JP2008103473A - Power storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power storage device compatible with both of high capacity and high output. <P>SOLUTION: The power storage device 1 is provided with a positive electrode 2 employing oxygen as a positive electrode active substance, a negative electrode 3 containing a negative electrode active substance having an ionization tendency higher than hydrogen, and an electrolytic layer 4 interposed between the positive electrode 2 and the negative electrode 3. When the electrolytic layer 4 contains water solution electrolyte, the power storage device 1 contains a capacitor substance 5 electrically conducted with the positive electrode 2 in the power storage device 1 to develop a capacitor function and having a capacity of not less than 50 F/g. When the electrolytic layer 4 contains an organic electrolyte, the power storage device 1 contains a capacitor substance 5 electrically conducted with the positive electrode 2 in the power storage device 1 to develop a capacitor function, and having a capacity of not less than 20 F/g. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electricity storage device having a positive electrode using oxygen as an active material.

  An energy storage device such as a primary battery, a secondary battery, and a capacitor is required to increase the energy density per unit volume or unit weight to increase the capacity. In addition to high capacity, high output is also required. Therefore, various power storage devices having various structures and materials have been developed so far. Usually, it is necessary to incorporate an active material in each of the positive electrode and the negative electrode in the battery, which hinders the increase in capacity of the battery.

  On the other hand, recently developed batteries include air batteries that charge and discharge using oxygen in the air as a positive electrode active material. In particular, examples of air metal batteries that have been put to practical use include a zinc-air battery including an air electrode (positive electrode) using oxygen as a positive electrode active material and a zinc electrode (negative electrode) using zinc as a negative electrode active material (patent) Reference 1). In this air battery, since oxygen in the air is used as the positive electrode active material, the capacity per unit volume can be increased. Therefore, the air battery is expected as a high capacity battery. However, while having an excellent feature of high capacity, it is difficult to increase the output in the air battery. That is, for example, on the negative electrode side made of a metal electrode or the like, it is possible to cope with the increase in output by making the metal electrode porous and increasing the surface area, but on the positive electrode side, the output is increased by oxygen diffusion and reaction. There is a problem of being rate-limited. For this reason, a current exceeding the rating could not be taken out and high output could not be achieved.

On the other hand, capacitors have been actively developed as power storage devices in recent years. For example, materials such as carbon materials and oxide nanosheets having a large specific surface area for realizing high-power capacitors have been developed. In addition to conventional electric double layer capacitors, pseudo-capacitance capacitors, lithium ion capacitors, and the like using an oxidation-reduction reaction on electrodes have been developed for the purpose of increasing the capacity. The feature of these capacitors is that a large output can be obtained as opposed to an air battery. However, the capacitor has an excellent feature of high output, but the capacitor has a problem that the capacity is reduced because charges accumulated in the electric double layer on the surface are used. Even in the above-described pseudo capacitance capacitor, lithium ion capacitor, etc., the capacity could not be sufficiently improved.
Therefore, an electricity storage device that can achieve both high capacity and high output is ideal, but its realization has been difficult.

By the way, when considering a method of using an electricity storage device, the electricity storage device is rarely required to always have a high output.
That is, for example, in the case of a primary battery, a constant high power is rarely used at all times, and there are many applications involving intermittent power consumption. Even in the case of a secondary battery, rapid discharge and rapid charge are not always necessary when considering applications such as electric vehicles and hybrid vehicles. For example, it suffices if rapid charging / discharging can be performed in a short time such as at acceleration start or during energy regeneration, and charging / discharging can be performed with a low current at other times.
Therefore, if a power storage device that can take out a large current as needed, for example, has a high capacity of an air battery and a high output of a capacitor, can be used for a very wide range of applications.

On the other hand, a device combining a battery and a capacitor (capacitor) has been developed.
Specifically, a high current pulse generator that generates a current pulse by combining a DC power source such as a primary battery and a secondary battery and a capacitor has been developed (see Patent Document 2). In this high current pulse generator, a high current electric impulse can be generated by combining a battery and a capacitor.

However, the high current pulse generator is not a power storage device that can achieve both high output and high capacity, but is merely a device that generates a high current electric impulse. In addition, since the battery and a capacitor provided outside the battery are combined, there is a possibility that the apparatus becomes large.
Thus, the development of an electricity storage device that combines the excellent characteristics of a battery and a capacitor, that is, an electricity storage device that can achieve both high capacity and high output as required, has been insufficient.

JP 2004-63346 A JP 2003-333871 A

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an electricity storage device that can achieve both high capacity and high output.

1st invention is the electrical storage device which has the positive electrode which uses oxygen as a positive electrode active material, the negative electrode containing the negative electrode active material which has an ionization tendency more than hydrogen, and the electrolyte layer interposed between the said positive electrode and the said negative electrode In
The electrolyte layer contains an aqueous electrolyte solution,
The electricity storage device is an electricity storage device characterized by containing a capacitor substance having a capacity of 50 F / g or more that is electrically connected to the positive electrode and exhibits a capacitor function in the electricity storage device.

A second invention is an electricity storage device having a positive electrode using oxygen as a positive electrode active material, a negative electrode containing a negative electrode active material having an ionization tendency higher than hydrogen, and an electrolyte layer interposed between the positive electrode and the negative electrode In
The electrolyte layer contains an organic electrolyte solution,
The electricity storage device is an electricity storage device characterized by containing a capacitor substance having a capacity of 20 F / g or more that is electrically connected to the positive electrode and exhibits a capacitor function in the electricity storage device.

The electricity storage device of the first invention is an electricity storage device containing an aqueous electrolyte in the electrolyte layer interposed between the positive electrode and the negative electrode, and is electrically connected to the positive electrode and has a capacitor function. It contains a capacitor substance with a capacity of 50 F / g or more.
Further, the electricity storage device of the second invention is an electricity storage device containing an organic electrolyte in the electrolyte layer interposed between the positive electrode and the negative electrode, and is electrically connected to the positive electrode and is a capacitor It contains a capacitor substance with a capacity of 20 F / g or more that exhibits its function.

  In the electricity storage device of the first invention and the second invention, if, for example, oxygen in the air is used as oxygen, the electricity storage device can function as a so-called air battery. Therefore, the power storage device has functions of an air battery and a capacitor, and can exhibit both high capacity and high output. That is, in the electricity storage device, a battery composed of the positive electrode, the negative electrode, and the electrolyte layer can function as a large-capacity air battery, and the capacitor substance can function as a high-power capacitor.

  In the electricity storage device, a large current can be discharged or charged from the capacitor (the capacitor material) in a short time. At this time, in the air battery composed of the positive electrode, the negative electrode, and the electrolyte layer, the capacitor serves as a buffer, and the occurrence of a voltage drop and the application of overvoltage can be prevented.

In the above electricity storage device, for example, when charging / discharging is not performed or when charging / discharging with a low current is performed, the air battery functions, and the capacitor can store charges corresponding to the electromotive force of the air battery. For example, when a large current is required in a short time, a large current can be extracted from the capacitor.
Therefore, the power storage device can cope with a case where a large current is required to be exchanged in a short period of time and a case where a long current operation is required with a low current.

Next, a preferred embodiment of the present invention will be described.
In the electricity storage device of the present invention, the positive electrode, the negative electrode, and the electrolyte layer constitute an air battery. The air battery here is preferably a secondary battery that can be repeatedly charged and discharged, but a primary battery can also be used.

When the electrolyte layer contains an aqueous electrolyte solution as in the first invention, a substance having a capacity of 50 F / g or more is used as the capacitor substance.
When a capacitor substance having a capacity of less than 50 F / g is used, the capacitor performance becomes insufficient as compared with the air battery performance, so that there is a possibility that the performance of the ordinary air battery is hardly affected. More preferably, it is 100 F / g or more.

When the electrolyte layer contains an organic electrolyte as in the second invention, a substance having a capacity of 20 F / g or more is used as the capacitor substance.
When a capacitor substance having a capacity of less than 20 F / g is used, the performance of the capacitor may be insufficient for the output of the air battery. More preferably, 40 F / g or more is good.

  In general, the aqueous electrolyte solution has a larger current output than the aqueous electrolyte solution and the organic electrolyte solution. Therefore, in the above electricity storage device, the capacity required for the capacitor material differs depending on whether it has an aqueous electrolyte or an organic electrolyte.

The capacitor substance is preferably disposed in the positive electrode (claim 6).
In this case, the electricity storage device of the present invention can be easily realized and the electricity storage device can be downsized.
A method of arranging the capacitor substance in the positive electrode can be realized by, for example, mixing the capacitor substance into a positive electrode material made of a positive electrode catalyst described later at the time of producing the positive electrode.

The capacitor substance is preferably disposed as a capacitor layer between the positive electrode and the electrolyte layer.
In this case, the electricity storage device of the present invention can be easily realized. In this case, the capacitor layer and the positive electrode can function sufficiently. That is, the capacitor layer can more fully exhibit the function as a capacitor in a state where it is completely immersed in the electrolytic solution. On the other hand, since it is necessary to take in oxygen, it is preferable that the positive electrode is in a dry state at least in a portion where oxygen is taken in. Therefore, as described above, by disposing the capacitor material as a member separate from the capacitor layer, that is, the positive electrode, the power storage device can more fully exhibit the two functions of the capacitor and the battery.

  The capacitor layer can be formed, for example, by coating the capacitor material in a layered manner on the surface of the positive electrode on the electrolyte layer side. Moreover, it can also form by arrange | positioning the said capacitor | condenser substance shape | molded in the shape of a film | membrane or a sheet | seat on the surface by the side of the said electrolyte layer of the said positive electrode.

The capacitor material preferably contains an oxide of one or more metals selected from ruthenium, manganese, iridium, tungsten, and iron (claim 3).
The capacitor material preferably contains a high specific surface area carbon material having a specific surface area of 500 m ² / g or more and an average pore diameter of 1 nm or more.
In these cases, the electricity storage device of the present invention can be easily realized, and the output of the electricity storage device can be further improved by the capacitor substance.

When the specific surface area of the high specific surface area carbon material is less than 500 m ² / g, there is a possibility that a sufficiently large current cannot be taken out from the electricity storage device. On the other hand, when the average pore diameter is less than 1 nm, ions may not easily enter and exit the capacitor material. More preferably, the specific surface area of the high specific surface area carbon material is 1000 m ² / g or more, and the average pore diameter is 2 nm or more.

The high specific surface area carbon material is preferably subjected to alkali treatment or electrolytic treatment (Claim 5).
In this case, the specific surface area of the high specific surface area carbon material can be further increased and activated. As a result, an electricity storage device that can exhibit a larger output can be realized.

When the high specific surface area carbon material is used as the capacitor material, the capacitor layer can be formed by kneading the high specific surface area carbon material with a binder and press-molding.
When the above-mentioned metal oxide is used as the capacitor substance, for example, the oxide, a conductive carbon material, and a polymer material such as polytetrafluoroethylene (PTFE) as a binder are kneaded and pressed. The capacitor layer can be formed by molding. When a metal oxide is used, a positive electrode containing a capacitor substance can be formed by mixing the capacitor substance made of a metal oxide into a positive electrode material made of a positive electrode catalyst or the like described later.

As the detailed configuration of the electricity storage device, various air battery configurations known at the present stage can be adopted except that the capacitor material is contained.
Specifically, for example, in a battery case, a positive electrode using oxygen in the air as a positive electrode active material and a negative electrode containing a negative electrode active material having an ionization tendency higher than hydrogen are disposed, and the positive electrode and the negative electrode An electrolyte layer is disposed between the positive electrode and the capacitor substance in the positive electrode, or the capacitor layer is disposed between the positive electrode and the electrolyte layer. In addition, the positive electrode has an air contact surface in contact with air on a surface facing the surface on the electrolyte layer side, and an oxygen permeable membrane having oxygen permeability and water repellency is disposed on the air contact surface. can do.

The positive electrode can be formed by, for example, pressing a positive electrode material containing a positive electrode catalyst capable of oxidizing and reducing oxygen and an organic binder onto a current collector. As the positive electrode catalyst, for example, a noble metal powder such as Pt supported on a support made of a carbon material can be used. As the carbon material, for example, activated carbon, graphite, carbon black, coke, carbon fiber, or the like can be used. The positive electrode material may contain an oxide and / or composite oxide of a metal such as Mn, Ni, and Co as an oxygen redox catalyst. As the oxygen redox catalyst, metal metalloporphyrins such as Mn, Ni, and Co, and organometallic complexes such as metal phthalocyanine can also be used.
As a method for supporting the catalyst on the support, for example, a method in which a carbon material and a solution of a metal salt and / or a metal complex are mixed and dried to be oxidized or reduced can be employed.
In addition, when the capacitor substance is disposed in the positive electrode, the positive electrode may be formed using the positive electrode material to which the capacitor substance is added.

Examples of the organic binder include polytetrafluoroethylene, polyvinylidene fluoride, and ethylene butadiene rubber.
As the positive electrode current collector, for example, a Ni mesh, a stainless mesh, a gold mesh, a copper mesh, a platinum mesh, or the like can be used.
As the oxygen permeable membrane, for example, a porous membrane made of polypropylene, polyethylene, polytetrafluoroethylene, polyester, polyphenylene sulfide, or the like, or a high oxygen permeable homogeneous membrane made of silicone resin, polymethylpentene, or the like is used. Can do.

Further, the electrolyte layer can be constituted by, for example, a separator impregnated with an electrolytic solution.
As the electrolytic solution, an alkaline electrolytic solution or an aqueous electrolytic solution such as a neutral salt aqueous electrolytic solution can be used, but an organic electrolytic solution can also be used.

  When a metal oxide is used as the capacitor substance, an aqueous electrolyte such as an alkali metal hydroxide aqueous solution or a metal salt aqueous solution is preferably used. This is because a metal oxide can exhibit a large capacity in an aqueous electrolyte solution.

As the alkali metal hydroxide used in the alkali metal hydroxide aqueous solution, for example, hydroxides such as K, Na, and Li can be used. The metal salt of the metal salt aqueous solution, for example, perchlorate, sulfate, chloride, nitrate, BF _4, phosphate, and organic acid salts. These electrolytes contain at least one additive selected from metal oxides, water-soluble polymers, brighteners such as saccharin that can suppress the formation of dendrites during charging, organic acids, and ammonium salts. can do.

When the above organic electrolyte is used as the electrolyte, it is possible to prevent the formation of dendrite during charging. In addition, when a metal electrode that is highly reactive with an aqueous electrolyte is used for the negative electrode, an organic electrolyte is preferably used.
The organic electrolyte solution can be obtained by dissolving a metal salt in an organic solvent.

As the organic solvent, ionic and / or nonionic organic solvents can be used.
As the ionic organic solvent, for example, a solvent comprising a combination of the following cation and anion can be used.

That is, as the cation, for example, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium, quaternary ammonium such as N, N, N-trimethyl-N-propylammonium, N-methyl- Examples include piperidinium such as N-propylpiperidinium, imidazolium such as 1-ethyl-3-methylimidazolium, and pyridinium such as 1-butylpyridinium.
Examples of the anion include trifluoromethanesulfonate, bromide, chloride, tetrafluoroborate, hexaflurophosphate, and bis (trifluoromethanesulfonyl) imide.

Moreover, as a nonionic organic solvent, 1 or more types of solvents chosen from propylene carbonate, ethylene carbonate, acetonitrile, etc. can be used, for example.
Moreover, the electrolyte used for organic electrolyte solution can be determined by a combination with a solvent. As the electrolyte, a metal salt having high solubility in an organic solvent can be used.

  The separator is an insulator that prevents electrical contact between the positive electrode and the negative electrode, and a substance that does not react with or dissolve in the electrolytic solution and can further impregnate the electrolytic solution can be used. As the shape, for example, a paper-like, cloth-like, non-woven-like, or gel-like separator can be used. As the material, for example, cellulose, polyamide, polyolefin, and fluororesin are suitable.

A negative electrode contains the negative electrode active material which has an ionization tendency more than hydrogen.
When the ionization tendency of the negative electrode active material is less than hydrogen, the generated electromotive force is reduced, and there is a possibility that the negative electrode active material may not function as an effective power storage device.
As said negative electrode active material, zinc, iron, magnesium, aluminum, lithium, hydrogen etc. can be used, for example. The form can be used in the state of intercalation with pure metals or compounds, or others. Further, it may be flat or porous. The negative electrode preferably has a current collector such as copper, stainless steel, or noble metal so that the negative electrode does not lose its current collecting function even after the negative electrode active material is consumed.

  As the shape of the power storage device, various shapes such as a coin shape, a cylindrical shape, and a square shape can be employed. Cases corresponding to these shapes can be used as the battery case that houses the positive electrode, the negative electrode, the electrolyte layer, and the like.

  The air battery composed of the positive electrode, the negative electrode, and the electrolyte layer is usually a primary battery. However, in an air battery using an organic electrolyte solution or an aqueous electrolyte solution, generation of dendrites can be prevented by appropriately selecting an electrode material or adding an appropriate additive. Next battery can be used. For example, Japanese Patent Application Laid-Open No. 2004-63346 proposes a technique that makes it possible to convert an air battery to a secondary battery. In the present invention, for example, this technique can be used to make a secondary battery. .

(Example 1)
Next, examples of the electricity storage device of the present invention will be described.
As shown in FIG. 1, the electricity storage device 1 of this example includes a positive electrode 2 that uses oxygen in the air as a positive electrode active material, a negative electrode 3 that contains a negative electrode active material that has an ionization tendency higher than hydrogen, and a positive electrode 2 and a negative electrode 3. And an electrolyte layer 4 interposed therebetween. The electrolyte layer 4 contains an aqueous electrolyte solution. In addition, the electricity storage device 1 contains a capacitor substance 5 having a capacity of 50 F / g or more that is electrically connected to the positive electrode 2 and the negative electrode 3 in the electricity storage device 1 and exhibits a capacitor function. Specifically, in this example, the capacitor material is disposed as a capacitor layer 5 between the positive electrode 2 and the electrolyte layer 4.

Hereinafter, the electricity storage device 1 of this example will be described in detail.
As shown in FIG. 1, the electricity storage device 1 of this example includes a positive electrode 2, a negative electrode 3, and an electrolyte layer 4 disposed in a battery case 7. The positive electrode 2 is formed by pressure-bonding a positive electrode catalyst made of a carbon material carrying Pt to a current collector made of Ni mesh. The negative electrode 3 is made of zinc foil. The electrolyte layer 4 is formed by impregnating a porous separator with an electrolytic solution.
The capacitor layer 5 is made of an activated carbon sheet (carbon 90 wt%, PTFE (binder) 10 wt%, carbon weight 10 mg) having a specific surface area of 3000 cm ² / g and a center pore diameter of 2 nm.

  As shown in FIG. 1, the positive electrode 2, the negative electrode 3, and the electrolyte layer 4 are disposed in the battery case 7 with the electrolyte layer 4 sandwiched between the positive electrode 2 and the negative electrode 3. The positive electrode 2 is disposed with the side (not shown) on which the positive electrode catalyst of the positive electrode 2 is supported facing the electrolyte layer 4 side. Further, a capacitor layer 5 made of the capacitor material is disposed between the positive electrode 2 and the electrolyte layer 4.

  The battery case 7 includes a main body portion 71 having a concave cross section that is open at the top, and a cap portion 72 that closes the opening portion of the main body portion 71. The cap portion 72 has a through hole 75 for supplying air into the battery at the central portion thereof. The body portion 71 and the cap portion 72 are sealed with an insulating seal material 8. The positive electrode 2, the negative electrode 3, the electrolyte layer 4, and the capacitor layer 5 are housed in the battery case 7 with the negative electrode 3 facing the bottom of the main body 71. Further, the surface of the positive electrode 2 that faces the surface on the electrolyte layer 4 side is an air contact surface 25 that comes into contact with air. On the air contact surface 25 side on the positive electrode 2, an oxygen permeable membrane 6 made of a polypropylene porous membrane is disposed.

Next, a method for manufacturing the electricity storage device 1 of this example will be described.
Specifically, first, a Pt-supported carbon catalyst (Pt 20 wt%) was prepared as a positive electrode catalyst. A positive electrode material obtained by mixing polytetrafluoroethylene with this Pt-supported carbon catalyst was pressure-bonded to a metal mesh made of Ni and vacuum-dried to obtain a plate-like positive electrode 2 (Pt support amount 1 mg / cm ² ).
Moreover, as the negative electrode 3, a zinc foil was prepared.

Next, a 6N aqueous potassium hydroxide solution was prepared as an electrolytic solution, and a separator made of a polyamide nonwoven fabric was immersed in the electrolytic solution. In this way, a separator impregnated with the electrolytic solution was obtained as the electrolyte layer 4.
Next, as the capacitor layer 5, an activated carbon sheet made of 90 wt% carbon and 10 wt% polytetrafluoroethylene and containing 10 mg of carbon was prepared.

  Next, as shown in FIG. 1, a battery case 7 for coin cells was prepared, and the negative electrode 3 was arranged in the main body 71. Next, the electrolyte layer 4 was disposed on the negative electrode 3, and the capacitor layer 5 was disposed on the electrolyte layer 4. Further, the positive electrode 2 was disposed on the capacitor layer 5. The positive electrode 2 was disposed with the surface on which the positive electrode material was pressure-bonded facing the electrolyte layer 4 (capacitor layer 5). Next, an oxygen permeable membrane 6 made of a polypropylene porous membrane was disposed on the positive electrode 2.

  Next, the opening of the main body 71 of the battery case 7 was closed with a cap 72 having a through hole 75. At this time, as shown in FIG. 1, the insulating sealing material 8 was disposed in the gap between the main body portion 71 and the cap portion 72, and the battery case 7 was sealed. In this way, the electricity storage device 1 was produced. This is referred to as a battery E1.

Moreover, in this example, as shown in FIG. 2, the electrical storage device 1 (battery E2) which contains the capacitor substance in the positive electrode 2 was produced. The battery E2 does not have the capacitor layer 5 between the positive electrode 2 and the electrolyte layer 4 like the electricity storage device 1 of the battery E1 (see FIG. 1). Instead, the capacitor material (not shown) is contained in the positive electrode 2 (see FIG. 2).
The battery E2 contains in the positive electrode 2 a positive electrode catalyst made of a carbon material not carrying a noble metal and a capacitor substance. The battery E2 does not have the capacitor layer 5, and is the same as the battery E1 except that the battery E2 has a positive electrode containing a positive electrode catalyst made of a carbon material not supporting a noble metal and a capacitor substance. It is the electrical storage device 1 which has the structure of (refer FIG. 2).

In producing the battery E2, first, 45 wt% of activated carbon as a positive electrode catalyst, 45 wt% of a manganic acid nanosheet (capacity 900 F / g) as a capacitor material, and 10 wt% of a binder (polytetrafluoroethylene) are kneaded to form a sheet. A positive electrode material was produced by molding into a negative electrode. 11 mg of this positive electrode material was pressure-bonded to a metal mesh made of Ni and vacuum-dried to obtain a plate-like positive electrode 2.
In addition, the manganic acid nanosheet was synthesize | combined according to the method as described in Unexamined-Japanese-Patent No. 2003-335522.

Furthermore, the same negative electrode 2 and electrolyte layer 3 as the battery E1 were prepared.
Next, a battery case 7 for coin cells was prepared, the negative electrode 3 was disposed in the main body 71, and the electrolyte layer 4 was disposed on the negative electrode 3. Further, the positive electrode 2 was disposed on the electrolyte layer 4. The positive electrode 2 was disposed with the surface on which the positive electrode material was pressure-bonded facing the electrolyte layer 4 side. Next, an oxygen permeable membrane 6 made of a polypropylene porous membrane was disposed on the positive electrode 2.

  Next, similarly to the battery E1, the opening of the main body 71 of the battery case 7 is closed with a cap 72 having a through hole 75, and the gap between the main body 71 and the cap 72 is insulated with the insulating sealing material 8. And the battery case 7 was sealed. In this way, an electricity storage device 1 (battery E2) was produced.

Moreover, in this example, the electrical storage device (air battery) which did not contain a capacitor substance was produced for the comparison of the said battery E1 and the battery E2. This is designated as battery C1. The battery C1 has the same configuration as the battery E1 except that the battery C1 does not have a capacitor layer made of a capacitor material.
The battery C1 was produced in the same manner as the battery E1 except that the capacitor layer was not disposed.

Moreover, in this example, three types of electrical storage devices (battery E3, battery E4, and battery C2) using zinc perchlorate aqueous solution as an electrolytic solution were produced.
The battery E3 was produced in the same manner as the battery E1, except that a 1M zinc perchlorate aqueous solution was used as the electrolytic solution instead of the 6N potassium hydroxide aqueous solution. That is, the battery E3 is an electricity storage device that contains a zinc perchlorate aqueous solution as an electrolytic solution, and a capacitor layer made of a capacitor material (activated carbon sheet) is formed between the positive electrode and the electrolyte layer.

The battery E4 was produced in the same manner as the battery E2 except that a 1M zinc perchlorate aqueous solution was used as the electrolytic solution instead of the 6N potassium hydroxide aqueous solution. That is, the battery E4 is an electricity storage device that contains a zinc perchlorate aqueous solution as an electrolytic solution, and contains a capacitor substance (MnO ₂ ) in the positive electrode.

  The battery C2 was produced in the same manner as the battery C1 except that a 1M zinc perchlorate aqueous solution was used as the electrolyte instead of the 6N aqueous potassium hydroxide solution. That is, the battery C2 is an electricity storage device that contains a zinc perchlorate aqueous solution as an electrolytic solution and does not contain a capacitor substance.

Furthermore, in this example, two types of power storage devices (battery E5 and battery C3) using an organic electrolytic solution as the electrolytic solution were produced.
Battery E5 was used except that a 0.5M organic zinc electrolyte (bis (trifluoromethanesulfonyl) imide zinc propylene carbonate solution) was used as the electrolyte instead of the 6N aqueous potassium hydroxide solution. It was produced in the same manner as the battery E1. That is, the battery E5 is an electricity storage device that contains an organic zinc electrolyte as an electrolyte and in which a capacitor layer made of a capacitor material (activated carbon sheet) is formed between the positive electrode and the electrolyte layer.

  The battery C3 was produced in the same manner as the battery C1 except that an organic zinc electrolytic solution having a concentration of 0.5 M was used as the electrolytic solution instead of the 6N aqueous potassium hydroxide solution. That is, the battery C3 is an electricity storage device that contains an organic zinc electrolyte as an electrolyte and does not contain a capacitor material.

Next, charge / discharge characteristics at the time of voltage switching of 1.5 to 0.5 V were examined for each power storage device (battery E1 to battery E5 and battery C1 to battery C3).
Specifically, after each power storage device was kept at 1.5V for a certain time, the voltage was changed to 0.5V and discharged. The change in the discharge current value at this time was examined. Thereafter, each power storage device was kept at a voltage of 0.5 V for a certain time, and then the voltage was changed to 1.5 V to be charged. The change in the charging current value at this time was examined.

FIG. 3 shows changes in the discharge current value when the voltages of the battery E1, the battery E2, and the battery C1 are changed from 1.5V to 0.5V. FIG. 4 shows changes in the discharge current value when the voltages of the battery E3, the battery E4, and the battery C2 are changed from 1.5V to 0.5v. Further, FIG. 5 shows changes in the discharge current value when the voltages of the battery E5 and the battery C3 are changed from 1.5V to 0.5V. FIG. 5 also shows changes in the charging current value when the voltages of the battery E5 and the battery C3 are changed from 0.5V to 1.5V. Further, FIG. 6 shows changes in the charging current value when the voltages of the battery E1, the battery E2, and the battery C1 are changed from 0.5V to 1.5V. In addition, since the change of the charging current value when the voltage of the battery E3, the battery E4, and the battery C2 was changed was substantially the same as that of the battery E1, the battery E2, and the battery C1, respectively, illustration was abbreviate | omitted.
3 to 6, the horizontal axis indicates the elapsed time, and the vertical axis indicates the current value during discharging or charging.

  As can be seen from FIG. 3, the battery E1 and the battery E2 were observed to have a significant increase in current value in a short time compared to the battery C1 when switching the voltage during discharge. Similarly, the battery E3 and the battery E4 also have a significant increase in current value compared to the battery C2 (see FIG. 4), and the battery E5 also has a significant increase in current value compared to the battery C3. Observed (see FIG. 5).

  Further, as is known from FIG. 6, the battery E1 and the battery E2 were observed to increase in current value when the voltage was switched during charging as compared with the battery C1. Similarly, the battery E3 and the battery E4 also observed an increase in current value during charging compared to the battery C2 (not shown), and the battery E5 also observed an increase in current value during charging compared to the battery C3. (See FIG. 5).

  Thus, it can be seen that the batteries E1 to E5 containing the capacitor material can extract a larger current at the time of discharging or charging than the batteries C1 to C3 not containing the capacitor material.

Next, the change of the discharge voltage when the battery E1 and the battery C1 were each discharged from the open state with a constant current was examined. The result is shown in FIG.
As can be seen from FIG. 7, the battery E <b> 1 has a reduced voltage change compared to the battery C <b> 1. Therefore, it can be seen that the voltage drop is suppressed in the battery E1.

  As described above, it can be seen that in the batteries E1 to E5 containing the capacitor substance, the capacity is generally excellent, but a large current can be taken out from the air battery which is difficult to take out a large current at the time of discharging. It can also be seen that a large current can be extracted from the capacitor material even during charging. Therefore, the batteries E1 to E5 can achieve both high capacity and high output.

  Although not clearly shown in this example, even when the metal electrode of the negative electrode in the battery E5 is changed from zinc to Mg, Li, or Al, a significant improvement in current value was observed as in the battery E5. . Therefore, when an organic electrolyte is used as the electrolytic system, other metal electrodes such as Mg, Li, or Al can be used as the negative electrode, in addition to zinc.

Sectional drawing of the electrical storage device which shows the structure of the electrical storage device (battery E1 and battery E2) concerning Example 1 which has a capacitor layer between a positive electrode and an electrolyte layer. Sectional drawing of the electrical storage device which shows the structure of the electrical storage device (battery E3 and battery E4) which contains a capacitor substance in a positive electrode concerning Example 1. FIG. The diagram which shows the change of the discharge current value when the voltage of each electrical storage device (battery E1, battery E2, and battery C1) concerning Example 1 is changed. The diagram which shows the change of the discharge current value when the voltage of each electrical storage device (battery E3, battery E4, and battery C2) concerning Example 1 is changed. The diagram which shows the change of the discharge current value and charge current value when the voltage of each electrical storage device (battery E5 and battery C3) concerning Example 1 is changed. The diagram which shows the change of a charging current value when the voltage of each electrical storage device (battery E1, battery E2, and battery C1) concerning Example 1 is changed. The diagram which shows the change of the discharge voltage at the time of discharging each electrical storage device (battery E1 and battery C1) concerning Example 1 with the constant current from an open state, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power storage device 2 Positive electrode 3 Negative electrode 4 Electrolyte layer 5 Capacitor substance (capacitor layer)

Claims (7)

In an electricity storage device having a positive electrode using oxygen as a positive electrode active material, a negative electrode containing a negative electrode active material having an ionization tendency higher than hydrogen, and an electrolyte layer interposed between the positive electrode and the negative electrode,
The electrolyte layer contains an aqueous electrolyte solution,
The electricity storage device includes a capacitor substance having a capacity of 50 F / g or more that is electrically connected to the positive electrode and exhibits a capacitor function in the electricity storage device. In an electricity storage device having a positive electrode using oxygen as a positive electrode active material, a negative electrode containing a negative electrode active material having an ionization tendency higher than hydrogen, and an electrolyte layer interposed between the positive electrode and the negative electrode,
The electrolyte layer contains an organic electrolyte solution,
The power storage device includes a capacitor substance having a capacity of 20 F / g or more that is electrically connected to the positive electrode and exhibits a capacitor function in the power storage device.   3. The electric storage device according to claim 1, wherein the capacitor substance contains an oxide of one or more metals selected from ruthenium, manganese, iridium, tungsten, and iron. 4. The electricity storage device according to claim 1, wherein the capacitor substance contains a high specific surface area carbon material having a specific surface area of 500 m ² / g or more and an average pore diameter of 1 nm or more.   The electric storage device according to claim 4, wherein the high specific surface area carbon material is subjected to an alkali treatment or an electrolytic treatment.   6. The electrical storage device according to claim 1, wherein the capacitor substance is disposed in the positive electrode.   6. The electricity storage device according to claim 1, wherein the capacitor substance is disposed as a capacitor layer between the positive electrode and the electrolyte layer.

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