JP5353430B2 - Air battery system - Google Patents

Description

  The present invention relates to an air battery system.

  The air battery is a battery using oxygen as a positive electrode active material, and takes in air from the outside during discharge. Therefore, it is possible to increase the proportion of the negative electrode active material in the battery container as compared with other batteries having positive and negative electrode active materials in the battery. Therefore, in principle, the electric capacity that can be discharged is large, and it is easy to reduce the size and weight. Further, since the oxidizing power of oxygen used as the positive electrode active material is strong, the battery electromotive force is relatively high. Furthermore, since oxygen has a feature that it is a clean material without resource restrictions, the air battery has a small environmental load. As described above, the air battery has many advantages and is expected to be used for a battery for a portable device, a battery for an electric car, a battery for a hybrid car, a battery for a fuel cell car, and the like.

  The air battery causes a battery reaction by incorporating oxygen into the positive electrode as described above. That is, if the positive electrode is in contact with the oxygen-containing gas, for example, there is a possibility that self-discharge may occur even when the air battery is stopped. Further, in an open air battery, there is a possibility that moisture is always taken in from the outside even when the air battery is stopped, and in particular, in an air battery using a non-aqueous electrolyte, there is a concern that the battery life may be reduced due to moisture absorption.

  In order to solve such a problem, as described in Patent Document 1, a valve is provided on the casing so that the positive electrode is isolated from the air flow when the battery is not used, and the air flow is touched only when the battery is used. Air batteries have been proposed.

JP 2005-538513 A

  According to the air battery described in Patent Document 1, it is considered that when the battery is stopped, the valve of the housing is closed to prevent reaction with air and water, and self-discharge and moisture absorption can be suppressed. However, after the valve is closed, the reaction of oxygen remaining in the housing cannot be suppressed, and self-discharge occurs, which may reduce the battery life. In addition, when a large amount of current is required at the time of starting the battery (for example, in the case of in-vehicle use), in the air battery described in Patent Document 1, the oxygen partial pressure in the housing is reduced at the time of starting the battery. Therefore, there is a problem that a sufficient current cannot be obtained.

  In addition, as a result of researches on the reaction mechanism in the air battery at the time of charge / discharge of the air battery using the electrolyte, the present inventor can decompose the electrolyte at the time of battery charge / discharge depending on the type of the electrolyte used. It has been found that carbon dioxide is generated, which may lower the oxygen partial pressure in the battery and lower the battery output. In order to prevent this, it is conceivable to appropriately control the gas state in the battery.

  From the above, the conventional air battery has room for improvement regarding the control of the gas in the housing.

  This invention is made | formed in view of the above, and makes it a subject to provide the air battery system which can perform control of the gas in a housing | casing appropriately.

In order to solve the above problems, the present invention has the following configuration. That is,
The present invention includes a housing and a power generation unit housed in the housing. The housing includes a gas supply unit that can be opened and closed, a gas discharge unit that can be opened and closed, and a pressure in the housing. The air battery system is provided with a pressure adjusting unit.

  In the present invention, the “power generation section” refers to a power generation section of an air battery, and refers to a portion having a positive electrode, an electrolyte layer, and a negative electrode in this order. The form of the “gas supply unit” is not particularly limited as long as gas can be sent from the outside of the housing to the inside of the housing. The form of the “gas discharge part” is not particularly limited as long as it can discharge gas from the inside of the housing to the outside of the housing. The form of the “pressure adjusting unit” is not particularly limited as long as the pressure in the housing can be controlled and adjusted according to the use state of the battery.

  In the present invention, it is preferable that the gas supply unit and the gas discharge unit are closed when the battery is started, and the inside of the housing is pressurized by the pressure adjustment unit. By pressurizing the inside of the housing at the time of starting the battery, for example, it is possible to increase the oxygen partial pressure inside the housing, so that the discharge reaction at the positive electrode can be promoted, and a sufficient current can be obtained even at the time of starting the battery. Can be obtained.

  In particular, it is preferable that the oxygen-containing gas is supplied into the casing simultaneously with pressurization in the casing at the time of starting the battery. Thereby, since the oxygen partial pressure in a housing can be raised further, the discharge reaction in a positive electrode can be promoted more.

  On the other hand, in the present invention, when the battery is started, the gas supply unit is closed, the gas discharge unit is opened, and the oxygen-containing gas whose pressure is increased is supplied into the housing through the pressure adjustment unit. Also good. Thereby, since the oxygen-containing gas with an increased oxygen partial pressure is supplied at the time of starting the battery, the discharge reaction at the positive electrode can be promoted.

  In the present invention, it is preferable that the gas supply unit and the gas discharge unit are closed when the battery is stopped, and the inside of the housing is decompressed by the pressure adjustment unit. When the battery is stopped, the inside of the housing is depressurized, for example, the oxygen partial pressure, moisture pressure, and other residual gas partial pressure in the housing can be reduced, so self-discharge, moisture absorption, deterioration, etc. when the battery is stopped Can be suppressed, and a decrease in battery life can be suppressed.

  In the present invention, the casing is provided with a gas supply section and a gas discharge section that can be opened and closed, and a pressure adjustment section that adjusts the pressure in the casing. Therefore, the gas supply section, the gas discharge section, and the pressure By appropriately controlling the operation of the adjusting unit, it is possible to appropriately control the gas in the housing. Thereby, for example, self-discharge while the battery is stopped can be suppressed, a sufficient output can be obtained at the time of battery start, and further a decrease in battery life can be suppressed.

1 is a diagram schematically showing an air battery system 100 in a normal operation state. It is a figure for demonstrating operation | movement of the air battery system 100 from a normal driving | running state to a battery stop state. It is a figure for demonstrating operation | movement of the air battery system 100 from a battery stop state to a normal operation state. It is a figure for demonstrating operation | movement of the air battery system 100 from a battery stop state to a normal operation state.

  Hereinafter, the case where the air battery system according to the present invention is applied to a lithium air battery provided with a power generation unit having a positive electrode, a negative electrode, and an electrolyte layer interposed between the positive electrode and the negative electrode in a housing will be mainly described. . However, the present invention can also be applied to other air batteries (zinc-based air battery, aluminum-based air battery, sodium-based air battery, etc.) for the purpose of controlling oxygen in the casing.

1. Air battery system 100
FIG. 1 shows a state where the air battery system has been started for a while and the discharge reaction has been stabilized (for example, in a vehicle, a state where the motor or the like has started from a key-on state and shifted to a normal operation state. 1 is a diagram schematically showing an air battery system 100 in a “normal operation state”. As shown in FIG. 1, the air battery system 100 includes a power generation unit 40 having a positive electrode 10, a negative electrode 20, and an electrolyte layer 30 interposed between the positive electrode 10 and the negative electrode 20 in a housing 50. . In addition, a space 51 is provided in the upper part of the housing 50. When an oxygen-containing gas is supplied to the space 51, oxygen is taken into the positive electrode and used for a battery reaction. On the other hand, a gas supply unit 60 is provided outside the housing 50, and a supply pipe 61 of the gas supply unit 60 is inserted into the space 51 from the outside of the housing 50. The supply pipe 61 is provided with an opening / closing valve 62, and gas can be supplied to the space 51 by controlling the opening / closing of the opening / closing valve 62. In addition, a gas discharge unit 70 is provided on the side facing the gas supply unit 60 side outside the housing 50, and the discharge pipe 71 of the gas discharge unit 70 extends from the space 51 of the housing 50 to the outside of the housing 50. It extends to. The discharge pipe 71 is provided with an open / close valve 72, and gas can be discharged from the space 51 by controlling the opening / closing of the open / close valve 72. Further, a pressure adjusting unit 80 is provided outside the housing 50, and a pipe 81 is inserted from the pressure adjusting unit 80 into a space 51 in the housing 50. The pipe 81 is provided with an opening / closing valve 82, and the pressure of the housing 50 can be adjusted by controlling the opening / closing of the opening / closing valve 82 and the operation of the pressure adjusting unit 80. The opening / closing of the on-off valves 62, 72, and 82 and the operation of the pressure adjusting unit 80 can be appropriately controlled by the control unit 90 provided outside the housing 50 according to the battery usage state. ing. Hereinafter, the air battery system 100 will be described for each configuration.

(Positive electrode 10)
The positive electrode 10 contains a conductive material, a catalyst, and a binder that binds these. The positive electrode 10 is provided with a positive electrode current collector that collects the positive electrode 10 in contact with the inside or the outer surface of the positive electrode 10.

  The conductive material contained in the positive electrode 10 is not particularly limited as long as it can withstand the environment when the air battery system 100 is used and has conductivity. Examples of the conductive material contained in the positive electrode 10 include carbon materials such as carbon black and mesoporous carbon. Further, from the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the content of the conductive material in the positive electrode 10 is preferably set to 10% by mass or more. Further, from the viewpoint of making the form capable of exhibiting a sufficient catalytic function, the content of the conductive material in the positive electrode 10 is preferably 99% by mass or less.

  Examples of the catalyst contained in the positive electrode 10 include cobalt phthalocyanine and manganese dioxide. From the standpoint of achieving a form capable of exhibiting a sufficient catalytic function, the content of the catalyst in the positive electrode 10 is preferably 1% by mass or more. Further, from the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the catalyst content in the positive electrode 10 is preferably 90% by mass or less.

  Examples of the binder contained in the positive electrode 10 include polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE). The content of the binder in the positive electrode 10 is not particularly limited, but is preferably, for example, 10% by mass or less, and more preferably 1% by mass to 5% by mass.

  The positive electrode current collector can be used without particular limitation as long as it is made of a conductive material. For example, a foil, mesh, grid, or the like made of stainless steel, nickel, aluminum, iron, titanium, carbon, or the like can be used. In addition, the positive electrode current collector may function as a path that guides oxygen from the space 51 in the housing 50 to the positive electrode 10. That is, an oxygen layer 11 described later may be used as the positive electrode current collector 11.

  The positive electrode 10 can be produced, for example, by a method such as applying a paint composed of carbon black, a catalyst, and a binder to the surface of the positive electrode current collector by a doctor blade method. In addition, it can also be produced by a method such as thermocompression bonding of mixed powder containing carbon black and a catalyst.

<Oxygen layer 11>
The oxygen layer 11 has a function of guiding oxygen gas existing in the space 51 to the positive electrode 10. The oxygen layer 11 is a passage for air guided to the air electrode 10. For example, the oxygen layer 11 has a hole provided in the air electrode current collector that collects the air electrode 10 in contact with the inside or the outer surface of the air electrode 10. Functions as the oxygen layer 11.

<Negative electrode 20>
The negative electrode 20 contains an alkali metal that functions as a negative electrode active material. In addition, the negative electrode 20 is provided with a negative electrode current collector (not shown) that contacts the inside or the outer surface of the negative electrode 20 and collects the negative electrode 20.

  Examples of the alkali metal that can be contained in the negative electrode 20 include Li, Na, and K. Examples of the alkali metal compound that can be contained in the negative electrode 20 include a Li alloy. When the air battery system 100 is a lithium air secondary battery, it is preferable that Li is contained from the viewpoint of providing the air battery system 100 that can easily increase the capacity.

  The negative electrode 20 only needs to contain at least a negative electrode active material, and may further contain a conductive material that improves conductivity, or a binder that fixes an alkali metal or the like. From the viewpoint of suppressing a decrease in reaction field and a decrease in battery capacity, the content of the conductive material in the negative electrode 20 is preferably 10% by mass or less. Further, the content of the binder in the negative electrode 20 is not particularly limited, but is preferably 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less. The type and amount of the conductive material and binder that can be contained in the negative electrode 20 can be the same as in the case of the positive electrode 10.

  The negative electrode 20 is provided with a negative electrode current collector in contact with the inner or outer surface. The negative electrode current collector has a function of collecting the negative electrode 20. In the air battery system 100, the material of the negative electrode current collector is not particularly limited as long as it is a conductive material. Examples of the material for the negative electrode current collector include copper, stainless steel, and nickel. Examples of the shape of the negative electrode current collector include a foil shape, a plate shape, and a mesh (grid) shape. In the air battery system 100, the negative electrode 20 can be produced by the same method as that of the positive electrode 10, for example.

<Electrolyte layer 30>
The electrolyte layer 30 contains an electrolyte (liquid or solid) that is responsible for conduction of ions (alkali metal ions) between the positive electrode 10 and the negative electrode 20. It is particularly preferable to use an electrolytic solution.

When a liquid electrolyte (electrolytic solution) is used for the electrolyte layer 30, the form of the electrolytic solution is not particularly limited as long as it has metal ion conductivity. For example, an aqueous electrolytic solution or non-aqueous electrolysis is used. A liquid can be mentioned. It is preferable that the type of the electrolytic solution used for the electrolyte layer 30 is appropriately selected according to the type of metal ions to be conducted. For example, when a lithium-air battery is used, it is preferable to use a non-aqueous electrolyte. The non-aqueous electrolyte contains a lithium salt and an organic solvent. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO _4, LiAsF _{6 and} other inorganic lithium salts, LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC An organic lithium salt such as (CF ₃ SO ₂ ) ₃ can be exemplified. Examples of the organic solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate, γ-butyrolactone, sulfolane, acetonitrile, 1 , 2-dimethoxymethane, 1,3-dimethoxypropane, diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, other fluorine-based solvents and mixtures thereof. Moreover, it is preferable to use a hydrophobic solvent from the viewpoint of suppressing water from entering the battery. The concentration of the lithium salt in the non-aqueous electrolyte is, for example, not less than 0.2 mol / L and not more than 3 mol / L. In the air battery system of the present invention, a low-volatile liquid such as an ionic liquid can be used as the non-aqueous electrolyte.

  Moreover, when electrolyte solution is used for the electrolyte layer 30, it is preferable that the electrolyte layer 30 is made into the form by which the said electrolyte solution is hold | maintained at a separator or a gel polymer. Examples of the separator include porous membranes such as polyethylene and polypropylene, and nonwoven fabrics such as resin nonwoven fabrics and glass fiber nonwoven fabrics. Examples of the gel polymer include acrylate polymer compounds, ether polymer compounds such as polyethylene oxide, and crosslinked polymers containing these, methacrylate polymer compounds such as polymethacrylate, polyvinylidene fluoride, and polyvinylidene fluoride. Fluorine polymer compounds such as a copolymer of styrene and hexafluoropropylene can be used. The form of the gel polymer is not particularly limited as long as it is a form that can hold the electrolytic solution, such as a particulate form. The production of the electrolyte layer 30 is not particularly limited, but the electrolyte solution is contained in a suitably shaped separator or gel polymer filling layer, and the electrolyte solution is retained in the separator or gel polymer. The electrolyte layer 30 having a predetermined shape is produced.

<Power generation unit 40>
In the air battery system 100, a stacked body in which the positive electrode 10, the electrolyte layer 30, and the negative electrode 20 are stacked in this order can be used as the power generation unit 40. The method for laminating the positive electrode 10, the electrolyte layer 30, and the negative electrode 20 is not particularly limited, and a known method can be used.

<Case 50>
The housing 50 accommodates the power generation unit 40, and a space 51 is provided in the upper part of the housing 50. The space 51 exists on the positive electrode 10 side of the power generation unit 40. In the air battery system 100, the shape of the housing 50 is not particularly limited. As the constituent material of the casing 50, a material that can be used for the casing of the air battery, such as being stable with respect to the electrolyte to be used, can be appropriately used. A connection portion (for example, a hole) that can connect a supply pipe 61 of a gas supply unit 60 described later is provided on a side surface of the housing 50. In addition, a connection portion (for example, a hole) that can connect a discharge pipe 71 of a gas discharge unit 70 described later is provided on the side surface of the housing 50 that faces the side surface provided with the connection portion to which the supply pipe 61 can be connected. It has been. Furthermore, a connection part (for example, a hole) is provided on the upper surface of the housing 50 to which a pipe 81 extending from a pressure adjusting part 80 described later can be connected.

<Gas supply unit 60>
The gas supply unit 60 includes a supply pipe 61 connected to the side surface of the housing 50 and an opening / closing valve 62 provided in the supply pipe 61, and the opening / closing operation of the opening / closing valve 62 is controlled. In other words, the gas can be supplied from the outside to the space 51 in the housing 50. The forms of the supply pipe 61 and the on-off valve 62 are not particularly limited, and a known fluid pipe and a known electromagnetic valve can be used. The gas circulated through the supply pipe 61 is an oxygen-containing gas, and may be air, dry air, oxygen gas having a pressure of 1.01 × 10 ⁵ Pa and an oxygen concentration of 99.99%, or the like. In addition, the supply pipe 61 may be provided with a filter (not shown) so that moisture can be removed from the oxygen-containing gas. Further, a pump (not shown) may be provided so that the oxygen-containing gas can be efficiently supplied.

<Gas discharge part 70>
The gas discharge unit 70 includes a discharge pipe 71 connected to a side surface of the housing 50 opposite to a side surface on which the gas supply unit 60 is provided, and an open / close valve 72 provided in the discharge pipe 71. Thus, by controlling the opening / closing operation of the opening / closing valve 72, the gas can be discharged from the space 51 in the housing 50 to the outside of the housing 50. The forms of the discharge pipe 71 and the on-off valve 72 are not particularly limited, and a known fluid pipe and a known electromagnetic valve can be used. The gas discharged through the discharge pipe 71 is a residual gas that has not been subjected to the battery reaction. The discharge pipe 71 may be provided with a pump (not shown) so that the remaining gas can be discharged efficiently.

<Pressure adjustment unit 80>
The pressure adjustment unit 80 is a part that is provided outside the housing 50 and adjusts the pressure in the housing 50 (particularly, the space 51) according to the usage state of the battery. The form of the pressure adjusting unit 80 is not particularly limited as long as the pressure in the housing 50 can be controlled, and a known compressor or pump, a device combining these, or the like can be used. In particular, the pressure adjusting unit 80 is 0.10 × 10 ⁵ Pa (0.1 atm) or more and 3.0 × 10 ⁵ Pa (3 atm) or less, preferably 0.5 × 10 ⁵ Pa (0.5 atm) or more. It is preferable that the pressure in the casing 50 (space 51) can be adjusted and controlled within a range of 0.0 × 10 ⁵ Pa (2 atm) or less. Further, a tube 81 extends from the pressure adjusting unit 80 toward the space 51, and the tube 81 is provided with an on-off valve 82. The forms of the pipe 81 and the on-off valve 82 are not particularly limited, and a known fluid pipe and a known electromagnetic valve can be used.

<Control unit 90>
The control unit 90 is a part that emits a signal according to the usage state of the battery and controls the opening / closing operation of the on-off valves 62, 72, 82 and the operation of the pressure adjusting unit 80. A known control device can be used as the control unit 90.

2. Operation of Air Battery System 100 The air battery system 100 has the above-described configuration, controls the flow of gas in the space 51 in accordance with the usage state of the battery, and pressure in the housing 50. Is adjustable. That is, according to the air battery system 100, the gas control in a housing | casing can be performed appropriately. Hereinafter, the operation of the air battery system 100 according to the battery usage state will be described.

<Normal operation state>
As shown in FIG. 1, the air battery system 100 is in a state in which the on-off valve 62 of the gas supply unit 60 is opened in a normal operation state, and an oxygen-containing gas is always supplied from the outside to the space 51. It is in. On the other hand, the remaining gas that has not been subjected to the battery reaction is discharged to the outside through the gas discharge unit 70. Further, for the pipe 81 connected to the pressure adjusting unit 80, the on-off valve 82 is closed, and the pressure adjusting unit 80 and the space 51 are not in fluid communication. That is, in the normal operation state of the air battery system 100, there is a gas flow from the gas supply unit 60 to the gas discharge unit 70 in the space 51, and the pressure in the space 51 includes oxygen supplied from the outside. It is almost equivalent to gas. Further, the oxygen layer 11 is always formed on the surface of the positive electrode 10 on the space 51 side, and the battery reaction is stably performed by taking in oxygen therefrom. Thereby, for example, electric energy is stably supplied to a motor or the like mounted on the vehicle, and the operation / stop of the vehicle is smoothly performed.

<Normal operation state to battery stop state>
Next, the operation of the air battery system 100 from the normal operation state to the battery stop state will be described. FIG. 2 is a diagram for explaining an operation flow of the air battery system 100 from the normal operation state to the battery stop state. FIG. 2A schematically shows the air battery system 100 in a normal operation state as in FIG. FIG. 2B schematically shows the air battery system 100 in a state where the operation of the battery is stopped and the pressure in the housing 50 is adjusted. Further, FIG. 2C shows the air battery system after the state in the casing 50 (the state of gas in the space 51) is changed by adjusting the pressure in the casing 50 after the battery operation is stopped. 100 is shown schematically. In FIG. 2, the control unit 90 is omitted in order to avoid complication of the drawing.

As shown in FIG. 2B, when the operation of the air battery system 100 in the normal operation state is stopped, a signal is issued from the control unit 90, and the on-off valves 62 and 72 in the open state are closed. On the other hand, the on-off valve 82 in the closed state is opened. When the air battery system 100 is used as an in-vehicle power source, for example, a signal is sent from the known sensing means or the like to the control unit 90 so that the air battery system 100 is stopped by the key-off of the vehicle. do it. Further, after the on-off valve 82 is opened by a signal from the control unit 90, the pressure adjusting unit 80 (pump) is operated, and the inside of the housing 50 (particularly, the space 51) is depressurized. In this case, it is preferable that the pressure in the housing 50 is reduced until the pressure is about 0.5 × 10 ⁵ Pa (0.5 atm) to 0.7 × 10 ⁵ Pa (0.7 atm).

  As shown in FIG. 2C, when it is determined that the inside of the casing 50 has been depressurized and has reached a predetermined pressure, a signal is issued from the control unit 90, the on-off valve 82 is closed, and the space 51 is opened. The housing 50 is sealed with the low pressure. In this case, the pressure in the housing 50 is sensed by, for example, a pressure sensor (not shown), and a signal for closing the on-off valve 82 may be issued from the control unit 90 based on the sensing signal of the pressure sensor. . In the air battery system 100 in the battery stopped state, since the oxygen partial pressure of the oxygen layer 11 remaining in the space 51 is reduced, the battery reaction of the positive electrode 10 is suppressed. Therefore, according to the air battery system 100, gas control (particularly oxygen control) in the housing 50 can be appropriately performed from the normal operation state to the battery stop state, and self-discharge in the battery stop state can be suppressed. . In addition, since the partial pressure of the moisture remaining in the housing 50 is also reduced, moisture absorption by the power generation unit 40 in the battery stopped state can be suppressed, and a reduction in battery life can be suppressed.

<Battery stopped to normal operation>
On the other hand, in the air battery system 100 that has been depressurized while the battery is stopped, the oxygen partial pressure in the housing 50 is reduced, and even if the battery is started with such a low oxygen partial pressure, the positive electrode 10 is sufficient. It is considered that the battery reaction does not occur and the necessary current cannot be obtained when starting the battery. Further, when the electrolytic solution is decomposed by the charge / discharge reaction of the battery in the normal operation state and carbon dioxide or the like is generated in the housing 50, the oxygen partial pressure in the housing 50 is further reduced. Conceived, there is a concern about a decrease in output when starting the battery. In particular, when the air battery system 100 is used as an in-vehicle power source, it is considered that a larger amount of current is required than when the battery is started (for example, at the start of operation of the motor) than in a normal operation state. Further promotion is preferred. In order to satisfy such requirements, the air battery system 100 operates as follows from the battery stop state to the normal operation state.

  FIG. 3 is a diagram for explaining an operation flow of the air battery system 100 from the battery stop state to the normal operation state. FIG. 3A schematically shows the air battery system 100 in a battery stopped state, as in FIG. FIG. 3B schematically shows the air battery system 100 in a state where the battery is started and the pressure in the housing 50 is adjusted. Further, FIG. 3C shows that after the battery is started, the pressure in the housing 50 is adjusted to change the state in the housing 50 (the state of the gas in the space 51) to obtain a sufficient output. After that, the air battery system 100 in a state of transitioning to a normal operation state is schematically shown. In FIG. 3, as in FIG. 2, the control unit 90 is omitted in order to avoid making the drawing complicated.

As shown in FIG. 3B, when the air battery system 100 in the battery stopped state is started, a signal is issued from the control unit 90, and the on-off valve 82 in the closed state is opened. When the air battery system 100 is used as an in-vehicle power source, for example, a signal is emitted from the known sensing means or the like to the control unit 90 so that the air battery system 100 is started when the vehicle is turned on. The control unit 90 may generate a signal based on the above. Furthermore, after the on-off valve 82 is opened by a signal from the control unit 90, the pressure adjusting unit 80 (compressor) operates to pressurize the inside of the housing 50. In this case, it is preferable to pressurize until the pressure in the housing 50 is about 1.2 × 10 ⁵ Pa (1.2 atm) to 2.0 × 10 ⁵ Pa (2.0 atm). As a result, the oxygen partial pressure in the housing 50 can be increased as compared with that in the normal operation state, and the oxygen layer 12 with the increased oxygen partial pressure is formed on the surface of the positive electrode 10, and the battery reaction of the positive electrode 10 is promoted. And sufficient output can be obtained. Further, it is preferable to pressurize the inside of the housing 50 through the pipe 81 connected to the pressure adjusting unit 80 and simultaneously supply an oxygen-containing gas, preferably an oxygen gas having an oxygen concentration of 99.99%, from the outside. In this way, the oxygen partial pressure in the housing 50 can be further increased, and a larger output can be obtained when the battery is started.

  As shown in FIG. 3 (c), the inside of the housing 50 is pressurized to a predetermined pressure, and after obtaining sufficient output at the time of starting the battery, it is determined that the normal operation state may be entered. Then, a signal is issued from the control unit 90, the on-off valve 82 is closed, the on-off valves 62 and 72 are opened, and the normal operation state as described in FIG. 1 and FIG. For example, when the air battery system 100 is used as an in-vehicle power source, the control unit 90 shifts from the pressurized state at the time of battery start to the normal operation state based on the driving state of the vehicle, the amount of current required by the motor, and the like. A signal is issued, and a signal for opening the on-off valves 62 and 72 may be issued from the control unit 90 based on the signal.

  As described above, according to the air battery system 100, the pressure in the casing 50 is adjusted during the period from when the battery is stopped to the normal operation state, and gas control is appropriately performed, so that the battery of the positive electrode 10 can be obtained. Since the reaction is appropriately controlled, a sufficient output can be obtained without a shortage even when a larger amount of current is required at the time of starting the battery, such as an in-vehicle power source.

  Further, the air battery system 100 may be operated as described below from the battery stop state to the normal operation state. FIG. 4 is a diagram for explaining a flow of another mode of operation of the air battery system 100 from the battery stop state to the normal operation state. FIG. 4A schematically shows the air battery system 100 in a battery stopped state, similarly to FIG. 2C and FIG. 3A. FIG. 4B schematically shows the air battery system 100 in a state where the battery is started and gas control in the housing 50 is performed. Further, FIG. 4 (c) shows a sufficient output by changing the state in the housing 50 (the state of gas in the space 51) by adjusting the pressure in the housing 50 after the battery is started. After being obtained, the air battery system 100 in a state of transition to a normal operation state is schematically shown. In FIG. 4, as in FIG. 3, the control unit 90 is not shown in order to avoid the complexity of the drawing. 4 (a) and 4 (c) are the same as FIGS. 3 (a) and 3 (c), and the description thereof is omitted.

As shown in FIG. 4B, when the air battery system 100 in the battery stopped state is started, a signal is issued from the control unit 90, and the on-off valves 72 and 82 in the closed state are opened. When the air battery system 100 is used as an in-vehicle power source, for example, a signal is sent from the known sensing means or the like to the control unit 90 so that the air battery system 100 is activated in response to a key-on of the vehicle. do it. Further, after the on-off valves 72 and 82 are opened by a signal from the control unit 90, the pressure adjustment unit 80 (compressor) is operated to enter the space 51 in the housing 50 from the outside of the housing 50 through the pipe 81. A high-pressure oxygen-containing gas is supplied. As the oxygen-containing gas, air, preferably dry air, particularly preferably oxygen gas having an oxygen concentration of 99.99% can be used. The pressure of the high-pressure oxygen-containing gas is 1.1 × 10 ⁵ Pa (1.1 atm) or more and 3.0 × 10 ⁵ Pa ( ³ atm) or less, preferably 1.2 × 10 ⁵ Pa (1.2 atm) or more and 2 0.0 × 10 ⁵ Pa (2.0 atm) or less. Even in such a configuration, the gas in the housing 50 is controlled, and the oxygen partial pressure in the housing 50 can be increased as compared with the normal operation state, and the oxygen partial pressure is increased on the surface of the positive electrode 10. The oxygen layer 12 is formed, the battery reaction of the positive electrode 10 is promoted, and sufficient output can be obtained. In addition, since the on-off valves 72 and 82 are opened, a gas flow from the pressure adjusting unit 90 to the gas discharge unit 70 is generated in the space 51. For example, an impure gas (carbon dioxide or the like) is generated in the space 51. ) Exists, the impure gas can be forcibly discharged to the outside of the housing 50.

  Thus, according to the air battery system 100, the gas (especially oxygen) in the housing 50 is from the normal operation state to the battery stop state and from the battery stop state to the normal operation state. ) Can be appropriately controlled, so that self-discharge when the battery is stopped can be suppressed, sufficient output can be obtained when the battery is started, and deterioration of the battery life can be suppressed.

  In the above description, the air battery system 100 in which only one power generation unit 40 in which the positive electrode 10, the electrolyte layer 30, and the negative electrode 10 are stacked is housed in the housing 50 has been described. The present invention is not limited to the number and form of the power generation units 40 accommodated. A plurality of power generation units 40 may be accommodated in the housing 50. Further, the power generation unit 40 may be formed in another form such as a columnar shape or a cylindrical shape and accommodated in the housing 50. Even in this case, the gas control in the housing 50 can be appropriately performed.

  In the above description, the gas supply unit 60, the gas discharge unit 70, and the pressure adjustment unit 80 have been described as being connected to the side surface of the housing 50 with a predetermined positional relationship. Is not limited to this form, and the connection part of the gas supply part 60, the gas discharge part 70, and the pressure adjustment part 80 is limited as long as the gas control in the housing 50 can be appropriately performed. Not.

  Although the present invention has been described with reference to the most practical and preferred embodiments at the present time, the invention is not limited to the embodiments disclosed herein. However, the present invention can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification, and an air battery system with such a change is also understood to be included in the technical scope of the present invention. It must be.

  The air battery system of the present invention can be used for a small power source for portable devices, a large power source for in-vehicle use, and the like.

100 air battery system 10 positive electrode 11 oxygen layer (positive electrode current collector)
12 Oxygen layer 20 with increased oxygen partial pressure 20 Negative electrode 30 Electrolyte layer 40 Power generation unit 50 Housing 51 Space 60 Gas supply unit 70 Gas exhaust unit 80 Pressure adjustment unit 90 Control unit

Claims (5)

A housing, and a power generation unit housed in the housing;
The air battery system, wherein the housing is provided with a gas supply unit that can be opened and closed, a gas discharge unit that can be opened and closed, and a pressure adjusting unit that adjusts the pressure in the housing. 2. The air battery system according to claim 1, wherein the gas supply unit and the gas discharge unit are closed when the battery is started, and the inside of the housing is pressurized by the pressure adjusting unit. The air battery system according to claim 2, wherein an oxygen-containing gas is supplied into the housing simultaneously with pressurization in the housing. The gas supply unit is closed at the time of battery start, the gas discharge unit is opened, and an oxygen-containing gas whose pressure is increased is supplied into the housing via the pressure adjustment unit. 2. The air battery system according to 1. The air battery system according to any one of claims 1 to 4, wherein when the battery is stopped, the gas supply unit and the gas discharge unit are closed, and the inside of the housing is depressurized by the pressure adjusting unit.

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