Air cell

Abstract

To solve a problem in which an air cell has poor power output efficiency relative to their volume.SOLUTION: The present invention includes a negative electrode (container (negative electrode)) 108, a positive electrode (container (positive electrode)) 107 having a solution 221 containing hemoglobin separated from blood containing hemoglobin or red blood cells, and a separator 119 arranged on the negative electrode 108 and the positive electrode 107. The air electrode, which serves as the positive electrode, is composed of a gas diffusion layer through which air (oxygen) diffuses and a catalyst layer in which a reduction reaction of oxygen occurs. The catalyst layer etc. forms a catalyst electrode 312. When blood or hemoglobin (Hb) comes into contact with air (oxygen) 305, it becomes an oxy-type with oxygen adsorbed (oxyhemoglobin (HbO2)) and outputs electricity.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an air (oxygen) battery and a method for manufacturing an air (oxygen) battery.

Background Art

[0002] In order to achieve the full-scale popularization of electric vehicles, it is essential to significantly increase the energy density and reduce the cost of the battery serving as the power source. In addition, as a clean energy, a battery that does not emit carbon dioxide is required.

[0003] A metal-air battery using oxygen in the air as a positive electrode active material has attracted attention as a next-generation vehicle battery because a battery having a high energy density can be configured. An air battery is a general term for a battery that uses oxygen (O2) in the air as a positive electrode active material and a metal such as lithium (Li), zinc (Zn), aluminum (Al), magnesium (Mg), iron (Fe), etc. as a negative electrode active material (also simply called an air battery).

[0004] An air battery is a battery that uses oxygen in the atmosphere as a positive electrode active material. The positive electrode in the battery container only needs to be a thin-layer catalytic electrode that reduces oxygen, and a larger portion occupied by the negative electrode active material can be ensured compared to a battery using other solid active material positive electrodes. An air battery exhibits several times the energy density compared to other batteries.

[0005] An air battery employs a material that takes in oxygen in the air. During discharge, the metal dissolved from the negative electrode moves to the positive electrode and reacts with the oxygen taken in from the air to generate electricity. During charging, conversely, a reaction occurs in which the metal releases oxygen and moves from the positive electrode to the negative electrode.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In an air battery, air is fed into the positive electrode. O2 in the air is reduced at the positive electrode to become OH - (aq) . However, since the reduction reaction occurs only at the oxygen intake holes and the peripheral part of the positive electrode, it becomes a non-uniform reaction, and there is a problem that the efficiency is poor. Therefore, it causes the output not to be generated with respect to the volume of the air battery.

Means for Solving the Problems

[0008] The air battery of the present invention includes a positive electrode, a negative electrode, a separator, a solution having hemoglobin near the positive electrode, and an aqueous solution having chromium or the like between the separator and the second electrode.

[0009] The present invention includes a negative electrode (container (negative electrode)) 108, a positive electrode (container (positive electrode)) 107 having a solution 221 containing hemoglobin separated from blood or red blood cells containing hemoglobin, and a separator 119 disposed between the negative electrode 108 and the positive electrode 107.

[0010] The air electrode serving as the positive electrode is composed of a gas diffusion layer through which air (oxygen) diffuses and a catalyst layer where the reduction reaction of oxygen occurs. The catalyst layer or the like forms a catalyst electrode 312. When in contact with air (oxygen) 305, blood or hemoglobin (Hb) adsorbs oxygen and becomes an oxy form (oxyhemoglobin (HbO2)), and outputs electric power.

[0011] The present invention uses an aqueous hemoglobin solution for the positive electrode. Hemoglobin (Hb) binds to oxygen in the air and changes to oxyhemoglobin (HbO2), functioning as an air battery. Hb(O2) <――> Hb +O2(aq)

[0012] This equilibrium is rapid, and when the dissolved oxygen decreases, oxygen can be replenished from hemoglobin in the order of milliseconds. Note that hemoglobin (Hb) bound to oxygen is called oxyhemoglobin (HbO2). When an aqueous hemoglobin solution is used for the positive electrode of an air battery, high efficiency can be expected with a uniform reaction. 1 / 2O 2(aq) + H2O (aq) + 2e - → 2OH - (aq)

Advantages of the Invention

[0013] Conventionally, since blood from livestock etc. that was discarded was used, a low-cost air (oxygen) battery (device) can be provided. Also, the generated power per unit capacity is large and it is highly efficient.

Brief Description of the Drawings

[0014]

Figure 1

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Figure 14

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing for explaining the embodiments for carrying out the invention, elements having the same function or similar configuration are denoted by the same reference numerals, and the description may be omitted. Further, there are cases where it is described in an enlarged, reduced or omitted manner.

[0016] The examples of the present invention described in this specification and the drawings can be combined with each other. Further, the examples described in this specification and the drawings include the present embodiment, similar forms of the present embodiment, and forms in which a part or all of the present embodiment is combined.

[0017] An air battery is a battery that utilizes the oxidizing power of air at the positive electrode. If the negative electrode is hydrogen, it is a fuel cell. The characteristic of an air battery is that the active material of the positive electrode is oxygen (O2), which is constantly supplied from the outside. Therefore, the proportion of the positive electrode in the battery volume is low, and the weight energy density is large. The energy density of a zinc-air battery is said to be more than five times that of a lithium-ion battery. In an example of the present invention, an air battery (device) will be illustrated and described as one aspect, but it goes without saying that the present invention is also applicable to an oxygen battery (device), a fuel cell (device), and the like.

[0018] FIG. 1 is a configuration diagram and an explanatory drawing of the air battery of the present invention. In an example of the present invention, for ease of illustration and for ease of understanding, the drawings are schematically illustrated.

[0019] In this specification and the drawings, a configuration consisting of a negative electrode 108 and an aqueous solution 227 may be expressed as a negative electrode. A configuration consisting of a positive electrode 107 and a solution 221 (an aqueous solution containing hemoglobin, etc.) may be expressed as a positive electrode.

[0020] The container (positive electrode) 316 has an air hole 317 for taking in air (oxygen) 305. In the case of a button-type battery, the hole diameter of the air hole 317 is about 0.5 to 1 mm as an exemplary embodiment, and the number is 2 to 6. The air hole 317 is usually covered with a sealing tape so that air does not flow in before use. It is peeled off during battery use to take in air.

[0021] The diffusion paper 315 is provided for the purpose of uniformly diffusing the air (oxygen) 305 from the air hole 317 to the air electrode (positive electrode) 107. As an exemplary position embodiment, cellulose is exemplified for the diffusion paper 315. When the diffusion paper 315 is not arranged, the air (oxygen) 305 flowing in from the air hole 317 does not diffuse throughout the air electrode, and the discharge reaction concentrates on the catalyst layer near the air hole 317. This phenomenon becomes particularly prominent in the case of high-current discharge. By providing the diffusion paper 315, the inflowing air (oxygen) 305 is uniformly diffused throughout the air electrode, and the discharge reaction occurs throughout the catalyst layer.

[0022] The water-repellent film 314 is generally made of a microporous resin film mainly composed of PTFE. It allows the air (oxygen) 305 in the atmosphere to pass through to the air electrode and retains the electrolytic solution (blood·hemoglobin) 221 in the battery, preventing leakage of the liquid.

[0023] PTFE is one of the fluororesins. It is polytetrafluoroethylene. It is a typical fluororesin like PVDF, PCTFE, and PFA. Fluororesins have high cold resistance and heat resistance, and the usable temperature range is -250°C to 260°C. Also, they have excellent chemical resistance and are hardly attacked by high-concentration and high-temperature acids and alkalis. The air electrode is composed of a catalyst layer and a gas diffusion layer. The catalyst layer is a sheet composed of carbon, an oxygen reduction catalyst, and a PTFE binder pressed onto a nickel net.

[0024] In the catalyst layer, a solid-liquid-gas three-phase interface is formed. To increase the efficiency of the reaction, it is necessary for many of these three-phase interfaces to exist. Therefore, the catalyst layer needs to have appropriate hydrophilicity and appropriate water repellency.

[0025] Since PTFE powder tends to become fibrous when shear force is applied, a binder with water repellency is suitable. Carbon includes graphite, carbon black, activated carbon, etc. Even for the same type of carbon, the structure, physical properties, and battery characteristics can vary greatly depending on the raw materials and manufacturing methods.

[0026] Generally, carbon black and activated carbon with small particle size and high specific surface area are used. Also, the gas diffusion layer is a layer aimed at smooth gas diffusion to the catalyst layer. Generally, a porous PTFE film is often used and is pressure-bonded to the catalyst layer.

[0027] The separator 119 electrically insulates the positive and negative electrodes and conducts ions. Generally, cellophane film or polypropylene film with micropores is used. Separating hemoglobin from blood and using hemoglobin are efficient for an air (oxygen) battery.

[0028] Hemoglobin is a major component of blood. It adsorbs oxygen and delivers it to the body. It can be said to be the very foundation of life. Hemoglobin is contained in the red blood cells of blood. Even when hemoglobin is separated from red blood cells, its important functions of oxygen adsorption and desorption are maintained. Hemoglobin is used to transport oxygen in all mammals (including whales) other than humans.

[0029] Hemoglobin is composed of a heme complex and the protein globin. Looking at the details of oxygen adsorption by hemoglobin, an oxygen molecule coordinates to the iron(II) heme complex. This bond is not simply electrostatic; there is orbital overlap, and the oxygen molecule coordinates obliquely to the heme plane. It is amazing that such a covalent oxygen molecule repeats adsorption and desorption at high speed within 1 second, which is unthinkable without the role of globin.

[0030] One gram of hemoglobin contains 3.4 mg of iron. One molecule of oxygen binds to one iron atom. One kilogram of hemoglobin contains 3.4 g, that is, 0.061 M (mol / dm 3 ) of iron.

[0031] This means that one kilogram of hemoglobin contains 0.061 M (mol / dm 3 ) of oxygen. In terms of weight, it is 1.95 g, and when it becomes a gas, it is 1.4 (L liters).

[0032] That is, one kilogram of hemoglobin contains 1.4 (L liters) of oxygen. The solubility of oxygen in water is 8 mg / L at 25 degrees (°C). Therefore, hemoglobin holds oxygen 390 times that of dissolved oxygen.

[0033] The air battery of the present invention uses blood·hemoglobin 221. When blood·hemoglobin 221 binds to air (oxygen), it outputs electric power. It also has a color measuring device 234 for measuring or monitoring the color of blood·hemoglobin 221.

[0034] The air battery of the present invention includes a negative electrode (container (negative electrode)) 108 having an acidic (or neutral) aqueous solution, a positive electrode (container (positive electrode)) 107 having blood containing hemoglobin or a solution containing hemoglobin separated from red blood cells, and a separator 119 disposed between the negative electrode 108 and the positive electrode 107.

[0035] The periphery of the negative electrode 108 is filled with an acidic (or neutral) aqueous solution 227, and the periphery of the positive electrode 107 is filled with blood, or hemoglobin 221, etc., or an aqueous solution containing these. When it comes into contact with air (oxygen) 305, blood or hemoglobin (Hb) becomes an oxygen-adsorbed oxy-type (oxyhemoglobin (HbO2)) (Figure 12).

[0036] As shown in Fig. 12, oxyhemoglobin (HbO2) and hemoglobin (Hb) have different absorptions in the visible region. Therefore, from the absorbance measurement, the change and the change rate from hemoglobin (Hb) to oxyhemoglobin (HbO2) can be confirmed. As a measuring instrument for absorbance, a colorimeter 234 will be described. The colorimeter 234 measures or detects the transmittance or reflectance of a specific wavelength.

[0037] Hemoglobin becomes bright red when it binds to oxygen. Therefore, the oxygen saturation (the ratio of hemoglobin bound to oxygen) can be measured, obtained, or observed by measuring the absorbance or chromaticity.

[0038] Fig. 12 is an absorbance curve showing which light is absorbed more by oxyhemoglobin (HbO2) bound to oxygen and hemoglobin (Hb) released from oxygen. The color of light is represented by the wavelength on the horizontal axis. The wavelength w1 is red light (R), and the wavelength w2 is infrared light (IR).

[0039] The two graphs (solid line, dotted line) show which wavelengths HbO2 and Hb absorb well and which wavelengths they do not absorb much. The lower the line goes, the less it means that the wavelength is absorbed (the better it passes through).

[0040] Hemoglobin bound to oxygen is bright red. This is because it passes through without absorbing much red color. Hemoglobin released from oxygen becomes blackish. This is because it absorbs light well.

[0041] When red (R) light is applied to blood and more hemoglobin and oxygen are bound in the blood, more light is transmitted and the amount of light received by the sensor increases. Infrared light (IR) passes through the blood with little change whether hemoglobin and oxygen are bound or not.

[0042] If the amount of HbO2 increases and the amount of Hb decreases, the red light (R) received by the sensor will increase, while the infrared light (IR) will not change much. Conversely, if the amount of HbO2 decreases and the amount of Hb increases, the red light will decrease and the infrared light will not change much. That is, if the ratio of R / IR received by the sensor is known, the ratio of HbO2 to Hb, i.e., the oxygen saturation, can be determined.

[0043] The relationship between the ratio of the fluctuation components of the transmitted light amounts of red light (R) and infrared light (IR) and the SpO2 value varies depending on the LED wavelengths of R and IR used. The relational expression between the two is called the calibration constant.

[0044] In the color measuring device 234 of the present invention, the LED of the light emitting source can be changed. Therefore, by selecting the emission wavelength of the LED, the wavelengths w1 and w2 can be arbitrarily set. In the oxygen desorber 207, the ratio, amount, and oxygen saturation of the converted oxyhemoglobin are quantified by the method described with reference to FIG. 12 and the like.

[0045] FIG. 12 shows the oxygen saturation being measured or observed from the relationship between the ratio of the fluctuation components of the transmitted light amounts of red light (R) and infrared light (IR) and the SpO2 value as the color measuring device 234. That is, the amount and ratio of oxyhemoglobin adsorbed with oxygen are measured, observed, or acquired. As shown in FIG. 12, the infrared light IR (wavelength w2) passes through the blood with little difference whether the hemoglobin is combined with oxygen or not.

[0046] If the amount of HbO2 increases and the amount of Hb decreases, the red light (R, wavelength w1) received by the light receiving sensor (not shown) will increase, while the infrared light (IR) will not change much. If the amount of HbO2 decreases and the amount of Hb increases, the infrared light (IR, wavelength w2) will not change much. That is, if the ratio of R / IR received by the sensor is known, the ratio of HbO2 to Hb, i.e., the oxygen saturation, can be determined.

[0047] The %SpO2 is obtained from the R / IR ratio by means of a calibration constant. The relationship between the ratio of the fluctuating components of the transmitted light amounts of red light (R) and infrared light (IR) and the SpO2 value varies depending on the wavelengths of the LEDs of the light emission sources of R and IR used. A calibration constant is obtained from the relationship between the two. The calibration constant is determined by experimentally obtaining the correlation with the SaO2 value.

[0048] In the color measuring device 234 of the present invention, the LED of the light emission source can be changed. Therefore, the wavelengths w1 and w2 can be arbitrarily set. Also, light (R, IR) of a specific wavelength may be transmitted through a color filter from a light source such as white light and irradiated onto blood, hemoglobin, etc. The above embodiments are descriptions of embodiments of the color measuring device 234 using R / IR. The color measuring device 234 of the present invention is not limited thereto.

[0049] FIG. 11 is an explanatory diagram of the color measuring device 234 in another embodiment. FIG. 11 shows an xy chromaticity diagram. However, it is not necessary to limit the representation of the chromaticity change to xy chromaticity. uv chromaticity or u'v' chromaticity may be used.

[0050] The chromaticity is obtained by preparing three physical filters (a combination with a sensor) and measuring the reflected (or transmitted) light from the sample. At this time, a physical filter whose transmission characteristics are adjusted so that the response characteristics of each sensor become response characteristics (or linear characteristics therefrom) is used.

[0051] Hemoglobin in blood is bright red when combined with oxygen, for example, at the a coordinate in FIG. 11. Hemoglobin in the state of dissociating oxygen is dark red and is at the b coordinate in FIG. 11. The difference between the a coordinate and the b coordinate is indicated as △xy. Therefore, by observing or measuring the a coordinate and the b coordinate, obtaining △xy, and when △xy becomes a predetermined value or more, it can be determined that hemoglobin has combined with oxygen. The ratio at which hemoglobin has combined with oxygen to become oxyhemoglobin can also be obtained.

[0052] As described above, the color measuring device 234 used in the air battery device of the present invention has a light emitting source (not shown), and the light from the light emitting source passes through or is reflected by the blood or hemoglobin in the positive electrode or the like, and the light is received by the light receiving sensor.

[0053] Blood or hemoglobin absorbs, transmits, or reflects light of a specific wavelength according to the oxygen binding or uptake state. Also, the chromaticity of the transmitted light (or reflected light) changes according to the absorption state or distribution ratio of the light of the wavelength.

[0054] The color measuring device 234 obtains the oxygen binding state or the like of blood or hemoglobin by measuring or acquiring changes in R / IR, chromaticity, etc. according to the light or distribution of a specific wavelength.

[0055] Based on the measurement data of the color measuring device 234, the discharge, discharge rate, discharge speed of blood or hemoglobin from the oxygen remover 207, or the injection, injection rate, injection speed of blood or hemoglobin into the oxygen remover 207 are changed or set, implemented, and the air battery device is controlled.

[0056] The data of the color measuring device 234 measures, observes, or acquires blood or hemoglobin used as a reference in advance, and sets a calibration value or a reference value. Using the calibration value or the reference value, calibration of R / IR, XY chromaticity, etc. is performed.

[0057] For example, in FIG. 12, an element that generates light of wavelength W1 (such as an LED) is irradiated, and the transmittance or reflectance of the wavelength W1 is measured. An element that generates light of wavelength W2 (such as an LED) is irradiated. The transmittance or reflectance of the wavelength W2 is measured. From the ratio (proportion), absolute value of the reflectance or transmittance of the light of wavelength W1 or and wavelength W2, the proportion and change rate of oxyhemoglobin (HbO2) and hemoglobin (Hb) are evaluated, measured, or observed. Or, light from a light-emitting element (not shown) is transmitted through a filter that transmits wavelength W1 and a filter that transmits wavelength W2, and the ratio (proportion), absolute value of the transmittance of the light of wavelength W1 or and wavelength W2 is measured, etc. From the measured values, the proportion and change rate of oxyhemoglobin (HbO2) and hemoglobin (Hb) are evaluated, measured, or observed.

[0058] The wavelength W1 is a wavelength at which the difference in absorbance (transmittance) between oxyhemoglobin (HbO2) and hemoglobin (Hb) is large. The wavelength W2 is a wavelength at which the difference in absorbance (transmittance) between oxyhemoglobin (HbO2) and hemoglobin (Hb) is small. By comparing the absorbance of wavelength W1 based on the absorbance of wavelength W2, the change rate and the like of oxyhemoglobin (HbO2) and hemoglobin (Hb) can be quantitatively grasped and measured. The separator 119 separates the negative electrode (cathode) and the positive electrode (anode). The separator 119 allows hydrogen ions and water to permeate.

[0059] The red color of red blood cells is the color of a red pigment called hemoglobin (Hb). The amount of hemoglobin is as much as 12 to 16 g in 100 ml of blood. Hemoglobin contains a lot of iron. Oxygen (O2) is bound to this iron, and red blood cells transport oxygen (O2) throughout the body. When iron rusts, it looks reddish-brown. The red color of blood is the color of rust formed by the combination of the iron of hemoglobin (Hb) and oxygen (O2).

[0060] The blood of arthropods such as shrimps and crabs and mollusks such as octopuses, squids, and snails is pale blue. This is because a substance called hemocyanin (Hc), rather than hemoglobin (Hb), transports oxygen. Hemocyanin contains a large amount of copper instead of iron. The blood turns the color of rusted copper, that is, from green to blue like an old copper statue.

[0061] The present invention is illustrated and described by taking hemoglobin that binds to oxygen as an example, but is not limited thereto. Needless to say, for example, hemocyanin (Hc), myoglobin, chlorophyll, etc. may also be used. Hemoglobin, hemocyanin (Hc), myoglobin, chlorophyll, etc. utilize the actions and operations such as binding and reduction with oxygen or carbon dioxide.

[0062] The blood in the artery becomes bright red because hemoglobin rich in oxygen is flowing. The blood in the vein becomes dark red because it contains a large amount of carbon dioxide. Therefore, when hemoglobin (Hb) binds to oxygen and becomes oxyhemoglobin (HbO2), it changes from dark red to bright red. Hemoglobin (Hb) bound to oxygen is called oxyhemoglobin (oxygenated hemoglobin) and exhibits the bright red color of arterial blood. This change is measured with a color measuring device 234. Even hemocyanin (Hc), myoglobin, and chlorophyll change color due to binding to oxygen or the like. This change is measured with a color measuring device 234.

[0063] By monitoring (measuring) the absorbance or color, it is possible to quantitatively grasp the degree to which hemoglobin has changed to oxyhemoglobin (HbO2). By quantitatively grasping this, it is possible to quantitatively grasp and control the fatigue degree (usage state) of the air battery (the timing of battery replacement).

[0064] The above embodiments are descriptions of the embodiment of the color measuring device 234. The color measuring device 234 of the present invention is not limited thereto. FIG. 11 is an explanatory diagram of the color measuring device 234 in another embodiment, or an explanatory diagram of a method for detecting a color change or the like. FIG. 11 shows an xy chromaticity diagram. However, it is not necessary to limit to xy chromaticity to represent the change in chromaticity. It may be uv chromaticity or u'v' chromaticity.

[0065] Chromaticity is obtained by preparing three physical filters (plus a combination of sensors) and measuring the reflected (or transmitted) light from the sample. At this time, a physical filter with its transmission characteristics adjusted so that the response characteristics of each sensor become response characteristics (or linear characteristics therefrom) is used.

[0066] Hemoglobin (Hb) not bound to oxygen is dark red. For example, it becomes the b coordinate in FIG. 11. When hemoglobin (Hb) binds to oxygen, it changes to a bright red color, for example, becoming the a coordinate in FIG. 11. When oxyhemoglobin (HbO2) releases oxygen, it becomes hemoglobin (Hb) and changes to a dark red color, becoming the b coordinate in FIG. 11.

[0067] Therefore, depending on the change state between hemoglobin (Hb) and oxyhemoglobin (HbO2), it moves or changes between the a coordinate and the b coordinate in FIG. 11. The difference between the a coordinate and the b coordinate is indicated as △xy. Therefore, by monitoring and measuring the a coordinate and the b coordinate and determining which position coordinate of △xy it is, the change amount, change ratio, or change state of hemoglobin (Hb) and oxyhemoglobin (HbO2) can be quantified. Also, when △xy becomes equal to or greater than a predetermined value, it can be determined that a corresponding amount or a specified amount of oxyhemoglobin has been formed. By the above method, by observing the color change of the aqueous solution 221 with the color measuring device 234, the fatigue degree and usage degree of the air battery can be quantified. At the positive electrode (anode) 107, oxyhemoglobin Hb(O2) in the aqueous solution (aq) is in rapid equilibrium with dissolved oxygen O2(aq). Hb(O2) (aq) <――> Hb + O 2(aq) That is, as long as Hb(O2) exists, oxygen is supplied to the aqueous solution, so it is an oxygen battery rather than an air battery. The oxygen reduction reaction differs between alkaline and acidic conditions, with different redox potentials as well. Under alkaline conditions, 1 / 2O 2(aq) + H2O (aq) + 2e - -> 2OH - (aq) Under acidic conditions, 1 / 2O 2(aq) + 2H + + 2e - -> H2O (aq)

[0068] Figure 13 is the potential-pH equilibrium diagram of water. As shown in Figure 13, the reduction potential of oxygen is 0.6V at pH = 11 in a zinc-air battery, and approximately 0.82V at pH = 6 - 7 in a chromium-oxygen battery. Chromium (Cr) divalent ions, Cr 2+ , are very strong reducing agents, and chromium (Cr) is oxidized to Cr 3+ . Cr 2+ → Cr 3+ + e - E0 = 0.41V When Cr 2+ comes into contact with Hb(O2), Cr 2+ is instantly oxidized to Cr 3+ . That is, it means that the oxygen supply by Hb(O2) is rapid.

[0069] This indicates that when an aqueous solution 227 of Cr 2+ exists at the negative electrode (cathode) and Hb(O2) exists at the positive electrode (anode), it functions as a battery. The overall reaction can be written as follows. The potential of the overall reaction is 1.23V. 2Cr 2+ + Hb(O2) + 2H + → 2Cr 3+ + Hb + H2O

[0070] An example of a specific embodiment of the present invention is shown. An aqueous chromium solution is used as the aqueous solution 227. Chromium(II) chloride is very soluble in water. Chromium(II) chloride is dissolved in a 3M (mol / dm 3 ) aqueous glycine solution to make the chromium(II) 1M (mol / dm 3 ). It is adjusted with an acid (HCl) or an alkali (NaOH). The pH is set to be 5 or more and 8 or less. Preferably, the pH is 6 or more and 7 or less. This is used as the cathode (negative electrode) aqueous solution 227. The addition of glycine is to prevent the hydrolysis of chromium(II).

[0071] Glycine is one of the glucogenic amino acids. In the present invention, it is not limited to amino acids such as glycine. It may be valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, lysine, histidine, alanine, serine, cysteine, asparagine, glutamine, glutamic acid, aspartic acid, proline, tyrosine, arginine, etc. Also, these may be mixed.

[0072] As another embodiment, in the cathode (negative electrode), the aqueous solution 227 is made acidic. The pH is set to be 0.5 or more and 3 or less. Preferably, the pH is 1 or more and 2 or less. That is, an aqueous chromium(II) chloride solution with a concentration of 10M (mol / dm 3 ) or more is used. Since the chromium(II) chloride is concentrated, the energy density becomes relatively high. In this case, the separator 119 uses a hydrogen ion permeable ion exchange membrane.

[0073] A concentrated aqueous hemoglobin solution is used for the anode (positive electrode). It is preferable to keep the pH neutral. When air (oxygen) contacts the liquid 221 at the anode, hemoglobin changes to the oxy form. Alternatively, bubbling (mixing with air (oxygen)) is performed at the anode (positive electrode) to change hemoglobin to the oxy form. When the cathode (negative electrode) and the anode (positive electrode) are connected, an electric current flows. The electromotive force is about 1.23V. Therefore, it functions as a battery with an electromotive force of 1.23V.

[0074] As the constituent material of the electrode 108, a material that has the same applied voltage as the electrolysis of water and is used for water decomposition can be used. For example, platinum, titanium (Ti), nickel (Ni), and zinc are exemplified. Also, stainless steel (SUS) may be used. Also, a configuration in which a plating film is formed on the surface of the electrode 108 by plating technology or the like may be used. Also, it is not limited to metal materials. For example, carbon may be used. Note that the same applies to the auxiliary electrode 514.

[0075] As the negative electrode 108, gold, platinum, acid-resistant stainless steel, carbon, aluminum alloy, titanium alloy, and nickel alloy are exemplified. In particular, stainless steel has acid resistance and is relatively inexpensive. For example, S-TEN, COR-TEN, and MARILOY are exemplified. Also, carbon-based electrodes are exemplified. As the positive electrode 107, gold, platinum, silver, zinc, stainless steel, aluminum alloy, titanium alloy, nickel alloy, and a mixture of graphite and activated carbon are exemplified.

[0076] Also, metals such as fibrous titanium, stainless steel, nitinol alloy (nickel-titanium), platinum-iridium alloy, and platinum configured or formed into a cylindrical, polygonal, rectangular net-like, or honeycomb structure may be used as the positive electrode 107. These are called stencil electrodes. The same applies to the auxiliary electrode 514. In FIG. 7 and the like, when the cathode is neutral, a cation exchange membrane can be used for the separator 119b.

[0077] The separator 119a is exemplified by a cation exchange membrane through which hydrogen ions permeate, a hydrophilic polymer membrane through which blood or hemoglobin does not permeate, or a glass filter. Also, cellophane film, polypropylene film having micropores, etc. are exemplified.

[0078] When the battery is depleted, chromium (II) is oxidized to chromium (III). To return chromium (III) to chromium (II), the auxiliary electrode is used as the positive electrode. When 1.23 V is applied, chromium (III) is reduced at the cathode and oxygen is generated at the anode. The schematic of a chromium (Cr)-oxygen battery is shown below. Hb(O2) <――> Hb + O2(aq) This equilibrium is rapid, and when the dissolved oxygen decreases, oxygen can be replenished from hemoglobin on the order of milliseconds. When an aqueous solution of hemoglobin 221 is used for the positive electrode (anode) of an air battery, high efficiency can be expected with a homogeneous reaction. 1 / 2O 2(aq) + H2O (aq) + 2e - → 2OH - (aq) There is 1.4 liters of oxygen in 1 kg of the aqueous hemoglobin solution. This is 390 times the dissolved oxygen. Since Hb(O2) is also in rapid equilibrium with air, the oxygen-saturated state can always be maintained by bubbling air.

[0079] By using hemoglobin, a battery with better efficiency, simplicity, and low cost than conventional air batteries can be constructed. Hemoglobin can be easily obtained from cows, etc.

[0080] The weakness is that hemoglobin is a living organism. Since it is auto-oxidized, it needs to be replaced. When not in use, refrigeration can improve the situation. Chromium divalent ion, Cr 2+ , is a very strong reducing agent and is itself oxidized to Cr 3+ . Cr 2+ →Cr 3+ +e - E0 = 0.407V r 2+ When it comes into contact with Hb(O2), Cr 2+ is instantaneously oxidized to Cr 3+ . That is, it means that the oxygen donation by Hb(O2) is rapid. This means that when an aqueous solution of Cr 2+ is present at the negative electrode and Hb(O2) is present at the positive electrode, it functions as a battery. The overall reaction can be written as follows. The electromotive force is about 1.2V. 4Cr 2+ + Hb(O2) + 2H2O -> 4Cr 3+ + Hb + 4OH - The electromotive force of the chromium - hemoglobin secondary battery is small, but since the reaction proceeds rapidly, the efficiency is good.

[0081] In addition to chromium (Cr), vanadium is exemplified as the negative electrode of the air secondary battery. It has two valences of divalent and trivalent and the following redox potentials. V 2+ The reducing power of 2+ is inferior to that of Cr, but it is easy to handle. V 3+ + e - → V 2+ E0 = -0.26V It is necessary to prevent the aqueous solutions of chromium (Cr) and vanadium (V) from forming hydroxide precipitates.

[0082] Note that the electrodes, etc. of the present invention are not limited to chromium (Cr) and vanadium (V). The electrodes may be composed of other metal materials. They may also be composed of conductive materials such as carbon. The aqueous solution is not limited to the aqueous solutions of chromium (Cr) and vanadium (V) either.

[0083] Since the present invention uses an aqueous hemoglobin solution 221 for the positive electrode 107, the solution is neutral and the pH is 7 - 8. In this range, metal ions often form hydroxide precipitates.

[0084] Cr(III) ions are no exception and precipitate in neutral aqueous solutions. As a solution, when a large amount of glycine is added (for example, at a concentration of 0.5M (mol / dm 3 3) or higher), it forms a glycine complex (Cr(gly)3). Gly forms glycinato ions to maintain dissolution. The same is true for V(III) ions.

[0085] To reduce Cr(III) to Cr(II) and V(III) to V(II) at the negative electrode 108, a voltage is applied between the negative electrode and the positive electrode (aqueous hemoglobin solution). Oxygen is generated from the positive electrode 107, but most of it is adsorbed by hemoglobin. For example, it becomes deoxygenated deoxyhemoglobin.

[0086] When the applied voltage is in a neutral solution, the oxygen generation potential at the positive electrode decreases. However, at the negative electrode, due to the burden of the reduction potentials of Cr(III) and V(III), it becomes about the same as the water decomposition voltage.

[0087] Complexes at the negative electrode include ammonia or amine (e.g., ethylenediamine) complexes in addition to glycine. Even if the complex becomes solid, it can be mixed with graphite and reused.

[0088] As shown in FIG. 1, the air battery of the present invention has a metal container (negative electrode) 308 and a metal container (positive electrode) 316, and the container (negative electrode) 308 and the container (positive electrode) 316 are electrically separated by an insulating gasket 311.

[0089] The gasket 311 closes the gap between the container (negative electrode) 308 and the container (positive electrode) and at the same time prevents fluid leakage or entry of foreign matter from the outside. Also, it holds the container (negative electrode) 308 and the container (positive electrode) so that they do not come into contact.

[0090] The container (negative electrode) 308 and the positive electrode are made of, for example, stainless steel or nickel alloy. Also, a metal plating film is formed on the surface. An aqueous chromium solution is filled so as to be in contact with the container (negative electrode) 308.

[0091] A specific embodiment of the present invention is shown. An aqueous chromium(II) solution is used as the aqueous solution 227. Chromium(II) chloride dissolves very well in water. Chromium(II) chloride is dissolved in a 3M (mol / dm 3 ) aqueous glycine solution to make the chromium(II) concentration 1M (mol / dm 3 ). Glycine is added to prevent the hydrolysis of chromium(II).

[0092] The aqueous glycine solution is preferably 2.5 M (mol / dm 3 ) or more and 3.5 M (mol / dm 3 ) or less. When chromium(II) chloride is dissolved, it is adjusted so that chromium(II) is 0.6 M (mol / dm 3 ) or more and 1.5 M (mol / dm 3 ) or less.

[0093] Also, an acid (HCl) or an alkali (NaOH) is added to adjust the pH. The pH is set to 5 or more and 8 or less. Preferably, the pH is 6 or more and 7 or less. This is used as the cathode (negative electrode) aqueous solution 227.

[0094] The aqueous solution 227 may be acidic. At the cathode (negative electrode), the aqueous solution 227 is made acidic. The pH is set to 0.5 or more and 3 or less. Preferably, the pH is 1 or more and 2 or less. A concentrated aqueous solution of chromium(II) chloride of 10 M (mol / dm 3 ) or more is used. Since chromium(II) chloride is concentrated, the energy density becomes relatively high. In this case, the separator 119 uses a hydrogen ion permeable ion exchange membrane.

[0095] Note that in the present invention, the aqueous solution 227 is not limited to an aqueous chromium(II) solution. For example, it goes without saying that an aqueous solution of 30 to 40 wt% high-concentration potassium hydroxide (KOH) or an organic charge solution may be used.

[0096] The diffusion paper 315 is provided for the purpose of uniformly diffusing air (oxygen) 305 from the air holes 317 to the air electrode (positive electrode) 107. As a positional embodiment, cellulose is exemplified for the diffusion paper 315. When the diffusion paper 315 is not arranged, the air (oxygen) 305 flowing in from the air holes 317 does not diffuse throughout the air electrode, and the discharge reaction concentrates on the catalyst layer near the air holes 317. This phenomenon becomes particularly prominent in the case of high-current discharge.

[0097] The air electrode serving as the positive electrode 107 is composed of a gas diffusion layer (diffusion paper 315) through which air (oxygen) diffuses and a catalyst layer (catalyst electrode 312) where the reduction reaction of oxygen occurs. The positive electrode 107 is formed by the catalyst electrode 312 and the like. The positive electrode 107 is formed by the catalyst electrode 312 and the like.

[0098] The gas diffusion layer (diffusion paper 315) enables smooth supply of air and plays a role in preventing intrusion of water from the outside air and leakage of the electrolytic solution to the outside air. It is made of a sheet formed by mixing carbon such as acetylene black with strong hydrophobicity and a highly water-repellent PTFE (polytetrafluoroethylene) binder and molding, or a porous PTFE film.

[0099] The catalyst layer (catalyst electrode 312) is composed of an oxygen reduction catalyst, a high specific surface area carbon, and a PTFE binder. The reduction reaction of oxygen occurs at the three-phase interface of the solid phase (catalyst·carbon), the liquid phase (electrolytic solution), and the gas phase (oxygen).

[0100] Examples of the decomposition catalyst include many substances such as noble metals such as silver and platinum, oxides such as manganese oxide, chromium oxide, and nickel-cobalt oxide, and various phthalocyanine-based compounds and porphyrin-based compounds.

[0101] The air electrode is composed of a catalyst layer (catalyst electrode 312) and a gas diffusion layer (diffusion paper 315). The catalyst layer (catalyst electrode 312) is obtained by pressing a sheet composed of carbon, an oxygen reduction catalyst, and a PTFE binder onto a nickel net. A three-phase interface of solid-liquid-gas is formed in the catalyst layer.

[0102] In order to increase the efficiency of the reaction, it is essential that many such three-phase interfaces exist. Therefore, the catalyst layer (catalyst electrode 312) requires a water-repellent film 314 having appropriate hydrophilicity and appropriate hydrophobicity.

[0103] PTFE powder tends to become fibrous when shear force is applied, so it is suitable as a binder with water repellency. Carbon includes graphite, carbon black, activated carbon, etc. Even for the same type of carbon, the structure, physical properties, and battery characteristics can vary significantly depending on the raw material and manufacturing method. Generally, carbon black and activated carbon with a small particle size and high specific surface area are used. Also, the gas diffusion layer (diffusion paper 315) is a layer for the smooth gas diffusion to the catalyst layer (catalyst electrode 312), and generally, a porous PTFE film is often used and is pressure-bonded to the catalyst layer (catalyst electrode 312).

[0104] Air (oxygen) moves or penetrates from the air holes 317 to the blood·hemoglobin 227. At the positive electrode 107, the potential required for hemoglobin to become methemoglobin (MetHb) is about +0.15V, and oxidation proceeds spontaneously.

[0105] The solution 221 of the positive electrode uses an aqueous hemoglobin solution separated from blood or red blood cells. The separator 119 is exemplified by a cation exchange membrane through which hydrogen ions permeate, a hydrophilic polymer membrane through which blood and hemoglobin do not permeate, or a glass filter. Also, cellophane film, a polypropylene film having micropores, etc. are exemplified.

[0106] Using blood or hemoglobin as the solution 221 of the positive electrode is inexpensive and sustainable. Using blood or hemoglobin at the positive electrode 107 realizes a highly efficient energy battery. Blood or hemoglobin can use the blood of pigs, cows, whales, etc. Since blood is something to be discarded, the material cost is also low. In FIG. 1, a color measuring device 234 is installed or arranged to measure, observe, or grasp the color of the solution 221 of the positive electrode.

[0107] Figure 2 is an explanatory diagram of the air battery (device) of the present invention. The air electrode serving as the positive electrode is composed of a gas diffusion layer through which air (oxygen) diffuses and a catalyst layer 312 where the reduction reaction of oxygen occurs. The catalyst layer constitutes the catalyst electrode 312. The positive electrode 107 is constituted by the catalyst electrode 312 and the like. In the catalyst layer, a three-phase interface of solid - liquid - gas is formed, and at this part, oxygen is reduced and diffuses into the solution 221.

[0108] In order to increase the efficiency of the reaction, it is necessary to have many three-phase interfaces. Therefore, the catalyst layer needs to have appropriate hydrophilicity and appropriate water repellency. The reduction reaction of oxygen occurs at the three-phase interface of the solid phase (catalyst · carbon), liquid phase (electrolyte solution), and gas phase (oxygen).

[0109] The catalyst electrode 312 is connected to the terminal electrode 202a. The negative electrode 108 is connected to the terminal electrode 202b. A load 301 is connected between the terminal electrode 202a and the terminal electrode 202b. Electrons (e - ) generated by the reduction reaction of oxygen flow through the load.

[0110] The catalyst electrode 312, the negative electrode 108, and the separator 119 are arranged in the container 102. A color measuring device 234 is arranged in the aqueous solution 221 part. As shown in FIG. 12, the composition state of hemoglobin and oxyhemoglobin can be quantitatively measured or observed by measuring the absorption coefficient (absorbance). By measurement or observation, the generation state of electrons (electric power) can be monitored, observed, and controlled. Also, the replenishment, replacement, fatigue state, and timing of the aqueous solution 221 can be appropriately grasped.

[0111] An aqueous chromium solution is used as the aqueous solution 227. Chromium(II) chloride dissolves very well in water. Chromium(II) chloride is dissolved in a 3M (mol / dm 3 ) glycine aqueous solution to make the chromium(II) 1M (mol / dm 3 ).

[0112] Also, it is adjusted with an acid (HCl) or an alkali (NaOH). The pH is set to 5 or more and 8 or less. Preferably, the pH is 6 or more and 7 or less. This is used as the cathode (negative electrode) aqueous solution 227. Glycine is added to prevent the hydrolysis of chromium (II).

[0113] As another embodiment, in the cathode (negative electrode), the aqueous solution 227 is made acidic. The pH is set to 0.5 or more and 3 or less. Preferably, the pH is 1 or more and 2 or less. That is, a concentrated 10M (mol / dm 3 ) or more chromium (II) chloride aqueous solution is used. Since the chromium (II) chloride is concentrated, the energy density becomes relatively high. In this case, the separator 119 uses a hydrogen ion permeable ion exchange membrane. At the negative electrode, the pH is measured with a pH meter 111, and when the pH reaches a certain level or more, the aqueous solution 227 is replaced or the aqueous solution 227 is injected into the negative electrode. The switch circuit 515 is controlled by the control circuit 101 and can control the generation and stop of the voltage. As shown in FIG. 3, an air hole 317 is formed or arranged in the container (positive electrode) 316 which is a part of the container 102.

[0114] An air blower 304 is arranged outside the air hole 317. The amount of air (oxygen) 305 injected from the air hole 317 into the aqueous solution 221 can be adjusted by the rotation speed of the air blower 304.

[0115] A color measuring device 234 is arranged in the aqueous solution 221, and the color measuring device 234 measures or monitors the color change of hemoglobin in the aqueous solution 221. Based on the color change of hemoglobin, the air volume of the air blower 304 is changed to adjust or control the reduction amount or rate at the positive electrode 107. FIG. 4 is an explanatory diagram of the configuration of a battery in which a plurality of air batteries (oxygen batteries) are connected in series to set or adjust the voltage value of the electromotive force.

[0116] As shown in Fig. 4(a), a positive electrode 107a and a negative electrode 108a form one air battery. A positive electrode 107b and a negative electrode 108b form one air battery. A positive electrode 107c and a negative electrode 108c form one air battery. A positive electrode 107d and a negative electrode 108d form one air battery.

[0117] The terminal electrode 202a serves as the positive terminal, and the terminal electrode 202b serves as the negative terminal. The connection wire 516a electrically connects the negative electrode 108a and the positive electrode 107b. The connection wire 516b electrically connects the negative electrode 108b and the positive electrode 107c. The connection wire 516c electrically connects the negative electrode 108c and the positive electrode 107d.

[0118] As shown in Fig. 4(b), in Fig. 4(a), the air battery composed of the positive electrode 107a and the negative electrode 108a and the air battery composed of the positive electrode 107b and the negative electrode 108b are connected by the connection wire 516a. The air battery composed of the positive electrode 107b and the negative electrode 108b and the air battery composed of the positive electrode 107c and the negative electrode 108c are connected by the connection wire 516b. The air battery composed of the positive electrode 107c and the negative electrode 108c and the air battery composed of the positive electrode 107d and the negative electrode 108d are connected by the connection wire 516c. The air battery composed of the positive electrode 107a and the negative electrode 108a and the air battery composed of the positive electrode 107b and the negative electrode 108b are connected by the connection wire 516a.

[0119] The terminal 517a is electrically connected to the positive electrode 107b. The terminal 517b is electrically connected to the positive electrode 107c. The terminal 517c is electrically connected to the positive electrode 107d.

[0120] As shown in Fig. 5, in the configuration of Fig. 4(b), a switch circuit 515a is arranged at the position of the terminal 517a, a switch circuit 515b is arranged at the position of the terminal 517b, a switch circuit 515c is arranged at the position of the terminal 517c, and a switch circuit 515d is arranged at the terminal electrode 202b. Also, a terminal 517a is arranged at the terminal electrode 202a. The outputs of switch circuits 515a, 515b, 515c, and 515d are short-circuited, and terminal 517b is disposed.

[0121] By turning on (closing) switch circuit 515a and turning off (opening) the other switch circuits 515, the electromotive force of one air battery (oxygen battery) is output between terminal 517a and terminal 517b.

[0122] By turning on (closing) switch circuit 515b and turning off (opening) the other switch circuits 515, the electromotive force of two air batteries (oxygen batteries) is output between terminal 517a and terminal 517b.

[0123] By turning on (closing) switch circuit 515c and turning off (opening) the other switch circuits 515, the electromotive force of three air batteries (oxygen batteries) is output between terminal 517a and terminal 517b.

[0124] By turning on (closing) switch circuit 515d and turning off (opening) the other switch circuits 515, the electromotive force of four air batteries (oxygen batteries) is output between terminal 517a and terminal 517b.

[0125] As described above, by turning on (closing) a specific switch circuit 515 from a plurality of switch circuits 515, a multiplied electromotive force can be output between terminal 517a and terminal 517b. The switch circuit 515 is controlled by the control circuit 101 and can vary the generated voltage.

[0126] FIG. 4 and FIG. 5 show a configuration in which a plurality of air (oxygen) batteries (devices) are connected in series to multiply (n times, where n is a positive number of 1 or more) the output electromotive force. The air (oxygen) battery device of the present invention is not limited thereto. For example, as shown in FIG. 6, air batteries may be connected in parallel to increase the output current.

[0127] FIG. 5 is a configuration diagram and an explanatory diagram of the air (oxygen) battery (device) of the present invention. In FIG. 6, the left side of the separator 119a is filled with an aqueous chromium solution 227, and the right side is filled with an aqueous hemoglobin solution 221. The left and right sides of the positive electrode 107a are filled with an aqueous hemoglobin solution 221.

[0128] The left side of the separator 119b is filled with an aqueous hemoglobin solution 221, and the right side is filled with an aqueous chromium solution 227 or the like. The left and right sides of the negative electrode 108b are filled with an aqueous chromium solution 227 or the like.

[0129] The left side of the separator 119c is filled with an aqueous chromium solution 227, and the right side is filled with an aqueous hemoglobin solution 221. The left and right sides of the positive electrode 107a are filled with an aqueous hemoglobin solution 221.

[0130] The left side of the separator 119d is filled with an aqueous hemoglobin solution 221, and the right side is filled with an aqueous chromium solution 227 or the like. The left and right sides of the negative electrode 108c are filled with an aqueous chromium solution 227 or the like.

[0131] The left side of the separator 119e is filled with an aqueous chromium solution 227, and the right side is filled with an aqueous hemoglobin solution 221. The left and right sides of the positive electrode 107c are filled with an aqueous hemoglobin solution 221.

[0132] The left side of the separator 119f is filled with an aqueous hemoglobin solution 221, and the right side is filled with an aqueous chromium solution 227 or the like. The left side of the negative electrode 108d is filled with an aqueous chromium solution 227 or the like.

[0133] As described above, the left and right sides of the separator 119 are filled with an aqueous hemoglobin solution 221 or an aqueous chromium solution 227 or the like. The left and right sides of the positive electrode 107 are filled with an aqueous hemoglobin solution 221.

[0134] In the above configuration, by making the separator 119, the positive electrode 107, and the negative electrode 108 common to the arrangement of the hemoglobin aqueous solution 221 or the chromium aqueous solution 227, etc., the volumetric capacity efficiency is improved, and the configuration is also simplified, enabling cost reduction.

[0135] The present invention configures air (oxygen) batteries (devices) in parallel, or in series, or in a combination of series and parallel, and appropriately configures the electromotive force and output current according to the purpose. FIG. 7 is a configuration diagram and explanatory diagram of an air (oxygen) battery (device) with an auxiliary electrode 514 added in addition to the configuration of the air (oxygen) battery (device).

[0136] For the anode (positive electrode), a concentrated hemoglobin aqueous solution 221 is used. The pH needs to be kept neutral. Air is constantly bubbled into the liquid 221 of the anode (positive electrode) to make the hemoglobin in the oxy form.

[0137] When the cathode (negative electrode) 108 and the anode (positive electrode) 107 are connected, a current flows. The electromotive force is about 1.23V in the case of a single layer. In the case of a multi-layer as shown in FIG. 4, it is a multiple of 1.23V.

[0138] FIG. 13 is a potential-pH equilibrium diagram of water. As shown in FIG. 13, the reduction potential of oxygen is 0.6V at pH = 11 in a zinc-air battery, and about 0.82V at pH = 6 - 7 in a chromium-oxygen battery. The aqueous solution 513 of the auxiliary electrode 514 uses phosphoric acid and sodium phosphate, and the pH is preferably about 6, which is neutral or weakly acidic.

[0139] Sodium phosphate is generally trisodium phosphate (English: trisodium phosphate) with the chemical formula Na3PO4. It is also called orthophosphoric acid sodium, tertiary sodium phosphate, or tertiary sodium phosphate. Note that it is not limited to sodium phosphate. Other sodium salts may also be used.

[0140] The electrodes (negative electrode 108, auxiliary electrode 514) do not need to be platinum. Many metals such as titanium and stainless steel can be used. Carbon may also be used. For the separator 119, if the cathode is neutral, an ordinary cation exchange membrane can be used.

[0141] When the battery is depleted, chromium (II) is oxidized to chromium (III). To return chromium (III) to chromium (II), the auxiliary electrode 514 is used as the positive electrode. When 1.23 V is applied, chromium (III) is reduced at the cathode and oxygen is generated at the anode. The ammeter 512a measures or evaluates the generated current.

[0142] The electrode voltage control circuit 114 consists of a variable DC power supply 112 and an ammeter 512b. The voltage generated by the variable DC power supply 112 is not limited to DC. For example, it may be pulsed or the like.

[0143] The variable DC power supply 112 is configured to be able to generate an arbitrary voltage in the range of 0 V to 10 V. In particular, the voltage between 0 and 1 V can be set accurately. Also, the magnitude of the flowing current and the direction of the current flow can be varied. Further, it is configured to be able to limit the flowing current to a predetermined current. The voltage value is controlled by the control circuit 101.

[0144] The control circuit 101 controls the variable DC power supply 112 and the switch circuit 515 of the electrode voltage control circuit 114. Also, it acquires the current value of the ammeter 512. Further, it obtains the absorbance data and chromaticity data measured or acquired by the color measuring device 234, and controls the output current etc. of the battery using these data. The switch circuit 515 is controlled by the control circuit 101 and can control the generation and stop of the voltage.

[0145] Turn on (close) the switch circuit 515a and the switch circuit 515b, and turn off (open) the switch circuit 515c and the switch circuit 515d. In the above switch state, an electromotive force is generated between the positive electrode 107 and the negative electrode 108, and it functions as a battery.

[0146] Turn on (close) switch circuits 515b and 515c, and turn off (open) switch circuits 515a and 515d. In the above switch states, a voltage (for example, 1.23 V) from the electrode voltage control circuit 114 can be applied between the auxiliary electrode 514 and the negative electrode 108. The auxiliary electrode 514 functions as a positive electrode. At the cathode, chromium (III) is reduced, and oxygen is generated at the auxiliary electrode 514. It functions as a storage battery.

[0147] Turn off (open) switch circuits 515b and 515d, and turn on (close) switch circuits 515a and 515c. In the above switch states, a voltage from the electrode voltage control circuit 114 can be applied between the auxiliary electrode 514 and the positive electrode 107.

[0148] The air battery device of the present invention is a type of air battery that uses oxygen in the air for charging and discharging. By using hemoglobin, which is an abundant resource, and in addition, it is easy to increase the capacity due to the increase in the size of the storage unit, a low-cost and large-capacity storage battery can be realized. Since an aqueous liquid is used as the electrolyte, high safety is also ensured.

[0149] The air battery device of the present invention illustrated in FIG. 7 has a function as a battery and a function as a storage battery. It functions as a battery between the negative electrode 108 and the positive electrode 107. By applying a voltage to the negative electrode 108 and the auxiliary electrode 514, the negative electrode 108 is reduced.

[0150] During charging, when chromium undergoes a chemical change, electrons are stored. On the other hand, during discharging, when hemoglobin changes to oxyhemoglobin due to the action with oxygen contained in the air, the stored electrons are released, so electricity can be taken out. In the embodiment of FIG. 7, charging and discharging cycles can be implemented. It can be utilized as a storage battery capable of repeated charging and discharging.

[0151] Since a battery is configured using hemoglobin such as blood that was previously considered waste, the cost can be reduced. In addition, charging and discharging can be performed, and by increasing the size of the storage unit, it is easily possible to increase the capacity, enabling a low-cost and high-capacity storage battery. Furthermore, since an aqueous liquid is used as the electrolytic solution, the possibility of ignition is extremely low, and higher safety can be ensured compared to storage batteries using organic solvents (non-aqueous systems).

[0152] Hereinafter, the configuration and power generation method (power output method) of the air (oxygen) battery device of the present invention will be described. FIG. 1 is an explanatory diagram of the configuration and power generation method (power output method) of the air (oxygen) battery device of the present invention. As shown in FIG. 1, a negative electrode 108 and a positive electrode 107 are provided. The positive electrode 107 utilizes the reduction reaction of hemoglobin.

[0153] For the solution 221 of the positive electrode, an aqueous solution of hemoglobin or blood itself is used. Oxyhemoglobin is used as hemoglobin. The separator 119 is a cation exchange membrane or a hydrophilic polymer membrane or glass filter through which blood or hemoglobin does not permeate.

[0154] The current collector such as the negative electrode 108 may be formed or constituted of stainless steel, titanium, copper, zinc, nickel, aluminum, copper, stainless steel, alloys thereof, sintered alloys, wire meshes, foamed metals, ceramics, etc. A carbon electrode may also be used.

[0155] In addition, a configuration or formation in which platinum, gold, silver, tin, zinc, tungsten, titanium, copper, or nickel is plated on the surface, or an alloy formed or arranged by combining them may be used. Appropriately, the aqueous solution 227 is preferably caused to flow in and out and replaced.

[0156] The aqueous solution 227 is composed of a pump (not shown) for causing the aqueous solution 227 to flow out from a container (not shown) in which the aqueous solution 227 is stored, a pump (not shown) for causing the aqueous solution 227 to flow into the container 102, etc.

[0157] Operate a stirring fan (not shown) to make the concentration of the aqueous solution 227 in the container 102 uniform. Also, at the positive electrode, use a stirring fan (not shown) to stir the solution 221. Further, by installing or arranging the pH meter 111 inside the container 102 or the like, measure the pH of the solution 221 and the aqueous solution 227. Also, it is preferable to inject an acid in a timely manner to adjust the pH. Further, according to the state of generation of electric power (electromotive force, current), inject water into the aqueous solution 227 in a timely manner.

[0158] In the embodiments of the present invention, the positive electrode 107, the negative electrode 108, etc. are expressed as electrodes, but are not limited thereto. Needless to say, any configuration, shape, and structure may be used as long as it can input and output electrons or charges.

[0159] In this specification and the drawings, the configuration consisting of the negative electrode 108 and the aqueous solution 227 may be expressed as the negative electrode. The configuration consisting of the positive electrode 107 and the solution 221 may be expressed as the positive electrode. By moving the position of the negative electrode 108 in the A direction or the B direction and adjusting the distance from the positive electrode 107, the reaction rate can be set or adjusted.

[0160] The same applies to the position of the positive electrode 107. By moving the position of the positive electrode 107 in a direction and adjusting the distance from the negative electrode 108, the reaction rate can be set or adjusted.

[0161] The separator 119 is, as an example, a cation exchange membrane. However, the separator 119 may be any one as long as it has a configuration or physical properties such that the hemoglobin at the positive electrode does not elute to the negative electrode.

[0162] The control circuit 101 controls the variable DC power supply 112 and the switch circuit 515 of the electrode voltage control circuit 114. Also, obtain the current value of the ammeter 512. Also, obtain the absorbance data and chromaticity data measured or obtained by the color measuring device 234, and control the air (oxygen) battery (device) and the electromotive force generation method using these data.

[0163] In the positive electrode 107 (catalytic electrode 312), hemoglobin adsorbs oxygen. Hemoglobin is a complex protein with a tetrameric structure formed by binding four subunits composed of a pigment (heme) containing iron and a protein (globin) contained in the red blood cells of vertebrates. Iron present in the central part of heme binds to one molecule of oxygen. That is, one hemoglobin can bind and transport four oxygen molecules.

[0164] Hemoglobin binds 1.36 mL of oxygen per gram. Hemoglobin bound to oxygen is called oxyhemoglobin and exhibits the bright red color of arterial blood.

[0165] Hemoglobin not bound to oxygen is called deoxyhemoglobin and exhibits the dark red color of venous blood.

[0166] As illustrated and described in FIGS. 11 and 12, the air battery device (fuel cell) of the present invention monitors the binding state with oxygen by measuring or grasping the chromaticity of blood or hemoglobin in chromaticity coordinates. In addition, blood or hemoglobin has absorption in the visible region and can be distinguished from the absorption of oxyhemoglobin.

[0167] Therefore, as shown in FIG. 12, by measuring the absorption coefficient (absorbance), the composition state of hemoglobin and oxyhemoglobin can be quantitatively measured or observed. By measurement or observation, the generation state of current (voltage) can be monitored, observed, and controlled.

[0168] As illustrated in FIG. 7, when the switch circuit 515a and the switch circuit 515b are turned on (closed), a current flows between the negative electrode 108 and the positive electrode 107, generating an electromotive force.

[0169] The blood to be used can be obtained in large quantities as the blood of cows, pigs, and chickens that are consumed as meat. The blood is collected in the blood collection container 220. The blood is put into the blood adjustment container 209. The preservation liquid container 203 contains the blood preservation liquid 204. The preservation liquid container 203 is made of polyvinyl chloride.

[0170] The blood preservation liquid 204 contains 2.20 w / v% of sodium citrate hydrate and 0.80 w / v% of citric acid hydrate as components. The blood preservation liquid 204 is injected into the blood adjustment container 209. It is used at a ratio of the blood preservation liquid 204 (mL) per 100 (mL) of the blood volume. However, if the storage period is short, the preservation liquid is not necessary and room temperature storage is also possible. For long-term storage, refrigerated storage is preferred.

[0171] The reason for injecting the blood preservation liquid 204 is to prevent the remaining blood in the positive electrode 107 (positive pole) from coagulating, and it can also be used if trying to wash. The liquid to be injected is not limited to the blood preservation liquid 204, and water, saline, etc. may also be used. Also, a solution obtained by dissolving citric acid in water may be used. In the blood adjustment container 209, the blood preservation liquid 204 and the blood are stirred by the stirrer 103 and mixed to become the adjusted blood 206.

[0172] The adjusted blood 206 is sent to the centrifuge 208. The centrifuge 208 is provided with a plurality of separation chambers 210 (separation chamber 210a, separation chamber 210b, separation chamber 210c, separation chamber 210d). The adjusted blood 206 is sequentially injected into the separation chamber 210. A rotating shaft 231 is arranged at the central position of the centrifuge 208, and the separation chamber 210 rotates around the rotating shaft 231. In the process of separating hemoglobin from the blood, if the blood is used as it is, the following processes can be omitted.

[0173] When the blood is centrifuged, red blood cells can be separated. When pure water is added to the separated red blood cells, the red blood cells burst due to osmotic pressure and hemoglobin elutes. When the shells of the red blood cells are separated by centrifugation, hemoglobin can be obtained. Before rotation, the whole blood is in a mixed state. When the centrifugation process starts, it is separated into layers of air, plasma, and red blood cells in the separation chamber 210.

[0174] Next, it decelerates and a slider (not shown) starts to move, and the separation process is started by applying pressure. Then, the sensor detects the interface between the air and the plasma, and a clamp (not shown) switches, and the plasma is transferred to the plasma bag. After finishing squeezing out the plasma, when the sensor detects the red blood cells, the clamp closes. For the red blood cell component, in order to ensure fluidity, viscosity adjustment is carried out by adding a blood preservation solution 204, saline, etc. If necessary, the red blood cell component is sent to the oxygen desorber 207. In the oxygen desorber 207, hemoglobin desorbs oxygen and becomes hemoglobin (Hb).

[0175] The red blood cell component contains hemoglobin. Also, hemoglobin is adjusted in terms of pH and temperature in the oxygen desorber 207. Blood or hemoglobin is introduced and placed in the oxygen desorber 207. In the oxygen desorber 207, oxyhemoglobin becomes hemoglobin. The pH is lowered. By lowering the temperature, the conversion and change to hemoglobin are improved. Since the hemoglobin from which oxygen has been desorbed changes to a dark red color, it is easy to measure or grasp the oxygen-binding state.

[0176] Hemoglobin is dark red and becomes bright red when bound to oxygen. Therefore, the oxygen saturation (the ratio of hemoglobin bound to oxygen) can be measured, obtained, or observed by measuring the absorbance or chromaticity.

[0177] A color measuring device 234 is arranged or attached to the oxygen desorber 207. In the oxygen desorber 207, oxyhemoglobin is released from oxygen and becomes hemoglobin. Or the ratio of hemoglobin from which oxygen has been released is increased. The oxygen desorber 207 discharges blood, etc. from the oxygen desorber 207 when it reaches a predetermined oxygen saturation or oxygen adsorption ratio or less.

[0178] The oxygen-depleted blood is sent to the pump 403 and injected into the positive electrode through the injection tube 222a. The injection timing and injection rate are adjusted or set by the opening and closing operation timing, opening and closing time, valve opening and closing angle, etc. of the solenoid valve 405. By adjusting the opening and closing angle of the valve, the flow rate per unit time can be controlled.

[0179] The aqueous solutions 221 and 227 are preferably stirred by a stirring fan 113 (not shown). Needless to say, the aqueous solutions 221 and 227 may also be stirred by vibrating the container 102 (including those by ultrasonic waves).

[0180] The solenoid valve 405 is not limited to an electromagnetic switch. It may be a valve that is manually opened and closed mechanically, or a device that automatically opens and closes by a change in pressure. The solenoid valve 405 may be in any form as long as it can allow a liquid or the like to flow out when opened and can suppress the retention or movement of the liquid or the like when closed. It may not only perform an opening and closing operation but also increase or decrease the flow rate. All of these are in conformity with the technical idea of the present invention.

[0181] At the negative electrode, the pH of the chromium aqueous solution 227 is measured with a pH meter 111. As shown in FIG. 10, when sulfuric acid or phosphoric acid is used as the aqueous solution 513, SO4 2- or PO4 3- or HPO4 2- does not permeate through the hot ion exchange membrane and thus remains at the auxiliary electrode. Therefore, the pH does not fluctuate significantly.

[0182] Since the aqueous solution 227 decreases, water or the like is filled or replenished in a timely manner. When a polymer membrane or a glass filter is used, fluctuations in pH are inevitable. In that case, an acid is added. The aqueous solution 227 is injected or replenished from the aqueous solution container 116 through the injection tube 222b. When the pH reaches a certain level or higher, the aqueous solution 227 is replaced, or the aqueous solution 227 is injected from the aqueous solution container 116 into the negative electrode.

[0183] The aqueous solution container 116 is disposed at the negative electrode. The aqueous solution container 116 and the negative electrode are connected by an injection tube 222b, and new aqueous solution is injected into the negative electrode through the injection tube 222b. Alternatively, at the negative electrode, the pH is measured by a pH meter 111, and when the pH reaches a certain level or higher, the aqueous solution 227 is replaced, or the aqueous solution 227 is injected from the aqueous solution container 116 into the negative electrode. Also, the deteriorated aqueous solution 227 is discharged from the discharge tube 223b. Alternatively, the pH is adjusted and then injected into the negative electrode again.

[0184] As shown in FIG. 7, an ammeter 512 is disposed in the path through which current flows. The ammeter 512 measures the current flowing through the path, and the measured current value and current change are sent to the control circuit 101. Based on the current value and the like, the control circuit 101 controls the on (closed) and off (open) states of the switch circuit 515, and changes or controls the output value of the variable DC power supply 112.

[0185] The space between the negative electrode 108 and the separator 119 is filled with an aqueous solution 227. Blood (hemoglobin) 221 is controlled by a solenoid valve 405 and filled into the positive electrode 107 through an injection tube 222a as shown in FIGS. 1 and 2.

[0186] The color changes as hemoglobin changes to oxyhemoglobin. The color change is measured and monitored by a color measuring device 234. When the measured value and the monitored value reach a predetermined reference value, the blood or hemoglobin is discharged to the collector 224, and new blood or hemoglobin (oxyhemoglobin) 221 is introduced into the positive electrode. After discharging the oxyhemoglobin, the solenoid valve 405 is opened, and blood or hemoglobin is introduced into the positive electrode through the injection tube 222a.

[0187] The blood or oxyhemoglobin discharged to the collector 224 is dried by warm air from the dryer 226 to become blood powder 225. The blood powder 225 made of dried blood or hemoglobin is a good protein and can be used as livestock feed or pharmaceutical material.

[0188] In the positive electrode 107, the amount of oxygen generated increases or decreases depending on the state of change to hemoglobin. By monitoring or observing the increase or decrease in the amount of oxygen bound, the amount of current (electric power) generated can be estimated.

[0189] By predicting the increase or decrease state of the amount of oxygen bound and controlling it with the control circuit 101, uniform current (electric power) generation control can be realized and predicted. The above can achieve good control by controlling with the control circuit 101.

[0190] As shown in FIG. 3, it is preferable to mix or bubble oxygen and air at the positive electrode. The production of oxyhemoglobin can be improved. When mixing or bubbling with oxygen or air, it is preferable to adjust the pH and temperature. Needless to say, bubbling or the like may be mixed with oxygen or the like and stirred, or vibration or the like may be applied for mixing.

[0191] The production of oxyhemoglobin (HbO2) can be improved by bubbling or the like. When mixing or bubbling with oxygen or air, it is preferable to adjust the pH and temperature. Needless to say, bubbling or the like may be mixed with oxygen or the like and stirred, or vibration or the like may be applied for mixing. Applying vibration can detach the oxygen attached to the positive electrode 107 and the negative electrode 108. The embodiment of FIG. 8 was an embodiment in which the oxyhemoglobin used for power generation was discharged to the collector 224, but the present invention is not limited thereto. FIG. 9 is an embodiment in which the aqueous solution 227 is discharged through the discharge pipe 223a, oxygen is detached from the oxyhemoglobin by the oxygen separator 207, and it is reused as hemoglobin.

[0192] A color measuring device 234 is arranged or attached to the oxygen separator 207. In the oxygen separator 207, oxyhemoglobin detaches oxygen to become hemoglobin. Or the ratio of hemoglobin from which oxygen has been detached is increased.

[0193] When the oxygen desorber 207 reaches a predetermined oxygen saturation and oxygen desorption rate, it discharges blood or the like from the oxygen desorber 207. Alternatively, oxygen is desorbed from oxyhemoglobin so as to maintain a predetermined oxygen saturation and oxygen desorption rate, and a fixed amount is sequentially injected and delivered as the aqueous solution 221 per unit time.

[0194] The hemoglobin from which oxygen has been desorbed is sent to the pump 403 and injected into the positive electrode through the injection tube 222a. The injection timing and injection rate are adjusted or set by the opening / closing operation timing, opening / closing time, valve opening / closing angle, etc. of the solenoid valve 405. By adjusting the valve opening / closing angle, the flow rate per unit time can be controlled.

[0195] The above matters are the same in other embodiments such as FIGS. 9 and 10. Also, some or all of them can be combined with other embodiments. Regarding the auxiliary electrode 514 as well, it can move in the A direction or the B direction and be positioned in the same manner as the negative electrode 108 in FIG. 9. Regarding the aqueous solution 513 as well, a pH meter 111 capable of measuring or observing the pH is arranged or attached. Also, although not shown, an aqueous solution container 116 (not shown) capable of injecting and replenishing the aqueous solution 513 is arranged or installed.

[0196] FIG. 10 is an embodiment of a configuration having the auxiliary electrode 514 described in FIG. 7. For ease of understanding, as one embodiment, a configuration is adopted in which a pump 403 for circulating the aqueous solution 513 and an opener 405 are attached to the configuration of FIG. 9.

[0197] The aqueous solution 513 is discharged from the discharge pipe 223b, and the deteriorated aqueous solution 513 is discharged. Also, the aqueous solution 513 is replenished. A part of the discharged aqueous solution 513 is pressurized by the pump 403 and injected into the container 102 from the injection tube 222c. The control circuit 101 controls the injectability with the opener 405.

[0198] By injecting the aqueous solution 513 from the injection tube 222c and discharging it through the discharge tube 223b, the aqueous solution 513 circulates and a constant pH state is always maintained. Also, the aqueous solution 513 in the container 102 is stirred.

[0199] The initial value of blood or hemoglobin is detected by absorbance, and after energization, the composition ratio of oxyhemoglobin and the oxidation product methemoglobin is detected. If necessary, as shown in FIG. 8, the used blood or oxyhemoglobin 221 is discharged from the discharge tube 223a to the collector 224. The blood or hemoglobin (hemic iron in an oxidized state) 221 discharged to the collector 224 is dried to become blood powder 225 and recovered.

[0200] In the examples of the present invention, blood and hemoglobin 221 taken from mammals and the like are used, but the present invention is not limited thereto. For example, artificial red blood cells (Hb-V) in the form of encapsulating Hb solution in liposomes, hemoglobin vesicles as artificial red blood cell preparations, artificial oxygen carriers composed of hemoglobin nanoparticles, etc. may be used.

[0201] Also, mollusks such as squids and octopuses, and arthropods such as crayfish and spiders have "hemocyanin" instead of hemoglobin. Hemocyanin is a giant protein with a molecular weight of several million, and the key to oxygen transport is two copper ions in the active center.

[0202] The copper ions can exist in two states: monovalent and divalent. When oxygen is not bound, they act as monovalent copper ions, and when an oxygen molecule comes, they change to divalent copper ions and can transfer electrons to oxygen. Therefore, hemocyanin can be adopted as the positive electrode material 221 of the air battery device and the electromotive force generation method of the present invention.

[0203] When oxygen ions and hydroxyl groups are generated at the negative electrode, metal powders such as zinc, iron, copper, aluminum, magnesium, and lead are introduced into the negative electrode to combine with the metal to form metal oxides and metal hydroxides. By generating metal oxides, oxides, and metal hydroxides, the power generation efficiency is improved. The substance introduced into the negative electrode is not limited to metals.

[0204] When internal leakage occurs in the air battery device (fuel cell device) of the present invention, such as an aqueous solution, the air battery (device) stops, generates an alarm and an audible alarm, and a warning is issued.

[0205] Figure 14 is an explanatory diagram of a vehicle (automobile, train, bicycle, bus, truck, etc.) having an air battery or the like of the present invention. In the vehicle, substances such as blood are stored in a blood adjustment container 209 as fuel, and electric power is generated by an air battery device (fuel cell) held inside, and the vehicle runs with the generated electric power.

[0206] In addition, in Figure 14, the "vehicle" is illustrated and described, but the present invention is not limited thereto. Needless to say, the present invention can also be applied to automobiles, ships, fuel cells, airplanes, forklifts, iron-making devices, etc. equipped with fuel cells (air battery devices).

Industrial Applicability

[0207] According to the present invention, since blood of livestock or the like that was conventionally discarded is used, a low-cost air (oxygen) battery (device) can be provided. In addition, the generated power per unit capacity is large and the efficiency is high.

Explanation of Signs

[0208] 101 Control circuit 102 Container 103 Stirring fan 107 Positive electrode 108 Negative electrode 109 Gas collector 110 Pipe 111 pH meter 112 Variable DC power supply 114 Electrode voltage control circuit 115 Switch circuit 116 Aqueous solution container 119 Separator 120 Gas storage vessel 201 Air battery (air (oxygen) battery device) 202 Terminal electrode 203 Preservation solution container 204 Blood preservation solution 205 Preservation solution injection tube 206 Adjusted blood 207 Oxygen desorber 208 Centrifuge 209 Blood conditioner 210 Separation chamber 220 Blood collection container 221 Blood · Hemoglobin 222 Injection tube 223 Discharge tube 224 Collector 225 Blood powder 226 Dryer 227 Aqueous solution 231 Rotating shaft 234 Color measuring device 301 Load 304 Blower fan 305 Air (oxygen) 308 Container (negative electrode) 311 Gasket 312 Catalytic electrode 314 Water repellent film 315 Diffusion paper 316 Container (positive electrode) 317 Air hole 403 Pump 405 Electromagnetic valve · Switch 411 Gas flow meter 512 Ammeter 513 Aqueous solution 514 Auxiliary electrode 515 Switch circuit 516 Connection wire 517 Terminal

Claims

【Claim 1】 a first electrode, a second electrode, a separator, hemoglobin near the first electrode, an aqueous solution having chromium between the separator and the second electrode, characterized in that it is an air battery.

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