JP2006004817A - Vehicle-mounted secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle secondary battery in which stable and sufficient electromotive force can be exerted, and in which a charge and discharge are possible with a simple constitution. <P>SOLUTION: This is the on-vehicle secondary battery provided with a power generating part and a charging part, and the power generating part is provided with at least an acidic medium in which a first electrode is arranged and a basic medium in which a second electrode is arranged, the acidic medium and the basic medium are arranged adjacent or near to each other, reactants are contained in at least either of the acidic medium or the basic medium, the power charging part is provided with a reactant reproducing means in which the reactants are reproduced from the power generating products formed by the power generation at the power generating part, and furthermore a power supplying means is provided which supplies the power for actuating the reactants reproducing means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle secondary battery, and more particularly, to provide an in-vehicle secondary battery that can be charged and discharged while reusing electrolyte components with a simple configuration.

  In recent years, due to increasing environmental problems, research and development of hybrid technology combining an electric motor and an engine and a fuel cell vehicle have been actively conducted in the automotive technology to reduce carbon dioxide. However, secondary batteries currently in use often use harmful compounds such as lead, which is a problem in disposal. Further, since the power storage capacity per volume is not sufficient, there is a problem that the weight of the battery to be loaded causes an increase in the weight of the entire automobile, resulting in a decrease in fuel consumption.

  On the other hand, in the field of control, not only the engine, but also the mission, all drive wheels, human handles and accelerator / brake operations are monitored and optimally controlled to improve fuel economy and improve passenger safety. It is going to be done. In addition, air conditioners and audios are indispensable items for realizing a comfortable moving space. Electric power required in automobiles is greatly increased, and an increase in battery capacity is required.

  Here, a battery is a device that directly converts chemical energy of a substance into electrical energy. In addition, a primary battery that provides power until the chemical energy is used up, a secondary battery that can be reused by storing the chemical energy again after charging, and a substance with chemical energy from the outside is continuously supplied. By doing so, it can be classified as a fuel cell that obtains electric energy. Currently, many types of batteries are being developed, but each battery has its advantages in terms of environmental safety, economy, amount of electric energy that can be supplied, portability and storage, environmental compatibility, and recyclability. Therefore, the batteries are selected according to the purpose of use and put into practical use. The important technical elements common to all batteries are what kind of chemical reaction is used, how the reaction is promoted, and how the chemical is stored and supplied.・ It is in the point of collecting.

  In a battery, there are two types of chemistry: a reducing agent that causes a reduction reaction (provides electrons or pulls out oxygen) and an oxidizing agent that triggers an oxidation reaction (draws electrons from the partner or supplies oxygen). Use substances. By causing the chemical reaction separately at the two electrodes facing each other, the energy of the generated electrons is extracted to the outside (the ions generated at the two electrodes as the electrons are generated are neutralized inside the battery). Their reaction efficiencies depend on the type and reaction mode of chemical substances used, the electrode material and activity, and the environment of the reaction field including the electrolyte. Further, what kind of material is selected to configure the battery is a point related to the quality of the entire battery system including not only the above-described use but also the manufacturing and disposal.

  For example, a lithium ion secondary battery is excellent in the amount of electric energy and can be reused by charging. However, since lithium is a very unstable ignitable substance with respect to moisture and oxygen in the air, sufficient safety measures must be taken for battery packaging and usage environment in order to avoid the danger. Furthermore, collection and recycling after the battery life is indispensable, raising the overall cost from battery manufacture to use / disposal. This problem also applies to secondary batteries such as lead-based storage batteries, nickel cadmium storage batteries, and nickel metal hydride storage batteries. Further, when charging / discharging is repeated, there is a problem that the memory effect and electrolyte deterioration occur and the performance is lowered.

On the other hand, the secondary battery as described above is not suitable for continuously driving the device because it has a limit in the power that can be stored and takes time to charge. Under such circumstances, an example in which water generated in a hydrogen fuel cell is electrolyzed to regenerate hydrogen of the fuel and used as a secondary battery capable of continuously supplying electric power is disclosed (for example, Patent Document 1). reference). However, since hydrogen is a flammable gas, its storage and handling are not easy.
JP-A-7-99707

In view of the above, an object of the present invention is to solve the problems of the prior art.
That is, the present invention is capable of exhibiting a stable and sufficient electromotive force by promoting the electrode reaction, and can be charged and discharged while reusing the electrolyte components with a simple configuration. An object is to provide a battery.

The above object is achieved by the present invention described below.
That is, the first in-vehicle secondary battery of the present invention is an in-vehicle secondary battery including a power generation unit and a charging unit,
The power generation unit includes at least an acidic medium in which a first electrode is disposed, and a basic medium in which a second electrode is disposed,
The acidic medium and the basic medium are adjacent to or close to each other, and at least one of the acidic medium and the basic medium contains a reactive substance,
The charging unit includes a reactant regeneration unit that regenerates the reactant from the power generation product generated by the power generation in the power generation unit, and further supplies power for operating the reactant regeneration unit It is characterized by providing.

The second in-vehicle secondary battery of the present invention is an in-vehicle secondary battery including a power generation unit and a charging unit,
The power generation unit is configured by sequentially connecting a plurality of unit power generation cells in series,
The unit power generation cell includes at least an acidic medium in which a first electrode is arranged and a basic medium in which a second electrode is arranged,
The acidic medium and the basic medium are adjacent to or close to each other, and at least one of the acidic medium and the basic medium contains a reactive substance,
The in-vehicle secondary battery is characterized in that the charging unit includes a reactive material regeneration unit that regenerates the reactive material from a power generation product generated by power generation in the power generation unit.

In the first and second in-vehicle secondary batteries of the present invention, it is preferable to apply at least one of the following first to eighteenth aspects.
(1) A 1st aspect is an aspect in which the said charging part is further equipped with the medium reproduction | regeneration means which reproduces | regenerates the said acidic medium and / or the said basic medium from the said electric power generation product.
(2) A 2nd aspect is an aspect from which the said acidic medium consists of acidic aqueous solution, and the said basic medium consists of basic aqueous solution.
(3) A third aspect is an aspect in which the reactant is contained in each of the acidic medium and the basic medium.
(4) In the fourth aspect, the first substance as the reactant contained in the acidic medium is the same substance as the second substance as the reactant contained in the basic medium. This is an embodiment.
(5) A fifth aspect is an aspect in which the reactant is hydrogen peroxide.

(6) In a sixth aspect, the reactant regeneration means has an anode and a cathode, and supplies the oxygen and water as the power generation products to the cathode to regenerate the hydrogen peroxide. It is a certain aspect.
(7) In a seventh aspect, the medium regeneration means arranges a cation exchange membrane, a bipolar membrane, and an anion exchange membrane to form a salt chamber, an acid chamber, and a base chamber, and the power generation in the salt chamber A mode in which a cell of a three-chamber cell system is provided in which a neutralized salt aqueous solution as a product is supplied and electrodialysis is performed, and the acidic aqueous solution and the basic aqueous solution are discharged from each of the acid chamber and the base chamber. is there.

(8) The eighth aspect is an aspect in which the power generation unit is provided with a flow path structure in which the acidic aqueous solution and the basic aqueous solution form a laminar flow therein.
(9) A ninth aspect is an aspect in which the unit power generation cell is provided with a flow path structure in which the acidic aqueous solution and the basic aqueous solution form a laminar flow therein.

(10) In a tenth aspect, the acidic aqueous solution is sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, perchloric acid, periodic acid, orthophosphoric acid, Polyphosphoric acid, nitric acid, tetrafluoroboric acid, hexafluorosilicic acid, hexafluorophosphoric acid, hexafluoroarsenic acid, hexachloroplatinic acid, acetic acid, trifluoroacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, maleic acid, malonic acid, phthalic acid , Fumaric acid, and picric acid.
(11) In an eleventh aspect, the basic aqueous solution contains sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, water One or more bases selected from the group comprising tetraethylammonium oxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide, or sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium borate, boron It is an embodiment containing one or more alkali metal salts selected from the group comprising potassium silicate, sodium silicate, potassium silicate, sodium tripolyphosphate, potassium tripolyphosphate, sodium aluminate, and potassium aluminate.

(12) The twelfth aspect is an aspect in which the acidic medium is composed of an acidic ion conductive gel and the basic medium is composed of a basic ion conductive gel.
(13) In a thirteenth aspect, the acidic ion conductive gel is obtained by gelling an acidic aqueous solution with water glass, anhydrous silicon dioxide, crosslinked polyacrylic acid, agar, or a salt thereof.
(14) A fourteenth aspect is an aspect in which the basic ion conductive gel is formed by gelling a basic aqueous solution with carboxymethyl cellulose, crosslinked polyacrylic acid, or a salt thereof.

(15) In the fifteenth aspect, the first electrode is platinum, platinum black, platinum oxide-coated platinum, silver, gold, titanium whose surface is passivated, stainless steel whose surface is passivated, and passivated surface. It is an embodiment composed of one or more materials selected from the group consisting of activated nickel, aluminum whose surface is passivated, carbon structure, amorphous carbon, and glassy carbon.
(16) In the sixteenth aspect, the second electrode is platinum, platinum black, platinum oxide-coated platinum, silver, gold, titanium whose surface is passivated, stainless steel whose surface is passivated, and passivated surface. It is an embodiment composed of one or more materials selected from the group consisting of activated nickel, aluminum whose surface is passivated, carbon structure, amorphous carbon, and glassy carbon.

(17) A seventeenth aspect is an aspect in which the first electrode and the second electrode have a plate shape, a thin film shape, a mesh shape, or a fiber shape.
(18) An eighteenth aspect is an aspect in which the first electrode and the second electrode are respectively disposed on the acidic medium and the basic medium by an electroless plating method, a vapor deposition method, or a sputtering method. Is

According to the present invention, it is possible to stably exhibit a sufficient electromotive force by promoting the electrode reaction, and while reusing the electrolyte components (reactants, etc.) with a simple configuration. An in-vehicle secondary battery that can be charged and discharged can be provided.
In addition, when no harmful metal is used for the electrode, the secondary battery for automotive use is ideal for applications such as automobiles because it can be made compact and lightweight while being simplified in packaging, and can be easily disposed of. Can be provided.

  Hereinafter, the first and second in-vehicle secondary batteries and their power generation methods (power generation mechanisms) according to the present invention will be described in detail.

<First in-vehicle secondary battery>
The first in-vehicle secondary battery of the present invention is roughly composed of two parts: (1) a power generation part and (2) a charging part.

(1) Power generation unit:
The power generation unit includes an acidic medium in which the first electrode is disposed and a basic medium in which the second electrode is disposed. The acidic medium and the basic medium are adjacent to each other or close to each other, and the reactive substance is contained in at least one of the acidic medium and the basic medium.
The battery of the present invention is a bipolar battery having a configuration including the above-described members. And it becomes possible to set it as a secondary battery by combining with the reproduction | regeneration means of the charging part mentioned later. In the present invention, a bipolar battery has a configuration in which an acidic medium and a basic medium are adjacent or close to each other, and a substance (reactive substance) for extracting electric energy and an electrode are included in these. I have it.

  The reactant contained in the acidic medium or the basic medium promotes the electrode reaction on the positive electrode side and / or the negative electrode side by the following action, and enables efficient generation of electric energy. That is, when such a reactive substance does not exist in an acidic medium or a basic medium, a sufficient electromotive force as a battery cannot be obtained.

  For example, when the reactive substance is contained in each of an acidic medium and a basic medium, the first substance that is the reactive substance in the acidic medium is first with hydrogen ions contained in the acidic medium. Reaction that takes electrons away from the electrodes. On the other hand, the second substance, which is a reactant in the basic medium, causes a reaction to donate electrons to the second electrode with hydroxide ions contained in the basic medium.

  In particular, the in-vehicle secondary battery according to the present invention includes: (1) the first substance and the hydrogen ion coexist in the acidic medium or in the vicinity of the electrode in contact with the acidic medium, and the first electrode as a reaction system substance. Cause a reaction to rob (oxidize) electrons. (2) The second substance and hydroxide ions coexist in the basic medium or in the vicinity of the electrode in contact with the basic medium, and both cause an electron (reduction) reaction to the electrode as a reaction system substance. Such reactions (1) and (2) proceed simultaneously to generate electrical energy for driving the external circuit.

Note that in the in-vehicle secondary battery of the present invention, in the bipolar reaction field, hydrogen ions in the acidic medium participate in the reaction of taking electrons from the first electrode by the first substance, and the concentration increase is It has the effect of promoting the reaction (shifting the chemical equilibrium in the direction of the production system). On the other hand, the hydroxide ions constituting the basic medium participate in the reaction of donating electrons to the second electrode by the second substance, and the increase in concentration has the effect of promoting the reaction. For this reason, it is possible to enhance the reaction by increasing the hydrogen ion concentration or hydroxide ion concentration, that is, lowering the pH in an acidic medium and increasing the pH in a basic medium, thereby increasing the output. It is also effective in that it has a configuration capable of.
Hereinafter, each member which comprises a power generation part is demonstrated in detail.

(Acid medium and basic medium)
In the present invention, the acidic medium refers to a medium having a pH of less than 7 (preferably, a pH of 3 or less), and is preferably capable of forming an acidic reaction field where hydrogen ions are present. Further, the basic medium is a medium exceeding pH 7 (preferably having a pH of 11 or more), and it is preferable that a basic reaction field where hydroxide ions are present can be formed.

  Each of these acidic medium and basic medium may be independently in any form of a liquid state, a gel state, and a solid state, but it is preferable that both the mediums have the same aspect. Moreover, as an acidic medium and a basic medium, it can use regardless of the kind of organic compound and an inorganic compound.

  A preferable combination of the acidic medium and the basic medium is, for example, a combination of an aqueous solution of an acidic aqueous solution such as sulfuric acid, hydrochloric acid, or phosphoric acid and a basic aqueous solution such as sodium hydroxide, potassium hydroxide, ammonia, or an ammonium compound; And combinations of ion conductive gels obtained by gelling these aqueous solutions with a gelling agent.

  More specifically, as the acidic aqueous solution, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, perchloric acid, periodic acid, orthophosphoric acid, polyphosphoric acid, Nitric acid, tetrafluoroboric acid, hexafluorosilicic acid, hexafluorophosphoric acid, hexafluoroarsenic acid, hexachloroplatinic acid, acetic acid, trifluoroacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, maleic acid, malonic acid, phthalic acid, fumaric acid It is preferable to use an aqueous solution containing at least one acid selected from the group consisting of picric acid, and it is more preferable to contain sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, which are strong acids.

  Basic aqueous solutions include sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrahydroxide hydroxide. One or more bases selected from the group comprising propylammonium and tetrabutylammonium hydroxide, or sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium borate, potassium borate, sodium silicate, An aqueous solution containing one or more alkali metal salts selected from the group comprising potassium silicate, sodium tripolyphosphate, potassium tripolyphosphate, sodium aluminate, and potassium aluminate can be used. Beam, and more preferably contains potassium hydroxide.

Furthermore, an acidic ion conductive gel as an acidic medium is obtained by gelling an acidic aqueous solution as described above with a gelling agent such as water glass, anhydrous silicon dioxide, crosslinked polyacrylic acid, agar, or a salt thereof. Is preferred.
On the other hand, a basic ion conductive gel as a basic medium is obtained by gelling a basic aqueous solution as described above using, for example, carboxymethylcellulose, crosslinked polyacrylic acid or a salt thereof as a gelling agent. Is preferred.
In addition, said acid and base may use only 1 type, and may mix and use 2 or more types. The method of using the gelling agent is also the same.

  In the power generation unit, it is essential that the acidic medium and the basic medium be adjacent to each other or close to each other. This is because the counter anion generated by releasing hydrogen ions in the acidic medium and the basic medium This is because it is possible to balance the charge by forming a salt with the counter cation generated by releasing the hydroxide ion in step (b). Therefore, for example, as described above, in the case where both media are composed of an acidic aqueous solution and a basic aqueous solution, a membrane having a property of allowing the generated cation and / or anion to permeate, or the generated cation. If a salt bridge capable of moving ions and / or anions is used, the acidic medium and the basic medium may be separated from each other. Moreover, it is not necessary for each of them to be adjacent to each other.

(Reactive substance)
When the reactive substance is contained in an acidic medium, any substance may be used as long as it is a substance (oxidant) that generates an oxidation reaction that takes away electrons from the first electrode with hydrogen ions in the acidic medium. Can be used. On the other hand, when contained in a basic medium, if it is a substance (reducing agent) that generates a reduction reaction that donates electrons to the second electrode with hydroxide ions in the basic medium, Any thing can be used.
Here, as a preferred embodiment, the first substance as the reactive substance contained in the acidic medium and the second substance as the reactive substance contained in the basic medium will be described in detail below.

  The first substance is preferably a substance that promotes the reaction when the hydrogen ion concentration is high. Specifically, hydrogen peroxide, oxygen, hypochlorous acid, hypobromous acid, hypohalous acid such as hypoiodous acid, and the like can be used. Alternatively, the first substance may be supplied in the state of a liquid containing these substances or a liquid that releases these substances by chemical change.

  Further, the second substance is preferably a substance that promotes the reaction when the hydroxide ion concentration is high. Specifically, hydrogen peroxide, hydrogen, hydrazine, or the like can be used. Further, the second substance may be supplied in the state of a liquid containing these substances or a liquid that releases these substances by a chemical change.

  As the first substance or the second substance, metal ions such as iron, manganese, chromium, and vanadium that can change their valence by an oxidation / reduction reaction, or a metal complex thereof can be used, and a liquid containing these also. Etc. can be used to supply these substances.

  Among the above, it is preferable that the first substance and the second substance are composed of the same component. Such a substance generates an oxidation reaction that takes electrons from the first electrode with hydrogen ions in an acidic medium, and in a basic medium, electrons move to the second electrode with hydroxide ions. It has the property of causing a reduction reaction to donate. In this case, the configuration of the battery becomes easy, the degree of freedom in selecting the separation membrane for the chemical substances on the positive electrode side and the negative electrode side, which has been a big problem with the conventional battery, is expanded, and the acidic medium and the basic medium are mixed. A separation membrane is not necessarily required when the state can be kept.

As a substance that can be used as both an oxidizing agent and a reducing agent, hydrogen peroxide is particularly preferable. The reason for this will be described later in detail. Note that it is preferable to supply hydrogen peroxide using a liquid containing hydrogen peroxide or a liquid that releases hydrogen peroxide by a chemical change in terms of easier handling. The “liquid” that is a means for supplying hydrogen peroxide may be in the form of a solution (including water, organic solvent, etc. as a solvent), a dispersion, or a gel. Moreover, it is desirable that these usage forms are selected by a preferable combination with the above-described acidic medium and basic medium forms.
In addition, hydrogen peroxide is mixed or dispersed in the medium before the start of the reaction, through a flow path installed in the vicinity of the electrode, by using a capillary, or directly into the medium. It is good also as a system added.

  When the first substance and the second substance are hydrogen peroxide, 2 (hydrogen ion, hydroxide) in a molar ratio with respect to hydrogen ions and hydroxide ions in the acidic medium and the basic medium, respectively. It is most preferable that it is contained so as to be 1 (hydrogen peroxide). This is because hydrogen peroxide reacts without excess or deficiency when it is contained in the above ratio from the power generation reaction described later.

According to the above configuration, when the hydrogen ion H ⁺ and the hydroxide ion OH ⁻ are involved in the reaction at the electrode, the first substance is accompanied by the hydrogen ion H ⁺ in the acidic medium. In the basic medium, the second substance causes a reduction reaction in which electrons are donated to the electrode together with hydroxide ions OH ⁻ . At this time, the electromotive force due to the oxidation reaction in the acidic medium is larger in principle than the oxidation reaction in the basic medium. This is because the hydrogen ion H ⁺ is a substance in the reaction system, so that in an acidic medium having a high hydrogen ion concentration, the chemical equilibrium is inclined to the production system, and as a result, the oxidation potential is increased. Further, the electromotive force due to the reduction reaction in the basic medium becomes larger in principle than the reduction reaction in the acidic medium. This is because the hydroxide ion OH ⁻ is a substance in the reaction system, so that in a basic medium having a high hydroxide ion concentration, the chemical equilibrium is inclined to the production system, and as a result, the oxidation potential is lowered.
For this reason, in the configuration of the bipolar battery of the present invention, the electromotive force generated by the oxidation / reduction reaction at the electrode is the main source of voltage obtained from the battery, and the location of the neutralization reaction inside the battery fluctuates. Compared with a bipolar battery in which an electromotive force is mainly used in a region having such a property, electric power can be stably generated.

(First electrode and second electrode)
In the present invention, the first electrode functions as a positive electrode, and the second electrode functions as a negative electrode. As materials for the first electrode and the second electrode, the same materials as those in the conventional battery can be used. More specifically, examples of the first electrode (positive electrode) include platinum, platinum black, platinum oxide-coated platinum, silver, and gold. Moreover, titanium, stainless steel, nickel, aluminum, etc. whose surface has been passivated can be mentioned. Furthermore, carbon structures such as graphite and carbon nanotubes, amorphous carbon, glassy carbon and the like can be mentioned. However, platinum, platinum black, and platinum oxide-coated platinum are more preferable from the viewpoint of durability.

  Examples of the second electrode (negative electrode) include platinum, platinum black, platinum oxide-coated platinum, silver, and gold. Moreover, titanium, stainless steel, nickel, aluminum, etc. whose surface has been passivated can be mentioned. Furthermore, carbon structures such as graphite and carbon nanotubes, amorphous carbon, glassy carbon and the like can be mentioned. However, platinum, platinum black, and platinum oxide-coated platinum are more preferable from the viewpoint of durability.

  In the present invention, it is preferable that both the first electrode and the second electrode have a plate shape, a thin film shape, a mesh shape, or a fiber shape. In particular, in the case of the embodiment of the present invention, it is preferable to have a mesh shape so as to be a discharge passage for the gas generated in the battery. Here, “mesh-like” indicates at least a porous state in which a through passage through which a gas to be discharged passes is present.

Specifically, as the mesh electrode, the above electrode material may be attached to a metal mesh, a punching metal plate, or a foamed metal sheet by an electroless plating method, a vapor deposition method, or a sputtering method. In addition, the above electrode material may be attached to cellulose or synthetic polymer paper using the same method or a combination thereof.
Further, when the first electrode and the second electrode are arranged in both media having high shape retention such as an ion exchange resin and an ion conductive gel, on the surface of the ion exchange resin and the ion conductive gel, It is also a preferred embodiment that a desired electrode material is disposed by using an electroless plating method, a vapor deposition method, or a sputtering method.

(2) Charging part:
The charging unit includes a reactant regeneration unit that regenerates the reactant from the power generation product generated by the power generation in the power generation unit described above. That is, when hydrogen peroxide is used as a reactant, the power generation product contains oxygen and water, and hydrogen peroxide is regenerated from this power generation product by the reactant regeneration means.

  A known technique (for example, Journal of Applied Electrochemistry Vol. 25 613- (1995)) can be used to regenerate reactants such as hydrogen peroxide. For example, when the reactant is hydrogen peroxide, a means such as an electrolysis cell that has an anode and a cathode, supplies oxygen and water as power generation products to the cathode, and regenerates hydrogen peroxide is applied. It is preferable. By synthesizing (regenerating) hydrogen peroxide from water and oxygen generated by the power generation reaction in this way, it is not necessary to replenish substances from the outside.

Moreover, it is preferable that a charging part is further equipped with the medium reproduction | regeneration means to reproduce | regenerate an acidic medium and / or a basic medium from an electric power generation product.
For regeneration of an acidic medium / basic medium, a known technique for electrically synthesizing an acid / base (for example, JP-A-7-178319) can be used. For example, when a sulfuric acid aqueous solution is used for the acidic medium and a sodium hydroxide aqueous solution is used for the basic medium, a three-chamber cell using a cation exchange membrane, a bipolar membrane, and an anion exchange membrane from the aqueous sodium sulfate solution produced after the reaction. A sulfuric acid aqueous solution and a sodium hydroxide aqueous solution may be synthesized by electrodialysis using a (salt chamber, acid chamber and base chamber) type cell.

  In this way, by regenerating the reactants, acidic medium and basic medium in the charging section, the electromotive force is easy to recover even after reuse (re-discharge) after charging, and the reaction field is always fresh. Can provide. Such an effect is exhibited because the in-vehicle secondary battery of the present invention (especially when hydrogen peroxide is used as a reactant) has a simple structure as compared with a lithium secondary battery. Therefore, the in-vehicle secondary battery of the present invention does not cause a drop in electromotive force even when it is repeatedly used as compared with various secondary batteries.

  The charging unit includes power supply means for supplying power for operating the reactant regeneration means. As the power supply means for operating the reactant regeneration means, a generator that generates electric power by using the rotation of the automobile engine during driving or the rotation of the wheels of the automobile during braking, or a solar cell may be used. it can. Specifically, the generator is preferably located between the engine and the wheel on the transmission path of the engine rotation, and further a clutch is provided between the engine and the generator. With such a configuration, the clutch is connected during running, so that power can be generated using the rotation of the engine, and during braking, the engine and generator are separated by the clutch, so that only the rotation of the wheels is achieved. Can be used to generate electricity. Furthermore, during the daytime, power can be generated even when idling is stopped by using power from the solar cell. By using the electric power from such a generator, it becomes possible to generate electric power while charging, and a battery that can continuously supply stable electric power can be obtained. As a result, it is possible to provide an in-vehicle secondary battery using hydrogen peroxide as a reactive material, which can be used as a power source for in-vehicle devices such as headlights, car air conditioners, and car stereos that are assumed to be used continuously.

  In addition, in the case of using a gel-like medium as an acidic medium and a basic medium, these regeneration methods are such that the neutralized salt aqueous solution generated by the reaction is discharged from the gel, and an acidic aqueous solution and a basic aqueous solution are newly added to the gel. You just have to supply it. What is necessary is just to reproduce | regenerate the acidic aqueous solution and basic aqueous solution which are newly supplied to a gel from the neutralized salt aqueous solution discharged | emitted in that case by said means.

(3) Preferred embodiment of the in-vehicle secondary battery of the present invention:
Hereinafter, preferred embodiments of the secondary battery of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. For convenience of explanation, the in-vehicle secondary battery of the present invention will be described using an example in which hydrogen peroxide is used as a reactant.

  The in-vehicle secondary battery shown in FIG. 2 includes two parts, a power generation unit 100 and a charging unit 200, and in addition, a charging in-vehicle generator 300 for charging is provided. The charging unit 200 includes a reactant regeneration unit 210 for regenerating hydrogen peroxide and a medium regeneration unit 220 for regenerating an acidic medium and / or a basic medium.

  As described above, the power generation unit 100 of the in-vehicle secondary battery includes an acid-base bipolar reaction field using a liquid such as a sulfuric acid aqueous solution as an acidic medium and a liquid such as a sodium hydroxide aqueous solution as a basic medium. Have As will be described later, oxygen, water, and sodium sulfate are generated as power generation products from hydrogen peroxide, a sulfuric acid aqueous solution, and sodium hydroxide as power generation occurs. When the electromotive force decreases as the power generation products increase, the charging unit 200 performs charging.

  In charging, first, oxygen and water are supplied to the reactant regeneration means 210 and regenerated into hydrogen peroxide using the on-vehicle generator 300 for charging, and this is again returned to the acidic medium and / or basic medium of the power generation unit. Supply inside. On the other hand, sodium sulfate, which is a neutralized salt, is supplied to the medium regeneration means, regenerated into sulfuric acid and sodium hydroxide using the on-vehicle generator 300 for charging, and these are supplied again into the acidic medium and the basic medium, respectively. To do. In this way, power generation and charging of the in-vehicle secondary battery of the present invention are performed.

A specific configuration of the power generation unit will be described with reference to FIG.
FIG. 3A is a schematic top perspective view of the power generation unit. As shown here, in the power generation unit, the capillary channel 1 (depth 50 μm, width 1000 μm) is interposed between the slide glass 11 and the cover glass 10 via a spacer (member 12 in FIG. 3B). Is formed. The capillary channel 1 has an inlet 2 and an inlet 3 for supplying a liquid acidic medium and a liquid basic medium, and an outlet 4 and an outlet 5 for discharging. For example, when the acidic aqueous solution a flows from the inlet 2 and the basic aqueous solution b flows from the inlet 3 to the capillary channel 1, if the viscosity and flow rate of both liquids are appropriate, at the confluence portion of the capillary channel 1 A laminar flow (Reynolds flow) is formed.

This laminar flow will be described with reference to FIG. FIG. 3B is a cross-sectional view seen from the flow direction of both media when the power generation section of FIG. 3A is cut along AA ′. As shown in this figure, the acidic aqueous solution a and the basic aqueous solution b form a laminar flow a and a laminar flow b, respectively, even at the confluence portion of the capillary channel 1, and cross each other even though they are in contact with each other. Without flowing through the capillary channel 1. And while forming the laminar flow a and the laminar flow b, it passes through a confluence | merging part and isolate | separates again in a branch part, the acidic aqueous solution a is discharged | emitted from the exit 4, and the basic aqueous solution b is discharged | emitted from the exit 5, respectively. And recovered.
Two electrodes 6 and 8 are provided at the bottom of the merged portion of the capillary channel 1 forming such a laminar flow, and power is taken out through the connection terminals 7 and 9 to the outside. Can do.

  Thus, in order to form a laminar flow and form a state in which two liquids are in contact with each other but do not mix, it can be realized by applying the characteristics of the viscous fluid in the capillary channel. This is a phenomenon (Reynolds flow phenomenon) that occurs when the constant Reynolds number (Re) is less than about 2000 depending on the viscosity and flow velocity of the liquid and the flow channel shape (tube diameter or flow channel width and depth). is there. When this phenomenon is used, the two liquids having an appropriate viscosity and moving speed in the capillary tube become laminar and are imparted with characteristics that are very difficult to mix. Therefore, when an electrode is placed in each laminar flow with the first substance and the second substance coexisting in both laminar flows, the oxidation reaction in the acidic medium and the reduction in the basic medium A reaction occurs, an electromotive force is developed, and a battery is obtained.

  When this power generation unit is a single unit cell, an increase in current amount and voltage can be achieved by arranging a plurality of unit cells in parallel or in series. Such a complicated structure of the capillary channel is used for ultrasonic grinding, semiconductor photolithography, glass, quartz, silicon, polymer film, plastic resin, ceramic, graphite, metal substrate, etc. Moreover, it can be easily manufactured by applying existing processing techniques such as sandblasting, injection molding, and silicon resin molding. Therefore, it is possible to construct a power generation unit having desired performance (current and voltage) by integrating unit cells and stacking a plurality of chips.

  Since the output voltage of the in-vehicle secondary battery is normally 12V, in order to use the unit cell in the present invention as the in-vehicle secondary battery, the unit cells are connected in series as many as necessary voltages can be obtained. Is required. Specifically, it is necessary to connect 12V in series by the number obtained by dividing 12V by the electromotive force at the maximum output of the unit cell and rounding up the decimal point. Further, in order to obtain a necessary current value, the necessary number of 12V units may be connected in parallel and used. At this time, the inlet 2 and the inlet 3 for supplying the liquid acidic medium and the liquid basic medium of all the unit cells and the outlet 4 and the outlet 5 for discharging are connected in series of the unit cells. Regardless of the parallel connection, it is preferable to join each in parallel to stabilize the output.

The reactant regeneration means in the charging unit is, for example, an electrolytic cell that has an anode and a cathode, and supplies oxygen and water generated by a power generation reaction to the cathode to produce hydrogen peroxide.
In addition, the medium regeneration means, for example, arranged a plurality of cation exchange membranes, bipolar membranes, and anion exchange membranes in order to form a salt chamber, an acid chamber, and a base chamber, and was generated by a power generation reaction in the salt chamber. This is a three-chamber cell type cell in which neutralized salt aqueous solution (sodium sulfate aqueous solution) is supplied and electrodialysis is performed to discharge the acidic aqueous solution and the basic aqueous solution from the acid chamber and the base chamber.

  As described above, as the charging unit, the electric power from the generator that generates electric power by using the rotation of the vehicle engine during driving or the rotation of the wheel of the vehicle during braking, or the electric power from the solar cell is used. That's fine. An in-vehicle secondary battery is configured by combining the power generation unit and the charging unit.

  When an aqueous sulfuric acid solution is used as the acidic medium and an aqueous sodium hydroxide solution is used as the basic medium, oxygen gas and an aqueous sodium sulfate solution are generated by the power generation reaction. In the charging section, an operation of regenerating the hydrogen peroxide, the sulfuric acid aqueous solution, and the sodium hydroxide aqueous solution as reactants from these products is performed.

A specific configuration of the charging unit will be described with reference to FIGS.
FIG. 4 is an explanatory diagram schematically showing the overall configuration of the charging unit. First, an aqueous sodium sulfate solution is supplied to the electrodialysis tank 20. The electrodialysis tank 20 has a structure composed of a desalting chamber 22 and a concentrating chamber 24 by alternately combining a cation exchange membrane and an anion exchange membrane in some cases. And an anode and a cathode are arrange | positioned at the both ends, a direct current is applied, and dialysis operation is performed. As a result, water desalinated from the desalting chamber 22 and concentrated sodium sulfate aqueous solution are generated from the concentration chamber 24. The desalinated water is appropriately supplied to the cathode chamber 34 and the anode chamber 32 of the reactant regeneration means 30, and the salt chamber 42, the acid chamber 44, and the base chamber 46 of the medium regeneration means 40. The aqueous sodium sulfate solution is supplied to the salt chamber 42 of the medium regeneration means 40.

  As shown in FIG. 5, the reactant regeneration means (represented by reference numeral 30 in FIG. 4) used for the regeneration of hydrogen peroxide is divided by a diaphragm 36 into an anode chamber 32 having an anode 32a and a cathode chamber 34 having a cathode 34a. The obtained electrolytic cell structure is taken. Water supplied from the desalting chamber 22 is supplied to the anode chamber 32 and the cathode chamber 34, oxygen generated by power generation is supplied to the cathode chamber 34, and a DC voltage is applied between the anode 32 a and the cathode 34 a, whereby the cathode Hydrogen peroxide is generated at 34a and the aqueous hydrogen peroxide solution is regenerated. The hydrogen peroxide solution generated in the cathode chamber 34 is supplied to the power generation unit. On the other hand, the liquid (water) in the anode chamber 32 is again circulated and supplied to the reactant regeneration means 30. In the regeneration of the aqueous hydrogen peroxide solution, there is almost no problem in the actual process even if the above-mentioned salted water (exactly, a thin sodium sulfate aqueous solution) is used.

  As shown in FIG. 6, the medium regeneration means (reference numeral 40 in FIG. 4) used for regeneration of the acidic medium and the basic medium is an electrodialysis tank, and includes a cation exchange membrane 47, an anion exchange membrane, and The salt chamber 42, the acid chamber 44 and the base chamber 46 are formed by alternately combining the 48 bipolar membranes 49. The aqueous sodium sulfate solution supplied from the concentration chamber 3 is supplied to the salt chamber 42 in the medium regeneration means 40 that is an electrodialysis tank using a bipolar membrane. A direct current is applied to the anode and the cathode arranged at the end, and electrodialysis with water decomposition is performed. As a result, sulfuric acid is regenerated in the acid chamber 44 from hydrogen ions generated by the water splitting phenomenon in the bipolar membrane 49 and sulfate ions permeated from the salt chamber 42, and in the base chamber 46 in the bipolar membrane 49. Sodium hydroxide is regenerated from hydroxide ions generated by the water splitting phenomenon and sodium ions permeated from the salt chamber 42. A part of the water discharged from the desalting chamber 22 is supplied to the acid chamber 44 and the base chamber 46 to adjust the concentration of the acid / base and supply it to the power generation unit. The liquid supplied to the salt chamber 42 is desalinated and supplied again to the medium regeneration means 40.

By providing the charging unit as described above, it is possible to charge and discharge while reusing the electrolyte constituent components (reactive substances, acidic medium, and basic medium) with a simple configuration.
In addition, what is necessary is just to provide a reactive material reproduction | regeneration means for each, when using 2 types of reactive materials.

<Second vehicle-mounted secondary battery>
A second in-vehicle secondary battery of the present invention includes a power generation unit and a charging unit,
The power generation unit is the same as the first in-vehicle secondary battery except that the power generation unit is configured by sequentially connecting a plurality of unit power generation cells in series.

  As an aspect in which a plurality of unit power generation cells are sequentially connected in series, a configuration in which a power generation unit as shown in FIG. 3 is used as a unit power generation cell, a plurality of unit power generation cells are prepared, and these are connected in series can be given. . A specific example is shown in FIG.

  That is, as shown in FIG. 9B, which is a cross-sectional view taken along the line AA ′ of FIG. 9A, as a unit power generation cell, the electrode 8 on the side where the laminar flow b is formed is not on the slide glass 11. The electrode 8 (corresponding to 8a) is provided from the side surface of the cover glass 10 to the back surface (the surface where the cover glass 10 does not contact the laminar flow b). Similarly, the electrode 6 on the slide glass 11 is also provided with the electrode 6 (corresponding to 6a) from the side surface to the back surface (the surface where the slide glass 11 does not contact the laminar flow a). As a result, as shown in FIG. 9A, electrodes are provided on the upper and lower surfaces of the unit power generation cell, and other unit power generation cells are sequentially stacked on the electrodes 8a and 6a of such unit power generation cell. Thus, it becomes possible to connect in series.

  According to the second in-vehicle secondary battery, it is not necessary to connect a plurality of unit power generation cells via wiring or the like, so that it is possible to reduce the size and weight. Moreover, since it is a simple structure, the combination according to a desired voltage is attained, and the applicability to various uses can be expanded.

<Power generation method (power generation mechanism)>
The power generation method (power generation mechanism) according to the present invention includes an acidic medium and a base in a state in which the acidic medium on which the first electrode is disposed and the basic medium on which the second electrode is disposed are adjacent to or close to each other. This is a power generation method in which power is generated by promoting an oxidation reaction in an acidic medium and / or a reduction reaction in a basic medium with a reactant contained in at least one of the basic media. Then, the reactant is regenerated from the power generation product generated by power generation and supplied to at least one of the acidic medium and the basic medium.
The power generation method of the present invention can be implemented, for example, by using the in-vehicle secondary battery of the present invention.

  According to the power generation method of the present invention, the electromotive force generated by the oxidation / reduction reaction at the electrode becomes the main source of the voltage obtained from the battery, and as a result, the power can be generated stably. In addition, charging and discharging can be performed while reusing the electrolyte constituents (reactive substances, acidic medium, and basic medium) with a simple configuration.

When the in-vehicle secondary battery of the present invention is used, the power generation mechanism in the power generation method of the present invention is considered as described below.
That is, the first substance contained in the acidic medium causes a reaction to take electrons from the first electrode with hydrogen ions, and the second substance contained in the basic medium produces hydroxide ions. Along with this, it is considered that power generation occurs by causing a reaction of donating electrons to the second electrode.
By this reaction, the first substance and the second substance are chemically changed into a plurality of substances having low internal energy, so that the corresponding energy can be released to the outside as electric energy to obtain electric power.

  In particular, when the acidic medium is an acidic aqueous solution, the basic medium is a basic aqueous solution, and the first substance and the second substance are both hydrogen peroxide, the hydrogen peroxide is separated from water and oxygen by a decomposition reaction. Generate. When this chemical reaction is performed separately in an oxidation reaction and a reduction reaction with separate electrodes as in the battery of the present invention, an electromotive force is generated. That is, since hydrogen peroxide has an oxidizing action in an acidic reaction field, and has a reducing action in a basic reaction field, an electromotive force is generated. By using such an acid-base bipolar reaction field, the power generation method of the present invention is realized.

  More specifically, the power generation method of the present invention will be described with reference to FIG. As shown in FIG. 1, in an acidic reaction field (acidic medium) in which a positive electrode (first electrode) is arranged, hydrogen peroxide acts as an oxidizing agent, and as shown in the following (Formula 1), excess hydrogen peroxide is used. Hydrogen oxide oxygen atoms receive electrons from the electrode and produce water. In the basic reaction field (basic medium) in which the negative electrode (second electrode) is arranged, hydrogen peroxide acts as a reducing agent, and as shown in the following (Formula 2), oxygen of hydrogen peroxide Atoms donate electrons to the electrode to produce oxygen and water. By these reactions, an electromotive force is generated and power generation is performed.

H ₂ O ₂ (aq) + 2H ⁺ + 2e ⁻ → 2H ₂ O (Formula 1)
H ₂ O ₂ (aq) + 2OH ⁻ → O ₂ + 2H ₂ O + 2e ⁻ (Formula 2)
In the above formula, “(aq)” indicates a hydrated state (the same applies to the following (formula 3)).

In the reaction field, a counter anion of hydrogen ions present in an acidic medium (corresponding to sulfate ion SO ₄ ^2- in FIG. 1) and a counter cation of hydroxide ions present in a basic medium. (In FIG. 1, sodium ion Na ⁺ ) forms a salt at the interface between the two media, so that the charge can be balanced. At this time, since the salt formed is more stable when ionized in an aqueous solution, the effect of the salt formation on the electromotive force is much smaller than the electromotive force in the oxidation or reduction reaction at the electrode. As a result, the bipolar battery of the present invention in which the electrode reaction is dominant has the property that stable power generation can be performed compared to the bipolar battery mainly based on the neutralization reaction at the acidic / basic medium interface. Become.

  The ionic reaction formula (when the charge balance is taken by ionic decomposition of water at the acidic / basic medium interface) that summarizes the half-reaction formulas of (Formula 1) and (Formula 2) is shown below (Formula 3) Show.

H ₂ O ₂ (aq) → H ₂ O + 1 / 2O ₂ (Formula 3)

  According to thermodynamic calculation, the enthalpy change (ΔH), entropy change (ΔS), Gibbs free energy change (ΔG, temperature T: unit is Kelvin (K)) of this reaction is ΔH = −94.7 kJ / mol, ΔS = 28 J / Kmol, and ΔG = ΔH−TΔS = −103.1 kJ / mol.

  The theoretical electromotive force (n is the number of electrons involved in the reaction, F is the Faraday constant) and the theoretical maximum efficiency (η) are E = −ΔG / nF = 1.07 V, η = ΔG / ΔH × 100 = Calculated as 109%. The theoretical feature of this reaction is that the entropy is increased by the hydrogen peroxide decomposition reaction and the sign of ΔS becomes positive. Therefore, the absolute value of ΔG becomes larger than ΔH, and the theoretical maximum efficiency exceeds 100%. In contrast, in other fuel cell reactions such as a hydrogen-oxygen system and a direct methanol system, the sign of ΔS is negative.

From these, in the power generation method of the present invention, the theoretical characteristics when hydrogen peroxide is used for the first substance and the second substance are listed below.
In other conventionally known fuel cells, in principle, the entropy change amount TΔS cannot be used for power generation and is released as heat. On the other hand, in this mechanism, the increase in entropy obtained by absorbing heat from the outside world can be used for power generation. When the reaction temperature T is high, the absolute value of ΔG increases and the electromotive force increases.

  In a practical battery, the output voltage is not determined only by the theoretical electromotive force of the ion reaction type, but the voltage is lowered due to an overvoltage or the like, and heat is simultaneously generated. For example, this heat becomes a big problem when unit batteries are stacked and integrated, or when batteries are incorporated into products. However, as described above, according to the power generation method of the present invention, the heat can theoretically be reused for power generation, and the overall heat generation may be reduced. In addition, ΔG corresponding to the total amount of energy that can be used for power generation is about half that of a hydrogen / oxygen fuel cell, but n = 1 (n = 2 in the case of a hydrogen-oxygen fuel cell). The theoretical electromotive force is about the same.

  A system for regenerating the reactant from the power generation product and supplying it to at least one of the acidic medium and the basic medium is the same as that of the secondary battery described above.

  From the above, in the power generation method in the in-vehicle secondary battery of the present invention, when hydrogen peroxide is used for the first substance and the second substance, in addition to the effects as described above, The following effects are obtained.

(1) Hydrogen peroxide does not release carbon dioxide with the reaction of converting chemical energy into electrical energy, but instead releases oxygen. In addition, the battery can be configured with an easy exterior because no ignitables, combustibles, harmful heavy metals, or the like are used as structural elements in the battery. Therefore, it has excellent environmental safety over the entire manufacturing, use, and disposal product cycle.
(2) Since hydrogen peroxide is a liquid at normal temperature and pressure, it does not require heavy metal cylinders for storage, and can be freely mixed with water, making it easy to gel, storability and portability Is excellent.
(3) Since it is not necessary to use oxygen as an oxidant, there is no hindrance to its use even in a closed environment where the amount of air is limited, and even in a harsh environment where the air contains a lot of dust and dirt.
(4) Hydrogen peroxide is an organic method as an industrial production method (a method of synthesizing anthraquinone as an intermediate (not consumed because it is reused many times), catalytic catalytic hydrogen reduction and air oxidation), etc. Has already been established, and even now, it is stably and inexpensively supplied. In addition, since the battery can be configured with a simple structure with few peripheral parts, the weight and volume of the entire battery system can be reduced, and cost reduction and high durability can be achieved.

The on-vehicle secondary battery and the power generation method of the present invention have been described above, but the configuration of the present invention is not limited to the configuration as described above.
For example, it is possible to use a battery having the above-described configuration and a conventional battery using hydrogen fuel or methanol fuel as a combined generator.

  The effects of the present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Example 1]
The in-vehicle secondary battery shown in FIG. 2 that includes the power generation unit shown in FIG. 3 and the charging unit shown in FIGS. -The voltage characteristics were determined and the battery was evaluated. The details of the power generation unit and the charging unit are as follows.

(Power generation part)
First, sulfuric acid (special grade 96%, Kanto Chemical Co., Inc.) and distilled water are mixed with a commercially available 3% by mass hydrogen peroxide aqueous solution (Japanese Pharmacopoeia Oxol, Kenei Pharmaceutical Co., Ltd.) and sample solution A (peroxidation). Hydrogen (9.1 mmol / l, sulfuric acid 0.1 N (0.05 mol / l)) was prepared.
Further, sodium hydroxide (special grade 97%, Kanto Chemical Co., Inc.) and distilled water were mixed with the same hydrogen peroxide aqueous solution as sample liquid A, and sample liquid B (hydrogen peroxide 9.1 mmol / l, sodium hydroxide 0 .1N (0.05 mol / l)) was prepared.

  Then, as a unit cell, the sample liquid A was injected from the inlet 2 shown in FIG. 3 and the sample liquid B was injected from the inlet 3 by an external pump. The flow rates of the sample liquids A and B were both 24 μl / sec (Reynolds number Re: about 670) at the center of the flow path, and the experimental temperature was room temperature (about 20 ° C.). Note that the other conditions such as the material and the channel structure were applied as shown in the explanation of FIG.

Gas generation was not observed on the surface of the first electrode (platinum thin film, area: 0.026 cm ² ) 8 on the bottom surface of the flow channel in contact with the sample liquid A, whereas on the bottom surface of the flow path in contact with the sample liquid B Oxygen gas generation was observed on the surface of the second electrode (platinum thin film, area: 0.026 cm ² ) 6. This is because the first electrode 8 functions as a positive electrode by generating water by the reaction of (Formula 1) described above, and the second electrode 6 is oxygenated by the reaction of (Formula 2) described above. This is because water is generated and functions as a negative electrode.

FIG. 7 shows current-voltage characteristics obtained in the unit cell of the battery. In the case of this example, an open circuit voltage of 650 mV and a maximum output of 160 μW / cm ² (electromotive voltage: 230 mV, current of 0.7 mA / cm ² ) were obtained.

As shown in FIG. 8, the connection electrode 7 of this unit cell 400 and the connection electrode 9 of another unit cell 410 are connected, and the connection electrode 7 of another unit cell 410 and the connection electrode 9 of another unit cell 420 are connected. Connect. By repeating in this way, 53 unit cells were connected in series. At this time, the inlet 2, the inlet 3, the outlet 4, and the outlet 5 of each unit power generation unit are connected in parallel. In this manner, 53 unit cells were connected to form a power generation unit. A maximum output of 8.3 mW / cm ² (electromotive voltage: 12.2 V, current 0.7 mA / cm ² ) was obtained from the power generation unit. The performance degradation of each unit power generation unit due to series connection of unit cells was hardly observed.

(Charging part)
After the power generation, charging was performed as shown in FIGS. 4 to 6 (however, the configuration excluding the electrodialysis tank 20). That is, first, the sodium sulfate aqueous solution generated after power generation was supplied to the salt chamber 42 of the three-chamber bipolar membrane electrodialysis tank (medium regeneration means 40). While the water generated after power generation is continuously supplied to the acid chamber 44 and the base chamber 46, a direct current voltage between the anode and the cathode (a battery charger (100V) driven by a commercial power source (power supply means)) 15%) was applied using a Yuasa motorcycle charger (MB-2012). As a result, it was confirmed that a certain concentration of sulfuric acid and sodium hydroxide were continuously regenerated from each of the acid chamber 44 and the base chamber 46.

In addition, the anode chamber 32 and the cathode are applied to a hydrogen peroxide cell (produced by Permerek Electrode Co., Ltd., 1.25 dm ² diaphragm type) as a reactant recycling means 30 while applying a DC voltage (5 V) between the anode 32a and the cathode 34a. When the sodium sulfate aqueous solution generated after power generation was adjusted to 0.02 mol / l and supplied at a rate of 5 ml / min in each of the chambers 34, the cathode chamber 34 was opened to the atmosphere and oxygen generated after power generation was simultaneously supplied. It was confirmed that a 1 mol / l aqueous hydrogen peroxide solution could be regenerated continuously.

  When hydrogen peroxide, sulfuric acid, and sodium hydroxide regenerated in the charging section were reused as reactants, acidic medium, and basic medium, respectively, and power generation was performed, the same characteristics as the first power generation were obtained.

[Comparative Example 1]
A secondary battery similar to the unit cell of Example 1 was evaluated in the same manner as in Example 1 except that hydrogen peroxide was not included in the sample solution. The sulfuric acid and sodium hydroxide concentrations of the sample liquids A and B injected from the inlet 2 and the inlet 3 of the power generation unit were both 0.1 N. The flow rate and the experimental temperature are the same as in Example 1.
The current-voltage characteristics are shown in FIG. In Comparative Example 1, the open circuit power (200 mV) due to the liquid voltage was measured, but no significant current was obtained.

  As described above, according to the present embodiment, it has been found that effective voltages and currents are obtained as shown in FIG. 7, and sufficient electric energy can be stably supplied as a power generation unit. In addition, it was confirmed that charging and discharging are possible while reusing the electrolyte constituent components with a simple configuration.

It is a figure which shows the electric power generation mechanism in the battery of this invention. It is explanatory drawing which shows the structure of the vehicle-mounted secondary battery of this invention. (A) is a schematic top perspective view of one embodiment of the power generation unit in the battery of the present invention, and (b) is a diagram of both media when the power generation unit shown in (a) is cut along AA ′. It is sectional drawing seen from the direction of the flow. It is explanatory drawing which showed the whole structure of the charging part roughly. It is explanatory drawing which showed schematically the structure of the reactive material reproduction | regeneration means. It is explanatory drawing which showed schematically the structure of the medium reproduction | regeneration means. It is a figure which shows the current-voltage characteristic in an Example and a comparative example. It is a schematic diagram which shows the example of a connection of the unit cell in an Example. (A) is a schematic diagram which shows the upper surface of a unit power generation cell, (b) is sectional drawing which shows the A-A 'cross section of a unit power generation cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Capillary flow path 2, 3 ... Inlet 4, 5 ... Outlet 6, 6a ... Electrode (2nd electrode)
7: Connection terminals 8, 8a: Electrode (first electrode)
DESCRIPTION OF SYMBOLS 9 ... Connection terminal 10 ... Cover glass 11 ... Slide glass 12 ... Spacer a ... Acidic aqueous solution b ... Basic aqueous solution 100 ... Power generation part 200 ... Charging part 300- ..Charging power source 210... Reactive substance regeneration means 220... Media regeneration means 400... First unit power generation unit 410.

Claims (20)

An in-vehicle secondary battery comprising a power generation unit and a charging unit,
The power generation unit includes at least an acidic medium in which a first electrode is disposed, and a basic medium in which a second electrode is disposed,
The acidic medium and the basic medium are adjacent to or close to each other, and at least one of the acidic medium and the basic medium contains a reactive substance,
The charging unit includes a reactant regeneration unit that regenerates the reactant from the power generation product generated by the power generation in the power generation unit, and further supplies power for operating the reactant regeneration unit A vehicle-mounted secondary battery comprising: An in-vehicle secondary battery comprising a power generation unit and a charging unit,
The power generation unit is configured by sequentially connecting a plurality of unit power generation cells in series,
The unit power generation cell includes at least an acidic medium in which a first electrode is arranged and a basic medium in which a second electrode is arranged,
The acidic medium and the basic medium are adjacent to or close to each other, and at least one of the acidic medium and the basic medium contains a reactive substance,
The in-vehicle secondary battery, wherein the charging unit includes a reactive material regeneration unit that regenerates the reactive material from a power generation product generated by power generation in the power generation unit.   The in-vehicle secondary battery according to claim 1, wherein the charging unit further includes medium regeneration means for regenerating the acidic medium and / or the basic medium from the power generation product.   The in-vehicle secondary battery according to claim 1, wherein the acidic medium is made of an acidic aqueous solution, and the basic medium is made of a basic aqueous solution.   The in-vehicle secondary battery according to claim 1, wherein the reactant is contained in each of the acidic medium and the basic medium.   The first substance as the reactant contained in the acidic medium and the second substance as the reactant contained in the basic medium are the same substance. 5. The on-vehicle secondary battery according to 5.   The in-vehicle secondary battery according to claim 1, wherein the reactant is hydrogen peroxide.   8. The reactant regenerating means has an anode and a cathode, and supplies the oxygen and water as the power generation products to the cathode to regenerate the hydrogen peroxide. The secondary battery for vehicles described in 1.   The medium regeneration means arranges a cation exchange membrane, a bipolar membrane and an anion exchange membrane to form a salt chamber, an acid chamber and a base chamber, and a neutralized salt aqueous solution which is the power generation product in the salt chamber. 4. The cell according to claim 3, further comprising a three-compartment cell type cell that supplies and performs electrodialysis to discharge the acidic aqueous solution and the basic aqueous solution from each of the acid chamber and the base chamber. Automotive secondary battery.   The in-vehicle secondary battery according to claim 1, wherein the power generation unit is provided with a flow path structure in which the acidic aqueous solution and the basic aqueous solution form a laminar flow therein.   The in-vehicle secondary battery according to claim 2, wherein the unit power generation cell is provided with a flow path structure in which the acidic aqueous solution and the basic aqueous solution form a laminar flow therein.   The acidic aqueous solution is sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, perchloric acid, periodic acid, orthophosphoric acid, polyphosphoric acid, nitric acid, tetrafluoroboric acid , Hexafluorosilicic acid, hexafluorophosphoric acid, hexafluoroarsenic acid, hexachloroplatinic acid, acetic acid, trifluoroacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, maleic acid, malonic acid, phthalic acid, fumaric acid, and picric acid The in-vehicle secondary battery according to claim 4, comprising at least one acid selected from the group.   The basic aqueous solution is sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide. And one or more bases selected from the group comprising tetrabutylammonium hydroxide, or sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium borate, potassium borate, sodium silicate, potassium silicate, 5. The on-vehicle secondary battery according to claim 4, comprising at least one alkali metal salt selected from the group comprising sodium tripolyphosphate, potassium tripolyphosphate, sodium aluminate, and potassium aluminate.   The in-vehicle secondary battery according to claim 1 or 2, wherein the acidic medium is composed of an acidic ion conductive gel, and the basic medium is composed of a basic ion conductive gel. .   The secondary battery according to claim 14, wherein the acidic ion conductive gel is obtained by gelling an acidic aqueous solution with water glass, anhydrous silicon dioxide, crosslinked polyacrylic acid, agar, or a salt thereof.   The in-vehicle secondary battery according to claim 14, wherein the basic ion conductive gel is obtained by gelling a basic aqueous solution with carboxymethyl cellulose, crosslinked polyacrylic acid, or a salt thereof.   The first electrode is platinum, platinum black, platinum oxide coated platinum, silver, gold, surface passivated titanium, surface passivated stainless steel, surface passivated nickel, surface passivated The in-vehicle secondary battery according to claim 1 or 2, comprising at least one material selected from the group consisting of aluminum, carbon structure, amorphous carbon, and glassy carbon.   The second electrode is platinum, platinum black, platinum oxide coated platinum, silver, gold, surface passivated titanium, surface passivated stainless steel, surface passivated nickel, surface passivated The in-vehicle secondary battery according to claim 1 or 2, comprising at least one material selected from the group consisting of aluminum, carbon structure, amorphous carbon, and glassy carbon.   The in-vehicle secondary battery according to claim 1 or 2, wherein the first electrode and the second electrode are plate-shaped, thin-film-shaped, mesh-shaped, or fiber-shaped.   The said 1st electrode and the said 2nd electrode are respectively arrange | positioned by the electroless plating method, a vapor deposition method, or the sputtering method of the said acidic medium and the said basic medium respectively. The secondary battery for vehicles described in 1.

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