TWI466372B - Reversible fuel cell, reversible fuel cell system, reversible fuel cell module, and, reversible fuel cell bank - Google Patents

Description

Reversible fuel cell, reversible fuel cell system, reversible fuel cell module and reversible fuel cell stack

The present invention relates to a reversible fuel cell system, a reversible fuel cell module, and a reversible fuel cell that can be utilized by storing electrical energy supplied during charging as chemical energy and then converting the stored chemical energy into electrical energy. Reversible fuel cell stack.

Secondary batteries and fuel cells are high-efficiency and clean energy sources. In recent years, the development of electric vehicles, fuel cell vehicles, and electric vehicles using such secondary batteries and fuel cells as power sources has been carried out worldwide.

Fuel cells are attracting attention with power supplies with high energy conversion efficiency and low environmental load. Fuel cells which have been developed and put into practical use include, for example, a polymer electrolyte fuel cell, an alkali electrolyte fuel cell, a phosphoric acid fuel cell, a molten carbonate fuel cell, and a solid oxide fuel cell.

The fuel cell cannot store electricity. However, a power storage system can be constructed by a combination of a fuel cell and a hydrogen production device by water electrolysis. Such a power storage system is called a "reversible fuel cell" (see Patent Document 1 and Patent Document 2). Such a reversible fuel cell in which a fuel cell and a water electrolysis device are combined is a water electrolysis which is a reverse reaction of power generation using natural energy or nighttime electric power when power is not generated. Thereby, the power generation system manufactures its own fuel.

On the other hand, secondary batteries are used as power tools and require large current discharge. Power supply for electrical and electronic equipment. In particular, nickel-hydrogen secondary batteries and lithium ion secondary batteries have attracted attention as batteries for hybrid electric vehicles that are driven by engines and batteries.

Usually, the secondary battery is charged by receiving a supply of electric energy, and can store electricity. However, the secondary battery cannot be charged without power. Therefore, the secondary battery is not sufficiently convenient. Therefore, Patent Document 3 discloses a secondary battery that can be charged using a gas. Further, Patent Document 4 discloses a novel fuel cell in which a fuel cell and a secondary battery are combined using manganese hydroxide as a positive electrode active material and a hydrogen storage alloy as a negative electrode active material.

Patent Documents 5 and 6 propose a method of cooling a battery. That is, a cooling method that utilizes the protrusions provided on the surface of the battery case to dissipate heat efficiently is included. Further, there is proposed a cooling method in which a metal plate having holes to be bored is provided between the assembled batteries, and cooling air is passed through the holes.

[Advanced technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-348694

Patent Document 2: Japanese Patent Laid-Open Publication No. 2005-65398

Patent Document 3: Japanese Patent Laid-Open Publication No. 2010-15729

Patent Document 4: Japanese Patent Laid-Open Publication No. 2010-15783

Patent Document 5: Japanese Patent Laid-Open Publication No. 2009-016285

Patent Document 6: Japanese Patent Laid-Open Publication No. 2003-007355

The secondary battery can store electricity. However, the active material mass of the negative electrode and the positive electrode depends on the volume of the battery. Thus, there is a limit to the amount of capacitance that can be stored in the battery. The nickel-hydrogen secondary battery has a small weight ratio (weight ratio) of the reducing substance to the oxidizing substance which can be stored with respect to the weight of the active material. For example, in the AB5 type hydrogen storage alloy containing a bismuth alloy-nickel alloy, the weight ratio of hydrogen that can be stored is about 1.2% by weight. Therefore, it is difficult for the secondary battery to greatly increase the energy density.

On the other hand, the fuel cell uses the hydrogen or oxygen supplied from the outside to generate electricity (discharge). Therefore, the fuel cell does not have the problem of the energy density limit generated by the secondary battery. Generally, in order to use a fuel cell, the electrode portion must use a device or member capable of supplying hydrogen and oxygen. Moreover, the tracking performance of the fuel cell to the load fluctuation is inferior to that of the secondary battery. Therefore, it is difficult to use only a fuel cell for a device power source such as a vehicle having a large load variation. Generally, a fuel cell is used together with a power storage device such as a secondary battery or a capacitor. Further, the reaction site of the fuel cell is a very small interface between the solid (electrode), the liquid (electrolyte), and the three phases of the gas (hydrogen, oxygen). Therefore, the output characteristics of the fuel cell are inferior to those of the secondary battery. In order to improve the output characteristics, there is also a method of using platinum in the catalyst. However, this method is more costly.

Further, the gas taken out from the hydrogen production apparatus (for example, Patent Document 1) is hydrogen and oxygen having a ratio of hydrogen to oxygen of 2:1. Therefore, care must be taken to ensure safety.

The secondary battery disclosed in Patent Document 3 can be obtained by receiving a gas supply. The fuel cell is discharged like a battery. Therefore, the secondary battery does not have a case where the capacitance of the secondary battery is limited by the mass of the active material. However, a device or member for supplying hydrogen and oxygen is required in the electrode portion.

The "fuel cell battery" disclosed in Patent Document 4 receives a gas supply from an independently arranged gas storage chamber and generates (discharges) the gas. Therefore, an additional device or member for supplying hydrogen and oxygen is not required in the electrode portion. Also, since the gas storage chambers are independently provided, safety is ensured. However, in the battery described in Patent Document 4, since manganese hydroxide is used as the positive electrode active material, after repeated charge and discharge, trimanganese tetraoxide which is not useful for the charge and discharge reaction is formed. Therefore, the fuel cell has a problem of poor life characteristics.

A zinc-manganese primary battery is widely known as an aqueous solution battery using manganese dioxide as a positive electrode. The zinc-manganese battery is used as a dedicated primary battery and is not used as a secondary battery. The reason is as follows. That is, the positive electrode of the manganese battery generates a change in manganese dioxide MnO ₂ → oxygen (hydrogen oxyhydroxide) MnOOH → manganese hydroxide Mn(OH) ₂ during discharge. At this time, when discharge is performed until manganese hydroxide is formed, trimanganese tetraoxide Mn ₃ O _{4 which} cannot be charged is generated. That is, when the discharge process [oxygen (hydrogen oxyhydroxide) → manganese hydroxide] and the charging process [manganese hydroxide → oxygen (hydrogen oxy) manganese] are repeated, there is a tetraoxide which is an irreversible substance generated in the positive electrode. The problem of increased tri-manganese.

The trimanganese tetraoxide has a property of low conductivity. If the conductivity is low, charging takes time and it is difficult to fully charge. Moreover, if the conductivity is low, the charging efficiency is also deteriorated. Therefore, if the trimanganese tetraoxide is increased, the performance of the fuel cell Deterioration, after all, can not be used. Therefore, manganese dioxide is exclusively used for a primary battery, and the positive electrode active material as a secondary battery is not currently used.

The separator of one of the constituent elements of the battery prevents short circuit between the positive electrode and the negative electrode. The separator is an important part for the battery. The separator is composed of a material having a small thermal conductivity (a material that does not easily conduct heat). The wound battery is wound in a spiral shape by overlapping electrodes and separators. Therefore, the wound battery has several layers of separators from the center of the battery to the surface. Therefore, although the surface temperature of the wound battery is close to the ambient temperature, the temperature of the center portion is high. Therefore, even if the outside of the wound battery is cooled, the inside of the battery is not cooled to a necessary degree and is maintained at a high temperature.

Various methods for battery cooling have been proposed in Patent Documents 5 and 6. These are all effective for cooling the surface of the battery box. However, the wound battery is such that a separator having a small thermal conductivity is wound in several layers. Thus, these methods are not effective as a method of cooling a wound battery.

The present invention has been made in view of the state of the art described above. The present invention relates to a reaction mechanism for assembling a secondary battery excellent in load traceability in a fuel cell having a high energy density. This provides a reversible fuel cell that is excellent in power density, energy density, and load traceability, and that is excellent in safety and life characteristics.

The inventors and the like have made intensive studies to solve the above problems, and have completed the reversible fuel cell of the present invention.

The reversible fuel cell of the present invention (hereinafter referred to as "the present fuel cell") is provided a positive electrode containing manganese dioxide, a negative electrode containing a hydrogen storage material, a separator interposed between the positive electrode and the negative electrode, and an electrolyte; the negative electrode and the positive electrode power generation electrode, and supplied from the outside An electrode that conducts electrolysis of the above electrolyte.

According to this configuration, the positive electrode and the negative electrode each have an active material. Therefore, the present fuel cell has a function as a battery. That is, power generation can be performed without receiving a gas supply, and charging can also be performed using an electric current. Further, in the present fuel cell, when the current fuel cell in the fully charged state is further supplied with electric current, the electrolytic solution is decomposed by water. Thereby, oxygen and hydrogen are generated from the respective electrodes. Further, each of the positive electrode and the negative electrode has an electrode function for generating electricity using oxygen and hydrogen as fuel. That is, the positive electrode and the negative electrode of the present fuel cell not only have the function as the electrode of the present fuel cell, but also have an electrode function for performing water decomposition.

In the fuel cell system, the discharge reaction between the negative electrode and the positive electrode may be respectively represented by the formula (1) and the formula (3), and the charging reaction of the negative electrode and the positive electrode may be performed by the formulas (2) and (4), respectively. The reaction indicated.

MH → M+H ⁺ +e ^- (1)

M+1/2H ₂ → MH (2)

MnO ₂ +H ⁺ +e ^- → MnOOH (3)

MnOOH+O ₂ → MnO ₂ +H ₂ O (4)

In the formulas (1) and (2), M represents a hydrogen storage material.

As shown in the formulas (2) and (4) of the present fuel cell charging process, the negative electrode and the positive electrode are chemically charged by hydrogen and oxygen, respectively.

As shown in the above reaction formulas (3) and (4), the positive electrode active material is repeatedly charged and discharged between manganese dioxide and oxygen (hydrogen oxyhydroxide).

When manganese dioxide is discharged until it becomes manganese hydroxide, trimanganese tetraoxide is formed. The reason is that the inventors and the like believe that if manganese dioxide is not discharged until it becomes manganese hydroxide, trimanganese tetraoxide is not formed, and the deterioration of the positive electrode does not occur. Therefore, the inventors and others used experiments to confirm the matter. The experiment is shown below.

The inventors and the like investigated the change in the charge-discharge cycle characteristics of manganese dioxide in accordance with the depth of the discharge reaction. The results are shown in Figures 19A and B. 19A and B, the vertical axis is the electrode potential, and the horizontal axis is the discharge amount. The discharge curve shown in Fig. 19A was obtained by repeating charge and discharge by a single electron reaction 30 times. The discharge curve shown in Fig. 19B was obtained by repeating charging and discharging using a two-electron reaction for 30 times. According to Fig. 19A, even if charge and discharge were repeated, the discharge curve hardly changed. On the other hand, according to Fig. 19B, it is found that the discharge amount is also reduced as the charge and discharge are repeated. In addition, the single-electron reaction system changes the manganese dioxide into a discharge reaction of oxygen (hydrogen oxyhydroxide). The two-electron reaction system is a discharge reaction of manganese dioxide to manganese hydroxide via oxygen (hydrogen oxyhydroxide). From the experimental results shown in Figs. 19A and B, it is found that the discharge characteristics can be almost uniform only for a single electron reaction. Further, it was found that when a two-electron reaction occurs, the discharge characteristics are gradually deteriorated as the charge and discharge are repeated. From this, it is known that the electrode is gradually deteriorated.

The inventors and the like performed XRD measurement on the charged and discharged electrodes in order to investigate the cause of the deterioration. The result is shown in FIG. As shown in the graph (a) of Fig. 20, When charge and discharge were repeated by a single electron reaction, almost no new peak was generated except for the electrode crystal structure before the experiment (for comparison, the graph (s) of Fig. 20 indicates the electrode measurement result before the experiment). However, as shown in the graph (b) of Fig. 20, when charge and discharge are repeated by the two-electron reaction, the characteristic peak derived from manganese dioxide almost disappears, and on the other hand, a peak derived from trimanganese tetraoxide appears. From this phenomenon, it is understood that the formation of trimanganese tetraoxide can be suppressed by stopping the discharge at the stage where manganese dioxide becomes oxygen (hydrogen oxyhydroxide).

The manganese dioxide is oxidized by discharge, but if the electrode is brought into contact with oxygen, it returns to manganese dioxide, so that no reaction proceeds until manganese hydroxide causes irreversible trimanganese tetraoxide. That is, manganese dioxide can be successfully used as a positive electrode by bringing it into contact with oxygen and charging it at the stage of oxidation of manganese dioxide.

21A and B are graphs showing experimental results of being chargeable by bringing the positive electrode into contact with oxygen.

21 shows a potential of a positive electrode when manganese (oxygen oxychloride) is used as a positive electrode, silver (Ag) is used as a reference electrode, and a half-cell is formed using an alkali-based electrolytic solution. The change is relative to the time. The vertical axis of Fig. 21 indicates the positive electrode potential (V vs. Ag/AgCl), and the horizontal axis indicates the elapsed time (minutes). In a half-cell in which manganese dioxide is used as a positive electrode and silver is used as a reference electrode, the off potential at which the positive electrode becomes oxygen (hydrogen oxyhydroxide) due to discharge is -0.5 V. Before charging (time zero) of Fig. 21, since the positive electrode potential was -0.5 V, the positive electrode was oxygen (manganese hydroxide).

(i) of Fig. 21A is a pattern of a potential with respect to a reference electrode after pressurized introduction of oxygen in a positive electrode. (ii) of Fig. 21A is a graph in which the supply of oxygen is stopped and discharge is performed at 0.2C. As shown in Fig. 21A, when the positive electrode was brought into contact with oxygen (solid line), the positive electrode was almost fully charged at the stage of 60 minutes, and then discharged at 0.2C. On the other hand, when oxygen is not exposed (dotted line), the positive electrode is almost charged. From this, it was confirmed that the use of oxygen causes a cathode reaction (redox reaction) of the fuel cell, and a discharge occurs due to the reaction of the secondary battery after blocking the oxygen. Fig. 21B shows the state of charge by oxygen gas when it is discharged in accordance with 0.2C. It can be seen from the figure that even during discharge, oxygen can be charged. From the experimental results shown in Figs. 21A and B, it was confirmed that charging can be performed by supplying oxygen to the positive electrode.

In the reaction formula of the fuel cell, H _{2 of the} formula (2) may also be hydrogen. Further, O _{2 of the} formula (4) may be oxygen dissolved in the electrolytic solution. Therefore, in the fuel cell, a first oxygen storage chamber in which an electrolyte having dissolved oxygen is stored, and a hydrogen storage chamber in which hydrogen gas is held may be provided inside the battery.

According to this configuration, when the active material in the electrode in the fully charged state is further charged by the electric current, the negative electrode generates hydrogen by electrolysis of water (hereinafter referred to as "electrolysis"). The hydrogen can be stored in a hydrogen storage chamber. Further, oxygen generated by the positive electrode is dissolved in the high-pressure electrolyte by electrolysis. Therefore, oxygen can be stored as oxygen in the electrolyte and stored in the first oxygen storage chamber. That is, hydrogen and oxygen generated by the negative electrode and the positive electrode by electrolysis can be stored in the respective storage chambers without being in contact with each other and reacting.

The hydrogen stored in the hydrogen storage chamber and the oxygen stored in the first oxygen storage chamber are converted into electrical energy and can be utilized when the battery is discharged. In particular, the oxygen generated by the positive electrode is dissolved in the electrolytic solution and is not stored in a gaseous state. Thus, the safety of oxygen disposal is enhanced. The electric energy can be taken out as a secondary battery when the battery is discharged. Therefore, it can be rapidly discharged and can improve load traceability.

As described above, the capacitance of the secondary battery is determined in accordance with the amount of the active material contained in the electrode material. Therefore, it is difficult for the secondary battery to have high energy density. However, the electric energy that can be taken out of the fuel cell is stored in the chemical storage form in each storage chamber.

As a result, by increasing the withstand voltage performance and the sealing performance of each of the storage chambers and the battery containing the same, the chemical energy storage amount per unit volume can be increased, and the volumetric energy density of the fuel cell can be increased.

According to this configuration, the manganese dioxide of the positive electrode temporarily becomes oxygen (hydrogen oxyhydroxide) due to discharge. However, manganese dioxide is returned by being charged by the oxygen dissolved in the electrolyte. Therefore, the positive electrode is not subjected to discharge until the manganese dioxide is further changed from oxygen (hydrogen oxyhydroxide) to other substances. By charge and discharge, the active material of the positive electrode changes between manganese dioxide and manganese (hydrogen oxyhydroxide). Therefore, trimanganese tetraoxide which does not contribute to charge and discharge is not produced. Further, since trimanganese tetraoxide is not formed, the decrease in conductivity can be suppressed.

The first oxygen storage chamber and the hydrogen storage chamber of this configuration do not necessarily have to have a dedicated independent space. The storage chambers may be formed in a gap of a composite material containing active materials such as positive and negative electrodes or in a gap formed in the interior of the battery.

In the fuel cell, the first oxygen storage chamber and the hydrogen storage chamber may be distinguished by a movable member.

According to this configuration, the first oxygen storage chamber and the hydrogen storage chamber can also be disposed adjacent to each other. Since the two chambers are separated by the movable member, if the hydrogen generated by the overcharge causes the pressure of the hydrogen storage chamber to be high, the movable member is deformed by the pressure. By this deformation, the electrolytic solution in the first oxygen storage chamber is compressed, and the pressure of the electrolytic solution is equalized with the pressure of the hydrogen storage chamber to form a high pressure. The bulk modulus of the liquid is very large compared to the gas. Therefore, the amount of deformation of the movable member is only a small amount. The movable member may be an engageable member and may also contain an elastomer. The movable member may also have a thin plate-like or film-like configuration. Further, the movable member may be a positive electrode or a negative electrode. The movable member may be a synthetic resin such as rubber or polypropylene or a thin metal film.

A communication path may also be provided between the first oxygen storage chamber and the hydrogen storage chamber. In this case, the pressure of the hydrogen storage chamber can also be transmitted to the electrolyte solution of the first oxygen storage chamber via the movable member disposed in the communication passage. In this case, the movable member may also be a piston.

In the fuel cell, the movable member may be a flexible member, and the flexible member preferably contains the positive electrode, the negative electrode, and the separator.

The fuel cell is disposed inside the cylindrical case, and the cylindrical positive electrode and the cylindrical negative electrode are disposed via the partition plate via a radial space, and are adjacent to the positive electrode and opposite to the partition plate. Forming the first oxygen storage chamber in a surface manner, and facing the opposite side of the negative electrode from the separator Forming the hydrogen storage chamber; the first oxygen storage chamber is disposed in the radial space, and the hydrogen storage chamber is disposed inside the negative electrode or the hydrogen storage chamber is disposed in the radial space, and The first oxygen storage chamber may be disposed inside the positive electrode. In this configuration, the box functions as an exterior body.

Further, the fuel cell may further include: a negative electrode terminal that is electrically connected to one end of the case and electrically coupled to the negative electrode; and is disposed at the other end of the outer casing in the axial direction and electrically coupled to the positive electrode a positive electrode terminal; a protrusion provided on any one of the positive electrode terminal or the negative electrode terminal; and a hole portion provided in any one of the positive electrode terminal or the negative electrode terminal; and 2 reversible fuels The battery is connected in series, and the protrusion is fitted to the hole. In this configuration, the box can function as an exterior body.

The fuel cell module of the present invention may further comprise a plurality of battery cells connected in series; the battery cells are provided with: a plurality of reversible fuel cells; and a relative arrangement of the plurality of the reversible fuel cells The plurality of reversible fuel cells are connected in parallel to each other via the current collector plate, wherein the plurality of current collector plates are connected to the positive electrode terminal, and the other current collector plate is connected to the negative electrode terminal.

Further preferably, the fuel cell further includes: a casing having a tubular body portion and a bulging portion that is disposed at a two-end opening of the body portion and that bulges toward an outer layer of the opening portion and covers the opening portion The first oxygen storage chamber described above The tubular current collector is disposed in the inner space of the bulging portion inside the casing; the tubular current collector is housed in the axial direction in the outer casing, and the two ends are open to the first oxygen storage chamber; and the positive electrode is disposed on the current collector The outer periphery; the separator covers the periphery of the positive electrode; the hydrogen storage chamber is formed between the separator and the outer casing; the negative electrode is filled in the hydrogen storage chamber; and the electrolyte is stored in the first oxygen The inside of the storage chamber is transported between the first oxygen storage chambers through the current collector.

The fuel cell may further include: an outer casing having a tubular body; and a rod-shaped current collector that penetrates the positive electrode, the negative electrode, and the separator; and the positive electrode, the negative electrode, and the separator are oriented toward the shaft of the body The positive electrode has a notch formed by cutting a part of the outer circumference, and the outer circumference of the positive electrode is in contact with the inner surface of the body other than the notch; the positive electrode The negative electrode has a meandering cross section that is open toward the inner circumferential direction, and the negative electrode is in contact with the current collector; and the hydrogen is formed by the space between the negative electrode and the current collector. a storage chamber; the outer diameter of the negative electrode is smaller than an inner dimension of the body; and an electrolyte retention portion that communicates with the notch portion is provided between the negative electrode and the body; the first oxygen storage chamber includes the above The notch portion and the electrolyte solution retention portion.

In this configuration, the exterior body may include a tubular body and a cover member that covers the opening of the body. Further, the exterior body may include a bottomed cylindrical can and a cover member provided on the opening.

If the outer casing has a cylindrical shape, since the outer diameter of the positive electrode is larger than the inner diameter of the body, the positive electrode abuts against the outer casing. Further, since the size of the positive electrode hole penetrating the current collector is larger than the outer diameter of the current collector, the positive electrode does not contact the current collector. Similarly, the pore size of the negative electrode is smaller than the outer diameter of the current collector, and the negative electrode is in contact with the current collector.

The reversible fuel cell system of the present invention may further include: the fuel cell, and an oxygen storage source and a hydrogen storage source connected to the fuel cell; and the oxygen storage source may supply oxygen or oxygen dissolved in the electrolyte to the fuel a battery, and the oxygen generated by the fuel cell is stored in a state of gas or dissolved in the electrolyte; and the hydrogen storage source supplies hydrogen to the fuel cell and can be stored by the fuel cell. hydrogen.

The reversible fuel cell system of the present invention may further include: the fuel cell, a salt concentration adjusting device connected to the fuel cell and removing moisture contained in the electrolyte, and a fuel cell connected to the fuel cell An oxygen concentration adjusting device that supplies oxygen to adjust the dissolved oxygen concentration.

In the fuel cell, H ₂ -based hydrogen of the formula (2) and O ₂ -based oxygen of the formula (4) may also be used. Moreover, the hydrogen storage chamber may be provided with a hydrogen storage chamber for storing hydrogen gas generated by the negative electrode or for supplying hydrogen gas to the negative electrode, and configured to contact the negative electrode; the second oxygen The storage chamber is for storing oxygen generated by the above positive electrode or supplying oxygen to the positive electrode, and is disposed to contact the positive electrode.

According to this configuration, when the inside of the electrode is in a fully charged state, when the current is used In the case of charging, hydrogen generated by the negative electrode due to electrolysis and oxygen generated by the positive electrode may be separately stored in the hydrogen storage chamber and the second oxygen storage chamber without being in contact with each other and reacting. Therefore, hydrogen gas and oxygen gas can be stored in each storage chamber without adding a gas supply source, a supply passage, a pressure increasing device, or the like. Moreover, the stored hydrogen and oxygen are converted to electrical energy and can be reused when the battery is discharged. When the battery is discharged, electric energy can be taken out by the normal discharge reaction of the secondary battery. That is, electric energy is output via the electrode reaction of the secondary battery. Therefore, rapid charge and discharge, and excellent charge and discharge traceability can be obtained.

Preferably, in the fuel cell, the negative electrode includes a material that is disposed on a surface adjacent to the separator and has hydrophilicity, and a material that is disposed on a surface adjacent to the hydrogen storage chamber and has hydrophobicity, and/or the positive electrode contains a material that is disposed on a surface adjacent to the separator and has hydrophilicity, and a material that is disposed on a surface adjacent to the second oxygen storage chamber and that is hydrophobic.

According to this configuration, the surface of the negative electrode that is in contact with the separator is hydrophilic. This surface is almost always kept wet by the electrolyte. Thereby, this side prevents gas from passing through the negative electrode. Further, the ionic conductivity of the negative electrode is ensured. The surface of the negative electrode that is in contact with the hydrogen gas is hydrophobic. Thereby, since the negative electrode is not wet, good contact between the negative electrode and hydrogen gas is maintained. The surface of the positive electrode adjacent to the separator is hydrophilic. This surface is almost always kept wet by the electrolyte. Thereby, this surface prevents gas from passing through the positive electrode. Further, the ionic conductivity of the positive electrode is ensured. Further, the surface of the positive electrode that is in contact with oxygen is hydrophobic. Thereby, since the positive electrode is not wet, good contact between the positive electrode and oxygen is maintained. In addition, the partition is borrowed The gas is blocked by almost always containing the electrolyte. Thereby, the hydrogen storage chamber is independent of the second oxygen storage chamber. Therefore, hydrogen and oxygen are not mixed together and stored separately.

The secondary battery is reacted with a solid and a liquid. Therefore, since the secondary battery has a large reaction area, the output can be improved. However, the electrode belonging to the solid retains an oxidizing agent and a reducing agent. Therefore, the amount of energy of the secondary battery is small. On the other hand, the reaction surface of the fuel cell is a very small interface of three-phase contact such as solid (electrode), liquid (electrolyte), and gas (hydrogen, oxygen). Therefore, it is difficult for the fuel cell to increase the output. However, since the fuel cell directly supplies the oxidizing agent and the reducing agent as they are, the energy density becomes large. The battery that combines the strengths of the two is the fuel cell.

However, the characteristics of the secondary battery having the reaction surface between the solid (electrode) and the liquid (electrolyte) and the fuel cell characteristics having the reaction surface between the solid (electrode) and the gas and the liquid can be realized in a single electrode. It is possible to achieve higher output and greater energy capacity. Therefore, the interface of the electrode in contact with the electrolyte may be made hydrophilic, and the interface of the contact gas of the electrode may be made hydrophobic. Further, one of the electrodes may be made hydrophilic, and the other surface of the electrode may be made hydrophobic. Further, the entire electrode may be composed of a material having hydrophilicity and hydrophobicity.

In the fuel cell, the electrolyte solution may be held by the second oxygen storage chamber. In this configuration, the electrolyte may be held in the second oxygen storage chamber and oxygen may be held in the upper space. Therefore, when discharged, it is produced by the surface of the positive electrode. The resulting water is replenished to the electrolyte. The electrolysis at the time of charging is performed at the positive electrode interface. Therefore, it is preferable that the electrolyte is held by the second oxygen storage chamber.

In the case where the fuel cell has a cylindrical outer casing, the cylindrical positive electrode and the cylindrical negative electrode are disposed via the partition plate via the radial space inside the outer casing, and the above-mentioned separator is placed in contact with the above-mentioned outer casing. Forming the second oxygen storage chamber such that the positive electrode faces the opposite side of the separator, and forming the hydrogen storage chamber so as to contact the surface of the negative electrode opposite to the separator; the second oxygen storage The chamber is disposed in the radial space, and the hydrogen storage chamber is disposed inside the negative electrode, or the hydrogen storage chamber is disposed in the radial space, and the second oxygen storage chamber is disposed inside the positive electrode .

In this configuration, an additional member for forming the hydrogen storage chamber and the second oxygen storage chamber is not required. Thus, the present fuel cell has a simple configuration that only contains the necessary minimum limit members. Therefore, the size of the fuel cell can be reduced, and thereby the pressure resistance can be ensured. Moreover, the energy density of the fuel cell can be increased, and the assembly work of the fuel cell can be facilitated.

The fuel cell may include: a cylindrical positive electrode disposed in a radial space inside the outer casing; and a tubular negative electrode disposed inside the positive electrode via the separator; the second oxygen storage chamber The hydrogen storage chamber is formed inside the negative electrode. According to this configuration, if the positive electrode is disposed outside the negative electrode, the surface area of the positive electrode can be made larger than the surface area of the negative electrode. Because the output of the battery is proportional to the surface area of the electrode, this portion can increase the output.

Further, the fuel cell may further include: a negative electrode terminal that is electrically coupled to the negative electrode at one end of the outer casing axial direction, and is disposed at the other end of the outer casing axial direction and electrically coupled to the above a positive electrode terminal of the positive electrode, a protrusion portion provided on one of the positive electrode terminal or the negative electrode terminal, and a hole portion provided on any one of the positive electrode terminal or the negative electrode terminal; The protrusions are fitted to the holes in a manner of being connected in series.

According to this configuration, the projections of the two present fuel cells can be connected to the hole portion. Thereby, a plurality of the fuel cells can be connected in series without wiring. A convex portion may be provided on the outer circumference of the protruding portion, and a groove may be provided on the inner circumferential surface of the hole portion. In this case, the convex portion of the protruding portion may be fitted into the groove of the hole portion. Thereby, the two present fuel cells can be reliably connected.

The fuel cell module of the present invention may also be provided with a plurality of battery cells connected in series. The battery unit includes: a plurality of the present fuel cells; and a pair of current collector plates disposed to face the plurality of the fuel cells; wherein the positive electrode terminals are connected to one of the current collector plates, and The negative electrode terminals are connected to the other current collecting plate, and the fuel cells are connected in parallel to each other via the current collector plate.

According to this configuration, the present fuel cell is disposed between the conductive collector plates. Thereby, the wiring connecting the fuel cells can be omitted. Therefore, the modularization of the battery tends to be easy. The collector plate can also be provided with a nickel plated aluminum plate. A through hole may also be provided in the collector plate. Moreover, the protrusion of the fuel cell can also be passed through The hole is fitted into the hole portion of another fuel cell. Thereby, the current collector plate connects the batteries in series and in parallel, and becomes a holder that can fix each battery. Thereby, the assembly of the battery module tends to be easy.

The fuel cell may further include: an oxygen gas flow port connected to the second oxygen storage chamber; and a hydrogen gas flow port connected to the hydrogen storage chamber; and hydrogen gas in the hydrogen storage chamber and oxygen gas in the second oxygen storage chamber Can be taken out of the fuel cell individually.

In this configuration, the oxygen flow port may be provided on the outer casing, and the hydrogen gas flow port may be provided on the outer casing or the positive electrode terminal. Accordingly, the gas stored in the hydrogen storage chamber and the second oxygen storage chamber can be taken out of the fuel cell and stored in other containers. Further, hydrogen and oxygen can be supplied to the hydrogen storage chamber and the second oxygen storage chamber from a container provided outside.

The battery pack of the present invention may further include: a plurality of fuel cells connected to each other, a first hydrogen pipe having a conductor that is hermetically connected to the hydrogen gas flow port, and having a conductor; and having a gas-tight connection a first oxygen pipe containing a conductor; and the first hydrogen pipe is connected to the second hydrogen pipe via an insulator; the first oxygen pipe is connected to the second oxygen pipe via an insulator; adjacent to the first oxygen pipe; The first oxygen pipe and the first hydrogen pipe are electrically coupled by a conductor; the second hydrogen pipe is connected to the hydrogen tank, and the second oxygen pipe is connected to the oxygen tank. According to this configuration, the gas piping becomes a current path. Therefore, the wiring can be omitted.

The fuel cell can further have a contact with the above negative electrode and a negative electrode case in which a positive electrode is disposed opposite to each other, and a positive electrode case that is disposed to face the positive electrode and disposed opposite to the negative electrode; the negative electrode and the positive electrode are disposed to face each other across the separator, and the hydrogen storage chamber is formed in the hydrogen storage chamber In the space between the negative electrode case and the negative electrode, the second oxygen storage chamber is formed in a space between the positive electrode case and the positive electrode. According to this configuration, the negative electrode case and the positive electrode case have functions as a negative electrode terminal and a positive electrode terminal, respectively.

The battery module of the present invention may further include: a plurality of the present fuel cells connected in series to each other, contacting the positive terminal of the positive electrode of the fuel cell connected in series, and contacting the negative electrode of the fuel cell connected in series; The negative electrode terminal; the positive electrode case of the fuel cell and the negative electrode case of the fuel cell are disposed in contact with each other. According to this configuration, wiring for connecting the fuel cell is not required. Moreover, it is not necessary to prepare a pressure resistant container for each battery. It is only necessary to prepare one pressure-resistant structure for each module.

The fuel cell stack of the present invention may further include: a metal sling, a structure, a circuit breaker capable of opening and closing, and a bus bar; one end of the metal sling is attached to the reversible fuel cell module, and the hoist The other end of the cable is mounted on the structure, whereby the plurality of reversible fuel cell modules can be suspended from the structure, and the positive terminal and the negative terminal of the adjacent reversible fuel cell module can also be The circuit breakers are connected by the above bus bars.

According to this configuration, the reversible fuel cell module can be suspended from a structure such as an iron tower by a plurality of metal slings. The metallic sling can also be inserted into a pressure-resistant material such as an insomnia or an insulating tape. Such a reversible fuel cell module can also be plural The arrangement is performed, and the positive electrode and the negative electrode are connected by a conductive bus bar. Circuit breakers can also be placed between the busbars and the output of the battery system.

According to this suspension structure, it is first possible to set up a large structure. Large structures such as bridges or boilers have a large weight. Therefore, it is difficult to adopt a self-supporting structure that supports the weight from the lower portion. Here, by setting the suspension structure, the stress on each part of the battery can be made uniform, and the malfunction due to distortion can be eliminated. Moreover, by forming the suspension structure, it is possible to ensure the withstand voltage performance to the ground and the withstand voltage between the modules.

In the fuel cell, the manganese dioxide may have a catalytic function as a charging reaction in the positive electrode, and the hydrogen storage material may have a catalytic function as a charging reaction in the negative electrode.

According to this configuration, at the time of discharge, in the negative electrode and the positive electrode, the amount of electricity which is reduced by the discharge can be utilized by the hydrogen stored in the hydrogen storage chamber and the oxygen stored in the first or second oxygen storage chamber and the oxygen. It is supplemented by the charging performed. Specifically, in the negative electrode, as shown in the reaction formula (1) indicating the discharge reaction, protons are released from the hydrogen storage alloy (MH) in a charged state. Then, as shown in the reaction formula (2), the released amount of protons is supplemented with hydrogen. Thereby, the state of charge of the negative electrode is maintained.

On the other hand, in the positive electrode, as shown in the reaction formula (3) indicating the discharge reaction, manganese (MnO ₂ ) in a charged state is reduced to generate oxygen (manganese hydroxide) (MnOOH). The oxygen (hydrogen oxyhydroxide) is oxidized again by oxygen as shown in the reaction formula (4). Thereby, the state of charge of the positive electrode is maintained. Accordingly, hydrogen and oxygen in each storage chamber are consumed.

That is, the present fuel cell is lifted before hydrogen gas and oxygen are supplied, and the electric power lost by the discharge is immediately charged by hydrogen gas and oxygen. Therefore, the fuel cell almost always maintains a near full charge state. That is, since the negative electrode is almost always kept in a occluded state by using hydrogen gas, it is possible to suppress volume expansion and contraction of the negative electrode due to charge and discharge. As a result, the negative electrode has excellent life characteristics. Further, even if the amount of the active material is small, since the negative electrode has the above-described effects, the amount of the heavy and expensive hydrogen storage alloy can be reduced. As a result, the weight of the battery can be reduced and the cost can be reduced.

In the fuel cell, the positive electrode may contain manganese oxide in addition to manganese dioxide. Here, the "oxidized manganese" includes Mn ₂ O ₅ , Mn ₂ O ₇ and MnO ₅ . When the electrolytic solution is subjected to water decomposition, the oxidized high manganese is temporarily generated in the positive electrode due to the overcharge state of the positive electrode.

In the fuel cell, the content of trimanganese tetraoxide (Mn ₃ O ₄ ) contained in the positive electrode is preferably 5% by weight or less based on the weight of the positive electrode. If hydrogen and oxygen are supplied almost constantly, trimanganese tetraoxide is not produced. However, if hydrogen or oxygen is temporarily insufficient, trimanganese tetraoxide may be formed. When this amount exceeds 5% by weight, it may constitute a problem. When the amount is less than 5% by weight, it should be allowed according to the use. In addition, the "positive electrode weight" herein does not include the weight of the current collector.

In the fuel cell, the manganese dioxide content contained in the positive electrode is preferably in the range of 20 to 99.8% by weight based on the weight of the positive electrode. In addition, the "positive electrode weight" herein does not include the weight of the current collector.

In the fuel cell, the average particle diameter of the manganese dioxide contained in the positive electrode is preferably in the range of 1 to 100 μm. Here, the average particle diameter is a numerical value expressed by a sphere equivalent diameter measured by a light scattering method of JIS Z 8910.

In the fuel cell, the manganese dioxide contained in the positive electrode may be coated with carbon.

As the conductive treatment, cobalt is sometimes used. However, cobalt is a high unit price. Typically, electrically conductive materials use carbon. However, carbon is oxidized to carbonic acid gas. Therefore, it is difficult to ensure its conductivity. The interior of the fuel cell is in a hydrogen environment. Therefore, carbon is not oxidized and conductivity can be maintained.

In the fuel cell, the hydrogen storage material is preferably a hydrogen storage alloy or a metal selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, and Ni.

In the fuel cell, the separator is preferably a microporous membrane having an average pore diameter of 0.1 to 10 μm.

In the fuel cell, the negative electrode may include a material that is disposed on a surface adjacent to the separator and that is hydrophilic, and a material that is disposed adjacent to one surface of the hydrogen storage chamber and that is hydrophobic.

In the fuel cell, the electrolyte preferably contains a tackifier. Further, the tackifier may be at least one selected from the group consisting of lithium polyacrylate, sodium polyacrylate, and potassium polyacrylate.

In the fuel cell, the open terminal voltage is preferably in the range of 0.8 to 1.48V. That is, the terminal voltage at the time of opening one fuel cell alone may be In the range of 0.8~1.48V. When the positive electrode is oxygen (hydrogen oxyhydroxide) and the electrolyte pressure is 0.1 MPa, the terminal voltage is around 0.8 V. On the other hand, when the positive electrode is manganese dioxide and the electrolyte is at a high pressure, the terminal voltage becomes 1.48V. The open terminal voltage is determined by the state of charge of the positive electrode and the pressure of the electrolyte.

Further, the fuel cell may further include: an exterior body; and a current collector that penetrates the positive electrode, the negative electrode, and the separator toward the axial direction of the exterior body; wherein the positive electrode or the negative electrode is one of a first electrode electrically connected to the inner surface of the outer casing and electrically coupled to the inner surface; and the other of the positive electrode or the negative electrode not contacting the second electrode of the inner surface of the outer casing; the second electrode The electrode system is in contact with the current collector and is coupled to the current collector by a gas contact. On the other hand, the first electrode is a laminated battery that is not in contact with the current collector.

According to this configuration, the separator holds the electrolytic solution and insulates the positive and negative electrodes. The separator is capable of penetrating ions. The exterior system metal may be made of iron, aluminum or titanium. The exterior system has a terminal function as an electrode (first electrode) that is in contact with the exterior body. Further, the outer casing may be a hollow can. The positive and negative electrodes and the separator may also be formed into a sheet shape. Each of the electrodes may be laminated in the axial direction of the exterior body and housed inside the exterior body. The outer diameter of the first electrode (the dimension perpendicular to the thickness direction) may be made slightly larger than the inner diameter of the outer casing. The entire outer circumference of the first electrode system or a part thereof is in contact with the outer surface of the outer casing. The first electrode is press-fitted into the exterior body, and the first electrode has a heat resistance and is connected to the exterior body. Therefore, the exterior body can effectively cool the electrode.

On the other hand, the outer diameter of the second electrode can also be made smaller than the inner diameter of the outer casing. The second electrode is not in contact with the exterior body and is insulated. The outer casing may be a can, and may also include iron, aluminum or titanium.

The heat generated by the first electrode is directly transmitted to the exterior body. Since there is no poor conductor of heat on the way, the thermal slope (temperature difference) is small. The heat generated by the second electrode is conducted to the first electrode via the separator. The separator with a small thermal conductivity set on the way is only one piece, which does not become a large thermal resistance. Therefore, the thermal slope can be suppressed to be small. Further, the electrode group including the positive and negative electrodes and the separator has a large pressure in the axial direction and is pressed into the exterior body. Thereby, the second electrode is strongly pressed against the first electrode. Therefore, the heat transfer of the second electrode is largely changed. The reason why the temperature gradient of the wound battery is large is that a plurality of separators which are not easy to conduct heat are interposed between the outer casing and the electrodes, and it is difficult to perform winding with a large force in the structure, and thus between the electrodes Hot movements cannot be made larger.

As described above, the fuel cell system has a small temperature gradient and can reduce the temperature rise in the central portion of the battery. Therefore, it is not necessary to provide a tube or the like for making the refrigerant flow common inside the battery. Therefore, it is possible to simplify the structure and suppress the temperature rise. Moreover, it can be easily cooled to the inside of the battery by cooling the exterior body. Therefore, the temperature rise can be effectively suppressed.

Furthermore, the second electrode is in contact with the current collector and electrically coupled to the current collector. On the other hand, the first electrode is not in contact with the current collector. The positive and negative electrodes and the separator are provided with holes through which the current collector passes in the central portion. A rod-shaped current collector is passed through the hole. The pore diameter of the first electrode is larger than that of the rod current collector Outer diameter. Therefore, the first electrode does not come into contact with the current collector. The aperture of the second electrode is smaller than the outer diameter of the rod-shaped current collector. Therefore, the second electrode is in contact with the current collector and electrically coupled to the current collector. The material of the current collector contains metal. Therefore, the current collector has a function as a second electrode terminal. Moreover, the material of the current collector includes: iron, aluminum, or the like which is subjected to nickel plating.

In the fuel cell, the outer casing may have a cylindrical metallic body. The outer body may also be a bottomed cylinder having a cover. The outer casing may have a cylindrical metal body portion and two cover portions that cover the shaft-direction opening portion of the body portion. In this case, the current collector may penetrate the lid portion.

According to this configuration, the current collector can also pass through the cover portion and be supported by the two cover portions. The outer casing may be provided with a cover at the two end openings of the round pipe (tube). In this case, the exterior system is provided with a closed space formed by a circular tube and a cover. Further, an electrode group including a positive electrode and a negative electrode is housed in the sealed space. The cover can also be made of metal. The outer diameter of the first electrode may also be made slightly larger than the inner diameter of the outer body. Further, the outer diameter of the second electrode is made smaller than the inner diameter of the outer casing.

In the fuel cell, the side portion of the outer casing may have a substantially cylindrical shape, and the outer casing may have a bulging portion that is bulging in a dome shape at both ends in the axial direction.

According to this configuration, the exterior body may have a side portion in which the bulging portion is formed at one end, and a bulging portion that is attached to the opening portion at the other end of the side portion and that is different from the side portion. Alternatively, the exterior body may have a substantially cylindrical side portion having an opening at both ends in the axial direction, and a bulging portion attached to both ends thereof.

In any case, the exterior system has a dense shape surrounded by the bulging portion and the side portion. Closed space. The positive and negative electrodes and the separator are housed in a sealed space.

The outer diameter of the first electrode is made to be slightly larger than the inner diameter of the outer casing. The outer diameter of the second electrode is made smaller than the inner diameter of the outer body. With this configuration, the heat generated by the first electrode is directly transmitted to the exterior body. The heat generated by the second electrode is conducted to the first electrode via one separator. As described above, the present fuel cell can efficiently transfer heat generated by the electrodes to the exterior body. Therefore, the temperature slope can be lowered, and the temperature rise in the center portion of the laminated battery can be reduced.

Further, the laminated battery of the present invention may further include a hydrogen storage chamber that is provided in an inner space of the dome-shaped bulging portion of the outer casing and stores hydrogen gas generated by the negative electrode.

As described above, the fuel cell and the fuel cell system using the same are based on manganese dioxide used as a positive electrode active material. Further, during overcharging, hydrogen gas and oxygen gas generated by the negative electrode and the positive electrode are stored in a hydrogen state, an oxygen state, or oxygen dissolved in the electrolyte solution, respectively. Thereby, the chemical energy of hydrogen and oxygen can be converted into electrical energy and utilized. Therefore, energy utilization efficiency and energy density can be greatly improved. Also, there is no need to additionally provide equipment for supplying hydrogen and oxygen.

Furthermore, electric energy can be output via the electrode reaction of the secondary battery. Therefore, the tracking of load changes is greatly improved compared to conventional fuel cells. Further, during the charge and discharge reaction of the positive electrode, trimanganese tetraoxide which is an irreversible substance is not generated. Therefore, the life characteristics can be greatly improved.

In addition, the fuel cell can suppress the temperature rise inside the battery, and does not Need extra space for cooling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the voltage coefficient of one fuel cell has a lower value below volts. Therefore, when a high voltage is required, the multiple fuel cells are connected in series and modularized before being used. In addition, regarding a combined system including a fuel cell and other devices, it is called a "fuel cell system."

Before describing the individual embodiments, the common matters of the embodiments will be described. That is, first, the negative electrode, the positive electrode, the electrolytic solution, and the separator will be described. Then, the individual embodiments will be described.

<negative electrode>

The negative electrode used in the reversible fuel cell of the present invention contains a hydrogen storage material. The hydrogen storage material is not limited to a hydrogen storage alloy as long as it can absorb and release hydrogen. The hydrogen storage material may be, for example, a hydrogen absorbing alloy, such as a hydrogenation catalyst, which adsorbs hydrogen from the surface of the catalyst. The hydrogenation catalyst may, for example, contain Ni, Fe, Ti, Al, Ga, As, Se, Mg, Sb, Te, Tl, Pd, Sc, Bi, Ca, V, Cr, Mn, Co, Cu, Zn and Ru. One or more metals or alloys are selected. The hydrogen storage material may be one or more selected from the group consisting of Ni, Fe, Ti, Pd, Sc, V, Mn, and Co. These metals or alloys are alkali resistant and have excellent hydrogen dissociation adsorption rates.

Hydrogen storage materials can also be hydrogen absorption from the viewpoint of hydrogen storage capacity. gold. The material of the hydrogen storage alloy may be a general user such as Mm (Metalum), Ni, Co, Mn or Al type AB5 alloy. Further, the material may be an AB2 type alloy containing a transition metal containing nickel as a main component and a rare earth metal containing more. Further, the material may be an AB3 alloy, an A2B7 alloy, a Ti-Fe alloy, a V alloy, a Mg alloy, or a Pd alloy.

The average particle diameter of the hydrogen storage alloy contained in the negative electrode is preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 50 μm. When the average particle diameter of the hydrogen storage alloy is less than 5 μm, the specific surface area of the alloy particles becomes large. Therefore, the surface of the particles of the hydrogen storage alloy is easily corroded by alkali. Such corrosion leads to a decrease in the hydrogen storage amount and a decrease in the utilization rate of the hydrogen storage alloy in the negative electrode. Moreover, since the electrical conductivity also deteriorates, the discharge characteristics of the battery deteriorate. When the average particle diameter exceeds 100 μm, the specific surface area of the particles becomes small. Therefore, the hydrogen occlusion release reaction of the negative electrode becomes slow. Therefore, the discharge characteristics of the battery deteriorate. Further, in the first embodiment to be described later, the average particle diameter of the hydrogen storage alloy contained in the negative electrode is 20 μm.

In general, on the surface of the particles of the hydrogen storage alloy, there are an oxide film which causes a decrease in capacity, and/or an impurity which does not contribute to the charge and discharge reaction. Therefore, the hydrogen storage alloy can also be activated. The method of the activation treatment includes, for example, a surface modification treatment method in which an acid storage treatment is performed on a hydrogen storage alloy, and an oxide film existing on the surface of the alloy particles is removed. Further, the method of the activation treatment includes a surface modification treatment method using alkali treatment. In addition, the method of using acid treatment is included as a next step Washing steps. This water washing step is a step for removing the treatment liquid attached to the hydrogen storage alloy. On the other hand, the surface modification treatment method using the alkali treatment is a surface modification treatment method having a small number of steps because the water washing step is not included. Further, when a high-temperature aqueous alkali solution is used, the effect of the treatment is enhanced. In the first embodiment to be described later, a surface modification treatment method using alkali treatment is employed.

The hydrogen storage alloy may also be a hydrogen storage alloy represented by a general composition formula RE _(1-x) Mg _x Ni _y Al _z . When the hydrogen storage alloy of the above composition formula is used, a good negative electrode can be obtained as compared with the case of using the conventional AB5 system. The negative electrode has: less self-discharge, higher capacity retention, higher discharge voltage, and good high discharge rate characteristics. Further, the negative electrode does not require activation by acid treatment or alkali treatment as described above. Further, the crystal structure of the hydrogen storage alloy having the above composition has a superlattice phase. Here, in the formula, the RE selects at least one or more elements from the group consisting of La, Ce, Pr, and Nd. Further, the subscripts x, y, and z are ranges expressed by 0.01 ≦ x ≦ 0.2, 4.0 ≦ y 4.9, and 0.05 ≦ z ≦ 0.3, respectively.

When the total amount of the hydrogen storage alloy powder, the binder, and the conductive additive to be added as needed is 100% by weight, the weight ratio of the hydrogen storage alloy of the negative electrode may be in the range of 80 to 99.8%.

The negative electrode includes a paste type negative electrode and a non-paste type negative electrode. The paste type negative electrode is produced by mixing a hydrogen storage alloy powder, a binder, and a conductive powder to be added as needed to form a paste. Coating and filling the paste on a current collector Medium, make it dry. Then, the current collector is rolled by rolling or the like to obtain a negative electrode. The non-paste type negative electrode is produced by stirring a hydrogen storage alloy powder, a binder, and a conductive powder to be added as needed. The powder obtained by stirring was dispersed in the current collector. Then, the current collector is rolled by rolling or the like to obtain a negative electrode.

The binder used in the negative electrode includes, for example, sodium polyacrylate, methyl cellulose, carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), ethylene-vinyl alcohol, ethylene. - vinyl acetate copolymer (EVA), polyethylene (PE), polypropylene (PP), styrene butadiene rubber (SBR), styrene-ethylene-butylene-styrene copolymer (SEBS), Sanxian Glue, Guanhua bean gum, and pectin. When the total amount of the hydrogen storage alloy powder, the binder, and the conductive additive to be added is 100% by weight as a whole, the weight of the binder to be blended in the negative electrode is preferably 0.1 to 10% by weight.

The conductive auxiliary agent for the negative electrode may be any powder having conductivity. The conductive auxiliary agent may be, for example, a carbon powder such as graphite powder, acetylene black or graphitized carbon black. Further, the conductive auxiliary agent may be a metal powder such as nickel powder, copper powder or cobalt powder. When the total amount of the hydrogen storage alloy powder, the binder, and the conductive additive to be added is 100% by weight, the weight of the conductive auxiliary agent to be blended in the negative electrode is preferably 0.1 to 10% by weight.

The current collector for the negative electrode may be, for example, a secondary metal substrate such as a punched metal plate, a porous metal or a gold mesh. Further, the current collector for the negative electrode may be a foamed nickel substrate, a mesh sintered fiber substrate, a felt-plated substrate which is a non-woven fabric of a plated metal, or the like. Three-dimensional substrate. Among them, in the case of producing a non-paste type hydrogen storage alloy electrode, a composite material containing a hydrogen storage alloy powder is dispersed. Therefore, the secondary substrate can also be used as a conductive substrate.

<positive>

The positive electrode contains manganese dioxide as an active material. The average particle diameter of the positive electrode active material may be in the range of 1 to 100 μm, preferably 10 to 50 μm. When the average particle diameter of the positive electrode active material is less than 1 μm, the specific surface area of the positive electrode active material particles becomes large. Therefore, the amount of bonding used to bond the particles to the particles is increased. This phenomenon causes a decrease in the active material content ratio of the positive electrode composition and a decrease in the positive electrode capacity. Moreover, since the electrical conductivity is also deteriorated, the discharge characteristics of the battery are deteriorated. When the average particle diameter exceeds 100 μm, the charging rate by the contact between the oxygen-containing electrolyte and the positive electrode active material tends to decrease due to the diffusion rate of oxygen. Further, the specific surface area of the particles is small. This phenomenon suppresses the charge and discharge reaction of the positive electrode and also deteriorates the discharge characteristics of the battery. Also, since the electrodes become non-dense, the energy density is lowered. Further, in the first embodiment to be described later, the positive electrode active material has manganese dioxide having an average particle diameter of 10 μm.

When the total amount of the positive electrode active material, the binder, and the conductive auxiliary agent to be added as needed is 100% by weight, the weight ratio of the positive electrode active material to be mixed in the positive electrode may be in the range of 20 to 99.8% by weight. When the weight ratio of the positive electrode active material is less than 20% by weight, tri-manganese tetraoxide which is an irreversible component is easily formed in the positive electrode when it is rapidly discharged. On the other hand, if the weight ratio of the positive active material exceeds When 99.8 wt%, the production of the electrode is difficult.

The positive electrode active material is usually a composite of manganese dioxide particles and a material having a surface and having conductivity. The electrically conductive material may be a metal material, a carbon material, a conductive ceramic, or a conductive polymer. Further, the material may be a carbon material from the viewpoint of conductivity and alkali resistance. The carbon material is not particularly limited as long as it has electrical conductivity. The carbon material includes, for example, graphitized carbon black (KB), acetylene black (AB), furnace black, graphite, graphene, fibrous carbon, vitreous carbon, and activated carbon. The specific surface areas of the above KB and AB are preferably from 50 to 3,000 m ² /g.

Usually, when carbon is used as a material having conductivity, carbon is oxidized to become carbon dioxide, and conductivity cannot be maintained. However, the interior of the fuel cell is in a hydrogen environment. Therefore, carbon is not oxidized and conductivity can be maintained.

The thickness of the carbon-coated coating film may be, for example, in the range of 0.01 to 5 μm. If the thickness of the carbon coating film is less than 0.01 μm, the conductivity improvement is insufficient. Therefore, at the time of charge and discharge, current concentration on the surface of the active material is likely to be generated. Therefore, it is difficult to improve the high charge and discharge rate characteristics. On the other hand, when the thickness of the carbon coating film exceeds 5 μm, there is a possibility that the electrode capacity density is lowered. The coverage of the carbon coating film is preferably 0.1 to 20% by weight based on 100% by weight of the positive electrode active material. If the coverage is less than 0.1% by weight, the conductivity improvement is insufficient. Therefore, current concentration on the surface of the active material is likely to occur at the time of charge and discharge. Therefore, it is difficult to improve the high charge and discharge rate characteristics. On the other hand, when the coverage ratio exceeds 20% by weight, there is a problem that the electrode capacity density is lowered. A preferred lower limit of the coverage ratio is 0.2% by weight, more preferably The lower limit is 0.5% by weight. Further, the upper limit of the coverage ratio is preferably 5% by weight, and more preferably the upper limit is 2% by weight.

The method of the conductive treatment is a method in which a carbon coating film can be formed on the surface of the positive electrode active material particles. The method includes, for example, a known technique such as sputtering, vapor deposition, mechanical polishing, heating, electroless plating, and spray drying. Among them, the mechanical polishing method and the heating method do not require the use of a large-scale apparatus, and a carbon coating excellent in uniformity can be formed by a simple method. For example, mechanical milling methods include imparting mechanical energy to the powder particles and utilizing a mechanical chemical reaction on the surface of the particles to initiate a strong surface fusion between the particles. This method is a technique for obtaining a microparticle composite material, and is a method of coating carbon on the surface of a particle of an active material powder. Mechanical milling can also be carried out in a hydrogen environment. When it is in a hydrogen atmosphere, it is easy to form a carbon coating film on the surface of the positive electrode active material particle.

The heating method includes heat treatment such as mixing the positive electrode active material with the carbon precursor and performing heating in a non-oxidizing atmosphere. Thereby, a film made of carbon is formed. In the heat treatment, for example, a carbon precursor gas such as a butane gas is held in a non-oxidizing gas atmosphere for 0.1 to 5 hours in a heat treatment furnace such as a rotary kiln maintained at 400 to 2000 °C. When the heat treatment temperature is less than 400 ° C, carbonization is less likely to occur, and thus the effect of improving the conductivity of the positive electrode active material may be lowered. On the other hand, if the heat treatment temperature exceeds 2000 ° C, the apparatus becomes bulky. Therefore, not only the cost is increased, but also the active material is damaged. Moreover, when the heat treatment time is less than 0.1 hour, there is a case where carbon is not easily coated uniformly. On the contrary, if When the heat treatment time exceeds 5 hours, the heat source is driven for a long time. So the cost is increased. The heat treatment environment is not limited to butane gas, and may be methane gas, ethane gas, propane gas, or a mixed gas thereof. The heat treatment environment may be, for example, nitrogen, helium, neon, argon, hydrogen, carbon dioxide, or a carbon precursor gas subjected to dilution with the mixed gas or the like.

The positive electrode is produced by mixing the positive electrode active material powder, the binder, and the conductive powder added as needed to form a paste. The paste was applied and filled in a current collector, and dried. Then, the current collector is rolled by rolling or the like to obtain a positive electrode.

The positive electrode binder includes, for example, sodium polyacrylate, polytetrafluoroethylene (PTFE), methyl cellulose, carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), Ethylene-vinyl alcohol, ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), polypropylene (PP), and styrene-ethylene-butylene-styrene copolymer (SEBS). Among these, polytetrafluoroethylene (PTFE) is fibrillated by stirring. Therefore, the positive electrode active material powder and the conductive auxiliary agent to be added as needed can be fixed in a mesh shape. The weight ratio of the binder to be mixed in the positive electrode is preferably in the range of 0.1 to 20% by weight, based on 100% by weight of the total amount of the positive electrode active material powder, the binder, and the conductive auxiliary agent to be added as needed.

The conductive auxiliary agent for the positive electrode may be a powder which is not oxidized at the positive electrode potential and can maintain conductivity. The conductive auxiliary agent may be, for example, a powder of carbon, nickel, cobalt hydroxide (Co(OH) ₂ ), cobalt monoxide (CoO), or cobalt. The weight ratio of the conductive auxiliary agent to be blended in the positive electrode is preferably from 0.1 to 60% by weight in the total amount of the positive electrode active material powder, the binder, and the conductive additive to be added as needed.

The current collector for the positive electrode may be, for example, a secondary foil substrate such as a metal foil, a punched metal plate, a porous metal, or a gold mesh. Further, the current collector for the positive electrode may be a three-dimensional substrate such as a foamed metal substrate, a mesh-like sintered fiber substrate, or a felt-plated substrate which is a non-woven fabric of a plated metal. When the current collector for a positive electrode is a punched metal plate, a three-dimensional substrate, or a foamed metal substrate, sufficient current collecting property can be obtained, and a positive electrode having a structure in which an oxygen-soluble electrolyte solution is easily immersed can be obtained.

Charging the positive electrode is achieved by bringing the positive electrode into contact with the oxygen-dissolved electrolyte. When the thickness of the positive electrode is too large, the oxidation rate (charging speed) of the positive electrode tends to decrease depending on the oxygen diffusion rate. Therefore, the thickness of the positive electrode varies depending on the concentration of oxygen dissolved in the electrolytic solution, but is preferably in the range of 50 to 2000 μm. If the thickness of the positive electrode is less than 50 μm, the positive electrode capacity becomes small. When the thickness of the positive electrode exceeds 2000 μm, since the diffusion of oxygen is insufficient, there is a possibility that the positive electrode remains unoxidized.

<electrolyte>

The electrolytic solution used in the present invention is preferably an oxygen-dissolved electrolyte in which oxygen is dissolved in the electrolytic solution in a range of 0.02 to 200 g/L. When the oxygen concentration dissolved in the electrolytic solution is less than 0.1 g/L, since the oxygen concentration is low, it takes a long time to oxidize the positive electrode active material. When the oxygen concentration exceeds 200 g/L, the electrolyte is corroded and the negative electrode is damaged.

The concentration of dissolved oxygen in the electrolyte is adjusted by adding hydrogen peroxide to In the electrolyte, the concentration of dissolved oxygen can be increased. Alternatively, when this adjustment is made, the hydraulic pressure of the electrolyte is raised in accordance with Henry's law, and the dissolved oxygen concentration can be increased. For example, if oxygen is sealed in a hydraulic pressure of 100 MPa, about 26 g of oxygen can be dissolved in one liter of the electrolytic solution.

However, a method of increasing the concentration of dissolved oxygen by adding hydrogen peroxide to the electrolytic solution uses a high concentration of hydrogen peroxide. Since high concentration hydrogen peroxide is highly corrosive, peroxide is easily formed when it comes into contact with combustibles. Therefore, it is preferable to adjust the dissolved oxygen concentration by increasing the hydraulic pressure of the electrolytic solution. In this case, the hydraulic pressure of the electrolyte is preferably 0.1 MPa to 10 GPa. By using a high-pressure or ultra-high pressure electrolyte, not only the dissolved oxygen concentration can be increased, but also oxygen generated during overcharge can be dissolved in the electrolyte. In addition, the operating voltage of the battery can also be increased.

The oxygen-dissolved electrolyte can be oxidized (charged) by bringing the positive electrode active material into contact with the positive electrode. When the oxygen-dissolved electrolyte is set to a high pressure or an ultrahigh pressure, oxygen generated during charging is dissolved in the electrolytic solution. Therefore, there is no need to store a space for oxygen, and the dissolved oxygen concentration in the electrolyte can be increased.

Regarding the hydraulic pressure range of the above electrolyte solution, if the hydraulic pressure of the electrolyte is less than 0.1 MPa, it is difficult to increase the dissolved oxygen concentration in the electrolyte. Therefore, not only is it time consuming to oxidize the positive electrode active material, but it is also difficult to efficiently dissolve oxygen generated during charging in the electrolytic solution. It is substantially difficult to form the hydraulic pressure of the electrolyte to an ultrahigh pressure exceeding 10 GPa.

The electrolyte used in the present invention is preferably dissolved using an alkali water which is usually used. liquid. From the viewpoint of suppressing dissolution of the alloy component from the electrolytic solution, it is preferred to use one type of alkali substance such as lithium hydroxide (LiOH), sodium hydroxide (NaOH), or potassium hydroxide (KOH) alone, but it is also possible Use two or more types. The concentration of the alkali substance of the electrolyte is preferably 1 to 10 mol/L, more preferably 3 to 8 mol/L.

The tackifier can also be dissolved in the electrolyte. The electrolyte that dissolves the tackifier has a slower oxygen diffusion rate because of its high viscosity. By slowing down the oxygen diffusion rate, the negative electrode is not easily contacted with oxygen, thereby reducing the self-discharge reaction of the negative electrode. Moreover, since the viscosity of the electrolytic solution is also improved, the liquid leakage resistance can also be improved. The material of the tackifier may be any material that has water absorbency and can increase the viscosity of the electrolyte. Such materials include, for example, polyacrylates, polystyrene sulfonates, polyvinyl sulfonates, gelatin, starch, polyvinyl alcohol (PVA), and fluororesins.

The tackifier is preferably a polyacrylate from the viewpoint of high water absorbability, high water retention, high gelation strength, and alkali resistance. Specifically, the polyacrylate includes lithium polyacrylate, sodium polyacrylate, potassium polyacrylate, and the like. These may be used alone or in combination of two or more.

The weight ratio of the tackifier is preferably from 0.1 to 30% by weight, more preferably from 1 to 20% by weight, based on 100% by weight of the total of the electrolyte and the tackifier. When the weight ratio of the tackifier exceeds 30% by weight, the active material and the electrolyte become inaccessible because the viscosity of the electrolyte is too high. Therefore, not only the proton conductivity is lowered, but also the electrolyte is not easily circulated. If the weight ratio of the tackifier is less than 0.1% by weight, sufficient effects by the addition of the tackifier cannot be obtained.

<separator>

The separator used in the present invention is preferably a separator which allows protons to penetrate but oxygen does not easily pass. The material of the separator includes, for example, polyolefins such as polyethylene (PE), polypropylene (PP), polybutene (PB), and ethylene propylene rubber; polyphenylene sulfide, polyvinyl fluoride, polyamine, and polyphthalamide. A resin such as an amine, a polyamidimide or a perfluorosulfonic acid (Nafion). These may be used alone or in combination of two or more.

The separator may contain inorganic particles in addition to the above resins. The weight ratio of the inorganic particles is preferably in the range of 10 to 80% by weight, based on 100% by weight of the total of the resin and the inorganic particles. The inorganic particles may be oxide ceramics such as alumina, titania, zirconia, magnesium, cerium oxide, cerium oxide, and iron oxide. Further, the inorganic particles may be nitride ceramics such as titanium nitride or boron nitride. Further, the inorganic particles may also be: aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, magnesium-aluminum serpentine ( Ceramics such as amesite), bentonite, and zeolite may also be glass fibers. These may be used alone or in combination of two or more. By containing the inorganic particles in the resin, not only the liquid immersion property and the electrochemical stability can be improved, but also the separator due to heat can be suppressed from being melted.

The separator may be, for example, a fibrous aggregate such as woven fabric or non-woven fabric, or may be in the form of a film such as a microporous membrane. Further, the separator may be in the form of a sheet bonded by the plurality of layers.

When the separator is a microporous membrane, the pore size is preferably in the range of 0.1 to 10 μm. In the present embodiment, the separator is preferably a microporous film made of polypropylene (thickness: 20 μm, average pore diameter: 0.2 μm). If used with a thickness of 20μm, and 20μm The separator with an average pore size increases the probability of a short circuit. In addition, the method of obtaining the average pore diameter of the separator includes photographing a magnification of 5000 times using a scanning electron microscope (SEM), and taking only the outermost surface of the aperture gauge 30. The separator may also be sealed with a water wetted with an electrolyte or water. The water seal separator is highly gas impermeable. By using a water-sealed separator, it is possible to more reliably prevent hydrogen and oxygen from coming into contact with each other and reacting through the separator.

Hereinafter, the present invention will be more specifically described based on more detailed embodiments. Further, the present invention is not limited by the embodiments.

(First embodiment)

1A and 1B are schematic cross-sectional views showing the structure of a reversible fuel cell C1 (hereinafter simply referred to as "battery C1") according to the first embodiment of the fuel cell basic structure. The battery C1 converts chemical energy of hydrogen and oxygen into electric energy and utilizes it. Also, the battery C1 converts electrical energy into chemical energy and stores it. The main components of the battery C1 include a negative electrode 4, a positive electrode 6, a negative electrode case 1, and a positive electrode case 2. The negative electrode 4 and the positive electrode 6 are opposed to each other via the separator 5. The negative electrode case 1 has a hydrogen storage chamber 8. The positive electrode case 2 has an oxygen storage chamber 7.

The negative electrode active material of the negative electrode 4 contains a hydrogen storage alloy represented by La _0.54 Pr _0.18 Nd _0.18 Mg _0.1 Ni _4.5 Al _0.1 . The negative electrode 4 was produced by using AB, CMC, and SBR to prepare a slurry composite having a weight ratio of 97:1:1:1. Further, the slurry composite material is applied to a punched metal plate on which a steel material is plated with nickel.

The positive electrode active material of the positive electrode 6 contains manganese dioxide. Manufacturing system of positive electrode 6 The slurry composite materials having a weight ratio of 97:0.5:2:0.5 were prepared using AB, CMC and PTFE. Further, the slurry composite material was filled in foamed nickel. Further, the manganese dioxide of the positive electrode active material was previously charged in a rotary kiln (700 ° C, 1 hour, butane gas atmosphere). Thereby, a conductive thin film is formed on the manganese dioxide. The coverage of the conductive film (carbon coating film) can be obtained by subjecting the obtained manganese dioxide to heat treatment in an oxygen atmosphere and calculating the weight difference between the manganese dioxide before and after the heat treatment. The coverage of the carbon coating film was 0.9% by weight based on 100% by weight of the manganese dioxide.

The separator 5 contains a microporous film made of polypropylene (thickness: 20 μm, average pore diameter: 0.2 μm). The electrolyte 3 is held in the separator 5.

The electrolytic solution 3 contained a 6 mol/L aqueous potassium hydroxide solution. Further, the electrolytic solution 3 contained 5% by weight of sodium polyacrylate as a tackifier.

As shown in FIG. 1A, the negative electrode 4 and the positive electrode 6 have a structure in which the separator 5 is interposed. Further, the surface of the negative electrode 4 that is not in contact with the separator 5 is hermetically covered by the box-type negative electrode case 1. The internal space formed by the negative electrode 4 and the negative electrode case 1 constitutes the hydrogen storage chamber 8. The hydrogen storage chamber 8 directly stores the hydrogen gas generated by the negative electrode without requiring an additional member such as a pressure increasing device. Further, the hydrogen storage chamber 8 is provided in a state of being adjacent to the negative electrode 4. Therefore, hydrogen gas can be supplied to the direct negative electrode 4 without interposing a communication path or an additional member.

The side of the positive electrode 6 that is not in contact with the separator 5 is covered by the box type positive electrode case 2. The internal space formed by the positive electrode 6 and the positive electrode case 2 constitutes an oxygen storage chamber 7 for storing oxygen. The oxygen storage chamber 7 stores the electrolytic solution 3 having a high hydraulic pressure (for example, 10 MPa). Therefore, the oxygen generated by the positive electrode 6 is dissolved in the electrolytic solution, and is stored in the oxygen storage chamber 7 in the form of dissolved oxygen. That is, the oxygen generated by the positive electrode 6 is directly stored in the oxygen storage chamber 7 without requiring an additional member such as a pressure increasing device. Further, the oxygen storage chamber 7 is designed to be in a state of being adjacent to the positive electrode 6. Therefore, oxygen can be directly supplied to the positive electrode 6 without providing a communication path or an additional member.

The hydrogen storage chamber 8 and the oxygen storage chamber 7 are distinguished by a movable wall member 9. The wall member 9 includes a positive electrode 4, a negative electrode 6, and a separator 5. The wall member 9 can also be a flexible member.

The side of the negative electrode 4 that contacts the hydrogen storage chamber 8 contains a large amount of hydrophobic material. Thereby, the hydrogen storage alloy of the negative electrode 4 can be brought into contact with hydrogen gas without being wetted. Further, the surface of the negative electrode 4 that contacts the separator 5 is hydrophilic. Thereby, the face will prevent hydrogen from passing through the negative electrode 4. This surface is almost always kept wet by the electrolyte. Thereby, the ionic conductivity of the negative electrode 4 is ensured.

The operation of the battery C1 constructed as described above is as follows. The battery C1 includes a positive electrode 6 having a positive electrode active material and a negative electrode 4 having a negative electrode active material. Therefore, at the initial charging, the electrode of the battery C1 stores electric energy. In addition, in order to facilitate the description, the present specification is referred to as "overcharge" when the capacitance of the active material in the electrode is charged. Oxygen and hydrogen are produced in an overcharged state.

After the electrode of the battery C1 is initially charged, if the current is further supplied continuously, hydrogen gas is generated from the anode 4, and oxygen is generated from the cathode 6. Hydrogen is stored It is stored in the hydrogen storage chamber 8. When charging is performed, the pressure inside the hydrogen storage chamber 8 rises. Therefore, the hydrogen storage chamber 8 is expanded by the influence of the hydrogen pressure. The hydrogen storage chamber 8 and the oxygen storage chamber 7 are separated by a movable wall member 9. Therefore, if the hydrogen storage chamber 8 expands, the wall member 9 is displaced or deformed, causing the electrolyte 3 of the oxygen storage chamber 7 to be compressed. The deformation of the wall member 9 continues until the pressure of the hydrogen storage chamber 8 and the oxygen storage chamber 7 is substantially uniform. Accordingly, the electrolytic solution 3 of the oxygen storage chamber 7 is at a high pressure. As a result, oxygen generated by the positive electrode 6 is dissolved in the electrolytic solution 3. Thereby, the electrolytic solution 3 becomes an oxygen-dissolved electrolyte.

The electrolyte 3 of the present fuel cell may have a hydraulic pressure in the range of 0.1 MPa to 10 GPa. In the battery C1 of the present embodiment, the electrolytic solution 3 has a hydraulic pressure in the range of 1 MPa to 10 MPa.

When the battery C1 is discharged, a discharge reaction as a secondary battery is initiated between the negative electrode 4 and the positive electrode 6. Thereby, a current flows through the load. At this time, the amount of electricity of the negative electrode 4 and the positive electrode 6 is reduced by discharge. The amount of electric power reduced by the negative electrode 4 and the positive electrode 6 is supplemented by charging by hydrogen gas and oxygen stored in the hydrogen storage chamber 8 and the oxygen storage chamber 7. That is, the negative electrode 4 produces a reaction represented by the chemical formula (2). As a result, the amount of protons released from the hydrogen absorbing alloy (MH) in a charged state is supplemented by hydrogen. Thereby, the state of charge of the negative electrode is maintained. On the other hand, the positive electrode 6 produces a reaction represented by the chemical formula (4). As a result, oxygen (hydrogen oxyhydroxide) which is formed by reduction of manganese dioxide (MnO ₂ ) in a charged state is again oxidized by oxygen. Thereby, the state of charge of the positive electrode is maintained. That is, manganese dioxide is used as a reaction catalyst function of the positive electrode. On the other hand, a hydrogen storage alloy is used as a reaction catalyst function of a negative electrode.

The manganese dioxide in the positive electrode 6 is reduced to oxygen (hydrogen oxyhydroxide) by discharging. Oxygen (hydrogen oxyhydroxide) is oxidized by oxygen in the electrolyte to return manganese dioxide. Therefore, manganese dioxide is almost always present in the positive electrode 6. Therefore, the SOC (State of Charge) of the positive electrode is maintained at nearly 100%. Further, the positive electrode 6 faces the oxygen storage chamber 7, and is constantly exposed to oxygen. Therefore, the discharge reaction of manganese dioxide does not proceed until manganese dioxide becomes manganese hydroxide, so that trimanganese tetraoxide (Mn ₃ O ₄ ) which is an irreversible component is not formed. Therefore, since the deterioration of the positive electrode 6 is suppressed, the life characteristics are greatly improved.

The hydrogen storage alloy in the negative electrode 4 releases protons upon discharge. Therefore, the amount of hydrogen in the hydrogen storage alloy is lowered. However, the negative electrode 4 faces the hydrogen storage chamber 8, and is often exposed to hydrogen gas. Therefore, the protons released from the hydrogen storage alloy (MH) are supplemented with hydrogen. As a result, the hydrogen absorbing alloy which releases hydrogen returns to a state in which hydrogen is occluded. Therefore, in the negative electrode 4, there is an alloy in which hydrogen is almost always absorbed. As a result, the SOC of the negative electrode was maintained to be nearly 100%.

Fig. 22 is a view showing the relationship between the potential (vertical axis) and the SOC (horizontal axis) of the manganese dioxide electrode. As shown in Fig. 22, the potential of the battery C1 is in the vicinity of a high potential indicated by manganese dioxide (MnO ₂ ). That is, the battery C1 maintains a high discharge potential.

The battery C1 of the present embodiment stores electric energy supplied during overcharging in the storage chambers 7 and 8 in the form of chemical energy. Then, the battery C1 converts the stored chemical energy into electrical energy and can be utilized. So, unlike the conventional second Battery, the capacitance of battery C1 is not limited by the amount of active material. Therefore, by increasing the pressure resistance performance and the sealing performance of the storage chambers 7 and 8, and the battery C1, the hydrogen storage amount and the dissolved oxygen amount per unit volume can be increased. Thereby, the energy density of the battery C1 can be greatly increased (for example, several tens of times) compared to the conventional secondary battery. Further, the storage chambers 7 and 8 directly store hydrogen gas generated by the anode 4 during overcharge or oxygen generated by the cathode 6. Therefore, it is not necessary to add a booster or a communication path in which a gas is installed. Therefore, the battery C1 has a simple structure and thus belongs to a battery which can be inexpensively manufactured and supplied. In particular, oxygen is dissolved in the electrolyte and stored. Therefore, the safety of the relevant oxygen intake can be greatly improved.

Further, as described above, when the battery C1 is discharged, electric energy is output by the reactions shown by the formulas (1) and (3). Therefore, compared with the conventional fuel cell, the traceability and power of the load are greatly improved. Thereby, the battery C1 can also be used for applications in which, for example, a vehicle requires a momentary high output load variation. At this time, the battery C1 can be used alone without adding a secondary battery or a power storage device such as a capacitor.

(Variation of the first embodiment)

Fig. 1B is a schematic cross-sectional view showing the structure of a battery C1' according to a modification of the first embodiment. The battery C1' has substantially the same structure as the battery C1 of the first embodiment. That is, the main constituent elements of the battery C1' include a negative electrode 4' and a positive electrode 6' that face each other across the separator 5', a negative electrode case 1' that forms the hydrogen storage chamber 8', and an oxygen storage chamber 7'. Positive box 2'. The main differences are as follows. That is, the electrolyte 3' in which oxygen is dissolved is stored in the oxygen storage chamber 7' of the battery C1. another In one aspect, the oxygen storage chamber 7' of the battery C1' holds oxygen and electrolyte 3'. That is, the oxygen storage chamber 7' partially holds the electrolyte 3'.

The side of the negative electrode 4' that contacts the hydrogen storage chamber 8' contains a large amount of hydrophobic material. On the other hand, the side of the negative electrode 4' that contacts the separator 5' is hydrophilic. Further, the side of the positive electrode 6' that contacts the oxygen storage chamber 7' contains a large amount of hydrophobic material. Thereby, the manganese dioxide of the positive electrode 6' can be exposed to oxygen without being wet. The side of the positive electrode 6' that contacts the separator 5' is hydrophilic. Thereby, the face prevents oxygen from passing through. This surface is almost always kept wet by the electrolyte. Thereby, the ionic conductivity of the positive electrode 6' is ensured. The electrodes 4' and 6' are on the side of the gas storage chambers 8' and 7', and may be coated or sprayed with hydrophobic carbon or Teflon. Further, the electrodes 4' and 6' are in contact with one side of the separator 5', and may be coated or sprayed with a hydrophilic modified nylon. Further, vinyl acetate having both hydrophilic and hydrophobic properties may be granulated and used as a binder.

The separator 5' holds the electrolyte 3'. Further, in the present embodiment, the both surfaces of the separator 5' are wetted by the electrolytic solution 3'. Therefore, the partition 5' has a function as a water seal partition. Thereby, the gas impermeability of the separator 5' is improved. As a result, it is possible to more reliably prevent hydrogen and oxygen from coming into contact with each other and reacting through the separator 5'.

The hydrogen storage chamber 8' and the oxygen storage chamber 7' are configured not to communicate with each other. The oxygen storage chamber 7' is filled with an electrolytic solution of the same type as the electrolytic solution 3' interposed between the positive and negative electrodes, which is about 1/3 of the volume of the oxygen storage chamber 7'.

When the amount of the electrolytic solution 3' filled in the oxygen storage chamber 7' is small, the amount of water to be electrolyzed becomes small. As a result, the amount of hydrogen and oxygen generated during overcharging is reduced. another On the other hand, if the amount of the electrolyte is large, the storage volume of the gas is reduced. From this point of view, the amount of the electrolyte 3' filled in the oxygen storage chamber 7' is preferably in the range of 20 to 50%, more preferably 25 to 40%, of the volume of the oxygen storage chamber 7'.

The operation of the battery C1' configured as described above is as follows. The battery C1' is charged by a current as usual before being in a fully charged state as a secondary battery. When the battery C1' reaches the fully charged state, if the current is continuously supplied, hydrogen gas is generated from the anode 4', respectively, and oxygen is generated from the cathode 6'. The hydrogen and oxygen are stored in the hydrogen storage chamber 8' and the oxygen storage chamber 7' without being in contact with each other. Then, the negative electrode 4' and the positive electrode 6' are charged by hydrogen or oxygen stored in the storage chamber 8' or 7'.

When the battery C1' starts to discharge, a normal discharge reaction as a secondary battery occurs between the negative electrode 4' and the positive electrode 6'. Thereby, a current flows through the load. At this time, the electric quantity of the negative electrode 4' and the positive electrode 6' is reduced by discharge. The amount of electric power reduced by the negative electrode 4' and the positive electrode 6' is supplemented by charging by hydrogen gas and oxygen stored in the hydrogen storage chamber 8' and the oxygen storage chamber 7'. That is, the negative electrode 4' releases a part of protons from the hydrogen storage alloy (MH) in a charged state, and is supplemented with hydrogen. Thereby, the state of charge of the negative electrode is maintained. On the other hand, in the positive electrode 6', oxygen (hydrogen oxyhydroxide) (MnOOH) which is produced by reduction of manganese dioxide (MnO ₂ ) in a charged state is oxidized again by oxygen. Thereby, the state of charge of the positive electrode is maintained. After the hydrogen and oxygen of the storage chambers 7' and 8' are consumed, the battery C1' is discharged in the same manner as a normal secondary battery.

That is, the battery C1' of the present embodiment can be used as a secondary battery. The charge is stored in the electrode. Further, the battery C1' can store the electric energy supplied during overcharging in the storage chambers 7' and 8' in the form of a gas. In addition, the battery C1' can re-convert the stored energy into electrical energy that can be utilized.

Furthermore, the battery C1' improves the pressure resistance and sealing performance of the storage chambers 7' and 8' and the battery C1' containing the batteries. Thereby, the gas storage amount per unit volume is increased. As a result, the energy density of the battery C1' can be increased (e.g., several times as many as 10 times) as compared with the conventional secondary battery. Therefore, when the overcharge is directly stored in the storage chambers 7' and 8', the hydrogen generated by the negative electrode 4' or the oxygen generated by the positive electrode 6'. Therefore, it is not necessary to add a boosting device or a communication path in which a gas is installed. Therefore, since the battery C1' has a simple configuration, it is a battery that can be inexpensively manufactured and supplied.

Further, as described above, when the battery C1' is discharged, electric energy is outputted by the electrode reaction of the secondary battery. Therefore, compared with the conventional fuel cell, the traceability and power of the load are greatly improved. Thereby, the battery C1' can also be used for applications in which, for example, a vehicle requires a momentary high output load variation. At this time, the battery C1' can be used alone without adding a power storage device such as a secondary battery or a capacitor.

(Second embodiment)

Next, a battery C2 according to the second embodiment of the present fuel cell will be described. The battery C2 has a battery structure which is excellent in pressure resistance and easy to take. 2A and B are cross-sectional views showing the configuration of the battery C2. In addition, FIG. 2B is a cross-sectional view taken along line D-D of FIG. 2A. The battery C2 has the same as FIG. 1A and B The battery C1 of the first embodiment described above has the same basic structure. However, the battery C2 has a tubular outer casing 10 as shown in FIG. 2A. Thereby, the battery C2 has excellent pressure resistance and handling properties. Moreover, the battery C2 has an increased energy density and is easy to use. In addition, the negative electrode, the positive electrode, the separator, and the electrolytic solution, which are the basic elements of the battery of the present embodiment, have the same materials and structures as those of the battery C1 of the above-described first embodiment except for the following description.

As shown in FIG. 2A, the tubular outer casing 10 more specifically has a cylindrical portion 10a and a bottom portion 10b. The bottom portion 10b is connected to one end of the cylindrical portion 10a and belongs to the bottom of the outer casing 10. Inside the bottom portion 10b, a negative electrode 14, a positive electrode 16, and a separator 15 interposed between the negative electrode 14 and the positive electrode 16 are housed. The negative electrode 14 and the positive electrode 16 are formed into a bottomed cylindrical shape. The negative electrode 14 and the positive electrode 16 have cylindrical peripheral walls 14a and 16a and bottom portions 14b and 16b. The positive electrode 16 is disposed on the inner side of the exterior body 10 via a radial space. The negative electrode 14 is disposed on the inner side of the positive electrode 16 via the separator 15. The battery C2 constitutes an oxygen storage chamber 19 in a space (radial space) between the outer casing 10 and the positive electrode 16. On the other hand, the space formed inside the negative electrode 14 constitutes the hydrogen storage chamber 18.

The exterior body 10 is formed of a conductive material (specifically, iron which is subjected to nickel plating). The outer surface of the bottom portion 16b of the positive electrode 16 is joined to the inner surface of the bottom portion 10b of the outer casing 10. Thereby, the exterior body 10 has the function as the positive terminal of the battery C2. On the other hand, the right end portion 14c of the opposite side (the right side of FIG. 2A) of the bottom portion 14b of the negative electrode 14 is joined to the disk-shaped negative electrode terminal 11. Specifically, the negative electrode The right end portion 14c of the 14 is disposed to protrude to the right side from the right end faces 10c and 16c of the outer casing 10 and the positive electrode 16. The inner diameter surface 17a of the donut-shaped insulating member 17 is fitted to the outer peripheral surface of the right end portion 14c. The insulating member 17 covers the right end faces 10c and 16c of the exterior body 10 and the positive electrode 16. Further, the inner surface (the left side of FIG. 2A) of one surface of the negative electrode terminal 11 is joined to the right end portion 14c of the negative electrode 14.

The electrodes 14 and 16 are flexible. Thus, when the hydrogen storage chamber 18 generates hydrogen due to overcharge, causing a high pressure, the pressure of the hydrogen storage chamber 18 is transferred to the oxygen storage chamber 19. As a result, the electrolytic solution 13 in the oxygen storage chamber 19 is compressed to have a high pressure. The high pressure electrolyte dissolves more oxygen inside.

Here, the side of the negative electrode 14 that contacts the hydrogen storage chamber 18 contains a large amount of hydrophobic material. Thereby, the hydrogen storage alloy of the negative electrode 14 can be brought into contact with hydrogen gas without being wet. Further, the side of the negative electrode 14 that is in contact with the separator 15 is hydrophilic, and thus the state of being wetted by the electrolyte is almost always maintained. Thereby, hydrogen gas is prevented from passing through the anode 14 and the ionic conductivity of the anode 14 is ensured.

The size of the exterior body 10 will be described. The outer diameter of the outer casing 10 may range from 13.5 mm to 14.5 mm. Further, the length of the exterior body 10 may be in the range of 49.0 mm to 50.5 mm. Further, the outer diameter of the outer casing 10 may be in the range of 10.5 mm to 9.5 mm. Further, the length of the exterior body 10 may be in the range of 42.5 mm to 44.5 mm. By the size of the exterior body 10 being within the above range, dimensional compatibility with a commercially available single-three battery or single-four battery can be achieved.

According to the battery C2 of the second embodiment configured as described above, the first In addition to the effects obtained by the battery C1 of the embodiment, the following effects can be obtained.

The exterior body 10 of the battery C2 has a tubular structure as shown in Figs. 2A and B. Therefore, it is possible to easily ensure excellent pressure resistance and increase energy density. Moreover, since most of the batteries C2 are connected in parallel and in series, a battery module having a large charge and discharge capacity can be easily formed. In particular, in the battery C2 of the present embodiment, the oxygen storage chamber 19 is formed in the radial space. Further, the hydrogen storage chamber 18 is formed inside the negative electrode 14. Therefore, additional members for forming the hydrogen storage chamber 18 and the oxygen storage chamber 19 are not required. Therefore, the battery C2 has a simple configuration and can be formed using only the necessary minimum limit members. Therefore, the battery C2 has a small size and thus has high pressure resistance and energy density. However, since the number of parts is small, the assembly work of the battery C2 is easy.

(First modification of the second embodiment)

The battery C2' according to the modification of the second embodiment has substantially the same structure as the battery C2 of the second embodiment. The differences are as follows. That is, the electrolyte 13 in which oxygen is dissolved is stored in the oxygen storage chamber 19 of the battery C2. On the other hand, the oxygen storage chamber 19 of the battery C2' holds oxygen and the electrolyte 13. That is, the oxygen storage chamber 19 partially holds the electrolytic solution 13. Moreover, each electrode may not have flexibility.

Further, the side of the positive electrode 16 that contacts the oxygen storage chamber 19 contains a large amount of hydrophobic material. Thereby, the manganese dioxide of the positive electrode 16 can be brought into contact with oxygen without being wet. The side of the positive electrode 16 that contacts the separator 15 is hydrophilic, and thus is almost always kept wet by the electrolyte. Thereby, blocking oxygen through The positive electrode 16 is passed through and the ionic conductivity of the positive electrode 16 is ensured. The electrodes 14 and 16 are on the side of the gas storage chambers 18 and 19, and may be coated or sprayed with hydrophobic carbon or Teflon. Further, the electrodes 14 and 16 may be coated or sprayed with modified nylon on one side of the separator 15 side.

(Second variation of the second embodiment)

Next, a battery C3 according to a second modification of the second embodiment of the fuel cell will be described. Fig. 3 is a partial cross-sectional view showing the connection structure of the battery C3. The battery C3 is a part of the external structure of the battery C2 of the second embodiment. Hereinafter, the description will be focused on the change. The battery C3 is provided with a negative electrode terminal 11 electrically coupled to the negative electrode 14 at one end in the axial direction (the axial direction of the exterior body 10). Further, the battery C3 is provided with a positive electrode terminal electrically connected to the positive electrode 16 and belonging to the exterior body 10 at the other end in the axial direction. Moreover, as shown in FIG. 3, the protrusion part 11d is provided in the center of the negative electrode terminal 11. Further, a bottom recess 10d is provided at the center of the bottom portion 10b of the exterior body 10. The protrusion 11d and the bottom recess 10d are formed in a shape that can be fitted. Thereby, the two batteries C3 can be connected in series.

According to this configuration, the plurality of batteries C3 can be connected in series without wiring. Moreover, in the example shown in FIG. 3, the convex part is provided in the outer peripheral axis direction of the protrusion part. On the other hand, a groove is provided on the inner peripheral surface of the bottom recess. Therefore, the convex portion constituting the protruding portion is fitted into the groove of the bottom concave portion. However, the shape of the fitting portion may be other methods.

Threads can also be formed on the positive terminal (outer body 10) and the negative terminal 11. unit. In other words, the protruding portion 11d of the negative electrode terminal 11 may be a male screw, and the female portion may be formed on the bottom portion 10b of the exterior body 10 to form a female screw. Thereby, the two batteries C2 can be connected more reliably.

Further, in the battery C3, an oxygen storage chamber (not shown) may be filled with an electrolyte in which oxygen is dissolved. Alternatively, it can be filled with electrolyte and oxygen.

4A and B are structural views of a battery module B3 which is formed by connecting a plurality of batteries C3. The battery module B3 has a pair of conductive collector plates 25 disposed opposite to each other. The plurality of batteries C3 are disposed between the collector plates 25. One of the collector plates 25 is in contact with the exterior body 10 belonging to the positive terminal. The other collector plate 25 is in contact with the negative terminal 11. The battery C3 is arranged in parallel with each other in such a manner as to maintain this state. The battery module B3 is configured by connecting battery packs including a plurality of battery cells C3 connected in parallel in series (FIG. 4A).

With such a configuration, the wiring connecting the battery C3 can be omitted. Therefore, the assembly of the battery module B3 tends to be easy. Further, as shown in an enlarged view of a main portion surrounded by a circular circle in FIG. 4A, a through hole 25a may be provided in the current collector plate 25. In this case, the protruding portion 11d of the battery C3 is fitted into the bottom recessed portion 10d of the other battery C3 through the through hole 25a. Thereby, the assembly of the battery module B3 is easier. With this configuration, the plurality of batteries C3 are supported by the current collector 25. Therefore, the battery module B3 has a self-standing structure as a battery pack. Further, the battery included in the battery module B3 is not limited to the battery C3, and may be the battery C2.

In order to feed the cooling air in the parallel direction of the collector plate 25, a supply air can also be provided. Fan 27. The heat generated by the battery C3 is conducted to the collector plate 25. The battery C3 is indirectly cooled by the function of the collector plate 25 as a heat sink fin. The collector plate 25 has two functions of a conductive member and a heat dissipating member. Therefore, the material of the collector plate 25 can also have a high thermal conductivity and electrical conductivity. In this regard, aluminum has a lower electrical resistance and a greater thermal conductivity. Therefore, aluminum has a preferable characteristic as a material for forming the collector plate 25. However, since aluminum is easily oxidized, the contact resistance of the collector plate 25 is easily increased. Therefore, the aluminum plate contained in the current collector plate 25 can also be plated with nickel. Thereby, the contact resistance can be lowered. The collector plate 25 is provided with a plurality of refrigerant passages 26 for allowing the insulating oil for cooling to pass therethrough (see FIG. 4B). Further, the arrangement of the battery C3 (through hole 25a) may be formed in a zigzag arrangement (see FIG. 4B). Thereby, the cooling air from the blower fan 27 can be directly blown against the side surface of the battery C3. As a result, the cooling effect can be improved. Further, when the battery module is cold, the air blown by a heater (not shown) may be blown by the blower fan 27. Thereby, the battery module can be warmed up.

(Third variation of the second embodiment)

Next, a battery C4 according to a third modification of the second embodiment of the fuel cell will be described. 5A to C are cross-sectional views showing the configuration of the battery C4 (batteries C4a, C4b, and C4c). The battery C4 is a part of the battery C2 structure of the second embodiment of the present fuel cell. Hereinafter, the description will be focused on the change. The battery C4 is provided with a hydrogen flow port 28 that communicates with the hydrogen storage chamber 18 at the center of the negative electrode terminal 11. The outer casing 10 having the positive terminal The central portion of the bottom portion 10b is provided with an oxygen flow port 30 that communicates with the oxygen storage chamber 19. Hydrogen or oxygen stored in the storage chambers 18 and 19 of the battery C4 can be discharged through the flow ports 28 or 30 provided in the connecting portions 29 and 31.

Further, the hydrogen source and the oxygen source are disposed outside. Hydrogen and oxygen can be supplied to the storage chambers 18 and 19 through the flow ports 28 and 30. Further, the connecting portions 29 and 31 are provided as connecting means for realizing connection between the battery C4 and an external hydrogen source and an oxygen source. Further, the shape of the connecting portions 29 and 31 of the battery C4 may be the configuration shown in any of Figs. 5A to 5C. That is, in the example (battery C4a) shown in FIG. 5A, the connecting portion 29a has a protruding shape, and the connecting portion 31a has a through hole shape. Further, in the example (battery C4c) shown in Fig. 5C, the connecting portions 29c and 31c each have a shape of a projection. Moreover, in the example (battery C4b) shown in FIG. 5B, the connection portions 29b and 31b each have a through hole shape. Any shape can be selected as appropriate.

Fig. 6 is a configuration diagram of the battery pack S4. The battery pack S4 is connected to the plurality of batteries C4c. Further, a battery C4a or a battery C4b may be used in accordance with the shape of the connecting portion. The battery pack S4 is provided with a hydrogen first header tank 35 and an oxygen first header tank 36. These systems contain a conductive material. These are respectively provided with a plurality of connecting portions 35a and 36a. Thereby, the connection portion 29 of the battery C4 is airtightly connected to the connection portion 31. Thereby, the hydrogen storage chamber 18 and the oxygen storage chamber 19 of the battery C4 can communicate with the hydrogen first header tank 35 and the oxygen first header tank 36, respectively. For example, 30 batteries C4 are disposed between the hydrogen first header tank 35 and the oxygen first header tank 36, and are connected to the header tanks 35 and 36.

When 30 or more batteries C4 are used, the hydrogen first header tank 35 and the oxygen first header tank 36 may be added. When a plurality of hydrogen first gas headers 35 and oxygen first headers 36 are used, the hydrogen first gas headers 35 and the oxygen first headers 36 respectively pass through the insulating connecting members 32 containing the insulating material and 33, connected to the hydrogen second header tank 38 and the oxygen second header tank 39. Further, the adjacent oxygen first header tank 36 and the hydrogen first header tank 35 are electrically coupled via a conductive connecting member 34 containing a conductive material. The hydrogen second header tank 38 and the oxygen second header tank 39 are finally connected to the hydrogen tank and the oxygen tank (both TANK in the figure). In this configuration, hydrogen and oxygen generated by the battery C4 are collected in respective tanks and used for the battery C4. Further, hydrogen and oxygen can be supplied from the cells to the hydrogen storage chamber 18 and the oxygen storage chamber 19 of the battery C4. Thereby, the chemical energy of hydrogen and oxygen can be used for power generation. On the other hand, the negative electrode terminal 11 of the battery C4 and the exterior body 10 which is a positive electrode terminal are connected to the hydrogen first header tank 35 and the oxygen first header tank 36, respectively. Thereby, the electric system of the battery C4 is collected by the first headers 35 and 36. In the case where the plurality of first headers 35 and 36 are used, the conductive connecting members 34 are connected in series, and the electrical output is output from the battery pack S4.

In addition, in the battery C4, instead of the oxygen source, the oxygen electrolyte source in which the dissolved oxygen is dissolved may be connected. In this case, in the battery pack described above, the oxygen is in a state of being dissolved in the electrolytic solution, and functions as a working fluid.

(Third embodiment)

7A and B show a battery C5 according to a third embodiment of the present fuel cell. Construct a section view. The battery C5 is made of substantially the same material and structure as the battery C1 of the first embodiment described in FIGS. 1A and B. However, battery C5 differs from battery C1 in some of its construction. The following is a description centering on the differences.

The battery C5 converts chemical energy of hydrogen and oxygen into electric energy and uses it. Further, the battery C5 constitutes a reversible fuel cell structure in which a secondary battery reaction mechanism is incorporated in a fuel cell. The main constituent elements of the battery C5 include a negative electrode 54, a positive electrode 56, a negative electrode case 51, and an positive electrode case 52. The negative electrode 54 and the positive electrode 56 are opposed to each other via the separator 55. The negative electrode case 51 has a hydrogen storage chamber 58. The positive electrode case 52 has an oxygen storage chamber 59.

The main active material of the negative electrode 54 is a hydrogen storage alloy. The main active material of the positive electrode 56 is manganese dioxide. A separator 55 and an electrolytic solution 53 are interposed between the negative electrode 54 and the positive electrode 56. This electrolytic solution 53 is a KOH aqueous solution of an alkali-based aqueous solution generally used in a secondary battery.

The negative electrode 54 was produced as follows. That is, a negative electrode active material, a conductive filler, and a resin are added to a solvent to form a paste. The paste was applied onto a substrate to be formed into a plate shape and hardened. Similarly, the positive electrode 56 is produced as follows. That is, a positive electrode active material, a conductive filler, and a resin are added to a solvent to form a paste. The paste was applied onto a substrate to be formed into a plate shape and hardened.

The material of the conductive filler includes: carbon fiber, carbon fiber by nickel plating, carbon particles, carbon particles by nickel plating, organic fiber by nickel plating, Fibrous nickel, nickel particles, and nickel foil. These may be used alone or in combination. The resin can be used as a binder. The resin may be, for example, a thermoplastic resin having a softening temperature of up to 120 ° C, a resin having a curing temperature of from ordinary temperature to 120 ° C, a resin having an evaporation temperature of 120 ° C or lower and dissolved in a solvent, dissolved in water-soluble A resin in a solvent, a resin dissolved in a solvent soluble in an alcohol, or the like. As the substrate, a metal plate having conductivity like a nickel plate can be used. Further, instead of the substrate, a foamed nickel sheet may be used instead.

The side of the negative electrode 54 that contacts the hydrogen storage chamber 58 contains a large amount of hydrophobic material. Thereby, the hydrogen storage alloy of the anode 54 can be brought into contact with hydrogen gas without being wet. The side of the negative electrode 54 that contacts the separator 55 is hydrophilic. Thereby, the face prevents hydrogen from passing through the negative electrode 54. This surface is almost always kept wet by the electrolyte. Thereby, the ionic conductivity of the anode 54 is ensured. The side of the positive electrode 56 that contacts the oxygen storage chamber 59 contains a large amount of hydrophobic material. Thereby, the manganese dioxide of the positive electrode 56 can be brought into contact with oxygen without being wet. The side of the positive electrode 56 that contacts the separator 55 is hydrophilic. Thereby oxygen is prevented from passing through the positive electrode 56. This surface is almost always kept wet by the electrolyte. Thereby, the ionic conductivity of the positive electrode 56 is ensured.

The sides of the electrodes 54 and 56 on the sides of the gas storage chambers 58 and 59 may also be coated or sprayed with hydrophobic carbon or Teflon. Further, one side of the electrodes 54 and 56 on the side of the separator 55 may be coated or sprayed with modified nylon. Further, when an electrode is produced, vinyl acetate having a hydrophilic and hydrophobic property can be granulated and used as a binder. Also, it may contain granulated vinyl acetate. The binder is mixed with a hydrophilic material and applied to the separator 55 side of the electrodes 54 and 56. Further, a binder containing granulated vinyl acetate and a hydrophobic material may be applied to the sides of the gas storage chambers 58 and 59 of the electrodes 54 and 56.

The separator 55 has a structure in which protons (H ⁺ ) are penetrated but hydrogen gas and oxygen gas are not easily penetrated. Specifically, a material for forming the separator 55 may use a microporous film. The material of the microporous membrane includes polyolefin fibers such as polyethylene fibers and polypropylene fibers; polyphenylene sulfide fibers, polyvinyl fluoride fibers, and polyamide fibers. The electrolyte 53 is held in the separator 55. Further, in the present embodiment, both surfaces of the separator 55 are wetted by the electrolytic solution 53. Thereby, the partition 55 has a function as a water seal partition and has high gas impermeability. Further, it is possible to prevent hydrogen gas and oxygen from coming into contact with each other and reacting through the separator 55.

The negative electrode 54 and the positive electrode 56 have a structure in which the separator 55 is interposed. Further, the surface of the negative electrode 54 that is not in contact with the separator 55 is hermetically covered by the box-type negative electrode case 51. Therefore, the internal space formed by the negative electrode 54 and the negative electrode case 51 has a function as the hydrogen storage chamber 58. The hydrogen storage chamber 58 stores the hydrogen gas generated by the negative electrode 54 when an additional member such as a pressure increasing device or a communication path is not disposed between the negative electrode 54 and the negative electrode 54. Similarly, the side of the positive electrode 56 that is not in contact with the separator 55 is hermetically covered by the box type positive electrode case 52. The internal space formed by the positive electrode 56 and the positive electrode case 52 has a function as an oxygen storage chamber 59. The hydrogen storage chamber 58 is independent of the oxygen storage chamber 59, that is, a configuration in which the hydrogen storage chamber 58 and the oxygen storage chamber 59 do not communicate with each other. In the oxygen storage chamber 59, The same type of electrolyte as the electrolyte 53 held by the separator 55 is filled in the oxygen storage chamber 59. Further, the oxygen storage chamber 59 may also be filled with an electrolyte. In this case, oxygen may also be dissolved in the electrolyte. In this case, the electrodes 54 and 56 are flexible, and the deformation of the hydrogen storage chamber 58 affects the oxygen storage chamber 59. Thereby, if the pressure of the hydrogen storage chamber 58 is high due to hydrogen gas, the pressure of the electrolyte is high in a manner that the pressure of the hydrogen storage chamber 58 is almost uniform.

The negative electrode case 51 and the positive electrode case 52 may also be composed of a material having a high thermal conductivity and electrical conductivity. These may also be composed of a steel material such as aluminum. However, the steel is susceptible to oxidation, which tends to increase the contact resistance. Therefore, the aluminum contained in the negative electrode case 51 and the positive electrode case 52 can also be plated with nickel. Thereby, the contact resistance can be lowered. Each of the negative electrode case 51 and the positive electrode case 52 functions as a negative electrode terminal and a positive electrode terminal of the battery C5.

The amount of the electrolytic solution 53 filled in the oxygen storage chamber 59 is approximately two. It is more than 90% of the volume of the oxygen storage chamber 59. The other storage chamber 59 has a volume within the range of 20 to 40%. In the former case, oxygen generated by electrolysis is stored after being dissolved in the electrolyte. In the latter case, oxygen is stored in the oxygen storage chamber 59 in a gaseous state.

The operation of the battery C5 configured as described above is as follows. Battery C5 is charged as a secondary battery using current before it becomes fully charged. After the battery C5 reaches the fully charged state, if the current is continuously supplied, hydrogen gas is generated from the anode 54 and oxygen is generated from the cathode 56, respectively. The hydrogen and oxygen The gas systems are stored in the hydrogen storage chamber 58 and the oxygen storage chamber 59, respectively, without being in contact with each other.

When the battery C5 starts to discharge, a normal discharge reaction as a secondary battery occurs between the negative electrode 54 and the positive electrode 56. Thereby, a current flows through the load. At this time, the amount of electric power of the negative electrode 54 and the positive electrode 56 is reduced by discharge. The amount of electric power reduced by the negative electrode 54 and the positive electrode 56 is supplemented by charging by hydrogen gas and oxygen stored in the hydrogen storage chamber 58 and the oxygen storage chamber 59. Further, when the oxygen storage chamber 59 is filled with the electrolyte in which oxygen is dissolved, the positive electrode 56 is conveniently charged with oxygen in the electrolytic solution.

In the negative electrode 54, the protons released from the hydrogen storage alloy (MH) in a charged state are replenished with hydrogen. Thereby, the state of charge of the negative electrode is maintained. On the other hand, the positive electrode 56 is oxygen (hydrogen oxyhydroxide) (MnOOH) which is produced by reduction of manganese dioxide (MnO ₂ ) in a charged state, and is oxidized again by using oxygen. Thereby, the state of charge of the positive electrode is maintained. After the hydrogen and oxygen of the storage chambers 58 and 59 are consumed, the battery C5 is discharged in the same manner as the normal secondary battery.

That is, the battery C5 of the present embodiment can be electrically charged as a secondary battery, and the electric energy can be stored in the electrode. Further, the battery C5 stores electric energy supplied during overcharging in the storage chambers 58 and 59 in the form of gas (chemical energy). Moreover, the battery C5 can convert the stored chemical energy into electrical energy and use it again. Further, by increasing the pressure resistance and the sealing performance of the storage chambers 58, 59 and the battery C5 containing the same, the gas storage amount per unit volume can be increased. As a result, the energy density of the battery C5 can be made compared to the conventional secondary battery. A large (for example, a few times 10 times) increase. Further, in the storage chambers 58 and 59, hydrogen generated by the anode 54 or oxygen generated by the cathode 56 during overcharge is directly stored. Therefore, there is no need to add a booster or a communication path for the design gas. Therefore, the battery C5 has a simple structure and thus belongs to a battery that can be inexpensively manufactured and supplied.

When the battery C5 is discharged, electric energy is output by the electrode reaction of the secondary battery. Therefore, compared with the conventional fuel cell, the tracking of the load is greatly improved. As a result, the battery C5 can be used, for example, in a vehicle that requires a large load change with a high instantaneous output. At this time, the battery C5 does not require an additional secondary battery or a power storage device such as a capacitor, and can be used alone.

In the battery C5 of the present embodiment, the positive electrode 56 contains manganese dioxide as a positive electrode active material. Therefore, the positive electrode 56 has excellent durability and high life characteristics.

The outer peripheral surface 55a of the battery C5-based separator 55 shown in Fig. 7A is covered with an insulating portion 67 having the same thickness as the separator 55. The outer dimensions of the negative electrode case 51, the positive electrode case 52, and the insulating portion 67 are adjusted so that the outer peripheral surface 51a of the negative electrode case 51, the outer peripheral surface 52a of the positive electrode case 52, and the outer peripheral surface 67a of the insulating portion 67 are flush. The insulating portion 67 is made of a material having airtightness. Further, the separator 55 prevents the passage of gas by the action of the electrolytic solution. Therefore, even if oxygen or hydrogen reaches the outer peripheral surface 55a of the partition 55, the same does not leak to the outside of the battery C5.

A gradient 65 is provided in the opening portions of the negative electrode case 51 and the positive electrode case 52, respectively. 66. The widths of the gradients 65 and 66 are approximately equal to the thickness of the negative electrode 54 and the positive electrode 56. The negative electrode 54 and the positive electrode 56 are respectively provided with openings that cover the negative electrode case 51 and the positive electrode case 52.

Fig. 7B is a cross-sectional view showing the structure of a battery module B5 having a battery C5 shown in Fig. 7A. The main components of the battery module B5 include a positive electrode terminal 64, a negative electrode terminal 63, an insulating case 62 covering the battery C5, cover members 68 and 69, and a mounting bolt 70. The cover members 68 and 69 are members for locking and fixing the battery C5 in the axial direction of the insulating case 62. These main constituent elements are covered by a metal protective casing 61.

In the battery module B5, the plurality of batteries C5 are contained in the insulating case 62 in the axial direction of the insulating case 62. The outer peripheral surfaces 51a and 52a of the battery C5 are along the inner peripheral surface 62a of the insulating case 62 containing an insulating material. The side surface 51b of the negative electrode case 51 adjacent to the battery C5 and the side surface 52b of the positive electrode case 52 are in contact with each other. The negative terminal 63 and the positive terminal 64 of the battery module B5 are provided at the two ends of the plurality of batteries C5. The cover member 68 or 69 is fitted to the inner peripheral surface 61a of the protective case 61 in the outer layers of the negative electrode terminal 63 and the positive electrode terminal 64. Screw holes are formed in the cover members 68 and 69. Further, a bolt hole 70a is formed in the protective case 61. The protective case 61 and the cover members 68 and 69 are respectively fixed by the mounting bolts 70. Accordingly, the battery C5 and the positive and negative terminals 63 and 64 are housed inside the protective case 61.

An example of a battery pack configuration including a plurality of interconnected battery modules B5 is shown in Figs. 8A and B. In the battery pack S5, a battery module B5 is attached to one end of the metal sling 474, and the other end is attached to the iron tower 478. Thereby, the plurality of battery modules B5 can be suspended from the iron tower 478. The negative electrode terminal 63 and the positive electrode terminal 64 of the adjacent battery module B5 are connected by a bus bar 476 that can be opened and closed, and are connected by a bus bar 477.

The battery pack S5 as described above can also be applied to an electric power system. When the battery pack S5 is applied to a power system, the voltage is at a high voltage and a withstand voltage configuration is employed. Therefore, in this case, in order to ensure the withstand voltage performance to the ground, the circuit breaker 476 is also suspended by the insulated sling 474.

(Fourth embodiment)

9A and 7B are cross-sectional views showing the structure of a reversible fuel cell C10 (hereinafter simply referred to as "battery C10") according to a fourth embodiment of the fuel cell. Fig. 9A is a partial cross-sectional view showing the longitudinal direction. Fig. 9B is a cross-sectional view taken along line A-A of Fig. 9A. The battery C10 has a configuration covered by the outer casing 100. Inside the casing 100, a plurality of positive electrodes 110 formed in a tubular shape are accommodated in the axial direction of the casing 100 (in the X direction of FIG. 9A). Further, the negative electrode 120 is placed around the positive electrode 110 via the separator 130. Further, the negative electrode, the positive electrode, the separator, and the electrolytic solution of the essential elements of the battery C10 of the present embodiment may be the same as the battery C1 of the first embodiment except for the case described below. And structure.

The outer casing 100 has a cylindrical body portion 101 and a bulging portion 102. The bulging portion 102 is disposed at the two end openings of the body portion 101. The bulging portion 102 is facing far The outer layer of the opening is protruded from the direction of the opening and covers the opening. A packing 103 for holding the inside of the casing 100 in a liquid-tight manner is disposed between the body portion 101 and the bulging portion 102. The body portion 101 and the bulging portion 102 may be made of copper, preferably high tensile steel. Accordingly, the body portion 101 has a cylindrical shape, and the bulging portion 102 bulges toward the outer layer. Thereby, the outer casing 100 has a structure capable of withstanding such a high pressure even if the inside is ultrahigh pressure.

Oxygen storage chambers 136a and 136b are provided inside the outer casing 100 and in the inner space of the bulging portion 102. Further, the left and right oxygen storage chambers 136a and 136b are respectively distinguished by the partition plate 135. The oxygen storage chambers 136a and 136b are connectable to an external machine via flanges 211 and 212 mounted on the outer casing 100. The positive electrode 110, the negative electrode 120, the separator 130, and the current collector 134 are disposed in the space between the left and right oxygen storage chambers 136a and 136b and surrounded by the partition plate 135 and the body portion 101.

Fig. 10 is a partial cross-sectional view for explaining the electrode structure of the battery C10. The current collector 134 is a copper tube that is subjected to nickel plating and is perforated. The positive electrode 110 is formed by applying a paste-like composite material containing manganese dioxide around the current collector 134. The positive electrode 110 may also directly coat the composite material on the current collector 134. Further, the positive electrode sheet formed by applying the composite material to the foamed nickel is wound around the current collector 134 to form the positive electrode 110. A separator 130 is interposed between the positive electrode 110 and the negative electrode 120 containing the oxygen storage alloy. The separator 130 prevents the positive electrode 110 from coming into contact with the negative electrode 120. The oxygen storage chambers 136a and 136b located on the left and right sides of the outer casing 100 are connected to each other via the current collector 134 through. The electrolyte 137 in the oxygen storage chambers 136a and 136b can flow in the direction indicated by the arrow symbol in FIG.

Between the left and right partition plates 135 and the outer space of the separator 130, a hydrogen storage alloy having an average particle diameter of 20 μm is filled. In this configuration, the void ratio is about 35%. The size of the void ratio varies depending on the filling mode of the hydrogen storage alloy. The void ratio can also be greater than 35%. When the average particle diameter is 5 to 50 μm, the void ratio is about 30 to 60%. Such a void has the function as a hydrogen storage chamber 138. Further, the above average particle diameter is the same as that of the other embodiment, and the numerical value expressed by the sphere equivalent diameter measured by the light scattering method of JIS Z 8910 is used.

As shown by the broken line in FIG. 9A, the hydrogen storage chamber 138 of the battery C10 is connected to the hydrogen storage source 121 and the storage passage 122. The negative electrode 120 can be charged by using hydrogen gas supplied from the outside.

The current collector 134 of the positive electrode penetrates through the copper-made partition plate 135 to which nickel plating is applied. The two ends of the current collector 134 are supported by the partition plate 135. Therefore, the bulging portion 102 and the positive electrode 110 are electrically coupled via the partition plate 135. Thereby, the bulging portion 102 has a function as a positive electrode terminal of the battery C10. Further, the body 101 directly contacting the negative electrode 120 has a function as a negative electrode terminal. The filler 103 is not only waterproof but also insulating. Thereby, the filler 103 can prevent the positive electrode 110 from being short-circuited with the negative electrode 120.

The operation of the battery C10 configured as described above is as follows. The battery C10 is supplied with an electrolyte 137 having dissolved oxygen from one of the flanges 211 (the right side of FIG. 9A). The electrolytic solution 137 is an electrolytic solution in which oxygen is dissolved in a high concentration, and may be referred to as a "high-concentration oxygen-dissolved electrolyte." The electrolyte 137 having a high concentration of dissolved oxygen flows inside the tubular current collector 134, and is in contact with the positive electrode 110 through a punch hole provided in the current collector 134. Thereby, oxygen dissolved in the electrolytic solution is used, and oxygen (hydrogen oxyhydroxide) in the positive electrode is oxidized to become manganese dioxide. As a result, the positive electrode is charged. Thereby, the oxygen dissolved in the electrolytic solution is consumed and H ₂ O is generated, resulting in a decrease in the oxygen concentration in the electrolytic solution. The electrolyte 137 (low-concentration oxygen-dissolved electrolyte) having a lowered oxygen concentration is discharged to the oxygen storage chamber 136b on the left side, and finally discharged from the flange 212 to the outside of the system. On the other hand, the anode 120 is charged by hydrogen gas supplied from an external hydrogen storage source 121.

When an electric load is connected between the bulging portion 102 having the positive electrode terminal function and the body portion 101 having the negative electrode terminal function, the battery C10 is discharged by using an electric wiring (not shown). Thereby, current is supplied to the electrical load. The load current can be taken out from the two-end bulging portion 102. Therefore, the current flowing in the current collector 134 is divided into two parts, and the Joule heat loss is about 1/4.

Next, a case where the battery C10 is charged by performing the chemical energy conversion of electric energy will be described. The battery C10 can store hydrogen generated by overcharging in the hydrogen storage chamber 138. Further, the battery C10 can store oxygen in the oxygen storage chambers 136a and 136b in a state of being dissolved in the electrolytic solution. That is, the battery C10 of the present embodiment can convert electric energy into chemical energy and store it. Further, the battery C10 can appropriately convert chemical energy into electric energy and output it. Therefore, the battery C10 is different from the conventional secondary battery, and does not cause the amount of active substances. As a result, the storage capacity is limited.

Similarly to the battery C1 of the first embodiment, the battery C10 of the present embodiment is discharged by a battery reaction during discharge, and is charged by hydrogen gas and oxygen. At the time of such charge and discharge, manganese dioxide has a function as a reaction catalyst for the positive electrode. On the other hand, the hydrogen storage alloy has a function as a reaction catalyst for the negative electrode.

The power generation program using the battery C10 of the fourth embodiment is as shown in FIG. The battery C10 is connected to the pipe 220 via the flange 212. The electrolytic solution 137 which is deteriorated by the discharge of the battery C10 is sent to the first chamber 231 of the salt concentration adjusting device 230 via the pipe 220. A reverse osmosis membrane 233 is attached to the salt concentration adjusting device 230. The salt concentration adjusting device 230 is divided into the first chamber 231 and the second chamber 232 by the reverse osmosis membrane 233. The reverse osmosis membrane 233 has a function of selectively allowing moisture in the electrolyte 137 to penetrate. The penetrated moisture is discharged and stored in the second chamber 232, and is discharged from the drain port 234 out of the system. The electrolyte solution 137 of the salt concentration adjusting device 230 is sent to the oxygen concentration adjusting device 250 via the pipe 221 . The bottom of the oxygen concentration adjusting device 250 is connected to the oxygen storage source 251 and the storage passage 252. The dissolved oxygen concentration in the electrolyte is increased by the contact of oxygen with the electrolyte 137. Further, a storage passage 253 is separately provided in the oxygen concentration adjusting device 250, and oxygen generated by overcharging can be stored in the oxygen storage source 251. Thereby, the oxygen-dissolved electrolyte stored in the oxygen storage source 251 and stored at a high concentration can be returned to the oxygen concentration adjusting device 250. The electrolyte can be utilized for oxygen concentration reduction due to discharge whole.

The electrolyte 137 discharged from the oxygen concentration adjusting device 250 rises in temperature due to the use of the battery. The electrolyte 137 is cooled by the cooler 260 to a predetermined temperature. Then, the electrolytic solution 137 is boosted by the pump 270 and returned to the battery C10 via the pipe 222.

(Fifth Embodiment)

Fig. 12 is a schematic cross-sectional view showing the reversible fuel cell (hereinafter referred to as "battery C30") of the fifth embodiment of the fuel cell in the axial direction. Further, the negative electrode, the positive electrode, the separator, and the electrolytic solution of the essential elements of the battery C30 of the present embodiment may have the same substance/composition and composition as the battery C1 of the first embodiment described above, unless otherwise specified. structure. As shown in FIG. 12, the main components of the battery C30 include an exterior body 300, a current collector 310, and an electrode housed inside the exterior body. The exterior body 300 includes a circular tube 301 and a disk-shaped cover member 302. The cover member 302 is provided at an opening of both ends of the circular tube 301. The material of the round pipe 301 and the cover member 302 is a nickel plating of iron.

The material of the current collector 310 may be a conductive material in which nickel is plated on the rod iron. Both ends of the current collector 310 penetrate through holes provided in the center of the cover member 302. A nut 311 is screwed to both ends of the current collector 310. The current collector 310 is fixed to the cover member 302 by the nut 311. The nut 311 is in the shape of a bag. Thereby, the electrolyte inside the battery can be prevented from leaking to the outside. An insulating filler 312 is provided between the nut 311 and the cover member 302. Thereby preventing The current collector 310 is in electrical contact with the cover member 302. A filler 303 for sealing the inside of the battery is provided between the circular tube 301 and the lid member 302. The filler 303 is insulating. Therefore, the round pipe 301 can be prevented from being in electrical contact with the cover member 302. The current collector 310 is prevented from being corroded by the electrolyte by performing nickel plating.

The positive electrode 320 and the negative electrode 330 are laminated in the axial direction of the circular tube 301 (in the X direction of FIG. 12) via the separator 340. The positive electrode 320 and the negative electrode 330 are housed inside the exterior body 300. The separator holds the electrolyte. The separator 340 is capable of insulating the positive and negative electrodes and allowing ions to penetrate. The positive electrode 320 contains manganese dioxide filled in the foamed nickel. The negative electrode 330 contains a hydrogen storage alloy filled in the foamed nickel. Thereby, hydrogen gas can penetrate the negative electrode. The positive electrode 320 has an outer shape slightly larger than the inner diameter of the circular tube 301, and has a substantially disk shape. The positive electrode 320 cuts off a portion of the circumference that is 180 degrees apart from each other. The outer circumference of the positive electrode 320 abuts on the inner surface of the circular tube 301 except for the cut portion (refer to FIG. 13A). A notch 321 is formed between the cut portion of the positive electrode 320 and the circular tube 301. Inside the positive electrode 320, a PP filler 351 made of polypropylene having the same thickness as the positive electrode 320 is interposed between the positive electrode 320 and the current collector 310. The PP filler 351 insulates the positive electrode 320 from the current collector 310.

Fig. 13A shows a B-B cross section of the battery C30, and Fig. 13B shows a C-C cross section of the battery C30.

The negative electrode 330 has a disk shape. The negative electrode 330 has a cross-sectional shape that is open toward the inner side in the radial direction of the inner circumference. The current collector 310 is connected to the negative electrode 330 The hole in the center. The diameter of the through hole is smaller than the outer diameter of the current collector 310. Therefore, the inner diameter portion of the negative electrode 330 and the outer diameter portion of the current collector 310 abut each other. The hydrogen storage chamber 380 is formed by a space surrounded by the negative electrode 330 and the current collector 310. A separator 340 is interposed between the positive electrode 320 and the negative electrode 330. The outer peripheral surface of the negative electrode 330 in the radial direction is covered with the PP filler 352. The outer diameter of the PP filler 351 is smaller than the inner diameter of the circular tube 301. Therefore, a space (gap) 331 is formed between the PP filler 351 and the round pipe 301 (refer to FIG. 13B). Further, portions of the separator 340 and the hydrogen storage chamber 380 which are not facing the negative electrode 330 are covered with the PP filler 353.

A hydrogen supply port 373 is provided in the cover member 302. A hole 351a or 353a is provided in the positive electrode 320 and the PP filler 353. The holes 351a and 353a form a hydrogen passage 370 that communicates with the hydrogen storage chamber 380. The hydrogen supply port 373 is connected to the high-pressure hydrogen storage source 371 via the storage passage 372 as shown in FIG. High pressure hydrogen gas may be supplied to each hydrogen storage chamber 380 via the hydrogen passages 370.

In the lid member 302, an electrolyte inlet 365 and an electrolyte outlet 366 belonging to an electrolyte inlet and outlet in which oxygen is dissolved are provided at positions spaced apart by 180 degrees. The electrolyte inlets and outlets 365 and 366 are in communication with the notch 321 . Further, the notch 321 is in communication with the gap 331 between the PP filler 351 and the circular tube 301. Therefore, the electrolyte flowing in from the electrolyte inlet 365 circulates inside the battery C30 along the inner surface of the circular tube 301, and then flows out from the electrolyte outlet 366. As shown in FIG. 14, the electrolyte supply source 361 in which oxygen is dissolved at a high concentration is connected to the electrolyte inlet 365 via the supply passage 362. On the other hand, the electrolyte outlet The 366 is connected to the electrolytic solution adjustment chamber 363 via the discharge passage 364. The electrolytic solution adjusting chamber 363 is an electrolytic solution in which the oxygen concentration has been lowered.

Fig. 15 is a system diagram showing a battery C30 of a fifth embodiment including an electrolytic solution processing program. The electrolyte flowing out of the electrolyte outlet 366 of the battery C30 is sent to the cooler 326 via the pipe 364a. The electrolyte whose temperature rises due to the use of the battery is cooled by the cooler 326 and is at a certain temperature. Then, the electrolytic solution is pressurized by the pump 327, and sent to the electrolytic solution adjusting chamber 363 via the pipe 364b. Here, a part of the moisture is selectively removed from the electrolyte. Further, the electrolytic solution receives oxygen supply from the electrolytic solution supply source 361. Thereby, the oxygen concentration of the electrolytic solution is adjusted. Then, the electrolytic solution is returned to the battery C30 via the pipe 364c.

Next, the action of the battery C30 will be described. As described above, the hydrogen supplied from the hydrogen supply port 373 is guided to the hydrogen storage chamber 380, and the negative electrode 330 is charged. On the other hand, the electrolytic solution containing the high-concentration oxygen supplied from the electrolyte inlet 365 is supplied from the notch 321 to the positive electrode 320, and the positive electrode 320 is charged. H ₂ O is generated by charging the positive electrode 320. The H ₂ O is mixed in the electrolyte and discharged from the electrolyte outlet 366 to the outside of the battery C30.

Similarly to the charge and discharge of the battery C1 of the first embodiment, the battery C30 of the present embodiment is discharged by the function of the secondary battery during discharge, and is chemically charged by hydrogen gas and oxygen. That is, the battery C30 is discharged as a secondary battery while being charged by a gas. Also, at this time, dioxide Manganese has a function as a reaction catalyst for the positive electrode. On the other hand, the hydrogen storage alloy has a function as a reaction catalyst for the negative electrode. Moreover, the battery C30 can also be charged by the current. Hydrogen generated by overcharging can be stored in the hydrogen storage source 371 through the hydrogen passage 370 and the storage passage 372. Further, oxygen can be stored in a state of being dissolved in the electrolytic solution. In other words, the battery C30 of the present embodiment can convert electrical energy into chemical energy and store it. Therefore, unlike the conventional secondary battery, the storage capacity of the battery C30 is not limited by the amount of the active material.

In addition, hydrogen gas is supplied to the cathode of the battery C30. Therefore, even if it is discharged, the negative electrode is not oxidized. Therefore, the life of the negative electrode is not deteriorated by the expansion and contraction of the volume. The positive electrode is oxidized by oxygen dissolved in the electrolyte, and is in a charged state. Therefore, the positive electrode does not deteriorate due to discharge.

<Energy efficiency of related reversible fuel cells>

The relationship between the pressure and energy efficiency of the fuel cell is as follows. When the electric power is taken out by the chemical reaction, if the energy obtained from the chemical substance used is ΔH, the extracted electric quantity is ΔG, and the generated heat is T ΔS, ΔH=ΔG+T is established. ΔS relationship. △H is also called reaction heat or calorific value. △H is a negative value when a heat reaction such as a combustion reaction occurs. △G is called free energy. The ΔG system can be used as the energy extracted by the work, and is generally referred to as the energy of the effective energy (exergy).

TΔS is the heat generated by the reaction, expressed as the product of the change in entropy and temperature. Further, the ability of ΔG/ΔH to extract effective energy is called "energy efficiency". Storage efficiency at the time of charge and discharge of a nickel-hydrogen secondary battery (ie, discharge power amount to charge) The amount of electricity can be increased to 90~99%. On the other hand, the energy efficiency ΔG/ΔH when hydrogen is electrolyzed to generate hydrogen and oxygen is 83% at normal temperature. Therefore, the storage efficiency is difficult to exceed 83%.

One of the problems to be solved by the present fuel cell is to provide that the energy efficiency ΔG/ΔH is as close as possible to 1, and the ratio of heat (T ΔS) in ΔH is reduced as much as possible. A multi-scale device that converts ΔH into electrical energy (ΔG). In order to increase the power generation efficiency η (= ΔG / ΔH), it is sufficient to increase ΔG by decreasing T ΔS. ΔG is a value determined according to temperature and pressure. By increasing this value, the ΔG/ΔH value can be increased.

When a fuel cell is used to convert hydrogen into electric energy, 17% of the chemical energy ΔH obtained from hydrogen becomes heat (TΔS). In order to reduce the amount of heat generated, it is only necessary to feed high-pressure hydrogen into the fuel cell and perform power generation. Thereby, heat generation can be suppressed, and power generation efficiency can be improved. When hydrogen is produced from electric energy using a fuel cell, heat (T?S) equivalent to 17% of ΔH obtained from hydrogen is used. At this time, if hydrogen and oxygen are generated by normal pressure, work is performed on the atmosphere, resulting in loss. Here, the electrolysis system is carried out in a sealed space. Thereby, the TΔS used can be reduced to less than 17% of ΔH. Figure 23 shows the results of thermodynamic calculations. The larger the pressure shown in the figure, the smaller TΔS becomes.

The fuel cell is stored and utilized in a high pressure state without returning to atmospheric pressure by oxygen and hydrogen obtained by electrolysis of the electrolyte. Thereby, a higher power generation efficiency η can be achieved.

Furthermore, the potential V is proportional to the free energy ΔG system. That is, set V = △ G / FM Relationship (where F: Faraday constant, M: molecular weight). That is, the higher the potential V, the larger the ΔG and the higher the power generation efficiency η. As shown in Fig. 22, the present fuel cell system is maintained at a high potential almost always, and maintains high power generation efficiency η.

The terminal voltage of the fuel cell on average one open circuit is in the range of 0.8 to 1.48V. When the positive electrode discharge was performed, the composition thereof was almost changed to oxygen (hydrogen oxyhydroxide), and when the electrolyte pressure was 0.1 MPa, the terminal voltage was 0.8 V. When the positive electrode is charged, the composition thereof becomes almost manganese dioxide, and when the electrolyte pressure becomes a high voltage exceeding 10 MPa, the terminal voltage becomes 1.48V.

(Sixth embodiment)

Fig. 16 is a schematic cross-sectional view showing the cylindrical laminated type reversible fuel cell of the sixth embodiment of the present invention. The main constituent elements of the cylindrical laminated fuel cell battery 71 (hereinafter referred to as "stacked battery") shown in FIG. 16 include an exterior body 75, a current collector 77, and an electrode body housed inside the exterior body 75. 73. The exterior body 75 is provided with a bottomed cylindrical can 72 and a disk-shaped cover member 76. The cover member 76 is attached to the opening 72c of the cylindrical can 72. The cylindrical can 72 and the lid member 76 may be formed of iron or may be other metals. The outer diameter of the lid member 76 is larger than the inner diameter of the opening 72c of the cylindrical can 72, and the lid member 76 is housed in the electrode body 73, and then twisted and fitted to the cylindrical can opening 72c.

The electrode body 73 is provided with a positive electrode 73a containing a positive electrode active material, a negative electrode 73b containing a negative electrode active material, and a separator 73c. The separator 73c is interposed between the positive electrode 73a and the negative electrode 73b, and allows ion penetration but does not allow electrons to pass through. through. The positive electrode 73a, the negative electrode 73b, and the separator 73c are laminated in the axial direction of the cylindrical can 72 (in the X direction of FIG. 16), and are housed inside the exterior body 75. Further, an electrolytic solution (not shown) is held in the separator 73c. Each of the positive electrode 73a, the negative electrode 73b, and the separator 73c has a disk shape that is bored at the center. The outer diameter 73ab of the positive electrode 73a is smaller than the inner diameter 72a of the cylindrical can 72. Therefore, the positive electrode 73a does not come into contact with the cylindrical can 72. On the other hand, the outer diameter 73bb of the negative electrode 73b is larger than the inner diameter 72a of the cylindrical can 72. Therefore, the outer circumference 73bb of the negative electrode comes into contact with the inner surface 72a of the cylindrical can 72. Thereby, the negative electrode 73b is electrically coupled to the cylindrical can 72. The outer diameter 73bb of the negative electrode 73b may be larger than the inner diameter 72a of the cylindrical can 72 by 100 μm.

The material of the current collector 77 includes iron which has been subjected to nickel plating, and is a conductive material. The nickel plating is used to prevent the collector 77 from being corroded by the electrolyte contained in the separator 73c. The current collector 77 is provided with a rod-shaped shaft portion 77a and a retaining portion 77b disposed at one end of the shaft portion 77a. The shaft portion 77a of the current collector 77 is inserted into the center of the electrode body 73 including the positive electrode 73a, the negative electrode 73b, and the separator 73c in the axial direction of the outer casing 75 (the X direction in Fig. 16). The diameter of the hole 73aa provided in the center of the positive electrode 73a is smaller than the outer diameter of the shaft portion 77a. Therefore, the positive electrode 73a contacts the shaft portion 77a and is electrically coupled to the shaft portion 77a. On the other hand, the diameter of the hole 73ba provided in the center of the negative electrode 73b is larger than the outer diameter of the shaft portion 77a. Therefore, the negative electrode 73b does not contact the shaft portion 77a, and thus is electrically insulated from the shaft portion 77a.

The electrode body 73 is arranged in an overlapping state in the retaining portion 77b of the current collector. The retaining portion 77b prevents the electrode body 73 from coming off the end portion of the current collector 77. The shape of the retaining portion 77b is a disk shape. The retaining portion 77b is disposed on the cylindrical tank bottom 72b. An insulating plate 74 is disposed between the cylindrical can bottom portion 72b and the retaining portion 77b. Thereby, the current collector 77 is prevented from coming into contact with the cylindrical can 72 to cause an electrical short circuit. The end portion of the shaft portion 77a on the opposite side of the retaining portion 77b is supported by a bearing 78 provided at the center of the cover member 76. In order to prevent electrical short-circuiting between the cover member 76 and the shaft portion 77a, the bearing 78 has insulation properties. The shaft portion 77 penetrating the cover member 76 has a function as a positive electrode terminal 77d. The cylindrical can 72 has a function as a negative electrode terminal.

Next, the action and effect (especially, the cooling effect) of the sixth embodiment will be described.

<related cooling structure>

The negative electrode 73b is strongly pressed against the cylindrical can 72, and these are in close contact with each other. The heat generated by the negative electrode 73b is directly conducted to the cylindrical can 72 with less resistance. Further, the heat generated by the positive electrode 73a is conducted to the negative electrode 73b via the separator 73c. Although the separator 73c is not easily thermally conductive, it is thin (10 μm in the present embodiment) and is only one sheet. Therefore, the partition plate 73c does not excessively hinder heat conduction. As described above, the heat generated by the electrodes 73a and 73b is conducted to the cylindrical can 72 with a small thermal gradient. Thereby, the temperature rise inside the laminated battery can be suppressed.

As described above, the laminated battery can reduce the temperature rise of the center portion. Therefore, it is not necessary to provide a tube or the like for the refrigerant that does not flow through the inside of the battery. Moreover, the exterior body 75 is exposed to the outside. Therefore, the laminated battery can effectively suppress the temperature rise as compared with the conventional wound type battery. Here, the laminated battery of the embodiment is The difference in temperature rise between the conventional type and the wound type battery is shown by a calculation example.

The total heat transfer coefficient (U ₁ ) of the wound battery is shown as 1. On the other hand, the total heat transfer coefficient (U ₂ ) of the laminated battery of the present invention is as shown in the number 2.

Where n: number of windings; k, k ₊ , k _- , k _s : thermal conductivity; t, t ₊ , t _- , t _s : thickness; h ₀ , h ₁ : boundary film

Where k, k ^* : thermal conductivity; t, t ^* : thickness; h ₀ , h ₁ : interface film here 18650 battery as an example to try to calculate. The items of the wound battery are: t = 0.5 mm, t ₊ = t _- = t _s = 10 μm, k = k ₊ = k _- = 40 Wm ^-2 deg ^-1 , h ₀ = 100 Wm ^-2 deg ^-1 , h ₁ = ₁ Wm ^-2 deg ^-1 , k _s =1 Wm ^-2 deg ^-1 , n = 9 / 0.03 = 300.

If the equivalent value is substituted into the number 1, U ₁ = 0.0011 Wm ^-2 deg ^-1 can be obtained.

On the other hand, the laminated battery of the present embodiment is h ₀ = 100 Wm ^{- 2} deg ^-1 , t = 0.5 mm, k = 40 Wm ^{- 2} deg ^{- 1} h ₁ = 10000 Wm ^{- 2} deg ^-1 , t ^* = 0.009m, k ^* = 40Wm ^-2 deg ^-1 .

If the value is substituted into the number 2, U ₂ = 100 Wm ^-2 deg ^-1 can be obtained.

If the two are compared, the laminated battery of the present invention having a cooling structure can be said to have an excellent heat conduction of nearly 100,000 times as compared with the conventional wound type battery.

(Variation of the sixth embodiment)

Fig. 17 is a schematic cross-sectional view showing a tubular layer type reversible fuel cell (hereinafter referred to as "tube battery") according to a modification of the sixth embodiment of the fuel cell in the axial direction. The main components of the tube battery 81 shown in FIG. 17 include an exterior body 85, a current collector 87, and an electrode body 83 housed inside the exterior body 85. The outer casing 85 is provided with a circular tube 82 and a disk-shaped cover member 86. The cover member 86 is attached to the opening 82b at both ends of the circular tube 82. The round pipe 82 and the cover member 86 may be made of iron or may be other metals. The outer diameter of the cover member 86 is slightly larger than the inner diameter of the opening 82b of the circular tube 82. The cover member 86 is twisted and fitted to the circular tube opening portion 82b after being housed in the electrode body 83.

The electrode body 83 includes a positive electrode 83a containing a positive electrode active material, a negative electrode 83b containing a negative electrode active material, and a separator 83c. The separator 83c is interposed between the positive electrode 83a and the negative electrode 83b. The positive electrode 83a, the negative electrode 83b, and the separator 83c are laminated in the axial direction of the circular tube 82 (X direction in FIG. 17), and are housed inside the exterior body 85. Further, an electrolytic solution (not shown) is held in the separator 83c. The positive electrode 83a, the negative electrode 83b, and the separator 83c are each in the shape of a disk having a perforated hole at the center. The outer diameter 83bb of the negative electrode 83b is smaller than the inner diameter 82a of the circular tube 82. Therefore, the negative electrode 83b does not contact the round pipe 82. On the other hand, the outer diameter 83ab of the positive electrode 83a is larger than the inner diameter 82a of the circular tube 82. Therefore, the positive electrode 83a is in contact with the circle The inner surface 82a of the tube 82 electrically connects the positive electrode 83a to the circular tube 82. The outer diameter 83ab of the positive electrode 83a may be larger than the inner diameter 82a of the circular tube 82 by 100 μm.

The material of the current collector 87 includes a rod-shaped iron to which nickel plating is applied, and is a conductive material. The current collector 87 is provided with a shaft portion 87a at the center portion and an end portion 87b at the both end portions. The shaft portion 87a of the current collector 87 is inserted into the center of the electrode body 83 including the positive electrode 83a, the negative electrode 83b, and the separator 83c in the axial direction of the exterior body 85 (X direction in FIG. 17). The diameter of the hole 83ba provided in the negative electrode 83b is smaller than the outer diameter of the shaft portion 87a. Therefore, the negative electrode 83b is in contact with the shaft portion 87a and is electrically coupled to the shaft portion 87a. On the other hand, the diameter of the hole 83aa provided in the positive electrode 83a is larger than the outer diameter of the shaft portion 87a. Therefore, the positive electrode 83a does not contact the shaft portion 87a, and thus is electrically insulated from the shaft portion 87a.

The electrode body 83 is attached to the shaft portion 87a of the current collector, and is sequentially stacked in a string burned state. The two end portions 87b of the current collector 87 are supported by a bearing 88 provided at the center of the cover member 86. The bearing 88 is insulating. Thereby, the cover member 86 and the current collector 87 are prevented from being electrically short-circuited. The current collector end portion 87b of the through cover member 86 has a function as the negative electrode terminal 87d. The circular tube 82 has a function as a positive electrode terminal.

(Seventh embodiment)

Fig. 18 is a schematic cross-sectional view showing a cylindrical laminated type reversible fuel cell (hereinafter referred to as "doughnut battery") according to a seventh embodiment of the present invention, in the axial direction. The main constituent elements of the donut battery 41 shown in Fig. 18 include an exterior body 45, a current collector 47, and electrodes housed inside the exterior body. Body 43. The exterior body 45 is provided with an outer covering body 42 having a bottomed cylinder and a cover member 46. The cover member 46 is attached to the opening 42c of the outer covering 42. The outer wrap 42 and the cover member 46 may include iron that has been subjected to nickel plating. The outer covering body 42 and the lid member 46 are respectively provided with a cylindrical side portion 42a or 46a and a bulging portion 42b or 46b which is bulged toward the bottom in a dome shape. Additionally, the cover member 46 is shorter than the outer cover 42. The outer diameter of the cover member 46 is smaller than the inner diameter of the opening portion 42c of the outer package 42. The cover member 46 is joined to the outer package 42 via an insulating sealing member 48. The opening of the cover member 46 faces the opening of the outer package 42. The insulating sealing member 48 electrically insulates the outer covering 42 from the cover member 46. Moreover, the insulating sealing member 48 forms a sealed space inside the exterior body 45 by sealing the joint portion. The insulating sealing member 48 is a material having both insulation and sealing properties, such as asphalt pitch.

The electrode body 43 includes a positive electrode 43a containing a positive electrode active material, a negative electrode 43b containing a negative electrode active material, and a separator 43c. The separator 43c is interposed between the positive electrode 43a and the negative electrode 43b. The positive electrode 43 a, the negative electrode 43 b , and the separator 43 c are laminated in the axial direction of the outer covering 42 (the X direction in FIG. 18 ), and are housed inside the outer casing 45 . Further, an electrolytic solution (not shown) is held in the separator 43c. The positive electrode 43a, the negative electrode 43b, and the separator 43c are each in the shape of a disk having a hole in the center. The outer diameter 43aa of the positive electrode 43a is smaller than the inner diameter 42aa of the outer envelope 42. Therefore, the positive electrode 43a is not in contact with the outer cladding 42. On the other hand, the outer diameter 43ba of the negative electrode 43b is larger than the inner diameter 42aa of the outer covering 42. Therefore, the anode 43b contacts the inner surface 42a of the outer package 42. Thereby, the negative electrode 43b is electrically coupled In the outer body 42. The outer diameter 43ba of the negative electrode 43b may also be 100 μm larger than the inner diameter 42aa of the outer cladding 42.

The material of the current collector 47 includes iron which is subjected to nickel plating, and is a conductive material. The current collector 47 is provided with a rod-shaped shaft portion 47a and a retaining portion 47b attached to one end of the shaft portion 47a. The shaft portion 47a of the current collector 47 is inserted into the center of the electrode body 43 including the positive electrode 43a, the negative electrode 43b, and the separator 43c in the axial direction of the outer casing 45 (the X direction in Fig. 18). The diameter of the hole 43ab provided in the center of the positive electrode 43a is smaller than the outer diameter of the shaft portion 47a. Therefore, the positive electrode 43a is in contact with the shaft portion 47a and is electrically coupled to the shaft portion 47a. On the other hand, the diameter of the hole 43bb provided in the center of the negative electrode 43b is larger than the outer diameter of the shaft portion 47a. Therefore, the negative electrode 43b does not contact the shaft portion 47a and is electrically insulated from the shaft portion 47a.

The electrode body 43 is arranged in this order on the retaining portion 47b of the current collector. The retaining portion 47b prevents the electrode body 43 from falling off from the end of the current collector 47. An insulating pressing plate 44a is disposed at both ends of the electrode body 43 that is overlapped. The pressing plate 44a prevents the electrode body 43 from being damaged when the electrode body 43 is laminated and pressed. The material of the pressing plate 44a is suitable as a material for the insulating material and the structural material. The material includes, for example, polypropylene. The shape of the retaining portion 47b is a disk shape. The retaining portion 47b does not abut against the bulging portion 42b located at the bottom of the outer covering body. Therefore, the retaining portion 47b is electrically insulated from the outer covering 42a. The shaft portion 47a penetrates the hole 46d provided at the center of the cover member 46 at the opposite end portion 47c of the retaining portion 47b, and protrudes from the outer layer (rightward direction in the drawing) of the cover member 46. The shaft portion 47c penetrating the cover member 46 has a function as a positive electrode terminal. The outer package 42 has a function as a negative terminal. A hydrogen storage chamber 49 is provided in the internal space of the bulging portions 42b and 46b. That is, the hydrogen storage chamber 49 is disposed in the outer space of the exterior body surrounded by the inner faces 42ba and 46ba of the bulging portion and the electrode body 43.

(industrial availability)

This fuel cell system is quite suitable for industrial and residential power storage devices.

1‧‧‧Negative box

1'‧‧‧Negative box

2‧‧‧ positive box

2'‧‧‧ positive box

3‧‧‧ electrolyte

3'‧‧‧ electrolyte

4‧‧‧negative

4'‧‧‧Negative

5‧‧‧Baffle

5'‧‧‧ separated by a partition

6‧‧‧ positive

6'‧‧‧ positive

7‧‧‧Oxygen storage room

7'‧‧‧Oxygen storage room

8‧‧‧ Hydrogen storage room

8'‧‧‧ Hydrogen storage room

9‧‧‧ wall members

10‧‧‧Outer body

10a‧‧‧Cylinder

10b‧‧‧ bottom

10c‧‧‧Right end face

10d‧‧‧ bottom recess

11‧‧‧Negative terminal

11d‧‧‧protrusion

13‧‧‧ electrolyte

14‧‧‧negative

14a, 16a‧‧‧ wall

14b, 16b‧‧‧ bottom

14c‧‧‧Right end

15‧‧‧Baffle

16‧‧‧ positive

16b‧‧‧ bottom

17‧‧‧Insulating components

17a‧‧‧Inner diameter surface

18‧‧‧ Hydrogen storage room

19‧‧‧Oxygen storage room

25‧‧‧ Collector board

25a‧‧‧through hole

26‧‧‧Refrigerant access

27‧‧‧Send fan

28‧‧‧Hydrogen outlet

29‧‧‧Connecting Department

30‧‧‧Oxygen vents

31‧‧‧Connecting Department

32‧‧‧Insulated connecting members

33‧‧‧Insulated connecting members

34‧‧‧Electrically conductive connecting members

35‧‧‧ Hydrogen first header

35a, 36a‧‧‧ Connections

36‧‧‧Oxygen first header

38‧‧‧ Hydrogen second header

39‧‧‧Oxygen second header

41‧‧‧Donut battery

42‧‧‧Outsourcing (a: side, b: bulging)

42a, 46a‧‧‧ side

42aa‧‧‧Inner diameter

42b, 46b‧‧‧ bulging

42c‧‧‧ openings

43‧‧‧Electrode body (a: positive electrode, b: negative electrode, c: separator)

43a‧‧‧ positive

43aa‧‧‧outer diameter

43ab‧‧‧ hole

43b‧‧‧negative

43bb‧‧‧ hole

43c‧‧‧Baffle

44‧‧‧ Press plate

44a‧‧‧ Pressing plate

45‧‧‧Outer body

46‧‧‧Cover components

46d‧‧‧ hole

47‧‧‧ Collector (a: shaft part, b: anti-off part, c: thread part, d: end part)

47a‧‧‧Axis

47b‧‧‧Protection

48‧‧‧Insulated sealing member

49‧‧‧ Hydrogen storage room

51‧‧‧Negative box

51a‧‧‧outer surface

51b‧‧‧ side

52‧‧‧ positive box

52a‧‧‧ outer perimeter

52b‧‧‧ side

53‧‧‧ electrolyte

54‧‧‧negative

55‧‧‧Baffle

55a‧‧‧Outer surface

56‧‧‧ positive

58‧‧‧ Hydrogen storage room

59‧‧‧Oxygen storage room

61‧‧‧Protection shell

62‧‧‧Insulation shell

62a‧‧‧ inner circumference

63‧‧‧Negative terminal

64‧‧‧ positive terminal

65‧‧‧ gradient

66‧‧‧ gradient

67‧‧‧Insulation

67a‧‧‧ outer perimeter

68‧‧‧Cover components

69‧‧‧Caps

70‧‧‧Installation bolts

70a‧‧‧Bolt hole

71‧‧‧Cylinder laminated fuel cell battery

72‧‧‧Cylinder cans (a: inside the side)

72a‧‧‧Inner diameter

72b‧‧‧ bottom of the cylinder

72c‧‧‧ openings

73‧‧‧Electrode body (a: positive electrode, b: negative electrode, c: separator)

73a‧‧‧ positive

73aa‧‧‧ hole

73ab‧‧‧OD

73b‧‧‧negative

73ba‧‧‧ hole

73bb‧‧‧OD

75‧‧‧Outer body

76‧‧‧Caps

77‧‧‧ Collector (a: shaft part, b: anti-off part, c: thread part, d: positive terminal)

77a‧‧‧Axis

77b‧‧‧Protection Department

78‧‧‧ bearing

81‧‧‧ battery

82‧‧‧round tube (a: inside)

82b‧‧‧ openings

83‧‧‧Electrode body (a: positive electrode, b: negative electrode, c: separator)

83a‧‧‧ positive

83aa‧‧‧ hole

83b‧‧‧negative

83ba‧‧‧ hole

83c‧‧‧Baffle

85‧‧‧Outer body

86‧‧‧Caps

87‧‧‧ Collector

87a‧‧‧Axis

87b‧‧‧End

88‧‧‧ bearing

100‧‧‧ Shell

101‧‧‧ Body

102‧‧‧ bulging

103‧‧‧Filling

110‧‧‧ positive

120‧‧‧negative

121‧‧‧ Hydrogen storage source

122‧‧‧Storage access

130‧‧‧Baffle

134‧‧‧ Collector

135‧‧ ‧ partition

136a, 136b‧‧‧Oxygen storage room

137‧‧‧ electrolyte

138‧‧‧ Hydrogen storage room

211, 212‧‧‧Flange

220, 221, 222‧‧‧ piping

230‧‧‧Salt concentration adjustment device

Room 231‧‧‧

232‧‧‧Room 2

233‧‧‧ reverse osmosis membrane

234‧‧‧Drainage

250‧‧‧Oxygen concentration adjustment device

251‧‧‧Oxygen storage source

252‧‧‧Storage access

253‧‧‧ Storage path

260‧‧‧ cooler

270‧‧‧ pump

300‧‧‧Outer body

301‧‧‧ round tube

302‧‧‧covering components

303‧‧‧Filling

310‧‧‧ Collector

311‧‧‧ nuts

320‧‧‧ positive

321‧‧‧ gap

326‧‧‧cooler

327‧‧‧ pump

330‧‧‧negative

331‧‧‧ Space (gap)

340‧‧ ‧ partition

351, 352, 353‧‧‧PP filler

351a, 353a‧‧ hole

361‧‧‧electrolyte supply

362‧‧‧Supply access

363‧‧‧Electrolyte adjustment room

364‧‧‧Drainage path

364b‧‧‧Pipe

364c‧‧‧Pipe

365‧‧‧ electrolyte inlet

366‧‧‧Electrolyte outlet

370‧‧‧ Hydrogen pathway

371‧‧‧ Hydrogen storage source

372‧‧‧ Hydrogen storage path

373‧‧‧ Hydrogen supply port

380‧‧‧ Hydrogen storage room

474‧‧‧ sling

476‧‧‧Circuit breaker

477‧‧ ‧ busbar

478‧‧‧ Tower

B3‧‧‧ battery module

B5‧‧‧ battery module

C1‧‧‧Battery

C1'‧‧‧Battery

C10‧‧‧Battery

C2‧‧‧Battery

C2'‧‧‧Battery

C3‧‧‧Battery

C30‧‧‧Battery

C4‧‧‧Battery

C4a, C4b, C4c‧‧‧ batteries

C5‧‧‧Battery

S4‧‧‧ battery pack

S5‧‧‧ battery pack

1A is a schematic cross-sectional view showing the structure of a reversible fuel cell according to a first embodiment of the present invention, and is an example in which oxygen is dissolved in an electrolytic solution.

Fig. 1B is a modification of the reversible fuel cell according to the first embodiment of the present invention.

Fig. 2A is a cross-sectional view showing the structure of a fuel cell according to a second embodiment of the present invention.

2B is a cross-sectional view taken along line D-D of FIG. 2A.

Fig. 3 is a cross-sectional view showing the structure of a second modification of the fuel cell according to the second embodiment of the present invention.

Fig. 4A is a view showing a structure of a battery module composed of a fuel cell of a modification shown in Fig. 3, and a portion surrounded by a circular circle in the drawing is an enlarged view of a main part.

4B is a front elevational view of the collector plate of FIG. 4A.

Fig. 5A is a cross-sectional view showing a structure of a third modified example of the fuel cell according to the second embodiment of the present invention.

Figure 5B is a diagram showing changes in the shape of the connecting portion of the fuel cell in Figure 5A. example.

Fig. 5C shows another modification of the shape of the connecting portion of the fuel cell in Fig. 5A.

Fig. 6 is a view showing a configuration of a battery pack constituted by a fuel cell of a modification shown in Fig. 5C.

Fig. 7A is a cross-sectional view showing a structure in which a fuel cell according to a third embodiment of the present invention is configured as a unit cell.

Fig. 7B is an assembled cross-sectional view showing the structure when the unit cell of Fig. 7A is assembled and modularized.

Fig. 8A is a configuration diagram of a battery pack in which a fuel cell is connected in plural as shown in Fig. 7B.

Fig. 8B is a connection diagram of a fuel cell in the battery pack of Fig. 8A.

Fig. 9A is a partially cutaway side view showing the structure of a reversible fuel cell according to a fourth embodiment of the present invention.

Figure 9B is a cross-sectional view taken along line A-A of Figure 9A.

Fig. 10 is a schematic cross-sectional view showing the structure of an electrode portion in a reversible fuel cell according to a fourth embodiment of the present invention.

Fig. 11 is a system diagram for explaining a power generation program using a reversible fuel cell according to a fourth embodiment of the present invention.

Fig. 12 is a cross-sectional view showing the structure of a reversible fuel cell according to a fifth embodiment of the present invention.

Fig. 13A is a cross-sectional view taken along line B-B of Fig. 12;

Figure 13B is a cross-sectional view taken along line C-C of Figure 12 .

Fig. 14 is a system diagram showing the relationship between the reversible fuel cell and the external system according to the fifth embodiment of the present invention.

Fig. 15 is a system diagram for explaining an electrolytic solution processing procedure using a reversible fuel cell according to a fifth embodiment of the present invention.

Fig. 16 is a schematic structural view of a cylindrical laminated fuel cell according to a sixth embodiment of the present invention, and is a cross-sectional view in the axial direction.

Fig. 17 is a schematic structural view showing a modification of the cylindrical laminated fuel cell according to the sixth embodiment of the present invention, and is a cross-sectional view in the axial direction.

Fig. 18 is a schematic structural view showing a donut battery according to a seventh embodiment of the present invention.

Fig. 19A is a graph showing discharge characteristics (in the case of a single electron reaction) of a manganese dioxide positive electrode.

Fig. 19B is a view showing discharge characteristics (in the case of a two-electron reaction) of a manganese dioxide positive electrode.

Fig. 20 is a graph showing the results of XRD measurement, which is a measure for measuring the change in the composition of the manganese dioxide positive electrode in response to the difference in discharge depth.

Fig. 21A is a graph showing experimental results when a manganese dioxide electrode is charged by oxygen.

Fig. 21B is a graph showing another experimental result when the manganese dioxide electrode is charged with oxygen.

Fig. 22 is a schematic characteristic diagram showing the relationship between the composition of the positive electrode and the terminal voltage.

Figure 23 shows the free energy obtained by thermodynamic calculations due to pressure. The map of influence.

1‧‧‧Negative box

2‧‧‧ positive box

3‧‧‧ electrolyte

4‧‧‧negative

5‧‧‧Baffle

6‧‧‧ positive

7‧‧‧Oxygen storage room

8‧‧‧ Hydrogen storage room

9‧‧‧ wall members

C1‧‧‧Battery

Claims (22)

A reversible fuel cell comprising: a positive electrode containing manganese dioxide; a negative electrode containing a hydrogen storage material; a separator interposed between the positive electrode and the negative electrode; and an electrolyte; wherein the negative electrode and the anode The discharge reaction of the positive electrode is represented by the formulas (1) and (3), respectively; the charging reaction of the negative electrode and the positive electrode is represented by the formulas (2) and (4), respectively; the H ₂ hydrogen of the formula (2), O ₂ of the formula (4) is oxygen dissolved in the above electrolyte; MH → M + H ⁺ + e ^- (1) M + 1/2H ₂ → MH (2) MnO ₂ + H ⁺ + e ^- → MnOOH (3) MnOOH + O ₂ → MnO ₂ + H ₂ O (4) wherein, in the formulae (1) and (2), M represents a hydrogen storage material. A reversible fuel cell according to claim 1, wherein the first oxygen storage chamber in which the electrolytic solution in which oxygen is dissolved and the hydrogen storage chamber in which hydrogen gas is stored are provided inside. The reversible fuel cell of claim 2, wherein the first oxygen storage chamber and the hydrogen storage chamber are distinguished by a movable member. The reversible fuel cell of claim 3, wherein the movable member is a flexible member. The reversible fuel cell of claim 4, wherein the flexible member comprises the positive electrode, the negative electrode and the separator. The reversible fuel cell according to claim 2, wherein the cylindrical positive electrode and the cylindrical negative electrode are disposed via the partition plate via a radial space inside the cylindrical case, and are adjacent to the positive electrode Forming the first oxygen storage chamber so as to face the opposite side of the separator, and forming the hydrogen storage chamber so as to be adjacent to a surface of the negative electrode opposite to the separator; wherein the first oxygen The storage chamber is disposed in the radial space, and the hydrogen storage chamber is disposed inside the negative electrode; or the hydrogen storage chamber is disposed in the radial space, and the first oxygen storage chamber is disposed inside the positive electrode. The reversible fuel cell of claim 6, further comprising: a negative electrode terminal disposed at one end of the axial direction of the box and electrically coupled to the negative electrode; and a positive terminal disposed on the outer casing The other end of the axial direction of the body is electrically coupled to the positive electrode; and the protrusion is disposed on any one of the positive terminal or the negative terminal; The hole portion is provided on the other of the positive electrode terminal or the negative electrode terminal; and the protrusion portion and the hole portion are fitted to each other in such a manner that the two reversible fuel cells are connected in series. A reversible fuel cell module having a plurality of battery cells connected in series; the battery cell is provided with: a plurality of reversible fuel cells of claim 7; and a pair of collector plates, which are sandwiched by the plurality The above-mentioned reversible fuel cell is disposed in a relatively opposite manner; and the plurality of reversible fuel cells are connected to the current collector plate by connecting one of the current collector plates to the positive electrode terminal and the other collector plate to the negative electrode terminal Connected in parallel with each other. The reversible fuel cell of claim 1, wherein the hydraulic pressure of the electrolyte is 0.1 MPa to 10 GPa. The reversible fuel cell of claim 2, further comprising: a casing having a tubular body portion; and a two-end opening disposed at the body portion and bulging toward the outside of the opening portion a bulging portion covering the opening; the first oxygen storage chamber is disposed in an inner space of the bulging portion inside the outer casing; and the tubular current collector is housed in the axial direction inside the outer casing, wherein End The first oxygen storage chamber has an opening; the positive electrode is disposed on an outer circumference of the current collector; the separator covers a periphery of the positive electrode; the hydrogen storage chamber is formed between the separator and the outer casing; and the negative electrode is The electrolyte solution is stored in the first oxygen storage chamber, and the electrolyte is transported between the first oxygen storage chambers through the current collector. The reversible fuel cell according to claim 2, further comprising: an outer casing having a tubular body; and a rod-shaped current collector penetrating the positive electrode, the negative electrode and the separator; the positive electrode, The negative electrode and the separator are laminated in the axial direction of the body and housed inside the outer casing; the positive electrode has a notch formed by cutting a part of the outer circumference, and the outer circumference of the positive electrode is in contact with the notch The inner surface of the body other than the portion; the positive electrode does not contact the current collector; the negative electrode has a meandering cross section that is open in the inner circumferential direction, the negative electrode is in contact with the current collecting system; and the negative electrode and the set are The space surrounded by the electric body forms the hydrogen storage chamber; the outer diameter of the negative electrode is smaller than the inner dimension of the body portion, and an electrolyte that communicates with the notch portion is provided between the negative electrode and the body portion a retention portion; the first oxygen storage chamber includes the notch portion and the electrolyte solution retention portion. A reversible fuel cell system comprising: a reversible fuel cell of claim 10 or 11; and an oxygen storage source and a hydrogen storage source connected to the fuel cell; wherein the oxygen storage source can store oxygen or dissolve in the electrolyte The oxygen in the supply is supplied to the reversible fuel cell, and the oxygen generated by the reversible fuel cell is stored in a gas state or in a state of being dissolved in the electrolyte; and the hydrogen storage source supplies hydrogen to the reversible fuel cell. The hydrogen produced by the above reversible fuel cell can be stored. A reversible fuel cell system comprising: a reversible fuel cell of claim 10 or 11; a salt concentration adjusting device connected to the reversible fuel cell and removing moisture contained in the electrolyte; and adjusting oxygen concentration And a device connected to the reversible fuel cell, wherein the dissolved oxygen concentration is adjusted by supplying oxygen to the electrolyte. A reversible fuel cell module according to the first aspect of the invention, further comprising: a negative electrode case which is in contact with the negative electrode and disposed opposite to the positive electrode; and an positive electrode case which is in contact with the positive electrode And disposed opposite to the negative electrode; the negative electrode is disposed opposite to the positive electrode via the separator; The reversible fuel cell module is connected in series with a reversible fuel cell, and the reversible fuel cell further includes: a hydrogen storage chamber formed in a space between the negative electrode case and the negative electrode, and storing the negative electrode And a hydrogen storage chamber formed in a space between the positive electrode case and the positive electrode, and storing oxygen generated by the positive electrode; the positive electrode case of a reversible fuel cell and the reversible fuel cell adjacent thereto The negative electrode boxes are arranged in contact with each other. A reversible fuel cell stack comprising: a reversible fuel cell module of claim 14th, a metal sling, a structure, a circuit breaker capable of opening and closing, and a bus bar; one end of the metal sling Mounted on the reversible fuel cell module, the other end of the sling is mounted on the structure, so that the plurality of reversible fuel cell modules can be suspended from the structure, and the adjacent reversible fuel cell module The positive terminal and the negative terminal of the group are connected by the bus bar via the above-mentioned circuit breaker. The reversible fuel cell according to claim 1, wherein the manganese dioxide has a catalytic function as a charging reaction in the positive electrode, and the hydrogen storage material has a catalytic function as a charging reaction in the negative electrode. The reversible fuel cell of claim 1, wherein the positive electrode contains manganese oxide in addition to manganese dioxide. The reversible fuel cell according to the first aspect of the invention, wherein the content of the trimanganese tetraoxide (Mn ₃ O ₄ ) contained in the positive electrode is 5% by weight or less based on the weight of the positive electrode. The reversible fuel cell of claim 1, wherein the manganese dioxide contained in the positive electrode is coated with carbon. The reversible fuel cell of claim 1, wherein the hydrogen storage material is a hydrogen storage alloy, or at least selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, and Ni. 1 kind of metal. The reversible fuel cell of claim 1, wherein the separator comprises a microporous membrane having an average pore diameter of 0.1 to 10 μm. The reversible fuel cell of claim 1, wherein the negative electrode includes: a material disposed on a surface adjacent to the separator and having hydrophilicity, and disposed on a surface adjacent to the hydrogen storage chamber A material that is hydrophobic.