CN117957678A

CN117957678A - Battery having electron conduction function via electric double layer capacitor

Info

Publication number: CN117957678A
Application number: CN202280061063.0A
Authority: CN
Inventors: 佐想光广
Original assignee: Rabaut Cross Technology Corp
Current assignee: Rabaut Cross Technology Corp
Priority date: 2021-09-01
Filing date: 2022-09-01
Publication date: 2024-04-30
Also published as: JP2023061405A

Abstract

The present invention provides an ion-conductive battery which comprises hydrogen peroxide and has a structure in which a dipole electric dipole layer is formed between an anode made of metallic copper or an alloy thereof and a cathode made of a metal or an alloy thereof having a lower electrode potential than the anode and having a potential difference between electrodes, and in which electron conductivity from the anode to the cathode is exhibited, wherein the micro-capacitor has a current amplification phenomenon similar to avalanche amplification.

Description

Battery having electron conduction function via electric double layer capacitor

Technical Field

The present invention relates to a battery having electron conductivity from an anode to a cathode via an electric dipole formed between the cathode and the anode of an electron conductor close to each other in a battery generating electromotive force based on ion conduction in an electrolyte.

Background

In order to improve battery performance, first, an electrode potential difference that becomes electromotive force is increased, and a lithium ion battery is proposed. Other improvements of the battery include reduction of the internal resistance affecting the terminal voltage of the battery. The activation of the electrode reaction includes the structure of the electrode, and the like. For example, in a fuel cell using hydrogen peroxide as a fuel, since a metal electrode catalyzes disproportionation reaction of H ₂O₂ toward H ₂ O and O ₂, PEDOT (i.e., poly (3, 4-ethylenedioxythiophene)) is used, while a nickel mesh is used as a cathode in order to avoid occurrence of a loss due to the disproportionation reaction (non-patent document 1). Further, a technique of using copper iron cyanide (CuHCF) as an anode and using a Ni grid as a cathode has been proposed (non-patent document 2). However, these electrodes have problems in mass productivity, and therefore the present inventors have proposed a technique of simplifying the electrode structure of an anode of an air battery or a fuel cell focusing on the catalytic function of copper or an alloy thereof and using a copper electrode as the anode of the air electrode of the air battery instead of a carbon electrode (patent document 1). In the above-described electrode, it was found that when hydrogen peroxide is used instead of oxygen in the air, an electric dipole layer formed at the interface between copper or a copper electrode and an electrolyte exhibits a specific function or performance. That is, the present inventors have found that hydrogen peroxide is a dipole compound and has a high dipole moment, and therefore, when an electrolyte containing hydrogen peroxide is used, a dipole electric dipole layer is formed between electrodes, and even if a pair of electrodes are brought close to each other, a short circuit does not occur, and a separator-free battery having a power generation function can be formed (patent document 2). It has been found that when a structure is adopted in which the anode side and the cathode side are locally in contact with each other via a dipole, the dipole electric dipole layer forms a micro capacitor (a capacitor in the nano-scale region), and when a charge of a predetermined or more is accumulated, an electron conduction effect is exhibited via the electric dipole layer, and electrons flow from the anode side to the cathode side. Further, it was found that the structure in which the dipole electric dipole layer formed at the interface between the electrode and the electrolyte solution is opposed to the P-type semiconductor and the N-type semiconductor via the depletion layer is similar, and as a result, when electrons flow into the depletion layer, a phenomenon of avalanche amplification occurs.

In general, in a battery in which a cathode and an anode are opposed to each other via an electrolyte and connected by an external circuit, an electromotive force is generated based on a potential difference between electrodes of both electrodes, and an ion conduction in the electrolyte and a current flowing from the anode to the cathode are generated by performing electron exchange through a reaction of receiving electrons based on an oxidation reaction at an interface between an electrode on the cathode side and the electrolyte and a reaction of transferring electrons for a reduction reaction at an interface between an electrode on the anode side and the electrolyte. That is, a battery using an electrolyte is an ion-conductive battery.

For example, (1) as shown in fig. 9 (a), in the daniel cell, a copper plate is immersed in an aqueous copper sulfate solution, a zinc plate is immersed in an aqueous zinc sulfate solution, and the copper plate and the zinc plate are connected by an external circuit with a semipermeable membrane capable of moving ions therebetween being placed in opposition to each other, and the following reaction is performed.

Zinc plate surface: zn(s) →Zn ²⁺+2e^-

Copper plate surface: cu ²⁺+2e^- → Cu(s) ∈

(2) As shown in fig. 9 (b), in the lead acid battery, b(s) +so ₄ ^2-→PbSO₄(s)+2e^- oxidation reaction at the metallic lead electrode and PbO ₂(s)+4H⁺+SO₄ ^2-+2e^-→PbSO₄(s)+2H₂ O reduction reaction on the lead oxide surface are performed in a sulfuric acid aqueous solution, and charge and discharge are performed in an acidic electrolyte along with ion movement. (3) In the lithium ion battery, the lithium ion battery is charged and discharged in the electrolyte by the Li(s) to Li ⁺+e^- oxidation reaction on the lithium surface and the 2MnO 2(s) +li ⁺+e^-→LiMn₂O₄ reduction reaction on the manganese dioxide surface, accompanied by movement of lithium ions.

(4) In the hydrogen fuel cell, 2H ₂(g)→4H⁺+4e^- oxidation reaction is also performed on the hydrogen side, and on the air side, oxygen in the air reacts with electrons coming from the hydrogen side to be reduced, and reacts with diffused hydrogen ions to form water.

In this way, in various batteries using an electrolyte, electrons move from the cathode side to the anode side through an external circuit, but active materials or ions move from the anode side to the cathode side through the electrolyte, and an electromotive force is generated based on an electrode potential difference between a pair of electrodes. Therefore, the electrolyte is an ion conductor, and thus movement of energy becomes ion conduction. Thus, the ionic conductivity controls the internal resistance R of the battery. Therefore, in order to increase the output voltage V, it is necessary to reduce the internal resistance, but it is controlled by the mobility of ions conducting ions, and thus is limited.

Technical literature of the prior art

Patent literature

Patent document 1: japanese patent application laid-open No. 2021-142110

Patent document 2: japanese patent application No. 2021-073490

Non-patent literature

Non-patent document 1: chemical Communications,2018,Vol.54,Pages 11873-11876

Non-patent document 2: journal of Hydrogen Energy, ELSEVIER, vol.45, iss ue 47,25September 2020,Pages 25708-25718

Non-patent document 3: water transition english works: physicochemical advances (1936), 10 (3): pages 154 to 165

Disclosure of Invention

Technical problem to be solved by the invention

The present inventors have conducted intensive studies in view of the technical problems that various batteries using ion conduction of an electrolyte conduct ions in the electrolyte, and have an electron conductivity through an electric dipole layer formed at an interface between an electrode and the electrolyte and reduce internal resistance of the battery, and finally have achieved the present invention.

Technical means for solving the technical problems

The present invention provides a battery having electron conductivity through an electric double layer capacitor, which is an ion-conductive battery as follows: the cathode and the anode are connected by an external circuit, and are opposed to each other with an ion conductor, namely, an electrolyte, and power generation is performed based on an oxidation reaction of an active material at the cathode and a reduction reaction at the anode, the battery is characterized in that,

A plurality of protruding electrodes protruding in the cathode surface direction with a constant interval therebetween are provided on the anode surface, the protruding electrodes are brought close to the cathode surface facing each other, an electric double layer capacitor is formed between the protruding electrode ends of the anode and the cathode surface, and electrons are conducted from the protruding electrode ends of the anode to the cathode surface via the electric double layer capacitor.

Effects of the invention

According to the present invention, the battery can be made electronically conductive in addition to the ionic conductivity in the electrolyte. That is, it can be considered that: in the present invention, the protrusions of the anode are brought close to the cathode surfaces facing each other, and an electric double layer capacitor (herein, a micro capacitor) is formed between the protruding electrode ends of the anode and the cathode surfaces (see fig. 1), but electrons are collected and stored in the anode side, and as a result, an electron conduction state is achieved. The anode and cathode are initially non-conductive, but later negatively charged electrons flow from the protruding end of the anode to the cathode surface, exhibiting electron conductivity. That is, it is considered that electrons flow intensively from the protruding ends of the copper electrode to the portions of the counter aluminum electrode plate shown in fig. 8 (a) close to the protrusions, and holes are formed in the portions (see fig. 8 (b)). Then, the aluminum electrode underwent rapid progress of electrolysis due to collision with other atoms of the electrode, and a rugged state was observed around the hole, in which powder was sprayed on the surface of the aluminum electrode, and it was estimated that an avalanche amplification effect was exhibited from the relationship between the increase in the amount of current shown in fig. 5.

As shown in fig. 1, it can be considered that: the reason for exhibiting the above electron conductivity is that an electric double layer capacitor is formed between the protruding end of the anode and the cathode, but a phenomenon in which electrons flow from the anode side to the cathode side (electron conduction) is not conceivable. There are many reasons for electron conduction. One example is that electrons collected on the anode side flow to positive charges such as metal ions formed on the cathode side surface with an increase in electric field. In addition, a tunneling phenomenon can be considered, but a dipole electric dipole layer formed at an interface between an electrode and an electrolyte is similar to a structure in which a P-type semiconductor and an N-type semiconductor face each other via a depletion layer, and it is presumed that electron conduction occurs due to a phenomenon in which electrons flow into the depletion layer to cause avalanche amplification. In summary, in the ion conduction-based battery, electron conduction was found, and the internal resistance of the battery controlled by ion conduction was found to drastically decrease (fig. 5).

In the present invention, the electrolytic solution preferably contains a dipole compound represented by hydrogen peroxide, and the electric double layer capacitor formed from the anode end toward the cathode surface is a dipole electric double layer.

In the present invention, the anode is preferably made of copper or an alloy thereof, so as to have a catalytic function of promoting decomposition of hydrogen peroxide. On the other hand, the cathode is preferably made of magnesium, aluminum, zinc, and alloys thereof, and it ensures an electrode potential with the anode. When the alkaline electrolyte contains hydrogen peroxide, the electric dipole layer becomes a dipole electric dipole layer, which is preferable because it is likely to bring about a capacitor effect. Preferably, hydrogen peroxide water or sodium percarbonate is used to supply the hydrogen peroxide.

Drawings

Fig. 1 is a schematic diagram showing a micro capacitor of the present invention.

Fig. 2 is a schematic diagram showing an air battery to which the micro capacitor of the present invention is applied.

Fig. 3 (a) is a perspective view showing the structure of a copper electrode constituting the micro-capacitor of the present invention, and (B) is a sectional view showing a state in which a magnesium electrode and a copper electrode are combined.

Fig. 4 is a schematic diagram of a battery in which a plurality of micro capacitors are formed.

Fig. 5 is an illustration showing a power generation state in a state in which the micro capacitor of the present invention is applied to a magnesium air battery.

Fig. 6 (a) is a perspective view showing the structure of a copper electrode of a battery that forms a normal electric double layer capacitor, and (B) is a sectional view showing a state in which a magnesium electrode and a copper electrode are combined.

Fig. 7 (a) is a perspective view of a copper anode in which four protruding electrodes are cut on the surface of a copper electrode, and (b) is a sectional view of an electrode structure assembled by sandwiching an aluminum cathode with the copper electrode of fig. 7 (a).

Fig. 8 (a) is a photograph before use of the aluminum electrode plate used in combination with fig. 7 (a), and (b) is a photograph after use.

Fig. 9 (a) is a schematic diagram of a daniel cell, and (b) is a schematic diagram of a lead storage battery.

Detailed Description

As shown in fig. 2, in the present invention, a Mg or Al cathode plate and a Cu anode plate are immersed in an alkaline electrolyte containing hydrogen peroxide and are disposed so as to face each other. As shown in fig. 3 (a), a part of the copper electrode 10 was cut into a triangle shape and erected perpendicularly to the electrode surface, so that an acutely triangular projection electrode 11 having a height of 5 to 15mm was formed, and the tip of the projection electrode 11 was disposed so as to be in soft contact with the magnesium electrode surface. Preferably with a spacing where there is a dipole of at least one molecule. The protruding electrodes are formed at intervals of 150mm to 200mm, and electrons preferably flow in from the surrounding anode region.

The electromotive force in the cathode/alkaline electrolyte containing hydrogen peroxide/anode structure (i.e., the reaction of the metal-air cell) is as follows.

The oxidation reaction at the cathode side becomes 4/3Al→4/3Al ³⁺+4e^- or 2Mg→2Mg ²⁺+4e^-,

On the other hand, the reduction reaction at the anode side becomes O ₂+H₂O+4e^-→4OH^-.

In the present invention, hydrogen peroxide is added to the electrolyte in order to promote the reduction reaction at the anode side of the metal-air battery, thereby improving the cause that the ionization of the anode side positive electrode proceeds at a lower rate than the cathode side negative electrode.

That is, a part of the metallic copper is dissolved in hydrogen peroxide based on cu+h ₂O₂→Cu²⁺+OH+OH^- and cu+oh→cu+oh ^-, but it is considered that the decomposition of hydrogen peroxide is promoted based on haber u.wilrstatter linkage based on Cu ²⁺+HO₂ ^-→Cu+2HO₂,HO₂ group (non-patent document 3).

Further, according to the present invention, the electric dipole layer formed on the surface of the anode contains hydrogen peroxide and is formed of its dipole (dipole) function, and thus has an ion-permeable separator function. Therefore, even if the cathode and the anode of the counter electrode are in contact, the contact between the cathode and the anode is not shorted, and if the contact between the cathode and the anode is made by protrusions or the like arranged in a dot shape with a certain interval therebetween, the end of the dot-shaped protrusion will have an electric double layer capacitor structure (fig. 1), and a plurality of micro capacitors are dispersed on the electrode surface, and electrons are collected and flow by the electron conduction effect, and avalanche amplification is repeated (fig. 5), so that the same electrode structure without the micro capacitor function will exhibit 30% to twice or more of the power generation capacity.

In the present invention, sodium percarbonate is preferably added to supply part or all of hydrogen peroxide to the water-soluble electrolyte. Specifically, it is preferable to add from several% to several tens% of hydrogen peroxide water (vol%) or sodium percarbonate (wt%) to a neutral or alkaline aqueous solution containing 0.5 to 2.0 mol of an alkali metal or alkaline earth metal halide salt (especially, sodium chloride).

Instead of aluminum, magnesium or an alloy thereof may be used as the cathode.

By employing a cell structure of (-) Mg/nacl+h ₂O₂/Cu (+) a decomposition voltage required to decompose hydrogen peroxide or its decomposed hydroxyl groups is applied between the cathode and the copper anode. As the magnesium alloy electrode, a magnesium/aluminum/zinc alloy electrode of MAZ61 or MAZ31 may be used.

The cathode and the anode are disposed to face each other with a constant gap therebetween, and an electric double layer capacitor is formed at a contact portion between the cathode and the anode by a water-soluble electrolyte containing hydrogen peroxide, but the separator is preferably made of the same metal copper or copper alloy as the anode, and preferably has dot-like projections on a counter surface with a constant gap therebetween (fig. 3). The micro capacitor is constituted by a dipole having a dipole moment of 2.0e.s.u×10 ^-15 or more (for example, an anode and a cathode are opposed to each other with a nm-order interval of one molecule of hydrogen peroxide interposed therebetween), but a triangular electrode is projected from the anode surface so that electrons flow from the anode to the cathode locally.

Examples

The use of the copper electrode shown in fig. 3 constitutes a battery with a micro-capacitor of the concept shown in fig. 1.

An open-top square plastic container with a capacity of 3000ml was used. In fig. 2, a plurality of triangular projections 11 (fig. 3 (a)) having a height of 50mm to 100mm are cut at intervals of 150mm or 200mm in the up-down and left-right directions on a copper anode plate 10 having a thickness of 1mm and a length of 100×100mm, and as shown in fig. 3 (B), copper plates 10 are arranged with the projections 11 facing inward at both ends, and copper plates 10 are stuck back to back in the middle so that the projections 11 protrude toward both sides, sandwiching a magnesium cathode 20 having a thickness of 2mm and a length of 100×100 mm.

If the thus assembled electrode is used, a micro capacitor may be formed on the surface of the copper anode as shown in fig. 1.

On the other hand, as shown in fig. 6 (a), a spacer S formed by cutting a copper electrode plate into a T-shape and bending the end portion thereof was attached to a copper anode plate 10 having a thickness of 1mm and a length of 100×100 mm. The anode plate was used and both sides of the Mg cathode plate 20 having a thickness of 2mm and a length of 100×100mm were sandwiched via spacers S. Two Mg cathode plates 20 are alternately sandwiched by three copper anode plates 10 via spacers S (refer to (B) in fig. 6). If the electrodes thus assembled are used, a micro capacitor cannot be formed.

Approximately 1500ml of pure water was added to the plastic container, and the mixture was adjusted to an electrolyte solution containing 0.5 mol/l or more (preferably 1.5mol/l or more and 2 mol/l or less) of sodium chloride, and 50 to 100g of sodium percarbonate and 50ml of 30% hydrogen peroxide water were added thereto.

In the battery reaction, when a certain time elapses, hydrogen peroxide is consumed, and oxygen is reduced, so that 10ml of 30% hydrogen peroxide water is added every two or three hours.

In this example, the performance of the electrode structures of (a) and (B) in fig. 3 and the electrode structures of (a) and (B) in fig. 6 were compared, and thus the performance of the case where a micro capacitor was formed on the surface of a copper anode was compared with the case where a micro capacitor was not formed.

The conditions are the same except for the electrode structure, so the hydrogen peroxide fuel cell reaction in alkaline electrolyzed water is the same along with the magnesium air cell reaction. Accordingly, hydrogen peroxide is decomposed into H ₂O₂+2H₂O+2e^-→2H₂O+2OH^- by the following reaction formula, and on the other hand, not only the oxidation reaction of H ₂O₂+2OH^-→O₂+2H₂O+2e^- is generated on the anode side, but also the oxidation reaction of metal in the alkaline electrolyte becomes mg→mg ²⁺ +2e-, and the reaction of reducing oxygen to ionize on the anode side becomes O ₂+2H₂O+4e^-→4OH^-, resulting in a typical metal-air battery reaction. However, it is generally considered that oxygen is generated in the hydrogen peroxide fuel cell and the metal air cell reaction, but not only oxygen but also hydrogen is generated in the above-described structure. This is considered to be because, as described in non-patent document 3 (the "water transition" works, the "progress of physicochemical chemistry" (1963), 10 (3): pages 154 to 165), a catalytic action is generated on the surface of the copper anode, and the hydrogen peroxide and the hydroxide ions are decomposed, thereby generating a power generation reaction.

2H₂O₂→4·OH→H₂+O₂+4e^-

4OH^-→H₂+O₂+4e^-

Based on the above experimental results, it is found that the fuel cell with the micro capacitor shown in fig. 3 shows an increase in current value of more than twice as much as the case without the micro capacitor shown in fig. 6, although it is different depending on the structure of manufacturing the micro capacitor.

It is known that the collector discharge effect associated with the micro capacitor has a large influence on the power generation amount of the battery. Therefore, the structure of the present invention can provide a novel and useful structure as a hydrogen peroxide fuel cell of a 1-gap (com-partment) structure, and is thus unprecedented.

(Electronic conductivity in relation to the present invention)

The electron conductivity found in the electric double layer capacitor (micro capacitor) of the present invention is an unexpected phenomenon in a battery operated by ion conduction. Fig. 8 (a) and (b) show the results. The aluminum plate of fig. 8 (a) has a thickness of 1.5mm and an area of 15 square centimeters, and is used in combination with a copper electrode having four protrusions (see fig. 7 (a)) to form fig. 7 (b). The micro capacitor having an electric dipole layer formed between the protruding end of the copper electrode and the aluminum electrode plate collects electrons on the anode side, and when a certain charge is accumulated, electron conductivity with the cathode side is exhibited, and electrons flow to the cathode side. This is known as the electron conductivity of the ion-conducting cell. In a battery using an electrolyte mainly based on ion conduction, this phenomenon has not been known, and as shown in fig. 8 (b), four holes are formed in an aluminum motor facing a protrusion on the copper electrode side, and a rough electrode surface sprayed with powder is formed around the holes. From this, it is assumed that a phenomenon (electron conduction) in which electrons are discharged from the protrusions on the copper electrode side toward the aluminum electrode surface occurs, and that an avalanche effect is exhibited in which electrons reaching the aluminum electrode collide with surrounding metal atoms and are sequentially excited. The electrode structures of fig. 3 and 6 are the case where magnesium is used as the cathode, but it is considered that the cause of the increase in the amount of electricity generation is the same regardless of the presence or absence of the protrusion on the copper electrode.

Claims

1. A battery having electron conductivity through an electric double layer capacitor, which is an ion-conductive battery as follows: the cathode and the anode are connected by an external circuit, and are opposed to each other with an ion conductor, namely, an electrolyte, and power generation is performed based on an oxidation reaction of an active material at the cathode and a reduction reaction at the anode, the battery is characterized in that,

2. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

Electrons having negative charges flow from the anode end to the electron conductivity of positively charged metal ions formed on the cathode surface.

3. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

The electrolyte contains a dipole compound, and the electric double layer capacitor formed from the anode end toward the cathode surface is a dipole electric dipole layer.

4. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

The anode is made of copper or an alloy thereof, and the cathode is selected from magnesium, aluminum, zinc and an alloy thereof, and the alkaline electrolyte contains hydrogen peroxide.

5. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

The electrolyte contains a dipole compound having a dipole moment of 2.0 e.s.ux ^-15 or more, and is a water-soluble electrolyte that forms a dipole electric dipole layer at an interface with an electrode,

The battery is provided with a micro-capacitor which is formed by sandwiching at least one molecule of dipole between an anode and a cathode, and has a function of imparting an electron conduction effect from the anode toward the cathode.