intermediate | middle layer containing the said raw material composition.

  The present inventors form an electric double layer when charging a battery by forming an intermediate layer on a metal negative electrode using a composition containing a carbon-based material, and increase the instantaneous discharge capacity of the battery. As a result, the present invention has been completed. Specifically, the present invention provides the following.

  A first aspect of the present invention is a raw material composition for an intermediate layer that contacts and covers an electrode of a capacitor air battery, and includes a granular material containing a carbon-based material.

  A second aspect of the present invention is a negative electrode for a capacitor air battery, wherein the metal electrode layer is coated in contact with the first intermediate layer composed of the raw material composition of the first aspect of the present invention. And

  A third aspect of the present invention is a negative electrode for a capacitor air battery, wherein a catalyst layer containing a current collecting support is in contact with a second intermediate layer composed of the raw material composition of the first aspect of the present invention. It is characterized by being coated.

  A fourth aspect of the present invention is a capacitor air battery, which includes an air electrode layer, an electrolyte layer, and a negative electrode layer including the negative electrode for a capacitor air battery according to the third aspect of the present invention, wherein the first intermediate layer is an electrolyte. It is characterized by being in contact with the layer.

  According to the present invention, it is possible to provide a capacitor air battery having a novel structure in which a metal air battery and an electric double layer capacitor are combined, and having an instantaneous discharge capacity and a high energy density. Moreover, the intermediate | middle layer raw material composition for manufacturing the said capacitor air battery and the electrode which has an intermediate | middle layer containing the said raw material composition can be provided.

It is a figure which shows the one aspect | mode of the capacitor air battery of this invention. It is a figure which shows another one aspect | mode of the capacitor air battery of this invention. It is a figure which shows the one aspect | mode of the conventional metal air battery. 4 is a diagram showing an X-ray diffraction pattern of a surface of an intermediate layer of a negative electrode after a charge / discharge test of Example 2. FIG. 4 is a diagram showing an X-ray diffraction pattern on the surface of an intermediate layer of an air electrode after a charge / discharge test of Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. .

  The raw material composition according to the first aspect of the present invention constitutes an intermediate layer that is in contact with and covers the electrode of the capacitor air battery, and contains a granular material containing a carbon-based material.

  The carbon-based material can be used without any particular limitation as long as it can form a porous layer by bonding granular materials containing the carbon-based material to each other via a binder resin. The shape can be various shapes. For example, particle shape, rod shape, fiber shape, indeterminate shape, and the like can be mentioned, but not limited thereto.

  Examples of the carbon-based material include substances mainly composed of carbon atoms, such as carbon fine particles such as carbon black, carbon fibers such as carbon nanotubes and carbon fibers, layered carbon such as graphite, sheet-like carbon such as graphene, activated carbon, and the like. Can be mentioned. The carbon-based material may be conductive or non-conductive.

The granular material contained in the raw material composition according to the first aspect of the present invention may further contain an oxide-based material. As the oxide material, various ceramics, oxides such as metal and silicon can be used without any particular limitation. For example, it is preferable to use metal or silicon oxide. Among these, Al ₂ O ₃ , ZrO ₂ , SiO ₂ , MnO ₂ , TiO ₂ , V ₂ O ₅ , VO ₂ , Fe ₂ O ₃ , WO _{3 and the} like are preferable from the viewpoint of improving battery characteristics, TiO _2. , V ₂ O ₅ , ZrO ₂ , Fe ₂ O ₃ , and WO ₃ are more preferable.

In particular, oxide materials such as TiO ₂ , V ₂ O ₅ , ZrO ₂ , Fe ₂ O ₃ , and WO ₃ are filled because it is easy to enter and exit the crystal structure of multivalent ions such as aluminum ions derived from the negative electrode metal. It is easy to discharge and also functions as a kind of negative electrode material. Therefore, its use is preferred. In particular, TiO ₂ is more preferable because the electrochemical reaction accompanied by oxidation / reduction is stable, so that accumulation of by-products can be suppressed and charge / discharge of ions can be caused.

  The average particle diameter of the granular material containing the carbon-based material and / or oxide-based material is preferably 0.02 μm or more, and more preferably 0.05 μm or more. The average particle diameter is desirably 0.5 μm or more, and more desirably 10 μm or more. Moreover, it is preferable that it is 500 micrometers or less, and it is more preferable that it is 100 micrometers or less. The average particle diameter is desirably 50 μm or less, and more desirably 30 μm or more. An average particle diameter of 0.02 μm or more is preferable because, when a porous intermediate layer is formed, the metal forming the negative electrode can be eluted without hindering the contact between the electrolyte and the negative electrode. Further, if the average particle diameter is 500 μm or less, when a porous intermediate layer is formed, it is possible to prevent accumulation of reaction by-products on the electrode during charging and discharging of the negative electrode metal, and the formation area of the electric double layer is reduced. It becomes high and is preferable.

The particle diameter in the present invention is a 50% particle diameter (d ₅₀ ) obtained from a cumulative distribution curve measured with a laser diffraction particle size distribution measuring device.

Moreover, it is preferable that the BET specific surface area of the granular material containing the carbon-based material and / or the oxide-based material is 1 m ² / g or more, and more preferably 20 m ² / g or more. The BET specific surface area is desirably 100 m ² / g or more, and more desirably 300 m ² / g or more. Further, it is preferably 3000 m ² / g or less, and more preferably not more than 2000 m ² / g. The BET specific surface area is desirably 1000 m ² / g or less, and more desirably 700 m ² / g or more. When the BET specific surface area is 1 m ² / g or more, when a porous intermediate layer is formed, the contact between the electrolytic solution and the negative electrode is not hindered, and the metal forming the negative electrode can be eluted, which is preferable. When the BET specific surface area is 3000 m ² / g or less, when a porous intermediate layer is formed, it is possible to prevent accumulation of reaction by-products on the electrode during charge / discharge of the capacitor air battery, and formation of an electric double layer The area increases, which is preferable.

  The binder resin mixed with the carbon material and / or the granular material containing the oxide material may be any of various thermosetting or thermoplastic resins as long as the oxide material or the carbon material can be bonded to each other. You can choose from a wide range. Examples of the thermosetting resin include phenol resins and epoxy resins, and examples of the thermoplastic resin include olefin resins such as polyethylene and polypropylene, and fluorine resins such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE). And cellulose such as ethyl cellulose, polyamide resin and the like.

  The raw material composition according to the first aspect of the present invention is produced by mixing the above-mentioned carbon-based material and / or oxide-based material and the above-mentioned binder resin in a dry manner by a known method. Alternatively, it may be produced by wet mixing with a solvent.

  As a solvent that can be used when the raw material composition of the present invention is produced by a wet method, a known solvent can be used without any particular limitation. The solvent is preferably a solvent capable of dissolving the binder resin, and at least when used, a solvent capable of dispersing the oxide-based material and / or the carbon-based material by using a stirring means or the like is preferable. . For example, an aqueous solvent such as water and alcohol, an ester solvent such as butyl acetate, a pyrrolidone solvent, and the like can be given.

  The weight ratio of the binder resin to the particulate matter containing the carbon-based material and / or the oxide-based material is preferably 1/1 or more and 4/1 or less. If it is 1/1 or more, the permeability of the electrolyte in the pores of the porous intermediate layer is high, and if it is 4/1 or less, the strength of the intermediate layer is sufficiently high, It is preferable because it can withstand external force.

[Negative electrode for capacitor air battery]
The negative electrode for a capacitor air battery according to the second aspect of the present invention is a negative electrode for a capacitor air battery in which a metal electrode layer is coated in contact with the intermediate layer, and the intermediate layer is a composition according to the first aspect of the present invention. It is composed of objects.

  Any metal electrode layer can be used as long as it is a material used in a normal metal-air battery, which generates metal ions and electrons by an oxidation reaction and works as an active material. Examples of such a substance include aluminum, iron, magnesium, zinc, sodium, calcium, and lithium. Furthermore, alloys obtained by adding other metal elements to these metals can also be used. For example, an aluminum alloy or a magnesium alloy can be mentioned. As the aluminum alloy, Li, Mg, Sn, Zn, In, Mn, Ga, Bi, Fe, etc. can be alloyed alone or in combination of two or more. Aluminum alloys can be mentioned. Among these, aluminum alloys such as Al—Li, Al—Mg, Al—Sn, and Al—Zn are particularly preferable because they give a high battery voltage.

To coat the metal electrode layer with an intermediate layer,
1) Applying and drying a composition containing a granular material containing the carbon-based material and / or oxide-based material and a binder resin in a solvent on a metal electrode layer;
2) A composition in which a granular material containing a carbon-based material and / or an oxide-based material and a binder resin are mixed together is heated together with the metal electrode layer or molded by applying pressure without heating.
3) Pellets are formed by introducing a composition in which a particulate material containing a carbon-based material and / or an oxide-based material and a binder resin are mixed into a mold and heating or applying pressure without heating. Formed into a layered product, and the layered product is overlaid on the metal electrode layer,
4) A composition obtained by mixing a particulate material containing a carbon-based material and / or an oxide-based material and a binder resin is heated in contact with the metal electrode layer, or a layer is formed by applying pressure without heating. Molding into objects,
From these methods, it can be selected as appropriate.

  Since the capacitance of an electric double layer capacitor is proportional to the surface area of the electrode, it can function as an electric double layer capacitor with a high capacitance, especially by providing a porous layer with a large specific surface area on the electrode. Can be possible.

  Furthermore, the porous intermediate layer accumulates in the pores by-products such as metal oxides and metal hydroxides derived from the metal constituting the negative electrode and metal ions in the electrolyte, which are generated during charging and discharging. Thus, in order to suppress the accumulation of these on the surface of the metal electrode layer in contact with the electrolytic solution, the capacitor air battery can be charged and discharged over a long period of time. Therefore, it is preferable to set the thickness of the porous layer appropriately by optimizing the area where the ions in the electrolyte can interact and the amount of by-products that can be accumulated.

[Air electrode for capacitor air battery]
The air electrode for a capacitor air battery according to a third aspect of the present invention is an air electrode for a capacitor air battery in which a catalyst layer containing a current collecting support is coated in contact with the porous layer, the porous layer Is constituted by the first aspect of the present invention.

The air electrode of the present invention is only required to be coated with a catalyst layer that serves to absorb oxygen from the air and convert it into hydroxide ions in contact with the porous layer. The catalyst layer contains an air electrode catalyst material. As the air electrode catalyst material, various catalysts can be used without limitation as long as they are substances that receive electrons generated at the negative electrode and reduce oxygen. Perovskite complex oxides such as lanthanum manganite represented by La _(1-x) A _x MnO ₃ (0.05 <x <0.95; A = Ca, Sr, Ba), Mn ₂ O ₃ , Mn Manganese lower oxides such as ₃ O ₄ or carbon-based materials such as activated carbon, carbon, and carbon nanotubes are preferred because they have both oxygen reducing ability and conductivity.

The catalyst layer contains a current collecting support inside. The current collecting support may be in the center of the catalyst layer, or may be present in layers on one side of the catalyst layer. When the current collector support is present on one side of the catalyst layer, the positive electrode current collector can usually be disposed on the contact portion side of the air opposite to the electrolyte layer, but between the positive electrode layer and the porous layer. You may arrange in.

  As the positive electrode current collector, materials in a form conventionally used as a current collector, such as a porous structure such as carbon paper and a metal mesh, a network structure, a fiber, and a nonwoven fabric, can be used without particular limitation. For example, a metal mesh formed from SUS, nickel, aluminum, iron, titanium or the like can be used. As another positive electrode current collector, a metal foil having an oxygen supply hole can also be used.

  The catalyst layer may further contain a support not intended for current collection. Examples thereof include olefin resins such as polyethylene and polypropylene, fluorine resins such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), and polyamide resins.

To coat the catalyst layer with an intermediate layer,
1) A composition obtained by dissolving the above carbon-based material and / or oxide-based material and a binder resin in a solvent is applied to a catalyst layer and dried.
2) A composition obtained by mixing a granular material containing a carbon-based material and / or an oxide-based material and a binder resin in advance is heated together with the catalyst layer, or is formed by applying pressure without heating.
3) Pellets are formed by introducing a composition in which a particulate material containing a carbon-based material and / or an oxide-based material and a binder resin are mixed into a mold and heating or applying pressure without heating. To form a layered product, and layer the layered product on the catalyst layer.
4) A layered product obtained by heating a composition in which a granular material containing a carbon-based material and / or an oxide-based material and a binder resin are mixed in contact with the catalyst layer or by applying pressure without heating. To mold,
From these methods, it can be selected as appropriate.

  In the present invention, the intermediate layer is preferably porous. This is because the surface area of the electric double layer is increased by increasing the electrode surface area. At the same time, the intermediate layer accumulates in the pores byproducts such as metal oxides, metal hydroxides, etc. derived from the metal ions constituting the negative electrode and metal ions generated during charging and discharging, In order to suppress these accumulations on the surface of the metal electrode layer in contact with the electrolytic solution, it is considered that the capacitor air battery has a function of enabling long-term charge / discharge. Furthermore, it is possible to effectively prevent the dendrite generated in the negative electrode from reaching the air electrode and short-circuiting, and the evaporation of the electrolytic solution from the air electrode, which are disadvantages of a normal metal-air battery. Therefore, it is preferable to set an appropriate thickness.

[Capacitor air battery]
A capacitor air battery according to a fourth aspect of the present invention has an air electrode layer, a negative electrode layer, and an electrolyte layer, and the negative electrode layer includes the negative electrode for a capacitor air battery according to the second aspect of the present invention. The intermediate layer of the negative electrode for a battery is in contact with the electrolyte layer. Furthermore, the air electrode layer may include the air electrode for a capacitor air battery according to the third aspect of the present invention, and the air electrode porous layer may be in contact with the electrolyte layer. Hereinafter, the capacitor air battery will be described in more detail with reference to the drawings.

  The capacitor air battery of the present invention basically has a structure in which at least the air electrode layer and the negative electrode layer sandwich the electrolyte layer, and the negative electrode 2 for a capacitor air battery according to the second aspect of the present invention contained in the negative electrode layer is an intermediate layer 3. It arrange | positions so that the electrolyte layer 4 may be contact | connected in the surface provided with (FIG. 1). By providing the intermediate layer 3 at least on the negative electrode layer, an electric double layer is formed on the surface of the intermediate layer 3 in contact with the electrolyte solution based on the movement of the charged particles of the electrolyte in the electrolyte solution. Electricity is stored in the same manner as the multilayer capacitor. In the capacitor air battery, the capacitor air battery air electrode 1 of the third aspect of the present invention contained in the air electrode layer may be provided in contact with the electrolyte layer 4 on the surface on which the intermediate layer 3 is provided. (FIG. 2). By having two intermediate layers, a higher instantaneous discharge capacity and energy density can be achieved.

  On the other hand, since the conventional metal-air battery does not have the intermediate layer 3 in the electrode layer (FIG. 3), it can not be stored using the formation of the electric double layer, and the instantaneous discharge capacity is improved. Cannot be achieved.

  The electrolyte layer used in the capacitor air battery of the present invention is mainly composed of an electrolytic solution in which an electrolyte is dissolved in a solvent and has ionic conductivity. The type of the electrolytic solution varies depending on the type of metal constituting the negative electrode metal layer, but may be an electrolytic solution (aqueous electrolyte solution) using a water solvent, or an electrolytic solution using an organic solvent such as propylene carbonate (PC). (Organic electrolyte) may be sufficient. Moreover, it is also possible to add a polymer, a moisturizing polymer, water glass, etc. to this.

  For example, when zinc, aluminum, iron, magnesium, or the like is used as the negative electrode metal, an alkaline aqueous solution such as an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution, or a neutral electrolytic solution such as an aqueous sodium chloride solution is used. Can be used. In the case of lithium, sodium, calcium, etc., an organic electrolytic solution in which a quaternary ammonium salt or the like is dissolved in the electrolytic solution can be used. Moreover, you may use electrolyte solution, such as seawater and an ionic liquid.

  Examples of polymers that can be added to the electrolyte include polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinylidene fluoride (PVDF), polyurethane, polyacrylate, and cellulose.

  The capacitor air battery of the present invention may be newly supplemented with an electrolyte solution or water that has decreased due to evaporation or the like. The feature of this capacitor air battery, which is different from ordinary air batteries, is that the decrease in capacity can be recovered any number of times by replenishing the electrolyte or the like. Since the replenishment of the electrolytic solution accompanying evaporation affects the electrolyte concentration in the electrolytic solution, it is preferable to replenish a solvent such as water. Moreover, the capacitor air battery of the present invention can continue to use the battery as in the initial state by removing the precipitated crystals at any time even when the electrolyte is precipitated by increasing the solute concentration in the electrolytic solution. Further, when seawater or the like is used as the electrolyte to be replenished, it is possible to reduce the cost for replenishing the electrolyte or the like.

  The electrolyte layer of the present invention may further include a separator. Although it does not specifically limit as a separator, For example, polymer nonwoven fabrics, such as a nonwoven fabric made from a polypropylene, a nonwoven fabric made from polyphenylene sulfide, microporous films, such as olefin resin, such as polyethylene and a polypropylene, these woven fabrics, or these combinations are used. Can do.

  The capacitor air battery according to the present invention usually has a battery case that houses an air electrode, a negative electrode, and an electrolyte layer. The shape of the battery case is not particularly limited, but specifically, a desired shape applied to a secondary battery such as a coin type, a flat plate type, a cylindrical type, or a laminate type can be taken. The battery case may be an open air type or a sealed type. The battery case that is open to the atmosphere has a structure in which at least the air electrode can sufficiently come into contact with the atmosphere. On the other hand, a sealed battery case can be provided with an introduction pipe and an exhaust pipe for oxygen (air), which is a positive electrode active material. Moreover, you may provide structures, such as an injection hole for replenishing electrolyte solution etc., in a battery case.

  The manufacturing method of the capacitor air battery of this invention is demonstrated. The method for producing an air battery of the present invention is not particularly limited as long as the above-described air battery can be obtained, and the same method as the conventional method for producing a metal-air battery can be used.

  For example, when manufacturing a coin cell type battery, under an inert gas atmosphere, first, a negative electrode having a negative electrode layer and a porous layer is placed in a battery case so that the porous layer is inside, then, A separator is disposed on the negative electrode layer, and then an electrolytic solution is injected from above the separator. Next, an air electrode having an air electrode layer and an air electrode current collector is disposed, and a porous layer is disposed on the separator side. Examples of the method may include, but are not limited to, a method in which the battery is disposed in the air electrode side and then placed in the air electrode side battery case, and these are caulked last.

  The capacitor air battery of the present invention can be applied to a device in which a normal secondary battery or an electric double layer capacitor can be used. For example, a mobile phone, a mobile device, a robot, a personal computer, an in-vehicle device, various home electric products, and the like can be given. In addition to applications such as memory backup power supplies for personal computers and portable terminals, power supplies for measures against instantaneous power outages such as personal computers, various applications such as electric power generation or hybrid vehicles, solar power generation energy storage systems used in combination with solar cells, etc. It can be suitably used for various applications in the industrial field.

  The capacitor air battery of the present invention takes advantage of its characteristics and requires a high peak power for a very short time, and is usually suitable for application to an electric device that keeps a very low power output or is in a stopped state. ing. For example, electric vehicles, hybrid vehicles, electric scooters, construction machines, etc. need to be supplied with stable power for a long time when traveling at a constant speed, while high peak power must be supplied in a short time during acceleration. Don't be. The capacitor air battery of the present invention is particularly effective when applied to such an electrical device.

  Further, the capacitor air battery of the present invention can recover the battery capacity by, for example, supplementing the evaporated electrolyte with seawater or water, so that it can be used for power generation facilities, power supply facilities, etc. Especially suitable.

  Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<Example 1>
(Manufacture of negative electrode)
Activated carbon particles having a particle diameter of 6 μm, a BET specific surface area of 1600 to 2400 m ² / g, polyvinylidene fluoride (PVDF) as a binder, and N-methylpyrrolidone as a solvent were mixed at a weight ratio of 1: 1: 8 to form an ink. .
Subsequently, the manufactured ink was applied to a commercially available metal aluminum having a thickness of 1 mm using a doctor blade method. After the coating, firing was performed at 130 ° C. for 1 hour to provide a porous layer, which was cut into 25 mm × 35 mm to produce a negative electrode.

(Manufacture of air electrode)
Commercially available manganese oxide, activated carbon, and polyvinylidene fluoride (PVDF) were weighed in a weight ratio of 4: 4: 2, mixed thoroughly using ethanol as a solvent, and then a current collector was placed on a sheet made of Teflon (registered trademark) resin. After coating with a nickel mesh and drying at 120 ° C. for 1 h, it was processed to φ15 mm to form an air electrode.
(Manufacture of batteries)
The negative electrode produced above was fitted into one side of a fluororesin mold having an inner diameter of 25 mm and a length of 15 mm with the porous layer side up, and the negative electrode was used as the bottom of the cylinder to the fluororesin mold and 2 mol / L as the electrolyte. A capacitor air battery having the configuration of FIG. 1 was manufactured by sealing with the air electrode manufactured above so that air bubbles would not enter through gauze soaked with an aqueous NaOH solution.

<Example 2>
(Manufacture of activated carbon pellets)
Activated carbon and PVDF were mixed at a ratio of 8: 2 and pressed at a pressure of 20 MPa to prepare porous pellets.
A capacitor air battery having the configuration shown in FIG. 2 was produced in the same manner as in Example 1 except that the pellet produced above was sealed with an air electrode through a gauze soaked with an electrolyte during the production of the battery.

<Comparative example>
The aluminum-air battery of FIG. 3 was produced in the same manner as in Example 1 except that metal aluminum without an intermediate layer was used as the negative electrode.

[Battery evaluation 1]
The charge / discharge characteristics of the capacitor air batteries of Examples 1 and 2 and the aluminum air battery obtained in the comparative example were measured according to a conventional method. The electrolyte solution was replenished every time during the charge / discharge cycle. The capacity and current density of the batteries measured at the first, tenth and twentieth times are shown in Table 1, respectively.
[Battery evaluation 2]
The intermediate layer on the negative electrode side and the positive electrode side was taken out from the capacitor air battery of Example 2 after the charge / discharge characteristic evaluation, and the X-ray diffraction pattern of the surface was evaluated and shown in FIGS. 4 is an X-ray diffraction pattern of the surface of the intermediate layer facing the electric field layer provided on the negative electrode of Example 2, and FIG. 5 is an X-ray of the surface of the intermediate layer provided on the air electrode of Example 2. It is a diffraction pattern.

  Comparing the results of Example 1 and the comparative example, it can be seen that providing the intermediate layer on the negative electrode improves the battery capacity cycle characteristics and increases the current density. This result shows that by-products associated with charging / discharging are blocked from the negative electrode by the porous intermediate layer, and the by-products are deposited on the intermediate layer instead of depositing directly on the electrode, so that repeated charging / discharging is performed. This suggests that the battery capacity can be maintained and the current density is improved by the generation of the electric double layer. Moreover, from the result of Example 2, it was confirmed that the installation of the intermediate layer on the air electrode further increases this tendency.

  The current density of the first and second capacitor air batteries in which the intermediate layer is provided on the electrode can achieve a current density of 3 to 10 times that of a normal metal air battery in which no intermediate layer is provided. Such an increase in current density suggests that an electric double layer is formed in the intermediate layer during charging.

From the X-ray diffraction pattern of the surface of the intermediate layer facing the electric field layer provided on the negative electrode of Example 2 after the charge / discharge test of FIG. 4, Al (OH) _{3 as} a byproduct derived from the aluminum negative electrode was generated. It was confirmed that Furthermore, from FIG. 5, it was confirmed that Na ₂ O derived from NaOH in the electrolytic solution was deposited on the surface of the porous layer of the air electrode in addition to Al ₂ O ₃ derived from the aluminum negative electrode. From these results, by-products associated with charge / discharge are blocked from the negative electrode by the porous layer, and instead of depositing by-products directly on the electrode, they are deposited in the intermediate layer, thereby improving and maintaining the charge / discharge characteristics. It is suggested that it is possible.

1 Air electrode 2 Negative electrode 3 Intermediate layer 4 Electrolyte layer

Claims (8)

  A raw material composition for an intermediate layer, which contains a granular material containing a carbon-based material and is in contact with and coats an electrode of a capacitor air battery.   The raw material composition according to claim 1, wherein the granular material is a particle having an average particle diameter of 0.02 μm to 500 μm. The raw material composition according to claim 1, wherein the granular material has a BET specific surface area of 1 m ² / g or more and 3000 m ² / g or less.   The raw material composition as described in any one of Claims 1-3 in which the said granular material further contains an oxide type material.   A negative electrode for a capacitor air battery, wherein the metal electrode layer is in contact with and covered with the first intermediate layer made of the raw material composition according to any one of claims 1 to 4.   An air electrode for a capacitor air cell, in which a catalyst layer containing a current collecting support is coated in contact with a second intermediate layer composed of the composition described in any one of claims 1 to 4.   A capacitor air battery comprising: an air electrode layer; an electrolyte layer; and a negative electrode layer including the negative electrode for a capacitor air battery according to claim 5, wherein the first intermediate layer is in contact with the electrolyte layer.   The capacitor air battery according to claim 7, wherein the air electrode layer includes an air electrode for a capacitor air battery according to claim 6, and the second intermediate layer is in contact with the electrolyte layer.

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