Battery pack and method for removing hydrogen sulfide in battery pack

Abstract

To provide a battery pack which comprises a battery including a sulfide solid electrolyte and enables effective removal of hydrogen sulfide which may be generated from the battery, and a method for removing such hydrogen sulfide in the battery pack.SOLUTION: A battery pack 1 comprises: an outer container 10; a battery 20 housed in the outer container and including a sulfide solid electrolyte; and a hydrogen sulfide absorbent 40 housed in the outer container 10 or disposed in a flow path 30 communicating with the inside of the outer container 10. The hydrogen sulfide absorbent is selected from a group consisting of zinc oxide, limestone, dolomite, or a combination thereof. A method for removing hydrogen sulfide in the battery pack includes removing the hydrogen sulfide by the hydrogen sulfide absorbent in the battery pack.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery pack and a method for removing hydrogen sulfide in a battery pack. [Background technology]

[0002] Battery packs having multiple batteries are known. When the batteries have a sulfide solid electrolyte, the sulfide solid electrolyte may react with water to generate hydrogen sulfide (H2S). In response to this, a technology has been developed to suppress an increase in the concentration of hydrogen sulfide in the battery pack.

[0003] For example, Patent Document 1 discloses an all-solid-state battery pack in which an all-solid-state battery cell includes a positive electrode, a negative electrode, and a sulfide-based solid electrolyte, and is configured such that when the temperature of the all-solid-state battery cell rises to or exceeds a threshold value, an inert gas is ejected toward the all-solid-state battery cell with the increased temperature, and further, when the concentration of hydrogen sulfide rises to or exceeds a threshold value, a basic gas is ejected in addition to the inert gas.

[0004] Patent Document 2 discloses a battery pack to be mounted on a mobile object, the battery pack including a battery case housing an all-solid-state battery containing a sulfur-based material in the positive electrode and / or solid electrolyte, and an adsorbent disposed at the bottom of the battery case for adsorbing hydrogen sulfide, the adsorbent being disposed on the outer periphery of the bottom. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2022-014295 [Patent Document 2] JP 2022-167149 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present disclosure is to provide a battery pack capable of effectively removing hydrogen sulfide that may be generated from a battery including a sulfide solid electrolyte, and a method for removing such hydrogen sulfide in a battery pack. [Means for solving the problem]

[0007] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> Outer packaging, a battery including a sulfide solid electrolyte housed in the outer container; A hydrogen sulfide absorbent that is contained in the outer container or that is disposed in a flow path that communicates with the outer container. and the hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof; Battery pack. <Aspect 2> The battery pack according to claim 1 , further comprising a heater for heating the hydrogen sulfide absorbent. <Aspect 3> 3. The battery pack of claim 2, wherein a power source for the heater is the battery. <Aspect 4> the flow path is a circulation path for circulating gas in the outer container, The oxygen absorbent is further included, the oxygen absorbent being contained in the outer container or being disposed in a circulation path that communicates with the outer container. The battery pack according to any one of aspects 1 to 3. <Aspect 5> A method for removing hydrogen sulfide from a battery pack, comprising: The battery pack includes: Outer packaging, a battery including a sulfide solid electrolyte housed in the outer container; A hydrogen sulfide absorbent that is contained in the outer container or that is disposed in a flow path that communicates with the outer container. having the hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof; and The method includes removing the hydrogen sulfide with the hydrogen sulfide absorbent. A method for removing hydrogen sulfide from a battery pack. <Aspect 6> The battery pack further includes a heater that heats the hydrogen sulfide absorbent, The method further includes heating the hydrogen sulfide absorbent with the heater when one or more values ​​selected from a temperature, a pressure, and a concentration of the hydrogen sulfide of the battery pack become equal to or greater than a threshold value. The method according to embodiment 5. Aspect 7 the flow path is an exhaust flow path that exhausts gas within the outer container to the outside of the outer container, the hydrogen sulfide absorbent is disposed in the exhaust flow path; and When the temperature of the hydrogen sulfide absorbent becomes equal to or higher than a threshold value, exhaust from the exhaust passage is performed. The method according to embodiment 5 or 6. <Aspect 8> the flow path is a circulation path for circulating gas in the outer container, The battery pack further includes an oxygen absorber that is contained in the exterior container or that is disposed in the circulation path that communicates with the exterior container; and The method further includes removing oxygen from within the battery pack with the oxygen absorber. The method according to embodiment 5 or 6. <Aspect 9> The method of claim 8, further comprising: performing circulation in the circulation path when one or more values ​​selected from a temperature, a pressure, and a concentration of the hydrogen sulfide of the battery pack become equal to or greater than a threshold value. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a battery pack capable of effectively removing hydrogen sulfide that may be generated from a battery including a sulfide solid electrolyte, and a method for removing such hydrogen sulfide in a battery pack. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of a battery pack of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram showing an example of a battery pack of the present disclosure. [Diagram 3] FIG. 3 is a schematic diagram showing an example of a battery pack of the present disclosure. [Figure 4] FIG. 4 is a flow chart illustrating an example of a method of the present disclosure for removing hydrogen sulfide in a battery pack. [Diagram 5] FIG. 5 is a flow chart illustrating an example of a method of the present disclosure for removing hydrogen sulfide in a battery pack. [Figure 6] FIG. 6 is a flow chart illustrating an example of a method of the present disclosure for removing hydrogen sulfide in a battery pack. [Figure 7] FIG. 7 is a graph showing the hydrogen sulfide absorption capacity of zinc oxide and limestone as a function of temperature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present disclosure.

[0011] Hereinafter, a battery pack according to the present disclosure will be described with reference to the drawings. Note that the dimensional relationships in the drawings do not reflect the actual dimensional relationships.

[0012] Battery pack 1, a battery pack 1 of the present disclosure includes an outer container 10, a battery 20 containing a sulfide solid electrolyte housed within the outer container 10, and a hydrogen sulfide absorbent 40 housed within the outer container 10 or disposed within a flow path 30 that communicates with the outer container 10. The hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or a combination thereof.

[0013] As described above, in a battery containing a sulfide solid electrolyte, the sulfide solid electrolyte may react with water to generate hydrogen sulfide. If the battery is exposed to abnormal heat, the temperature of the generated hydrogen sulfide may become high, and the high-temperature hydrogen sulfide may be discharged outside the exterior container of the battery pack.

[0014] In this regard, the present inventors have discovered that hydrogen sulfide generated within the outer container can be effectively removed by disposing a hydrogen sulfide absorbent selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof within the outer container of the battery pack or within a flow path communicating with the outer container.

[0015] As shown in FIG. 7, according to the results of the study by the present inventors, zinc oxide has a high hydrogen sulfide absorption capacity in the temperature range from room temperature to 300° C., and limestone and dolomite have a high hydrogen sulfide absorption capacity at temperatures of 300° C. or higher. Therefore, by using these hydrogen sulfide absorbents alone or in combination, the generated hydrogen sulfide can be effectively removed. That is, at relatively low temperatures (temperature range from room temperature to 300° C.), hydrogen sulfide can be effectively removed by using zinc oxide. At relatively high temperatures (temperatures of 300° C. or higher), hydrogen sulfide can be effectively removed by using limestone and / or dolomite. At relatively low temperatures to relatively high temperatures, hydrogen sulfide can be effectively removed by using zinc oxide in combination with limestone and / or dolomite.

[0016] Each component of the battery pack of the present disclosure will be described below.

[0017] <Outer packaging> 1, in the first embodiment, a battery pack 1 of the present disclosure has an outer container 10. The size, shape, etc. of the outer container 10 are not particularly limited as long as it can accommodate, for example, a battery 20, a hydrogen sulfide absorbent 40, and optionally an oxygen absorbent, and can accommodate a flow path 30. The material of the outer container is not particularly limited as long as it can be, for example, a metal such as aluminum or stainless steel.

[0018] <battery> As shown in FIG. 1, the battery pack 1 of the present disclosure has a battery 20 including a sulfide solid electrolyte housed in an outer container 10. The battery may include a sulfide solid electrolyte in a positive electrode active material layer and / or a negative electrode active material layer. In addition, when the battery is a solid-state battery, the battery may include a sulfide solid electrolyte in a solid electrolyte layer. That is, the battery 20 may be a sulfide solid battery including a sulfide solid electrolyte in a solid electrolyte layer. In the present disclosure, the battery may be a battery in which an electrode laminate in which layers such as a current collector layer, an electrode active material layer, and an electrolyte layer are stacked is housed in a laminate film, that is, a so-called laminate battery (also called a pouch battery).

[0019] In the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as an electrolyte, and therefore a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. Also, the solid-state battery of the present disclosure may be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as an electrolyte.

[0020] The battery of the present disclosure may be a lithium ion battery, and in this case, examples of the sulfide solid electrolyte include, but are not limited to, an amorphous sulfide solid electrolyte, a crystalline sulfide solid electrolyte, or an argyrodite-type solid electrolyte. Specific examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11, Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 , Li 10 GeP2S 12 ), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x P.S. 6-x Cl x etc.; or combinations thereof, but are not limited to these.

[0021] The sulfide solid electrolyte may be a glass or a crystallized glass (glass ceramic).

[0022] The batteries 20 housed in the outer container 10 are electrically connected in series, in parallel, or in a combination of series and parallel. Although FIG. 1 shows a schematic of a plurality of batteries 20, the number of batteries housed in the outer container 10 may be one. The batteries 20 may have any form known in the art, such as a stacked type or a wound type. When each of the batteries 20 is composed of two or more unit batteries, in each battery 20, the unit batteries are electrically connected in series, in parallel, or in a combination of series and parallel. Although FIG. 1 shows a schematic example of a plurality of batteries arranged in parallel in the outer container 10, the arrangement of the batteries in the outer container 10 is not particularly limited and may be any arrangement. Thus, the plurality of batteries 20 may be stacked on top of each other or spaced apart from each other.

[0023] <Hydrogen sulfide absorber> As shown in Fig. 1, the battery pack 1 of the present disclosure has a hydrogen sulfide absorbent 40 that is housed in an outer container 10 or that is disposed in a flow path 30 that communicates with the inside of the outer container 10. Fig. 1 shows an embodiment in which the hydrogen sulfide absorbent 40 is disposed in the flow path 30, but as described above, the hydrogen sulfide absorbent 40 may be housed in the outer container 10.

[0024] The hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or a combination thereof. As described above, zinc oxide has a high hydrogen sulfide absorption capacity at temperatures from room temperature to 300° C., and limestone and dolomite have a high hydrogen sulfide absorption capacity at temperatures of 300° C. or higher. Therefore, by using these hydrogen sulfide absorbents alone or in combination, the generated hydrogen sulfide can be effectively removed.

[0025] <Heater> 2, the battery pack 1 of the present disclosure may further include a heater 50 that heats the hydrogen sulfide absorbent 40. With such a configuration, it is possible to promote the absorption of hydrogen sulfide by limestone and dolomite, which are hydrogen sulfide absorbents that operate at relatively high temperatures.

[0026] The power source for the heater may be a battery housed in the outer container, which can reduce the SOC (State Of Charge) of the battery housed in the outer container when hydrogen sulfide is generated.

[0027] The above is the first embodiment of the battery pack of the present disclosure.

[0028] <Flow path> In the second embodiment, the flow path 30 may be an exhaust flow path 31 that exhausts gas inside the outer container 10 to the outside of the outer container 10. That is, in this embodiment, the battery pack 1 does not need to be sealed.

[0029] In the third embodiment, the flow path 30 may be a circulation path 32 that circulates the gas in the outer container 10. That is, in this embodiment, the battery pack 1 may be sealed. When an oxygen absorbent described later is used, circulating the gas in the outer container 10 promotes absorption of oxygen by the oxygen absorbent.

[0030] <Oxygen absorber> 3, in a third embodiment, the battery pack 1 of the present disclosure may further include an oxygen absorbent 60 that is contained in the outer container 10 or that is disposed in a circulation path 32 that communicates with the inside of the outer container 10. In FIG. 3, an embodiment in which the oxygen absorbent 60 is disposed in the circulation path 32 is shown, but as described above, the oxygen absorbent 60 may be contained in the outer container 10.

[0031] The oxygen absorbent is not particularly limited as long as it is a material capable of absorbing oxygen. The oxygen absorbent may be a material capable of absorbing oxygen by reacting with oxygen, that is, by being oxidized. Examples of such materials include metals such as iron, and organic compounds such as vitamin C. In addition, the oxygen absorbent may be a material capable of absorbing oxygen by being oxidized at a temperature of 100°C or higher. Examples of such materials include paraffin. For example, when the hydrogen sulfide absorbent is in powder form, paraffin can not only absorb oxygen at a predetermined temperature, but also function as a binder for the hydrogen sulfide absorbent.

[0032] <Method for Removing Hydrogen Sulfide from a Battery Pack> In a first embodiment, a method of the present disclosure for removing hydrogen sulfide in a battery pack includes removing hydrogen sulfide with a hydrogen sulfide absorbent in a battery pack having an outer container, a battery including a sulfide solid electrolyte contained within the outer container, and a hydrogen sulfide absorbent contained within the outer container or disposed within a flow path communicating with the outer container, the hydrogen sulfide absorbent being selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof.

[0033] For the battery pack in the method of the present disclosure, reference may be made to the above description of the battery pack of the present disclosure.

[0034] The method of the present disclosure includes removing hydrogen sulfide with a hydrogen sulfide absorbent selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof, and by using such a method, hydrogen sulfide generated within the outer container can be effectively removed as described above.

[0035] The battery pack may further include a heater for heating the hydrogen sulfide absorbent.

[0036] The power source for the heater may be a battery contained within the outer container.

[0037] For the heater and its power source, reference may be made to the above description of the battery pack of the present disclosure.

[0038] The method of the present disclosure may further include heating the hydrogen sulfide absorbent with a heater when one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack reach or exceed a threshold value.

[0039] In the present disclosure, the "temperature of the battery pack" may be the temperature inside the outer container, the temperature of the battery, the temperature inside the flow path, etc. The "pressure of the battery pack" may be the pressure inside the outer container, the pressure inside the flow path, etc. The "hydrogen sulfide concentration of the battery pack" may be the concentration of hydrogen sulfide inside the outer container, the concentration of hydrogen sulfide inside the flow path, etc.

[0040] The method for measuring the temperature of the battery pack is not particularly limited, but may be, for example, a method of measuring using a heat detection unit such as a temperature sensor. The method for measuring the pressure of the battery pack is not particularly limited, but may be, for example, a method of measuring using a pressure detection unit such as a pressure sensor. The method for measuring the concentration of hydrogen sulfide in the battery pack is not particularly limited, but may be, for example, a method of measuring using a hydrogen sulfide concentration detection unit such as a hydrogen sulfide concentration sensor. The temperature, pressure, and hydrogen sulfide concentration of the battery pack may be constantly monitored, for example, by the above-mentioned sensors.

[0041] The threshold temperature of the battery pack is not particularly limited, and may be, for example, a value that can be determined as a temperature that generates hydrogen sulfide. Note that when the temperature of the battery pack is a temperature at or above the temperature at which limestone and dolomite effectively act as hydrogen sulfide absorbents, for example, a temperature at or above 300°C, heating by the heater may not be performed.

[0042] The threshold value of the pressure in the battery pack is not particularly limited, and may be, for example, a value that can be determined as a pressure increase associated with the generation of hydrogen sulfide.

[0043] The threshold value for the hydrogen sulfide concentration in the battery pack is not particularly limited, and may be, for example, a measurable value as the hydrogen sulfide concentration that indicates the generation of hydrogen sulfide.

[0044] As described above, the heater is intended to heat, in particular, limestone and dolomite, which are hydrogen sulfide absorbents that operate at relatively high temperatures, and therefore the heating temperature by the heater can be determined taking into consideration the temperature at which limestone and dolomite operate effectively as hydrogen sulfide absorbents.

[0045] The above is the first embodiment of the method of the present disclosure.

[0046] In the second embodiment, the flow path may be an exhaust flow path that exhausts the gas in the outer container to the outside of the outer container, and the hydrogen sulfide absorbent may be disposed in the exhaust flow path. In this case, the method of the present disclosure may further include exhausting from the exhaust flow path when the temperature of the hydrogen sulfide absorbent becomes equal to or higher than the threshold. The threshold temperature of the hydrogen sulfide absorbent can be appropriately designed based on the temperature at which the hydrogen sulfide absorbent functions effectively. That is, when the hydrogen sulfide absorbent is zinc oxide, the threshold can be set to a relatively low temperature, and when the hydrogen sulfide absorbent is limestone or dolomite, the threshold can be set to a relatively high temperature. By adopting such a method, exhausting from the exhaust flow path can be performed at a temperature at which the hydrogen sulfide absorbent functions effectively, and therefore, it is possible to suppress hydrogen sulfide from being exhausted to the outside of the outer container.

[0047] The method for measuring the temperature of the hydrogen sulfide absorbent is not particularly limited, but may be, for example, a method in which the temperature is measured by a heat detection unit such as a temperature sensor.

[0048] In a third embodiment, the flow path is a circulation path that circulates gas in the outer container, and the battery pack may further include an oxygen absorbent that is contained in the outer container or that is disposed in the circulation path that communicates with the outer container. In this case, the method of the present disclosure may further include removing oxygen from the battery pack by the oxygen absorbent.

[0049] In a third embodiment, the method of the present disclosure may further include circulating the gas in the circulation path when one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack reach or exceed a threshold value. By adopting such a method, it is possible to reduce the energy required for circulation compared to a case where the gas in the outer container is constantly circulated.

[0050] In the method of the present disclosure, the battery pack may have a control unit. The control unit may be connected to each of the heat detection unit, the pressure detection unit, and the hydrogen sulfide concentration detection unit. In this way, the control unit can operate the heater when one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are equal to or greater than a threshold value. In addition, the control unit can cause exhaust from the exhaust flow path when the temperature of the hydrogen sulfide absorbent is equal to or greater than a threshold value. Furthermore, the control unit can cause circulation in the circulation path when the temperature, pressure, and hydrogen sulfide concentration of the battery pack are equal to or greater than a threshold value.

[0051] Hereinafter, the method of the present disclosure for removing hydrogen sulfide in a battery pack will be described with reference to FIGS.

[0052] 4 is a flow chart showing an example of a first embodiment of the method of the present disclosure for removing hydrogen sulfide in a battery pack. In the first embodiment, the flow path of the battery pack may be an exhaust flow path or a circulation path. Furthermore, the battery pack may or may not further include an oxygen absorbent in addition to the hydrogen sulfide absorbent.

[0053] As shown in FIG. 4, in the first embodiment, at the start, one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are monitored by the heat detection unit, pressure detection unit, or hydrogen sulfide concentration detection unit.

[0054] Next, the control unit compares the temperature, pressure, and hydrogen sulfide concentration of the battery pack transmitted from each detection unit with the respective threshold values ​​(step S101). If one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are less than the threshold value, monitoring by each detection unit is continued.

[0055] On the other hand, when one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are equal to or greater than the threshold value, the control unit operates the heater for heating the hydrogen sulfide absorbent (step S102).

[0056] 5 is a flow chart showing an example of a second embodiment of the method of the present disclosure for removing hydrogen sulfide in a battery pack, in which the flow path of the battery pack is an exhaust flow path.

[0057] As shown in FIG. 5, in the second embodiment, the process from the start to step S202 is similar to the process from the start to step S102 in the first embodiment.

[0058] After step S202, the control unit compares the temperature of the hydrogen sulfide absorbent transmitted from the heat detection unit with a threshold value (step S203). If the temperature of the hydrogen sulfide absorbent is below the threshold value, the heating of the hydrogen sulfide absorbent by the heater is continued.

[0059] On the other hand, if the temperature of the hydrogen sulfide absorbent is equal to or higher than the threshold value, the control unit exhausts the gas from the exhaust passage (step S204).

[0060] 6 is a flow chart showing an example of a third embodiment of the method of the present disclosure for removing hydrogen sulfide in a battery pack. In the third embodiment, the flow path of the battery pack is a circulation path, and the battery pack further has an oxygen absorbent in addition to a hydrogen sulfide absorbent.

[0061] As shown in FIG. 6, in the third embodiment, the start is similar to the start and step S101 in the first embodiment.

[0062] In step S301, if one or more values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are equal to or greater than a threshold value, the control unit activates a heater to heat the hydrogen sulfide absorbent and circulates the hydrogen sulfide absorbent in the circulation path (step S302). [Explanation of symbols]

[0063] 1 Battery pack 10 Outer packaging 20 batteries 30 Flow Path 31 Exhaust flow path 32 Circulation Route 40 Hydrogen sulfide absorbent 50 Heater 60 Oxygen absorber

Claims

1. Outer packaging, a battery including a sulfide solid electrolyte housed in the outer container; A hydrogen sulfide absorbent that is contained in the outer container or that is disposed in a flow path that communicates with the outer container. and the hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof; Battery pack.

2. The battery pack according to claim 1 , further comprising a heater for heating the hydrogen sulfide absorbent.

3. The battery pack according to claim 2 , wherein a power source for the heater is the battery.

4. the flow path is a circulation path for circulating gas in the outer container, The oxygen absorbent is further included, the oxygen absorbent being contained in the outer container or being disposed in a circulation path that communicates with the outer container. The battery pack according to any one of claims 1 to 3.

5. A method for removing hydrogen sulfide from a battery pack, comprising: The battery pack includes: Outer packaging, a battery including a sulfide solid electrolyte housed in the outer container; A hydrogen sulfide absorbent that is contained in the outer container or that is disposed in a flow path that communicates with the outer container. having the hydrogen sulfide absorbent is selected from the group consisting of zinc oxide, limestone, dolomite, or combinations thereof; and The method includes removing the hydrogen sulfide with the hydrogen sulfide absorbent. A method for removing hydrogen sulfide from a battery pack.

6. The battery pack further includes a heater that heats the hydrogen sulfide absorbent, The method further includes heating the hydrogen sulfide absorbent with the heater when one or more values ​​selected from a temperature, a pressure, and a concentration of the hydrogen sulfide of the battery pack become equal to or greater than a threshold value. The method according to claim 5.

7. the flow path is an exhaust flow path that exhausts gas within the outer container to the outside of the outer container, the hydrogen sulfide absorbent is disposed in the exhaust flow path; and When the temperature of the hydrogen sulfide absorbent becomes equal to or higher than a threshold value, exhaust from the exhaust passage is performed. The method according to claim 5 or 6.

8. the flow path is a circulation path for circulating gas in the outer container, The battery pack further includes an oxygen absorber that is contained in the exterior container or that is disposed in the circulation path that communicates with the exterior container; and The method further includes removing oxygen from within the battery pack with the oxygen absorber. The method according to claim 5 or 6.

9. The method according to claim 8 , further comprising: performing circulation in the circulation path when one or more values ​​selected from a temperature, a pressure, and a concentration of the hydrogen sulfide in the battery pack reach or exceed a threshold value.

Images