Battery pack

Abstract

A battery storage body 1 comprises: a housing 11 that has an intake port 11a and an exhaust port 11b and stores at least one battery cell 2; a blower unit 14 that generates a flow of air inside the housing 11 from the intake port 11a to the exhaust port 11b; and an oxygen removal unit 15 that removes oxygen from the air flowing into the housing 11 through the intake port 11a.

Description

Technical Field

[0001] The present invention , electric relates to a battery pack.

Background Art

[0002] In recent years, as a solid electrolyte used in all-solid-state batteries, the development of sulfide-based solid electrolytes showing high ionic conductivity has been advanced. On the other hand, since sulfide-based solid electrolytes may react with moisture to generate hydrogen sulfide, in order to put all-solid-state batteries using sulfide-based solid electrolytes into practical use, countermeasures against such hydrogen sulfide have become an issue. Patent Document 1 describes a technique for efficiently removing hydrogen sulfide that may be generated inside a housing by providing a hydrogen sulfide removal unit at a communication port with the outside of the housing that houses a battery cell, without increasing the thickness or volume of the battery cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique described in Patent Document 1, nothing is considered about the influence when hydrogen sulfide continues to be generated. That is, nothing is considered about the possibility that hydrogen sulfide, which is a flammable gas, may react with oxygen and burn when the hydrogen sulfide concentration inside the housing rises to a certain level.

[0005] Therefore, an object of the present invention is to provide a battery pack that suppresses combustion even when a flammable gas is generated inside. Electric

Means for Solving the Problems

[0006] In order to achieve the above object, the battery of the present invention pack teeth, The battery comprises at least one battery cell that generates hydrogen sulfide as a flammable gas when it reacts with moisture, and a battery housing that houses at least one battery cell, wherein the battery housing A housing having an air intake and an exhaust port, and housing at least one battery cell, A circulation pipe is connected to the intake and exhaust ports, respectively, to circulate the air inside the enclosure, and is provided inside the enclosure or in the circulation pipe. The enclosure includes a blower unit that generates an airflow from the intake to the exhaust port, Installed in the circulation piping, It includes an oxygen removal unit that removes oxygen from the air flowing into the housing through the air intake.

[0008] Like this Electric According to IkePack, the oxygen concentration inside the enclosure can be reduced through the action of the air blower and oxygen removal unit. As a result, even if flammable gas is generated from the battery cells and the concentration of flammable gas inside the enclosure rises to a certain level, the possibility of that flammable gas reacting with the oxygen inside the enclosure and burning can be reduced. [Effects of the Invention]

[0009] According to the present invention, , electric Even if flammable gas is generated inside the pond pack, its combustion can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a battery pack according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram of a battery pack according to a second embodiment of the present invention. [Figure 3] This is a schematic diagram of a battery pack according to a third embodiment of the present invention. [Figure 4] This is a schematic diagram of a battery pack according to a fourth embodiment of the present invention. [Figure 5] This is a schematic diagram of a battery pack according to a fifth embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. Components common to each embodiment are denoted by the same reference numerals in the drawings, and redundant explanations will be omitted as appropriate. Furthermore, characteristic configurations and modifications in each embodiment are applicable to other embodiments, as long as they do not contradict each other, although they may be mentioned again below.

[0012] In the following embodiments, an all-solid-state battery containing a sulfide-based solid electrolyte is exemplified as a battery cell capable of generating flammable gases, and hydrogen sulfide is exemplified as the flammable gas targeted by the present invention; however, the present invention is not limited thereto. That is, the flammable gas targeted by the present invention may be any flammable gas other than hydrogen sulfide generated by an all-solid-state battery containing a sulfide-based solid electrolyte, for example, sulfur (including allotropes such as S, S2, and S8). Alternatively, it may be any flammable gas generated by another type of battery, for example, hydrogen, methane, ethane, ethylene, or carbon monoxide generated by a lithium-ion battery, or hydrogen generated by an aqueous solution battery such as an aqueous lithium-ion battery or a zinc anode battery. On the other hand, the flammable gas targeted by the present invention may also be the vaporized gas of an organic solvent used in the non-aqueous electrolyte of a lithium-ion battery. Examples of such organic solvents include ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, and propylpropionate.

[0013] (First Embodiment) Figure 1 is a schematic diagram of a battery pack according to the first embodiment of the present invention.

[0014] The battery pack 1 has a plurality of battery cells 2 and at least a pair of electrode terminals (not shown). The plurality of battery cells 2 are electrically connected to each other. The connection form is not particularly limited and may be in series, in parallel, or a combination thereof. Also, at least a part of the plurality of battery cells 2 may be constrained by a constraining member. The at least a pair of electrode terminals are electrically connected to the plurality of battery cells 2 by an electrical circuit (not shown) so as to be able to extract electric power from the plurality of battery cells 2. In FIG. 1, four battery cells 2 are shown, but the number of battery cells 2 included in the battery pack 1 is not limited to this. Note that the battery pack 1 may have a plurality of battery modules (assembled batteries) each including a plurality of battery cells 2. That is, the battery cells 2 may be modularized to form battery modules, and a plurality of such battery modules may be combined to form the battery pack 1.

[0015] The battery cell 2 is a all-solid-state battery and has a positive electrode, a negative electrode, and a solid electrolyte layer disposed between the positive electrode and the negative electrode. As an example, the positive electrode includes a positive electrode current collector and a positive electrode active material layer, and the negative electrode includes a negative electrode current collector and a negative electrode active material layer. The positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector are laminated in this order to form a laminate, which is housed in a battery case such as a laminate type, a cylindrical type, or a rectangular type. A reinforcing layer made of a curable resin may be provided around the laminate as needed.

[0016] Known materials generally used for all-solid-state batteries can be used for the positive electrode current collector and the negative electrode current collector, respectively. For example, metal materials such as aluminum, stainless steel, and titanium can be used for the material of the positive electrode current collector, and its form includes, for example, foil, film, sheet, mesh, etc. Also, for example, metal materials such as stainless steel, nickel, and copper can be used for the material of the negative electrode current collector, and its form includes, for example, foil, film, sheet, etc.

[0017] The positive electrode active material layer contains at least a positive electrode active material, and the negative electrode active material layer contains at least a negative electrode active material. The positive electrode active material is not particularly limited as long as it is a material that can occlude and release metal ions such as lithium ions. For example, sulfur, lithium-containing transition metal oxides, transition metal fluorides, polyanion compounds, transition metal sulfides, etc. can be used. Also, the negative electrode active material is not particularly limited as long as it is a material that can occlude and release metal ions such as lithium ions. For example, metallic lithium, metals or alloys capable of alloying with lithium, carbon materials such as graphite and hard carbon, transition metal oxides, transition metal sulfides, silicon, etc. can be used. The positive electrode active material layer and the negative electrode active material layer may each appropriately contain a solid electrolyte, a binder, etc.

[0018] The solid electrolyte layer contains at least a sulfide-based solid electrolyte. Examples of the sulfide solid electrolyte include glasses or glass ceramics such as Li2S-SiS2 systems, Li2S-B2S3 systems, Li2S-P2S3 systems, Li2S-P2S5 systems, Li2S-GeS2 systems, Li2S-B2S3 systems, Li3PO4-P2S5 systems, Li4SiO4-Li2S-SiS2 systems, etc. Li Ge 0.25 P 0.75 S4, Li 10 GeP2S 12 etc. can also be mentioned. Further, additives such as LiCl, LiBr, LiI, Li x MO[[ID=​​​​Furthermore, the battery pack 1 has a battery housing 3 that accommodates multiple battery cells 2. The battery housing 3 consists of a casing 11, an intake pipe 12, an exhaust pipe 13, a blower 14, and an oxygen removal unit 15.

[0020] The housing 11 has the function of housing multiple battery cells 2 while extending at least one pair of electrode terminals (not shown) to the outside. The housing 11 is provided with an air intake port 11a for introducing air into the housing 11 and an exhaust port 11b for discharging air from the housing 11. Inside the housing 11, fillers such as elastic materials, heat transfer materials, and heat insulating materials may be appropriately placed in the gaps between the battery cells 2 and between the battery cells 2 and the aforementioned restraining members. Although shown in a simplified manner in Figure 1, considering heat dissipation from the battery cells 2, it is preferable that multiple battery cells 2 are housed in the housing 11 with at least a portion of them in direct or indirect contact (for example, via the aforementioned restraining members). The shape of the housing 11 is not particularly limited and can be arbitrarily set according to the shape and arrangement of the battery cells 2 to be housed. As described above, the housing 11 may house multiple battery modules, each containing multiple battery cells 2.

[0021] The intake pipe 12 is connected at one end (downstream end) to the intake port 11a of the housing 11 via an on-off valve (not shown). The exhaust pipe 13 is connected at one end (upstream end) to the exhaust port 11b of the housing 11 via an on-off valve (not shown). The connection positions of the intake pipe 12 and the exhaust pipe 13 to the housing 11 (i.e., the positions of the intake port 11a and the exhaust port 11b in the housing 11) are not particularly limited, but it is preferable that they be in positions facing each other in order to allow air to circulate evenly throughout the inside of the housing 11. The intake pipe 12 may be provided with a filtration means such as an air filter to suppress the ingress of foreign matter from the outside.

[0022] The air blower unit 14 is installed in the exhaust piping 13 and has the function of generating airflow inside the housing 11. The air blower unit 14 is not particularly limited and can be a fan, blower, pump, compressor, etc. In this case, the air blower unit 14 may have the function of adjusting the flow rate of air flowing into the housing 11 by controlling the output of the control unit 4, which will be described later. Power may be supplied to the air blower unit 14 from the battery cell 2 in order to drive the air blower unit 14. Alternatively, a separate independent power source may be provided, which will ensure that the air blower unit 14 is reliably driven even if the output of the battery cell 2 has to be limited or stopped, as will be described later.

[0023] The oxygen removal unit 15 is provided in the intake piping 12 and has the function of removing oxygen from the air flowing into the housing 11. The oxygen removal unit 15 is not particularly limited, and any known oxygen removal agent commonly used to remove oxygen can be used. Examples of such removal agents include metal-based oxygen adsorbents containing iron, copper, nickel, etc., and organic oxygen adsorbents containing vitamin C, etc.

[0024] With this configuration, the oxygen inside the housing 11 is expelled to the outside by the action of the blower unit 14, and at the same time, the oxygen removal unit 15 removes oxygen from the air flowing into the housing 11, thereby reducing the oxygen concentration inside the housing 11. As a result, even if the sulfide-based solid electrolyte contained in the battery cell 2 reacts with moisture to generate hydrogen sulfide, and even if its concentration rises to a certain level inside the housing 11, the possibility of the flammable gas hydrogen sulfide reacting with the oxygen inside the housing 11 and burning can be reduced. In addition, the blower unit 14 generates an airflow inside the housing 11 from the intake pipe 12 to the exhaust pipe 13, so even if hydrogen sulfide is generated from the battery cell 2, it can be prevented from accumulating inside the housing 11. Therefore, the possibility of hydrogen sulfide reacting with the oxygen inside the housing 11 and burning can be further reduced.

[0025] Incidentally, regardless of the concentration of hydrogen sulfide, combustion of hydrogen sulfide will not occur unless the oxygen concentration inside the housing 11 exceeds the limiting oxygen concentration for hydrogen sulfide. From this viewpoint, it is preferable to monitor the oxygen concentration inside the housing 11, and for this purpose, the battery pack 1 has an oxygen sensor 16 for detecting the oxygen concentration inside the housing 11. The oxygen sensor 16 is not particularly limited, and known oxygen sensors such as zirconia type, electrochemical type, magnetic type, optical type, laser spectroscopic type, and yellow phosphorus emission type can be used. The position of the oxygen sensor 16 is not limited to the position shown in the figure, as long as it can detect the oxygen concentration inside the housing 11, and may be, for example, on the intake pipe 12 (specifically, downstream of the oxygen removal unit 15) or on the exhaust pipe 13.

[0026] Furthermore, the battery pack 1 has a control unit 4 that controls the air blower 14 based on the detection results of the oxygen sensor 16. The control unit 4 controls the output of the air blower 14 to adjust the flow rate of air (specifically, air from which oxygen has been removed) flowing into the housing 11 so that the oxygen concentration detected by the oxygen sensor 16 is less than the limit oxygen concentration of hydrogen sulfide. This ensures that combustion of hydrogen sulfide is reliably suppressed, regardless of the hydrogen sulfide concentration inside the housing 11. The control unit 4 may also have a function to control the output of the battery cells 2 based on the detection results of the oxygen sensor 16. For example, if the oxygen concentration detected by the oxygen sensor 16 exceeds or is likely to exceed the limit oxygen concentration of hydrogen sulfide (for example, if it exceeds a predetermined value set arbitrarily but below the limit oxygen concentration), the output of at least some of the battery cells 2 may be limited or stopped for safety. The control unit 4 may also store the detection results of the oxygen sensor 16 or transmit them to a server or blockchain network for immediate or future use.

[0027] Furthermore, from the perspective of reducing power consumption, the air blower 14 does not need to be in continuous operation. That is, the air circulation by the air blower 14 does not need to be constant. For example, when the oxygen concentration inside the housing 11 falls well below the limit oxygen concentration for hydrogen sulfide, the on-off valves (not shown) of the intake pipe 12 and exhaust pipe 13 may be closed and the operation of the air blower 14 may be stopped. Then, when the oxygen sensor 16 detects that the oxygen concentration inside the housing 11 has reached or is likely to reach the limit oxygen concentration for hydrogen sulfide, the air circulation by the air blower 14 may be restarted. That is, the on-off valves of the intake pipe 12 and exhaust pipe 13 may be opened and the air blower 14 may be activated, thereby reducing the oxygen concentration inside the housing 11. Alternatively, regardless of the detection result of the oxygen sensor 16, the on-off valves of the intake pipe 12 and exhaust pipe 13 may be opened and the air blower 14 may be activated periodically or steadily to the extent that the oxygen concentration inside the housing 11 can be kept low. On the other hand, if the battery cell 2 is stopped for a long period of time, the airflow by the blower 14 may be stopped. However, if hydrogen sulfide accumulates inside the housing 11 for any reason during that time, the sparks and heat generated when the battery cell 2 is started may act as an ignition source, potentially causing the hydrogen sulfide to burn. Considering such a possibility, it is preferable that the airflow by the blower 14 be started at the latest before the battery cell 2 is started. From this viewpoint as well, it is preferable to provide a separate, independent power source for driving the blower 14, as described above.

[0028] Furthermore, as mentioned above, if air circulation by the blower 14 is not performed continuously, from the viewpoint of reducing the number of parts, the other components (gas circulation members) 12-15 of the battery housing 3, excluding the casing 11, may be detachably attached to the casing 11. This allows the gas circulation members 12-15 to be normally removed and attached to the casing 11 to start air circulation by the blower 14 when an increase in oxygen concentration is detected by the oxygen sensor 16, specifically when an alarm is issued from the control unit 4 to indicate this. For example, if the battery pack 1 is used in an electric vehicle or a stationary storage battery, the gas circulation members 12-15 may be attached only when an alarm is issued from the control unit 4. This eliminates the need to attach the gas circulation members 12-15 to all storage batteries, such as those for electric vehicles and stationary storage batteries, thereby achieving further reductions in the number of parts and simplification of the manufacturing process.

[0029] Furthermore, the detection of oxygen concentration by the oxygen sensor 16 does not need to be performed continuously. Therefore, for example, the oxygen sensor 16 may be detachable from the housing 11, or an on-off valve may be provided between the oxygen sensor 16 and the housing 11. That is, in order to periodically or as needed detect the oxygen concentration inside the housing 11, the oxygen sensor 16 may be attached to the housing 11 each time, or the on-off valve between the oxygen sensor 16 and the housing 11 may be opened. Also, the control unit 4 may be physically separated from the housing 11 as shown in the figure, but it may also be directly attached to the housing 11, in which case it may be detachable. This also makes it possible to reduce the number of parts in the battery pack 1 during normal use.

[0030] Furthermore, problems related to the combustion of hydrogen sulfide do not occur if hydrogen sulfide is not generated in the first place, and in order to suppress its generation, it is preferable to keep the moisture concentration inside the housing 11 low. For this purpose, in addition to the oxygen removal section 15, the intake piping 12 may be provided with a filtration means to remove moisture from the air introduced into the housing 11. Examples of such filtration means include a moisture removal column, a moisture removal filter, and a breathable waterproof sheet. Also, for the same reason, the air inside the housing 11 may be replaced with an unreactive gas beforehand by filling the inside of the housing 11 with an unreactive gas while or after housing the battery cell 2 in the housing 11. The unreactive gas used at this time is not particularly limited as long as it does not contain moisture and oxygen, and for example, an inert gas (nitrogen, argon, helium, etc.) can be used.

[0031] In the illustrated example, the air blower 14 is located in the exhaust pipe 13, but its location is not particularly limited as long as it can generate airflow inside the housing 11. For example, it may be located in the intake pipe 12 or inside the housing 11. If the air blower 14 is located in the intake pipe 12, the on-off valve (not shown) of the exhaust pipe 13 may be adjustable to any desired opening. This allows the pressure inside the housing 11 to increase by reducing the opening when hydrogen sulfide is generated from the battery cell 2, thereby reducing the amount of hydrogen sulfide released from the battery cell 2.

[0032] In addition, the position of the air blower 14 is not limited to the position described above, and may be, for example, on the housing 11. That is, the air blower 14 may be directly attached to the exhaust port 11b of the housing 11, in which case the oxygen removal unit 15 may be directly connected to the intake port 11a of the housing 11. Alternatively, the air blower 14 may be directly attached to the intake port 11a of the housing 11, in which case the oxygen removal unit 15 may be directly connected to the inlet of the air blower 14. Alternatively, the air blower 14 may be directly attached to the intake port 11a of the housing 11 via the oxygen removal unit 15, in other words, it may be directly attached to the inlet of the oxygen removal unit 15 which is directly connected to the intake port 11a of the housing 11. Therefore, in such cases, from the viewpoint of reducing the number of parts, one or both of the intake piping 12 and the exhaust piping 13 may be omitted.

[0033] However, the presence of intake piping 12 and exhaust piping 13 offers the advantage of allowing arbitrary adjustment of the intake and exhaust positions relative to the housing 11. In other words, it becomes possible to select the optimal intake and exhaust positions according to the surrounding environment in which the battery pack 1 is installed. For example, by setting the intake position to a location that minimizes the intake of air containing a large amount of moisture or foreign matter, the risk of battery pack 1 malfunction can be reduced. Also, by moving the exhaust position as far away as possible from other surrounding devices and people, the risk of the exhausted air adversely affecting them can be reduced. Thus, it is preferable to provide intake piping 12 and exhaust piping 13 in order to reduce the risk of battery pack 1 malfunction and the risk of adversely affecting the surrounding environment.

[0034] (Second embodiment) Figure 2 is a schematic diagram of a battery pack according to a second embodiment of the present invention. This embodiment is a modification of the first embodiment and differs from the first embodiment in that it includes several additional configurations. The differences from the first embodiment will be described below.

[0035] In the first embodiment, as described above, the airflow generated inside the housing 11 by the air blower 14 prevents hydrogen sulfide from being generated from the battery cells 2, thus preventing it from accumulating inside the housing 11 and suppressing an increase in the hydrogen sulfide concentration inside the housing 11. However, it is undesirable, both from a safety and environmental perspective, for the hydrogen sulfide generated inside the housing 11 to be discharged directly to the outside of the battery pack 1 through the exhaust pipe 13. Therefore, in this embodiment, a hydrogen sulfide removal unit 21 is provided in the exhaust pipe 13 to remove hydrogen sulfide generated from the battery cells 2. This prevents hydrogen sulfide generated inside the housing 11 from leaking to the outside.

[0036] The hydrogen sulfide removal unit 21 is not particularly limited, and for example, a cylindrical metal container such as stainless steel filled with a hydrogen sulfide removal agent can be used. As such a removal agent, known agents commonly used to remove hydrogen sulfide can be used, such as ion exchange resins, activated carbon (especially activated carbon impregnated with basic compounds such as sodium hydroxide and potassium carbonate), activated alumina (especially activated alumina impregnated with potassium permanganate, etc.), zeolites, basic solids such as calcium oxide and calcium carbonate, basic liquids such as aqueous sodium hydroxide solution and aqueous sodium carbonate solution, and ionic liquids having reaction sites with acids such as amino groups. Since hydrogen sulfide may be at a temperature higher than room temperature due to the heat generated by the battery cell 2, it is preferable that the hydrogen sulfide removal agent can maintain its hydrogen sulfide removal performance even at high temperatures, and it is even more preferable that its removal mechanism is based on an irreversible reaction. This ensures reliable removal of hydrogen sulfide even at high temperatures and suppresses the re-release of the removed hydrogen sulfide. Furthermore, some removal agents may generate powder depending on the usage environment of the battery pack 1 (for example, when the battery pack 1 is used in an electric vehicle and subjected to vibration). In such cases, a filtration means such as an air filter may be installed downstream of the hydrogen sulfide removal unit 21, thereby suppressing the leakage of powder to the outside and preventing the powder from blocking the airflow or causing a dust explosion.

[0037] Furthermore, the exhaust piping 13 may be branched into two (via a three-way valve) downstream of the blower unit 14, with a hydrogen sulfide removal unit 21 provided in one of the branches, thereby allowing selection of the hydrogen sulfide discharge route. As a result, if the impact on the surroundings is minimal even when hydrogen sulfide is discharged to the outside, the hydrogen sulfide can be discharged without passing through the hydrogen sulfide removal unit 21, thereby suppressing deterioration of the hydrogen sulfide removal unit 21. Alternatively, if the blower unit 14 is installed inside the intake piping 12 or the housing 11, a similar effect can be obtained if a separate exhaust piping (via an on-off valve) is connected to the housing 11, distinct from the exhaust piping 13.

[0038] Furthermore, in this embodiment, a hydrogen sulfide sensor 22 is provided to detect the presence or concentration of hydrogen sulfide inside the housing 11, and the air blower 14 may be controlled by the control unit 4 based on the detection result. For example, when hydrogen sulfide is detected by the hydrogen sulfide sensor 22, the on / off valves (not shown) of the intake pipe 12 and exhaust pipe 13 may be opened and the air blower 14 may be activated, generating an airflow inside the housing 11. That is, the airflow by the air blower 14 may normally be stopped from the viewpoint of reducing power consumption and may be started in response to the generation of hydrogen sulfide from the battery cell 2. Also, even if flammable hydrogen sulfide gas is generated inside the housing 11, combustion of hydrogen sulfide will not occur unless its concentration reaches the combustion range. Therefore, the air blower 14 may be controlled so that the hydrogen sulfide concentration detected by the hydrogen sulfide sensor 22 is below the lower combustion limit, thereby adjusting the flow rate of air flowing into the housing 11, that is, the amount of gas containing hydrogen sulfide flowing out of the housing 11 may be adjusted. Furthermore, the output of the battery cells 2 may be controlled based on the detection results of the hydrogen sulfide sensor 22. For example, when hydrogen sulfide is detected by the hydrogen sulfide sensor 22, the output of at least some of the battery cells 2 may be limited or stopped for safety. The detection results of the hydrogen sulfide sensor 22 may also be stored in the control unit 4 or transmitted to a server or blockchain network through the control unit 4 for immediate or future use.

[0039] The hydrogen sulfide sensor 22 is not particularly limited, and known hydrogen sulfide sensors such as constant potential electrolytic type, semiconductor type, thermal conduction type, and electrical resistance type can be used. The position of the hydrogen sulfide sensor 22 is not limited to the position shown in the figure, as long as it can detect the presence or concentration of hydrogen sulfide in the housing 11. In the illustrated example, only one hydrogen sulfide sensor 22 is installed in the housing 11, but multiple hydrogen sulfide sensors 22 may be provided. In that case, a hydrogen sulfide sensor 22 may be provided near each battery cell 2. In addition, one of the multiple hydrogen sulfide sensors 22 may be installed downstream of the hydrogen sulfide removal unit 21 to detect whether the unit has broken through. If the hydrogen sulfide removal unit 21 has broken through, the control unit 4 may output a notification to inform the user of this.

[0040] Furthermore, when using multiple hydrogen sulfide sensors 22, they may be of the same type, but it is preferable that they be of different types. This allows the validity of the detection result of one hydrogen sulfide sensor 22 to be evaluated using other hydrogen sulfide sensors 22 of different types, and for example, it is possible to diagnose whether the hydrogen sulfide sensor 22 is malfunctioning due to the influence of coexisting gases. Alternatively, when using two or more hydrogen sulfide sensors 22, one hydrogen sulfide sensor 22 may perform detection continuously, while the other hydrogen sulfide sensor 22 may only perform detection when the other hydrogen sulfide sensor 22 detects hydrogen sulfide. This allows for obtaining a correct detection result from the other hydrogen sulfide sensor 22 even if the detection result of one hydrogen sulfide sensor 22 is incorrect.

[0041] Furthermore, hydrogen sulfide is generated due to an abnormality in the battery cell 2. Although the amount generated is small in the initial stages of the abnormality, it can increase rapidly after a long period of time. As a result, the hydrogen sulfide generated from the beginning of the abnormality can cause deterioration of the hydrogen sulfide removal unit 21, and when an attempt is made to remove a large amount of hydrogen sulfide, it may not be possible to remove it completely, potentially causing it to leak to the outside. To prepare for such a situation, multiple hydrogen sulfide removal units 21 may be provided, each functioning as a backup for the others. For example, as described above, if the exhaust pipe 13 branches into two downstream of the blower unit 14, and a hydrogen sulfide removal unit 21 is provided in one of them, a hydrogen sulfide removal unit 21 may also be provided in the other branch. Alternatively, if another exhaust pipe separate from the exhaust pipe 13 is connected to the housing 11, a hydrogen sulfide removal unit 21 may also be provided in that other exhaust pipe. This allows, for example, if the hydrogen sulfide sensor 22 detects that the hydrogen sulfide concentration inside the housing 11 has rapidly increased and exceeded a threshold, the airflow can be switched from the previously used hydrogen sulfide removal unit 21 to an unused hydrogen sulfide removal unit 21 in order to reliably remove the hydrogen sulfide. On the other hand, even if hydrogen sulfide is generated due to a malfunction in the battery cell 2, the conditions inside the housing 11 (presence or absence of coexisting gases, high or low temperature, high or low humidity, etc.) are not always the same. Therefore, it is preferable that the multiple hydrogen sulfide removal units 21 are of different types (i.e., characteristics), so that it is possible to select and use the hydrogen sulfide removal unit 21 with the most suitable characteristics depending on the situation at the time.

[0042] To suppress the generation of hydrogen sulfide, it is preferable to reduce the moisture concentration inside the housing 11 as described above, but it is also preferable to reduce the temperature inside the housing 11. However, it is undesirable for the temperature inside the housing 11 to be too low, as this may reduce the performance of the battery cells 2. For this reason, the battery pack 1 may have a temperature sensor 23 that detects the temperature inside the housing 11, and a temperature adjustment unit 24 that is controlled by the control unit 4 based on the detection result of the temperature sensor 23 and adjusts the temperature of the air flowing into the housing 11. This makes it possible to suppress the generation of hydrogen sulfide by raising the temperature inside the housing 11 even if the battery cells 2 generate heat, and to suppress the reduction in the performance of the battery cells 2 as the temperature inside the housing 11 decreases even if the outside air temperature decreases. In addition, the output of at least some of the battery cells 2 may be adjusted based on the detection result of the temperature sensor 23. For example, when the temperature detected by the temperature sensor 23 falls outside a predetermined range, the output of at least some of the battery cells 2 may be limited or stopped.

[0043] The temperature sensor 23 is not particularly limited, and for example, known temperature sensors such as contact type or non-contact type can be used. Examples of contact type temperature sensors include thermocouples, resistance thermometers, and thermistors, while examples of non-contact type temperature sensors include radiation thermometers. The position of the temperature sensor 23 is not limited to the position shown in the figure, as long as it can detect the temperature inside the housing 11. In the illustrated example, only one temperature sensor 23 is installed in the housing 11, but multiple temperature sensors 23 may be provided. In that case, a temperature sensor 23 may be provided near each battery cell 2. The detection results of the temperature sensor 23 may be stored in the control unit 4 or transmitted to a server or blockchain network through the control unit 4 for immediate or future use. The temperature adjustment unit 24 is not particularly limited, and for example, a combination of a known cooling device such as an air-cooled, water-cooled, or refrigerant-type device and a known heating device such as an electric heater or heat pump type can be used. The position of the temperature adjustment unit 24 is not limited to the position shown in the figure, as long as it can adjust the temperature of the battery cells 2. For example, the temperature control unit 24 may be located inside the housing 11 to directly adjust the temperature of the battery cell 2, or it may be located outside the housing 11 to indirectly adjust the temperature of the battery cell 2 via the housing 11.

[0044] Furthermore, the hydrogen sulfide removal unit 21 may be detachable from the housing 11 together with the exhaust pipe 13, and the temperature control unit 24 may also be detachable from the housing 11 together with the intake pipe 12. In addition, the hydrogen sulfide sensor 22 and the temperature sensor 23 may also be detachable from the housing 11, similar to the oxygen sensor 16.

[0045] The oxygen removal unit 15 is preferably replaced with a new one periodically or depending on usage conditions, and it is preferable that the control unit 4 outputs a notification to the user when a predetermined replacement period arrives or when replacement becomes necessary. When the battery pack 1 is used in an electric vehicle or a stationary storage battery, it is preferable that this notification is converted into a signal that appeals to the user's five senses, such as sight and hearing, and output.

[0046] Furthermore, when replacing the oxygen removal unit 15, it is preferable that the oxygen removal unit 15 is assigned an identifier 25 containing its own identification information in order to confirm whether it is a genuine product and has not exceeded its expiration date, and whether it meets predetermined usage conditions. The identifier 25 is not particularly limited and may be an information storage medium such as a wireless tag, or a code such as a one-dimensional code or a two-dimensional code, but it is preferably a code, and more preferably a two-dimensional code such as a QR code (registered trademark). Accordingly, it is preferable that the control unit 4 is equipped with a function to communicate with a reading device (not shown) that reads identification information from the identifier 25 and acquire the reading result, and that the information necessary for identifying a genuine product is recorded therein. As a result, the control unit 4 can determine whether the oxygen removal unit 15 meets predetermined usage conditions based on the acquired identification information. If the control unit 4 determines that the replaced oxygen removal unit 15 does not meet the predetermined usage conditions, it may notify the user of this and prevent output from at least some of the battery cells 2. The control unit 4 may also transmit the acquired identification information of the oxygen removal unit 15, its determination result, and the usage status of the oxygen removal unit 15 to a server or blockchain network. Alternatively, the reading result of the identifier 25 by the reading device may be transmitted to a server or blockchain network instead of the control unit 4, where the above-mentioned determination may be made, and the determination result may be transmitted to the control unit 4.

[0047] Preferably, the control unit 4 has the function of directly acquiring the usage status (usage time, etc.) of all communication target devices (blower unit 14, sensors 16, 22, 23, etc.), and indirectly acquiring the usage status of devices that are not communication target devices (oxygen removal unit 15, hydrogen sulfide removal unit 21, etc.). Furthermore, the control unit 4 may have a function to predict the lifespan of the oxygen removal unit 15 based on the acquired usage status in order to appropriately determine when the oxygen removal unit 15 needs to be replaced (lifespan). Alternatively, in addition to the above, the control unit 4 may have a function to transmit the acquired usage status to a server or blockchain network in order to enable an external management device to predict the lifespan of the oxygen removal unit 15. Preferably, the acquired usage status and lifespan prediction results are notified to the user from the control unit 4 or an external management device as needed, thereby enabling planned replacement of the oxygen removal unit 15 in accordance with the lifespan prediction. As a result, it is possible to reduce the possibility of increased maintenance costs due to premature replacement when it is not necessary, or serious malfunctions due to failure to replace when it is necessary. Furthermore, this type of lifespan prediction is advantageous because it eliminates the need to perform inspection work to determine when the oxygen removal unit 15 needs replacing, thereby reducing inspection costs, including labor costs. While programs and artificial intelligence (AI) can be used to predict the lifespan of the oxygen removal unit 15, using AI is preferable from the standpoint of prediction accuracy.

[0048] The timing at which the control unit 4 acquires and transmits data regarding the usage status of each device is not particularly limited. For example, it may be done periodically, automatically according to predetermined conditions, or remotely from an external source, and may be done irregularly. This allows for a more reliable understanding of the usage status of each device. However, if data is transmitted from multiple other battery packs in the same way, it is preferable that the data transmission by the control unit 4 is performed at a different timing from those transmissions, thereby ensuring reliable data transmission without congestion on communication lines or servers. Furthermore, it is preferable that the control unit 4 is powered and driven by a power source separate from the battery cells 2, so that data transmission can be reliably performed even if the output of the battery cells 2 must be stopped.

[0049] The lifespan prediction described above enables planned replacement of the oxygen removal unit 15. However, depending on the usage environment (region) of the battery pack 1 and the manufacturing status of the oxygen removal unit 15, it may not be possible to obtain a new or unused oxygen removal unit 15 when it is predicted to reach the end of its lifespan. In other words, if the demand for the oxygen removal unit 15 is concentrated in a particular region, or if a supply shortage occurs as a result, it may not be possible to obtain a new or unused oxygen removal unit 15 in a planned manner. To avoid this, it is preferable that the control unit 4 has a function to acquire location information and a function to transmit this location information, along with the usage status of each device, to a server or blockchain network. This makes it possible for an external management device to predict in advance the number and timing of oxygen removal units 15 required in each region, and based on this, it becomes possible to secure an optimal number of oxygen removal units 15 in stock for each region. In addition, the external management device may notify the user of the optimal source for the oxygen removal unit 15. As a result, it becomes possible to obtain the oxygen removal unit 15 when and where it is needed, enabling planned replacement of the oxygen removal unit 15.

[0050] Furthermore, the above explanation relating to the life prediction of the oxygen removal unit 15 also applies to all communication target devices whose usage status is directly acquired by the control unit 4, and also to other devices (such as the hydrogen sulfide removal unit 21) whose usage status is acquired indirectly. Incidentally, after replacing these parts, including the oxygen removal unit 15, it is preferable to recover the replaced parts and analyze their deterioration status, thereby improving the accuracy of the life prediction for each part. That is, taking the hydrogen sulfide removal unit 21 as an example, by recovering and analyzing it, the amount of hydrogen sulfide generated during use can be determined. Then, by comparing this amount with the usage status acquired in advance, data on the conditions and frequency under which abnormalities occur in the battery cell 2 can be obtained, and based on the acquired data, the accuracy of the life prediction for the hydrogen sulfide removal unit 21 can be improved. Such data may also be used to anticipate potential malfunctions when commercializing a new type of battery.

[0051] (Third embodiment) Figure 3 is a schematic diagram of a battery pack according to a third embodiment of the present invention. This embodiment is a modification of the first embodiment and differs from the first embodiment in that the configuration of the intake and exhaust piping has been changed. The differences from the first embodiment will be explained below.

[0052] In the first embodiment, both the upstream end (other end) of the intake pipe 12 and the downstream end (other end) of the exhaust pipe 13 are open to the outside, whereas in this embodiment, they are connected to each other, forming a circulation pipe 31 that circulates the air inside the housing 11 without discharging it to the outside. As a result, compared to the first embodiment, it is possible to suppress contact between the battery cell 2 and outside air containing moisture, thereby reducing the possibility of generating hydrogen sulfide.

[0053] In this embodiment, since the circulation piping 31 constitutes a closed circuit, as described above, the possibility of contact between the battery cells 2 and the outside air is almost eliminated. However, on the other hand, there is concern that the internal pressure of the housing 11 may rise or fall in some cases. An increase in internal pressure may occur, for example, when the temperature inside the housing 11 rises due to heat generation from the battery cells 2 or an increase in the ambient temperature, or when gases such as hydrogen sulfide are generated from the battery cells 2. A decrease in internal pressure may occur, for example, when the temperature inside the housing 11 falls due to a decrease in the ambient temperature. Therefore, it is preferable that the battery pack 1 has a pressure sensor 32 that detects the pressure inside the housing 11, and a pressure adjustment unit 33 that is controlled by the control unit 4 based on the detection result of the pressure sensor 32 and adjusts the pressure inside the housing 11. This makes it possible to suppress excessive increases or decreases in the internal pressure of the housing 11. In addition, the output of at least some of the battery cells 2 may be adjusted based on the detection result of the pressure sensor 32. For example, when the pressure detected by the pressure sensor 32 falls outside a predetermined range, the output of at least some of the battery cells 2 may be limited or stopped.

[0054] The pressure sensor 32 is not particularly limited, and known pressure sensors such as resistive, capacitive, piezoelectric, photoelectric, and MEMS (MicroElectroMechanical Systems) types can be used. The position of the pressure sensor 32 is not limited to the position shown in the figure, as long as it can detect the pressure inside the housing 11. Furthermore, the detection result of the pressure sensor 32 may be stored in the control unit 4 or transmitted to a server or blockchain network through the control unit 4 for immediate or future use.

[0055] The pressure adjustment unit 33 is not particularly limited, and can be, for example, an electric valve, a solenoid valve, a relief valve, a compressor, a gas cylinder, or an accumulator. Furthermore, the pressure adjustment unit 33 can be of a type that releases the internal pressure of the housing 11 or a type that pressurizes the housing 11. These two types (such as an electric valve and a compressor) can be used in combination, or they can be integrated into a single unit. This allows the pressure inside the housing 11 to be adjusted to an appropriate pressure depending on the situation. However, in this embodiment, when oxygen is removed from the housing 11 by the oxygen removal unit 15, the volume of air inside the housing 11 decreases, which may result in a decrease in the pressure inside the housing 11. Therefore, it is preferable to use a pressure adjustment unit 33 that pressurizes the housing 11, thereby adjusting the pressure inside the housing 11 to an appropriate pressure. That is, for example, the pressure inside the housing 11 can be adjusted to an appropriate pressure by compensating for the reduced volume of air with a compressor or a gas cylinder filled with inert gas. On the other hand, a pressure adjustment unit 33 that releases the internal pressure of the housing 11 is suitable when the internal pressure of the housing 11 rises due to the generation of gases such as hydrogen sulfide from the battery cell 2, but there is a concern that hydrogen sulfide inside the housing 11 may leak to the outside when the pressure is released. For this reason, when using a pressure adjustment unit 33 that releases the internal pressure of the housing 11, it is preferable that a hydrogen sulfide removal unit similar to the hydrogen sulfide removal unit 21 of the second embodiment is provided at its pressure outlet.

[0056] The position of the pressure adjustment unit 33 is not limited to the position shown in the figure, but it is preferable that a pressure adjustment unit 33 that pressurizes the inside of the housing 11 be provided in the housing 11. This allows, for example, when hydrogen sulfide is generated from the battery cell 2, the amount of hydrogen sulfide released from the battery cell 2 can be reduced by increasing the pressure inside the housing 11. In addition, outside air may be introduced into the housing 11 via the pressure adjustment unit 33 in order to further increase the pressure inside the housing 11 and thereby reduce the amount of hydrogen sulfide released from the battery cell 2. In that case, it is preferable that the pressure adjustment unit 33 is provided with a filtration means to remove components other than non-reactive gases contained in the outside air (for example, moisture and oxygen). Examples of such filtration means include a moisture removal column, a moisture removal filter, a breathable waterproof sheet, an oxygen removal column, and a nitrogen permeable membrane. The number of pressure adjustment units 33 is not limited to the one shown in the figure, but may be multiple.

[0057] Preferably, the circulation piping 31 is unitized as a gas flow unit together with the air blower 14 and the oxygen removal unit 15. This allows the circulation piping 31, including the air blower 14 and the oxygen removal unit 15, to be treated as a single component during the assembly of the battery pack 1, thereby reducing the number of parts and simplifying the manufacturing process. Furthermore, such gas flow units 14, 15, and 31 may be detachably attached to the housing 11, similar to the gas flow members 12 to 15 in the first embodiment, and the pressure adjustment unit 33 may also be detachably attached to the housing 11. In addition, the pressure sensor 32 may also be detachably attached to the housing 11, similar to the oxygen sensor 16.

[0058] It goes without saying that each configuration described in the second embodiment is also applicable to this embodiment. In that case, the hydrogen sulfide removal unit 21 may be provided in a location corresponding to the intake pipe 12 (specifically, downstream of the oxygen removal unit 15) rather than in a location corresponding to the exhaust pipe 13 (specifically, upstream of the oxygen removal unit 15) in the circulation piping 31. Also, in either case, the hydrogen sulfide removal unit 21 may be structurally and functionally integrated with the oxygen removal unit 15, thereby reducing the number of parts and making replacement due to deterioration easier. The temperature control unit 24 may also be provided in a location corresponding to the exhaust pipe 13 (specifically, upstream of the oxygen removal unit 15) rather than in a location corresponding to the intake pipe 12 (specifically, downstream of the oxygen removal unit 15) in the circulation piping 31. On the other hand, the hydrogen sulfide removal unit 21 and the oxygen removal unit 15 may be arranged in parallel, or a combination of series and parallel arrangements may be used. In other words, for example, a bypass pipe may be provided in the circulation piping 31 that bypasses the oxygen removal unit 15, and the hydrogen sulfide removal unit 21 may be provided in that bypass pipe. This allows air to be circulated only through the oxygen removal unit 15 when only oxygen is to be removed, and only through the hydrogen sulfide removal unit 21 when only hydrogen sulfide is to be removed, enabling adjustment according to the state of the battery cell 2. Alternatively, a bypass pipe may be provided in the circulation piping 31 that bypasses the oxygen removal unit 15 and the hydrogen sulfide removal unit 21 which are arranged in series, and the hydrogen sulfide removal unit 21 may be provided in that bypass pipe.

[0059] (Fourth embodiment) Figure 4 is a schematic diagram of a battery pack according to the fourth embodiment of the present invention. This embodiment is a modification of the third embodiment and differs from the third embodiment in that the circulation piping is omitted. The differences from the third embodiment will be explained below.

[0060] In this embodiment, the circulation piping 31 of the third embodiment is omitted, and accordingly, the air blower 14 is provided inside the housing 11, and the oxygen removal unit 15 is provided on top of the housing 11. Specifically, the air blower 14 is provided at the exhaust port 11b inside the housing 11, and the oxygen removal unit 15 is provided on top of the housing 11 such that its inlet and outlet are directly connected to the exhaust port 11b and intake port 11a of the housing 11, respectively. As a result, even without circulation piping, the air inside the housing 11 can be circulated without being discharged to the outside, and the same effects as in the third embodiment can be obtained. "Directly connected" here means, for example, that the inlet of the oxygen removal unit 15 and the exhaust port 11b of the housing 11 are connected without piping, and also includes the case where they are connected via the air blower 14. Therefore, in this embodiment as well, the position of the air blower 14 is not limited to inside the housing 11, but may be on top of the housing 11. That is, the air blower 14 may be directly attached to the exhaust port 11b on the outside of the housing 11. Alternatively, the blower unit 14 may be directly attached to the intake port 11a on the outside of the housing 11, in which case the outlet of the oxygen removal unit 15 and the intake port 11a of the housing 11 may be in communication via the blower unit 14. Needless to say, the position of the blower unit 14 inside the housing 11 is not particularly limited.

[0061] (Fifth embodiment) Figure 5 is a schematic diagram of a battery pack according to the fifth embodiment of the present invention. This embodiment is a modification of the first embodiment and differs from the first embodiment in that the configuration of the housing has been changed, and consequently the configuration of the intake and exhaust piping has also been changed. The differences from the first embodiment will be explained below.

[0062] In this embodiment, the housing 11 is equipped with a plurality of housing chambers 41, each housing a battery cell 2. Accordingly, the downstream end of the intake pipe 12 branches into multiple branches and is connected to the plurality of housing chambers 41 (specifically, each intake port 41a) via on-off valves (not shown). The upstream end of the exhaust pipe 13 also branches into multiple branches and is connected to the plurality of housing chambers 41 (specifically, each exhaust port 41b) via on-off valves (not shown). Although four housing chambers 41 are shown in Figure 4, the number of housing chambers 41 constituting the housing 11 is not limited to this. Furthermore, the number of battery cells 2 housed in the housing chambers 41 is not limited to the one shown, but may be multiple, and these may constitute a battery module (battery pack). In addition, the oxygen sensor 16 is provided downstream of the portion of the exhaust pipe 13 where the multiple branch pipes merge. Furthermore, the control unit 4 periodically or as needed performs a determination process to determine which of the plurality of housing chambers 41 is experiencing an increase in oxygen concentration.

[0063] In this determination process, the air blower 14 operates in conjunction with the sequential opening of the on-off valves of the intake pipe 12 and the exhaust pipe 13. This sequentially generates an airflow from each containment chamber 41 to the oxygen sensor 16, and the oxygen concentration in each containment chamber 41 is sequentially detected by the oxygen sensor 16. This detection method is advantageous because it can forcibly introduce air from the containment chamber 41 to the oxygen sensor 16, thus detecting even slight increases in oxygen concentration without missing them. Based on the detection results obtained in this way, it is determined which of the multiple containment chambers 41 has an increased oxygen concentration.

[0064] When an increase in oxygen concentration is detected in a specific containment chamber 41, the control unit 4 opens the on-off valves of the intake pipe 12 and exhaust pipe 13 connected to that containment chamber 41, and activates the blower unit 14. This allows air (specifically, air from which oxygen has been removed) to be introduced only into the containment chamber 41 where an increase in oxygen concentration has been detected, thereby lowering the oxygen concentration and more efficiently reducing the possibility of hydrogen sulfide combustion. The control unit 4 may also limit or stop the output of the battery cell 2 in the containment chamber 41 where an increase in oxygen concentration has been detected (specifically, the oxygen concentration has exceeded or is likely to exceed the limit oxygen concentration for hydrogen sulfide), thereby minimizing the impact on the overall output of the battery pack 1.

[0065] Furthermore, if cost and design constraints permit, an oxygen sensor 16 may be provided for each containment chamber 41. Although not shown, a temperature sensor 23 may also be provided for each containment chamber 41, and based on the results, the output of the battery cell 2 in the containment chamber 41 where an excessive temperature rise is detected may be limited or stopped. In addition, a circulation piping system may be configured by connecting the upstream end of the intake piping 12 and the downstream end of the exhaust piping 13, similar to the third embodiment.

[0066] Alternatively, instead of the oxygen sensor 16, a hydrogen sulfide sensor 22 from the second embodiment may be provided in the exhaust piping 13. This allows for the determination of which of the multiple containment chambers 41 is generating hydrogen sulfide using a procedure similar to the determination process described above. Once it is confirmed that hydrogen sulfide is being generated in a specific containment chamber 41, air (specifically, air from which oxygen has been removed) can be selectively or intensively introduced into that chamber 41. In this way, the combustion of hydrogen sulfide can be efficiently suppressed, similar to the case where the oxygen sensor 16 is provided. In this case as well, the output of the battery cell 2 in the containment chamber 41 where hydrogen sulfide generation has been confirmed may be limited or stopped as needed. In addition, in this case, a hydrogen sulfide removal unit 21 may be provided in the exhaust piping 13, similar to the second embodiment. [Explanation of symbols]

[0067] 1 Battery pack 2 battery cells 3. Battery housing 4. Control Unit 11 cabinets 11a Intake 11b Exhaust vent 12 Intake piping 13 Exhaust piping 14. Air blower 15. Oxygen Removal Unit 16. Oxygen Sensor 21. Hydrogen sulfide removal section (flammable gas removal section) 22. Hydrogen sulfide sensor (gas sensor) 23 Temperature Sensor 24 Temperature adjustment section 25 Identifiers 31 Circulation piping 32 Pressure Sensor 33 Pressure adjustment section 41 Confinement Rooms 41a Intake 41b Exhaust port

Claims

1. At least one battery cell that generates hydrogen sulfide as a flammable gas when it reacts with moisture, It comprises a battery housing that houses at least one of the battery cells, The aforementioned battery housing, A housing having an air intake and an exhaust port, and housing the at least one battery cell, A circulation pipe is connected to the intake port and the exhaust port, respectively, for circulating the air inside the housing, A blower unit is provided inside the housing or in the circulation piping, which generates an airflow inside the housing from the intake port toward the exhaust port, A battery pack comprising an oxygen removal unit provided in the circulation piping, which removes oxygen from the air flowing into the housing through the air intake port.

2. The battery pack according to claim 1, wherein the battery housing has a control unit for controlling the air blowing unit.

3. The battery housing has an oxygen sensor for detecting the oxygen concentration inside the housing, The battery pack according to claim 2, wherein the control unit controls the air blower to adjust the flow rate of the air flowing into the housing so that the oxygen concentration detected by the oxygen sensor is less than the limit oxygen concentration of the flammable gas.

4. The battery housing has a gas sensor that detects the presence or concentration of the flammable gas in the housing, The battery pack according to claim 2, wherein the control unit controls the air blower to adjust the flow rate of the air flowing into the housing so that the concentration of the flammable gas detected by the gas sensor is below the lower limit of combustion.

5. The battery housing has an oxygen sensor for detecting the oxygen concentration inside the housing, The battery pack according to claim 2, wherein the control unit operates the blower to generate the airflow when the oxygen concentration detected by the oxygen sensor is equal to or equal to the limit oxygen concentration of the flammable gas, or there is a possibility that it will be equal to or equal to that limit oxygen concentration.

6. The battery pack according to claim 2, wherein the battery housing comprises a pressure sensor for detecting the pressure inside the housing, and a pressure adjustment unit controlled by the control unit based on the detection result of the pressure sensor to adjust the pressure inside the housing.

7. The oxygen removal unit is assigned an identifier that includes identification information for the oxygen removal unit. The battery pack according to claim 2, wherein the control unit determines whether the oxygen removal unit satisfies predetermined conditions based on the identification information read from the identifier.

8. The battery pack according to claim 2, wherein the battery housing comprises a temperature sensor for detecting the temperature inside the housing, and a temperature adjustment unit controlled by the control unit based on the detection result of the temperature sensor to adjust the temperature inside the housing.

9. The battery pack according to claim 2, wherein the control unit predicts the lifespan of the oxygen removal unit based at least on the usage status of the air blower unit.

10. The battery pack according to claim 2, wherein the control unit acquires location information and transmits the acquired location information and at least the usage status of the air blower to an external source.

11. The battery pack according to claim 1, further comprising a combustible gas removal unit provided in the circulation piping, which removes the combustible gas flowing through the circulation piping from the exhaust port toward the intake port by the flow of air.

12. The battery pack according to claim 1, wherein the circulation piping, the air blowing unit, and the oxygen removal unit are detachably attached to the housing.

13. The at least one battery cell comprises a plurality of battery cells, The housing comprises a plurality of housing chambers for housing the plurality of battery cells, The battery pack according to claim 1, wherein both ends of the circulation piping each branch into a plurality of containers.

14. The battery pack according to claim 13, wherein the battery housing comprises at least one oxygen sensor for detecting the oxygen concentration in the plurality of housing chambers, and a control unit that switches which of the plurality of housing chambers to generate the airflow based on the detection result of the at least one oxygen sensor.

15. The battery housing has an oxygen sensor that detects the oxygen concentration inside the housing, The battery pack according to claim 2, wherein the control unit limits or stops the output of at least one battery cell when the oxygen concentration detected by the oxygen sensor exceeds or is likely to exceed the limit oxygen concentration of the flammable gas.

16. The battery housing includes at least one of a temperature sensor that detects the temperature inside the housing and a gas sensor that detects the presence of the flammable gas inside the housing. The battery pack according to claim 2, wherein the control unit adjusts the output of the at least one battery cell based on the detection result of at least one of the temperature sensor and the gas sensor.

17. The oxygen removal unit is assigned an identifier that includes identification information for the oxygen removal unit. The battery pack according to claim 2, wherein the control unit determines whether the oxygen removal unit satisfies predetermined conditions based on the identification information read from the identifier, and if it determines that the predetermined conditions are not met, it does not output the power from at least one battery cell.

18. The battery housing has a pressure sensor that detects the pressure inside the housing, The battery pack according to claim 2, wherein the control unit adjusts the output of the at least one battery cell based on the detection result of the pressure sensor.

19. The battery pack according to claim 13, wherein the battery housing comprises at least one oxygen sensor for detecting the oxygen concentration in the plurality of housing chambers, and a control unit that switches which of the plurality of battery cells to limit or stop the output of based on the detection result of the at least one oxygen sensor.

Images